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Chapter 6 - Revision history
2024-03-29T00:30:57Z
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KMiller at 18:04, 21 July 2014
2014-07-21T18:04:09Z
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>::[[Chapter_6#6.6.7 Water Cover Methods|6.6.7 Water Cover Methods]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>::[[Chapter_6#6.6.7 Water Cover Methods|6.6.7 Water Cover Methods]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>::[[Chapter_6#6.6.8 Drained Tailings Deposition Methods|6.6.8 Drained Tailings Deposition Methods]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>::[[Chapter_6#6.6.8 Drained <ins class="diffchange diffchange-inline">/ Sub-Aerial </ins>Tailings Deposition Methods|6.6.8 Drained <ins class="diffchange diffchange-inline">/ Sub-Aerial </ins>Tailings Deposition Methods]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Chapter_6#6.7 Selection and Evaluation of Alternatives|6.7 Selection and Evaluation of Alternatives]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Chapter_6#6.7 Selection and Evaluation of Alternatives|6.7 Selection and Evaluation of Alternatives]]</div></td></tr>
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KMiller
http://gardguide.com/index.php?title=Chapter_6&diff=12805&oldid=prev
KMiller: /* 6.0 PREVENTION AND MITIGATION */
2014-07-21T16:50:52Z
<p><span dir="auto"><span class="autocomment">6.0 PREVENTION AND MITIGATION</span></span></p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Salt budgets may also be critical at arid sites for pit lakes and surface impoundments where a negative water balance because of low precipitation and high evaporation can cause evapoconcentration or hyper saline conditions to develop with time.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Salt budgets may also be critical at arid sites for pit lakes and surface impoundments where a negative water balance because of low precipitation and high evaporation can cause evapoconcentration or hyper saline conditions to develop with time.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>===6.6.8 Drained Tailings Deposition Methods===</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>===6.6.8 Drained <ins class="diffchange diffchange-inline">/ Sub-Aerial </ins>Tailings Deposition Methods===</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Two legs of the “ARD Tetrahedron” (air and water) can be disrupted if fine-grained pyritic tailings can be dewatered and consolidated.  Creating a low-water content paste is one method of tailings management that has been used to accomplish this goal as well as to maximize the amount of solids that can be stored in a given tailings storage facility.  However, the energy and machinery involved in paste tailings production and placement is expensive and a certain amount of water must remain in the tailings to allow pipeline transport.  De-watering tailings passively with little additional equipment is an attractive alternative.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Two legs of the “ARD Tetrahedron” (air and water) can be disrupted if fine-grained pyritic tailings can be dewatered and consolidated.  Creating a low-water content paste is one method of tailings management that has been used to accomplish this goal as well as to maximize the amount of solids that can be stored in a given tailings storage facility.  However, the energy and machinery involved in paste tailings production and placement is expensive and a certain amount of water must remain in the tailings to allow pipeline transport.  De-watering tailings passively with little additional equipment is an attractive alternative.</div></td></tr>
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KMiller
http://gardguide.com/index.php?title=Chapter_6&diff=12804&oldid=prev
KMiller at 18:17, 7 July 2014
2014-07-07T18:17:03Z
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<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">::[[Chapter_6#6.6.8 Drained Tailings Deposition Methods|6.6.8 Drained Tailings Deposition Methods]]</ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Chapter_6#6.7 Selection and Evaluation of Alternatives|6.7 Selection and Evaluation of Alternatives]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Chapter_6#6.7 Selection and Evaluation of Alternatives|6.7 Selection and Evaluation of Alternatives]]</div></td></tr>
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KMiller
http://gardguide.com/index.php?title=Chapter_6&diff=12795&oldid=prev
KMiller: /* 6.6.8 Drained Tailings Deposition Methods */
2014-07-01T16:52:05Z
<p><span dir="auto"><span class="autocomment">6.6.8 Drained Tailings Deposition Methods</span></span></p>
