钙芒硝矿石的水浸工艺研究

Research on Water Leaching Process of Glauberite Ore

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-0.9 mm,液固比为1.5∶1,浸出温度为50℃,浸出时间为1 h。进而提出了二段逆流浸出工艺,浸出率为98%以上,浸出液中Na_2SO_4浓度提高了26%,达262 g/L,浸出液可以直接进入制硝系统生产元明粉,浸出渣中CaSO_4·2H_2O含量为70.34%,碱含量(Na_2O+0.658 K_2O)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。

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 implemen-ted. 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 con-centration of Na2S04 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 sodi-um sulfate. The content of CaS04 · 2H2O in the leaching slag was 70. 34% , and the alkali content （Na20 ＋ 0.658 K20） 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 materi-al for cement. The leaching process proposed in this paper could recover sodium sulfate and also u-tilize the leaching residue, which lay the foundation for the comprehensive utilization of the glauberite ore.