摘要:
硐室水溶法开采钙芒硝矿过程中外排矿石压覆土地,易造成水土污染和次生地质灾害.为此,进行钙芒硝矿石的高效水浸研究,试验确定了最优浸出参数:矿石粒度为-0.9mm,液固比为1.5∶1,浸出温度为50℃,浸出时间为1h.进而提出了二段逆流浸出工艺,浸出率为98%以上,浸出液中Na2SO4浓度提高了26%,达262g/L,浸出液可以直接进入制硝系统生产元明粉,浸出渣中CaSO4·2H2O含量为70.34%,碱含量(Na2O+0.658 K2O)为0.51%,满足标准《GB 175-2007通用硅酸盐水泥》对碱含量不大于0.60%的要求,浸出渣可作为水泥的原料.提出的高效浸出工艺既可回收硫酸钠,亦利用了浸出渣,为外排钙芒硝矿石的综合利用奠定了基础.
关键词:
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钙芒硝
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水浸
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二段逆流浸出
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元明粉
Abstract:
A considerable amount of glauberite ore was discharged and piled on the land when it was mined by solution mining in tunnel cavern, which might gave rise to water-soil pollution and secondary geological disaster.Therefore, water leaching research on glauberite ore was implemented.The optimum leaching parameters were determined as follows: the ore grain size was-0.9 mm, the ratio of liquid to solid was 1.5∶1, the leaching temperature was 50 ℃, and the leaching time was 1 h.Furthermore, a two-stage countercurrent leaching process was proposed.The concentration of Na2SO4 in the leaching solution was increased by 26% to 262 g/L with the leaching efficiency of more than 98%, and the leaching solution could be directly exported to produce sodium sulfate.The content of CaSO4·2H2O in the leaching slag was 70.34%, and the alkali content (Na2O + 0.658 K2O) was 0.51%, meeting the requirements of the alkali content no more than 0.60% of GB 175-2007 General Portland cement.The leaching slag could be used as raw material for cement.The leaching process proposed in this paper could recover sodium sulfate and also utilize the leaching residue, which lay the foundation for the comprehensive utilization of the glauberite ore.
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