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 16:52, 1 July 2014</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* Stage 3 is characterized by increased in-place density by means of application of underdrainage, which causes further consolidation and dissipation of positive pore pressures.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* Stage 3 is characterized by increased in-place density by means of application of underdrainage, which causes further consolidation and dissipation of positive pore pressures.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* Stage 4 develops as the drained deposit is allowed to air-dry and consolidate.  This consolidation can be quite significant and results from the development of negative or suction pressures in the deposit as air is entrained within the soil structure.  The resultant layer of air-dried waste is a stable, partially-saturated mass which has a lower permeability and greatly increased resistance to liquefaction under seismic loading.  The most significant attribute of the slurry's transformation from Stage 1 to  </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>* Stage 4 develops as the drained deposit is allowed to air-dry and consolidate.  This consolidation can be quite significant and results from the development of negative or suction pressures in the deposit as air is entrained within the soil structure.  The resultant layer of air-dried waste is a stable, partially-saturated mass which has a lower permeability and greatly increased resistance to liquefaction under seismic loading.  The most significant attribute of the slurry's transformation from Stage 1 to Stage 4 is the increase in the dry density of solids. For example, a gold tailings slurry initially at a solids content of 42% increases in dry solid density from approximately 0.83 kg/L (52 pounds per cubic foot [pcf]) to nearly 1.6 kg/L (100 pcf) merely by allowing settlement, drainage and air-drying in relatively thin layers prior to deposition of a fresh layer of tailings.  </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Stage 4 is the increase in the dry density of solids. For example, a gold tailings slurry initially at a solids content of 42% increases in dry solid density from approximately 0.83 kg/L (52 pounds per cubic foot [pcf]) to nearly 1.6 kg/L (100 pcf) merely by allowing settlement, drainage and air-drying in relatively thin layers prior to deposition of a fresh layer of tailings.  </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline"><div id="Figure 6-16" style="text-align:center">'''Figure 6-16: State of Solids during Deposition and Consolidation (L); Stage 4 Photo (R)'''<br /></ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">[[Image:Figure01 Chpt6 - new Fig6-16.jpg]]</div></ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>As the drying process continues and the moisture content has been reduced to approximately 20%, the dry density shows little increase with continued drying.  In practice, once this point has been reached, a new layer of tailings is added and the cycle begins again.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>As the drying process continues and the moisture content has been reduced to approximately 20%, the dry density shows little increase with continued drying.  In practice, once this point has been reached, a new layer of tailings is added and the cycle begins again.</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"><div id="Figure 6-17" style="text-align:center">'''Figure 6-17: Schematic Plan View, TSF with Three Depositional Zones'''<br /></ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">[[Image:Figure02 Chpt6 - new Fig6-17.jpg]]</div></ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In order to achieve Stage 4 conditions, air-drying of the thinly-deposited (100 to 150 mm) layer of tailings is typically facilitated through a systematic rotational waste discharge strategy.  Note that even though the tailings material in Figure 1 (R) is probably finer than 74 microns (<200 mesh), foot traffic is possible within several weeks of cessation of deposition. Vehicular traffic to conduct closure activities (e.g., placement of cover soils, liners, or soil amendments for revegetation) is also possible shortly after Stage 4 conditions are observed on the tailings surface (Reisinger et al., 2001).</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In order to achieve Stage 4 conditions, air-drying of the thinly-deposited (100 to 150 mm) layer of tailings is typically facilitated through a systematic rotational waste discharge strategy.  Note that even though the tailings material in Figure 1 (R) is probably finer than 74 microns (<200 mesh), foot traffic is possible within several weeks of cessation of deposition. Vehicular traffic to conduct closure activities (e.g., placement of cover soils, liners, or soil amendments for revegetation) is also possible shortly after Stage 4 conditions are observed on the tailings surface (Reisinger et al., 2001).</div></td></tr>
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KMiller
http://gardguide.com/index.php?title=Chapter_6&diff=12791&oldid=prev
KMiller: /* 6.10 References */
2014-07-01T15:55:32Z
<p><span dir="auto"><span class="autocomment">6.10 References</span></span></p>
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 15:55, 1 July 2014</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1070" >Line 1,070:</td>
