紫金铜尾矿中明矾石直接加压酸浸

Utilizing alunite comprehensively from Zijin copper tailings by directly pressure acid leaching

为解决传统明矾石提钾、铝研究一直存在的大规模产业化过程复杂、高成本等难题,以紫金矿业选铜尾矿浮选得到的明矾石为原料,首次提出采用硫酸直接加压酸浸新工艺,在明矾石未经过煅烧情况下铝、钾的浸出率可以分别达到98.54%、95.73%,远高于常压浸出效果,而且工艺过程简单,提取成本低,反应过程较佳的工艺参数为:温度220℃、酸矿比(g/g)为3:1、酸含量为25%(质量分数)、反应时间120 min、搅拌速率为600 r/min。通过X射线衍射和扫描电镜的分析表明:明矾石结构被充分破坏,浸出渣的主要成分为SiO_2。

In order to solve the difficulty of high cost and wide industrialization in the traditional techniques of extracting potassium and aluminum from alunite, the alunite floated from the tailings of Zijin copper ore was processed by non-roasting pressure acid-leaching. Compared with normal pressure leaching process, it can not only improve the leaching ratio of K and Al to 95.73% and 98.54%, respectively, but also have simpler technological route and low cost. Based on experimental research, the optimal leaching parameters are leaching temperature of 220 ℃, acid to ore ratio(g/g) of 3:1, initial acid concentration of 25%, leaching time of 120 min and stirring rate of 600 r/min. Analysis of the high pressure acid leaching residue by X-Ray powder diffraction and scanning electron microscope analysis indicates that crystal structure of alunite is completely destroyed, and the main chemical composition of leaching residue is SiO_2.