ABSTRACT

Excess pore water pressure (PWP) in gold tailings, deposited in the laboratory in a settling column, was observed for various rates of deposition. Rates of rise (vertical increase in height of settled tailings over time expressed in metres per year) of 10 m/yr and 20 m/yr were evaluated by depositing the gold tailings in layers. The maximum deposition rate achieved in the laboratory by depositing tailings to the full height of the settling column at once (full depth deposition) was also investigated. Maximum excess PWPs of 6 kPa generated within 3 to 9 minutes from the start of tailings slurry deposition were recorded. 90% of the maximum generated excess PWPs dissipated within the first 10 hours for coarse tailings and 30 hours for fine tailings. Dissipation of the remaining 10% occurred within 1.1 days and 10.4 days respectively. The excess PWPs were the highest for full depth (FD) deposition. Excess PWPs at an rate of rise (RoR) of 20 m/yr and 10 m/yr were 50% and 30% of the FD deposition. Dissipation of the excess PWPs occurred mostly during the sedimentation phase. It is shown that excess PWP build up on its own cannot be the mechanism that limits the RoR of gold tailings dams.

摘要

观察到金尾矿中过大的孔隙水压力（PWP）在实验室的沉降塔中沉积，观察到各种沉积速率。通过在层中沉积金尾矿来评估10 m / yr和20 m / yr的上升速率（沉降的尾矿的高度随时间的垂直增加，以米/年表示）。还研究了在实验室中通过将尾矿一次沉积到沉降塔的整个高度（全深度沉积）而获得的最大沉积速率。记录了从尾矿浆沉积开始3至9分钟内产生的6 kPa的最大过量PWP。粗尾矿在头10小时内消散了最大生成的过量PWP的90％，细尾矿在30小时内消散了。剩余的10％的耗散分别发生在1.1天内和10.4天内。对于全深度（FD）沉积，过量的PWP最高。20 m / yr和10 m / yr的上升速率（RoR）的过量PWP是FD沉积的50％和30％。多余PWP的消散主要发生在沉积阶段。结果表明，多余的PWP本身不能成为限制金尾矿坝RoR的机制。