<td colspan="2" class="diff-lineno">Line 1,070:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Brooks, W., 2011. Minera Panama SA, Personal Communication.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Brooks, W., 2011. Minera Panama SA, Personal Communication.</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">:Brown, B.S., and G. Greenway, updated.  Field Experience in the Use of Wick Drains to Consolidate Soft Tailings. Downloaded from: http://www.infomine.com/library/publications/docs/brown.pdf, May 20, 2013.</ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:British Columbia Acid Mine Drainage Task Force (BC AMD), 1989. Draft Acid Rock Drainage Technical Guide. BiTech Publishers Ltd., Vancouver, BC.  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:British Columbia Acid Mine Drainage Task Force (BC AMD), 1989. Draft Acid Rock Drainage Technical Guide. BiTech Publishers Ltd., Vancouver, BC.  </div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1108" >Line 1,108:</td>
<td colspan="2" class="diff-lineno">Line 1,110:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Faulkner, B.B., and J.G. Skousen, 1994. Treatment of acid mine drainage by passive treatment systems. In: Proceedings of the International Land Reclamation and Mine Drainage Conference, U.S. Bureau of Mines SP 06A-94, Pittsburgh, PA, 250-257.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Faulkner, B.B., and J.G. Skousen, 1994. Treatment of acid mine drainage by passive treatment systems. In: Proceedings of the International Land Reclamation and Mine Drainage Conference, U.S. Bureau of Mines SP 06A-94, Pittsburgh, PA, 250-257.</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">:Filas, B.A., and G.L. Zmudzinski, 1993.  Improving Fine Refuse Reclamation Potential by Managed Slurry Deposition.  Presented at the Society for Mining, Metallurgy, and Exploration, Inc. (SME) annual meeting, Reno, Nevada, February 15-18, 1993. </ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Germain, D. Normand Tassé, and Johanne Cyr 2003. Treatment of Acid Mine Effluents Using a Wood-Waste Cover.Proceedings of the 6th International Conference on Acid Rock Drainage (ICARD), Cairns, Australia, 12-18 July 2003, Australian Institute of Mining and Metallurgy, Melbourne.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Germain, D. Normand Tassé, and Johanne Cyr 2003. Treatment of Acid Mine Effluents Using a Wood-Waste Cover.Proceedings of the 6th International Conference on Acid Rock Drainage (ICARD), Cairns, Australia, 12-18 July 2003, Australian Institute of Mining and Metallurgy, Melbourne.</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1248" >Line 1,248:</td>
<td colspan="2" class="diff-lineno">Line 1,252:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Reardon, E.J., Moddle, P.M, 1985. Suitability of Peat as an Oxygen Interceptor Material for the Close-out of Pyritic Uranium Tailings: Column Studies. Uranium, 2: 83-110.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Reardon, E.J., Moddle, P.M, 1985. Suitability of Peat as an Oxygen Interceptor Material for the Close-out of Pyritic Uranium Tailings: Column Studies. Uranium, 2: 83-110.</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">:Reisinger, R.W., D.R. East, A.H. Gipson, J.E. Valera, and J.A. Gorman, 2001.  Reclamation of the Big Springs sub-aerial tailings facility, Nevada.  In: Tailings and Mine Waste ’01 Proceedings.  Eds.: Taylor & Francis - A. A. Balkema, Publishers.</ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Rich, D.H. and K.R. Hutchison, 1990. Neutralization and stabilization of combined refuse using lime kiln dust at High Power Mountain. p. 55-59. In: Proceedings, 1990 Mining and Reclamation Conference, 23-26 April 1990, West Virginia University, Morgantown, WV.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Rich, D.H. and K.R. Hutchison, 1990. Neutralization and stabilization of combined refuse using lime kiln dust at High Power Mountain. p. 55-59. In: Proceedings, 1990 Mining and Reclamation Conference, 23-26 April 1990, West Virginia University, Morgantown, WV.</div></td></tr>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Taylor, J.R., Guthrie, B., Murphy, N.C., and J. Waters, 2006. Alkalinity Producing Cover Materials for Providing Sustained Improvement in Water Quality from Waste Rock Piles. In: Proceedings of the 7th International Conference on Acid Rock Drainage (ICARD), March 26-30, St. Louis, MO, American Society of Mining and Reclamation, Lexington, KY.  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Taylor, J.R., Guthrie, B., Murphy, N.C., and J. Waters, 2006. Alkalinity Producing Cover Materials for Providing Sustained Improvement in Water Quality from Waste Rock Piles. In: Proceedings of the 7th International Conference on Acid Rock Drainage (ICARD), March 26-30, St. Louis, MO, American Society of Mining and Reclamation, Lexington, KY.  </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">:Ulrich, B, D.R. East and J. Gorman, 2000.  Subaerial Tailings Deposition – Design, Construction and Operation for Facility Closure and Reclamation.  Tailings and Mine Waste ’00.  A. A. Balkema Publishers (Editor).</ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:United States Environmental Protection Agency (USEPA), 2003. EPA and Hardrock Mining: A Source Book for Industry in the Northwest and Alaska. Prepared by EPA Region 10 with the technical assistance of Science Applications International Corporation.  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:United States Environmental Protection Agency (USEPA), 2003. EPA and Hardrock Mining: A Source Book for Industry in the Northwest and Alaska. Prepared by EPA Region 10 with the technical assistance of Science Applications International Corporation.  </div></td></tr>
