硫铁矿尾矿活化焙烧-二次碱浸脱硅制备铝精矿

Aluminum Concentrate Prepared by Activated Roasting-Secondary Alkaline Leaching Desilication of Pyrite Tailings

这是一篇冶金工程领域的论文。西南某地区硫铁矿选硫尾矿中的氧化铝含量高于46%,具有较高回收利用价值,但尾矿中的铝硅酸盐矿物中存在含量较高且晶体结构稳定的SiO_(2),导致尾矿的铝硅比(A/S)较低,仅为1.72。为了实现铝硅分离,制得铝精矿以回收利用该尾矿,通过活化焙烧使其中结构稳定的SiO_(2)转变为非晶态SiO_(2),再使用NaOH溶液二次浸出焙砂脱硅制备得到铝精矿。结果表明:在焙烧时间35 min,焙烧温度1140℃,一次碱浸NaOH浓度140 g/L,浸出温度110℃,浸出时间30 min,浸出液固比16的适宜条件下,铝硅比(A/S)提高到4.11;在二次碱浸NaOH浓度140 g/L、浸出温度110℃、浸出时间30 min、浸出液固比10的较佳条件下,得到铝硅比(A/S)为5.11的铝精矿,为该尾矿的综合利用打下了良好的基础。

This is an essay in the field of metallurgical engineering.Content of alumina in pyrite tailings in the southwest China is higher than 46%,and the alumina is of high recycling value.However,SiO_(2) with high content and stable crystal structure exists in aluminosilicate minerals in tailings,resulting in a low aluminosilicate ratio of Al_(2)O_(3)/SiO_(2) (A/S) of tailings,which is only 1.72.To realize the separation of aluminum and silicon,and obtain aluminum concentrate for recycling of the tailings,the SiO_(2) with stable structure is transformed into amorphous SiO_(2) by activated roasting.And then the calcine is leached twice with NaOH solution for desilicating to obtain the aluminum concentrate.The results show that under the optimum conditions of roasting time of 35 min,roasting temperature of 1140℃,the concentration of NaOH140 g/L in primary alkaline leaching,leaching temperature of 110℃,leaching time of 30 min,the ratio of liquid to solid 16,the aluminum-silicon ratio (A/S) increases to 4.11.Under the optimum conditions of NaOH concentration 140 g/L in secondary alkaline leaching,leaching temperature 105℃,leaching time 30min,and leaching liquid to solid ratio 10,the aluminum-silicon ratio (A/S) of 5.11 is obtained,which lays a good foundation for comprehensive utilization of the tailings.