Comprehensive recovery of Ca, V, Zn, and Si from black shale using a novel hydrochloric acid selective leaching-decarburization process
Comprehensive recovery of Ca, V, Zn, and Si from black shale using a novel hydrochloric acid selective leaching-decarburization process
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DOI：
10.1016/j.seppur.2022.122352
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发表时间：
2022-10
影响因子：
8.6
通讯作者：
Hong Liu;Yi-min Zhang;Peng Hu;Tao Liu;Jing Huang
中科院分区：
文献类型：
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作者：
Hong Liu;Yi-min Zhang;Peng Hu;Tao Liu;Jing Huang
采用传统的硫酸浸出法难以实现黑色页岩中有价元素的综合回收，且浸出渣中含有大量的硅和钙，是一种对环境有害的废弃物。设计了两段盐酸浸出工艺和浸出渣的后续净化工艺，以生产富硅渣。盐酸在第一浸出阶段中选择性地去除消耗酸的矿物如碳酸钙和黄铁矿，而金属钒和锌的浸出量分别仅为0.15%和9.82%。由于氟化钠和盐酸的共同作用，云母在第二段浸出中严重降解，钒的浸出率为90.3%，锌的浸出率为63.2%，而有害元素铁的浸出率仅为25.6%。将第二阶段的浸出渣在750 °C下焙烧2 h以除去碳后，获得二氧化硅纯度为95.5%的富硅渣。该方法有望实现黑色页岩的无废利用。
By traditional sulfuric acid leaching, the comprehensive recovery of valuable elements from black shale is difficult to achieve, and the leaching residue containing large amounts of silicon and calcium, is an environmentally harmful waste. A two-stage hydrochloric acid leaching procedure and a subsequent purification process of the leaching residue were designed to produce a silicon-rich residue. Hydrochloric acid selectively eliminates acid-consuming minerals like calcium carbonate and pyrite in the first leaching stage, while the metals vanadium and zinc were leached in amounts of only 0.15 % and 9.82 %, respectively. Mica was severely degraded in the second leaching stage due to the combined effects of sodium fluoride and hydrochloric acid, with leaching percentages of 90.3 % for vanadium and 63.2 % for zinc, while only 25.6 % of the hazardous element iron was leached. After roasting the leaching residue of the second stage for 2 h at 750 °C to remove carbon, silicon-rich residue with a silica purity of 95.5 % was obtained. The proposed method is expected to achieve waste-free utilization of black shale.