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KMiller
http://gardguide.com/index.php?title=Chapter_6&diff=12790&oldid=prev
KMiller: /* List of Figures */
2014-07-01T15:44:06Z
<p><span dir="auto"><span class="autocomment">List of Figures</span></span></p>
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 15:44, 1 July 2014</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Chapter_6#Figure 6-14|Figure 6-14: Subaqueous Tailings Disposal]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Chapter_6#Figure 6-14|Figure 6-14: Subaqueous Tailings Disposal]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Chapter_6#Figure 6-15|Figure 6-15: Water Cover Processes]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Chapter_6#Figure 6-15|Figure 6-15: Water Cover Processes]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:[[Chapter_6#Figure 6-16|Figure 6-16: Prevention and Mitigation Evaluation of Alternatives]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>:[[Chapter_6#Figure 6-16|Figure 6-16<ins class="diffchange diffchange-inline">: State of Solids during Deposition and Consolidation (L); Photo (R)]]</ins></div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:[[Chapter_6#Figure 6-<del class="diffchange diffchange-inline">17</del>|Figure 6-<del class="diffchange diffchange-inline">17</del>: Comparative Costs for Capillary Barrier Cover (CCBE), Complete and  </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">:[[Chapter_6#Figure 6-17|Figure 6-17: Schematic Plan View, TSF with Three Depositional Zones]]</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">:[[Chapter_6#Figure 6-18|Figure 6-18</ins>: Prevention and Mitigation Evaluation of Alternatives]]</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>:[[Chapter_6#Figure 6-<ins class="diffchange diffchange-inline">19</ins>|Figure 6-<ins class="diffchange diffchange-inline">19</ins>: Comparative Costs for Capillary Barrier Cover (CCBE), Complete and  </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Partial Desulphurization and Water Cover (Bussiere and Wilson, 2006)]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Partial Desulphurization and Water Cover (Bussiere and Wilson, 2006)]]</div></td></tr>
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KMiller
http://gardguide.com/index.php?title=Chapter_6&diff=12789&oldid=prev
KMiller: /* 6.7 Selection and Evaluation of Alternatives */
2014-07-01T15:38:50Z
<p><span dir="auto"><span class="autocomment">6.7 Selection and Evaluation of Alternatives</span></span></p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===6.7 Selection and Evaluation of Alternatives===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===6.7 Selection and Evaluation of Alternatives===</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>No universal solution exists for the prevention, control, and mitigation of ARD, NMD, and SD. While submergence is clearly the most geochemically-stable approach, subaqueous disposal of tailings and waste in natural water bodies, such as lakes or marine environments, can be contentious. The applicability of technologies to ARD sources and phase of mining is shown in Figure 6-<del class="diffchange diffchange-inline">15</del>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>No universal solution exists for the prevention, control, and mitigation of ARD, NMD, and SD. While submergence is clearly the most geochemically-stable approach, subaqueous disposal of tailings and waste in natural water bodies, such as lakes or marine environments, can be contentious. The applicability of technologies to ARD sources and phase of mining is shown in Figure 6-<ins class="diffchange diffchange-inline">18</ins>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Specific evaluation of methods for prevention and mitigation of ARD requires a clear definition of objectives and defined purpose. The specific environmental technologies and options that will work best will be site specific, often governed by climatic considerations. The applicability of several methods described in the preceding sections is summarized in Table 6-7. Some methods have been demonstrated to be effective at sites around the world while others have had limited demonstration. This is a simple summary only in order to broadly categorize the technology.  Some technologies may have been demonstrated in a few climate type but could be applicable to others.  As discussed throughout this Guide, site-specific considerations must be assessed during the evaluation of any ARD prevention technology.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Specific evaluation of methods for prevention and mitigation of ARD requires a clear definition of objectives and defined purpose. The specific environmental technologies and options that will work best will be site specific, often governed by climatic considerations. The applicability of several methods described in the preceding sections is summarized in Table 6-7. Some methods have been demonstrated to be effective at sites around the world while others have had limited demonstration. This is a simple summary only in order to broadly categorize the technology.  Some technologies may have been demonstrated in a few climate type but could be applicable to others.  As discussed throughout this Guide, site-specific considerations must be assessed during the evaluation of any ARD prevention technology.</div></td></tr>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Water covers are a proven technology from a geochemical perspective but are sustainable only in climates with a positive water balance (i.e., precipitation > evaporation). In climates with a suitable water balance, geotechnical and long-term hazards with respect to stability, extreme storms and floods, spillways, erosion, and other natural hazards such as seismic events must be considered.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Water covers are a proven technology from a geochemical perspective but are sustainable only in climates with a positive water balance (i.e., precipitation > evaporation). In climates with a suitable water balance, geotechnical and long-term hazards with respect to stability, extreme storms and floods, spillways, erosion, and other natural hazards such as seismic events must be considered.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><div id="Figure 6-16" style="text-align:center">'''Figure 6-<del class="diffchange diffchange-inline">16</del>: Prevention and Mitigation Evaluation of Alternatives'''<br /></div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><div id="Figure 6-16" style="text-align:center">'''Figure 6-<ins class="diffchange diffchange-inline">18</ins>: Prevention and Mitigation Evaluation of Alternatives'''<br /></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:PreventionandMitigationEvaluationofAlternatives.gif]]</div></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:PreventionandMitigationEvaluationofAlternatives.gif]]</div></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1020" >Line 1,020:</td>
<td colspan="2" class="diff-lineno">Line 1,020:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Cost and economic viability must be evaluated similar to the other criteria for environmental and social settings. Cost estimates are almost always site-specific. Standard engineering approaches are used to develop capital and operating cost estimates to evaluate options and to assist in selecting a technology. Detailed design of an ARD prevention or mitigation technology involves preparing a detailed cost estimate. The specific approaches and methods used to cost ARD prevention and mitigation technologies are beyond the scope of the GARD Guide, but are described in standard engineering text books. Site-specific pre-construction cost estimates and actual as-built construction costs may be found in the proceedings from the major ARD conferences and other sources.  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Cost and economic viability must be evaluated similar to the other criteria for environmental and social settings. Cost estimates are almost always site-specific. Standard engineering approaches are used to develop capital and operating cost estimates to evaluate options and to assist in selecting a technology. Detailed design of an ARD prevention or mitigation technology involves preparing a detailed cost estimate. The specific approaches and methods used to cost ARD prevention and mitigation technologies are beyond the scope of the GARD Guide, but are described in standard engineering text books. Site-specific pre-construction cost estimates and actual as-built construction costs may be found in the proceedings from the major ARD conferences and other sources.  </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>However, in general, cover systems for tailings and waste rock deposits are often costly. Although costs vary widely, soil covers costs can range from about $25,000 to $100,000 (USD) per hectare (ha); heavily dependent upon the proximity of borrow sources for the soil cover material. The application of synthetic and complex multi-layer covers can easily double this cost and therefore those technologies are usually applied at smaller sites. Figure 6-<del class="diffchange diffchange-inline">17 </del>as an example, summarizes relative costs of a few technologies for a particular site: capillary barrier cover (i.e., covers with capillary barrier effects (CCBE)), desulphurization covers, and water covers. As shown here, desulphurization may be the most attractive alternative of the three options for this particular site depending upon the consideration of other factors (e.g., ease of application and environmental and social requirements).</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>However, in general, cover systems for tailings and waste rock deposits are often costly. Although costs vary widely, soil covers costs can range from about $25,000 to $100,000 (USD) per hectare (ha); heavily dependent upon the proximity of borrow sources for the soil cover material. The application of synthetic and complex multi-layer covers can easily double this cost and therefore those technologies are usually applied at smaller sites. Figure 6-<ins class="diffchange diffchange-inline">19 </ins>as an example, summarizes relative costs of a few technologies for a particular site: capillary barrier cover (i.e., covers with capillary barrier effects (CCBE)), desulphurization covers, and water covers. As shown here, desulphurization may be the most attractive alternative of the three options for this particular site depending upon the consideration of other factors (e.g., ease of application and environmental and social requirements).</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><div id="Figure 6-17" style="text-align:center">'''Figure 6-<del class="diffchange diffchange-inline">17</del>: Comparative Costs for Capillary Barrier Cover (CCBE), Complete and <br />Partial Desulphurization and Water Cover (Bussiere and Wilson, 2006)'''<br /></div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><div id="Figure 6-17" style="text-align:center">'''Figure 6-<ins class="diffchange diffchange-inline">19</ins>: Comparative Costs for Capillary Barrier Cover (CCBE), Complete and <br />Partial Desulphurization and Water Cover (Bussiere and Wilson, 2006)'''<br /></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:ComparativeCostsforBarrierCover.gif]]</div></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:ComparativeCostsforBarrierCover.gif]]</div></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
</table>
KMiller
http://gardguide.com/index.php?title=Chapter_6&diff=12788&oldid=prev
KMiller: /* 6.6.7 Water Cover Methods */
2014-07-01T15:33:15Z
<p><span dir="auto"><span class="autocomment">6.6.7 Water Cover Methods</span></span></p>
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 15:33, 1 July 2014</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l883" >Line 883:</td>
<td colspan="2" class="diff-lineno">Line 883:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Minimization of water use and water losses is a critical objective, especially in arid climates. Key design options include minimizing process water discharged to tailings (i.e., thickening), use of low permeability liners and barriers, recycling of process waters along with any contaminated discharges and seepage to the mill, and the use of surface water retention ponds for evaporation (climate permitting). Treatment sludges are also frequently discharged to tailings impoundments and may be sent to voids for deep disposal in pit lakes for long-term management.  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Minimization of water use and water losses is a critical objective, especially in arid climates. Key design options include minimizing process water discharged to tailings (i.e., thickening), use of low permeability liners and barriers, recycling of process waters along with any contaminated discharges and seepage to the mill, and the use of surface water retention ponds for evaporation (climate permitting). Treatment sludges are also frequently discharged to tailings impoundments and may be sent to voids for deep disposal in pit lakes for long-term management.  </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Salt budgets may also be critical at arid sites for pit lakes and surface impoundments where a negative water balance because of low precipitation and high evaporation can cause evapoconcentration or hyper saline conditions to develop with time.  </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Salt budgets may also be critical at arid sites for pit lakes and surface impoundments where a negative water balance because of low precipitation and high evaporation can cause evapoconcentration or hyper saline conditions to develop with time<ins class="diffchange diffchange-inline">.</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">===6.6.8 Drained Tailings Deposition Methods===</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">Two legs of the “ARD Tetrahedron” (air and water) can be disrupted if fine-grained pyritic tailings can be dewatered and consolidated.  Creating a low-water content paste is one method of tailings management that has been used to accomplish this goal as well as to maximize the amount of solids that can be stored in a given tailings storage facility.  However, the energy and machinery involved in paste tailings production and placement is expensive and a certain amount of water must remain in the tailings to allow pipeline transport.  De-watering tailings passively with little additional equipment is an attractive alternative.</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">Sub-aerial tailings deposition (more specifically, thin-layer sub-aerial deposition) is a methodology for mineral waste management which has proven successful in a number of sites in environmentally sensitive areas of the western U.S.A., Canada and in the Pacific Rim.  Since about 1990, the method has been used to place tens of millions of cubic meters of tailings in an environmentally acceptable manner.  The method involves the sequential deposition of tailings slurry in thin layers around the perimeter of the tailings facility.  As each layer is deposited, particle settlement, desiccation, and consolidation occur in four distinct stages as detailed below and in Figure 1:</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">* In Stage 1, the slurry is in a super-saturated condition with solid particles completely suspended in the fluid.  There is minimal intergranular contact and a hydrostatic pore pressure distribution is present, resulting in an unstable condition which requires agitation for particles to remain in suspension.</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">* Stage 2 begins where the slurry has been initially deposited in a super-saturated plastic condition under water.  As the solid particles settle, low intergranular contact is established and bleeding of surface water has started, with further release of liquid induced by drainage and/or evaporation.  Loading of the settled deposit will result in formation of excess pore pressures which will slowly dissipate with seepage.</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">* Stage 3 is characterized by increased in-place density by means of application of underdrainage, which causes further consolidation and dissipation of positive pore pressures.</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">* Stage 4 develops as the drained deposit is allowed to air-dry and consolidate.  This consolidation can be quite significant and results from the development of negative or suction pressures in the deposit as air is entrained within the soil structure.  The resultant layer of air-dried waste is a stable, partially-saturated mass which has a lower permeability and greatly increased resistance to liquefaction under seismic loading.  The most significant attribute of the slurry's transformation from Stage 1 to </ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">Stage 4 is the increase in the dry density of solids. For example, a gold tailings slurry initially at a solids content of 42% increases in dry solid density from approximately 0.83 kg/L (52 pounds per cubic foot [pcf]) to nearly 1.6 kg/L (100 pcf) merely by allowing settlement, drainage and air-drying in relatively thin layers prior to deposition of a fresh layer of tailings. </ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">As the drying process continues and the moisture content has been reduced to approximately 20%, the dry density shows little increase with continued drying.  In practice, once this point has been reached, a new layer of tailings is added and the cycle begins again.</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">In order to achieve Stage 4 conditions, air-drying of the thinly-deposited (100 to 150 mm) layer of tailings is typically facilitated through a systematic rotational waste discharge strategy.  Note that even though the tailings material in Figure 1 (R) is probably finer than 74 microns (<200 mesh), foot traffic is possible within several weeks of cessation of deposition. Vehicular traffic to conduct closure activities (e.g., placement of cover soils, liners, or soil amendments for revegetation) is also possible shortly after Stage 4 conditions are observed on the tailings surface (Reisinger et al., 2001).</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">If the tailings are very fine grained, thin-layer sub-aerial deposition techniques can create a tailings mass that is relatively impermeable with little entrained moisture.  In fact, it can be demonstrated that the low permeability of the consolidated tailings materials in the initial lifts could allow regulating agencies to consider the tailings themselves as a "liner" in a double-liner configuration.  A drainage blanket beneath the tailings would be included in the design as a leach collection and detection system. Consequently, the design should require only one geosynthetic liner (beneath the drainage blanket) to satisfy a double-liner requirement.  </ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">If the tailings contain significant concentrations of reactive sulfides, the relative impermeability of the tailings mass created with sub-aerial placement techniques should also suppress ARD formation, either in the toe seepage (which should be minimized) or runoff from the revegetated surface.  Retrofitting existing tailings impoundments that have been designed as sub-aqueous facilities is also possible (Filas and Zmudzinski, 1993).  Inserting wick drains or implementing other passive methods that relieve the pore pressure in saturated tailings has also been considered (Brown and Greenway, undated).</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">In summary, the thin-layer sub-aerial tailings deposition method may provide a cost-effective minimum energy and equipment tailings management technology.    Advantages of the technology include:  </ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">* increased stored densities</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">* reduced seepage losses</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">* reduced ARD generation</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">* increased ease of surface reclamation at closure and </ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">* improved embankment stability.</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">More economical upstream construction may be feasible with sub-aerial deposited tailings.  In short, this technology fully embraces the concept of storing solids, not water, and in doing so, can better avoid ARD problems during operation and post closure</ins>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[#top|Top of this page]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[#top|Top of this page]]</div></td></tr>
</table>
KMiller
http://gardguide.com/index.php?title=Chapter_6&diff=12776&oldid=prev
WikiSysop: /* 6.10 References */
2012-06-09T19:50:57Z
<p><span dir="auto"><span class="autocomment">6.10 References</span></span></p>
<table class="diff diff-contentalign-left" data-mw="interface">
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 19:50, 9 June 2012</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1062" >Line 1,062:</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Department of Water and Forestry, Republic of South Africa (DWAF), 2007. Best Practice Guideline – H2: Pollution Prevention and Minimization of Impacts.  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Department of Water and Forestry, Republic of South Africa (DWAF), 2007. Best Practice Guideline – H2: Pollution Prevention and Minimization of Impacts.  </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:DeVries, N.H.C., 1996. “Process of Treating Iron-containing Sulfide Rocks and Ores.” U.S. Patent No. 5587001. http://www.patentstorm.us/patents/5587001.html<del class="diffchange diffchange-inline">/</del>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>:DeVries, N.H.C., 1996. “Process of Treating Iron-containing Sulfide Rocks and Ores.” U.S. Patent No. 5587001. http://www.patentstorm.us/patents/5587001<ins class="diffchange diffchange-inline">/fulltext</ins>.html.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Eger, P., and D. Antonson. 2002. “Use of Microencapsulation to Prevent Acid Rock Drainage,” report to MSE Technology Applications, Minnesota Department of Natural Resources, St. Paul, Minn.  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Eger, P., and D. Antonson. 2002. “Use of Microencapsulation to Prevent Acid Rock Drainage,” report to MSE Technology Applications, Minnesota Department of Natural Resources, St. Paul, Minn.  </div></td></tr>
</table>
WikiSysop
http://gardguide.com/index.php?title=Chapter_6&diff=12756&oldid=prev
Sbrionez: /* 6.6.6 Engineered Barriers */
2012-05-17T16:20:31Z
<p><span dir="auto"><span class="autocomment">6.6.6 Engineered Barriers</span></span></p>
<table class="diff diff-contentalign-left" data-mw="interface">
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 16:20, 17 May 2012</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''''Dry Covers Nomenclature'''''</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''''Dry Covers Nomenclature'''''</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*Alkaline Covers – Cover systems designed to release alkalinity to infiltrating waters.  Alkalinity generally consists of dissolved carbonate species that are derived from the dissolution of limestone (<del class="diffchange diffchange-inline">CaCo3</del>).</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*Alkaline Covers – Cover systems designed to release alkalinity to infiltrating waters.  Alkalinity generally consists of dissolved carbonate species that are derived from the dissolution of limestone (<ins class="diffchange diffchange-inline">CaCo<sub>3</sub></ins>).</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Dry Covers – Cover layer(s) consisting of earthen or synthetic materials in contrast to “wet” covers that involve water.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Dry Covers – Cover layer(s) consisting of earthen or synthetic materials in contrast to “wet” covers that involve water.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Organic Covers – Covers consisting of organic material that may act as a reductant (electron donor) that can scavenge or remove oxygen and possibly drive other reducing reactions such as sulphate reduction.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*Organic Covers – Covers consisting of organic material that may act as a reductant (electron donor) that can scavenge or remove oxygen and possibly drive other reducing reactions such as sulphate reduction.</div></td></tr>
</table>
Sbrionez