铜镍尾矿砂微波加热硫酸溶解实验研究

通过尾矿砂微波加热硫酸溶解新方法的实验,研究了硫酸浓度、液固比及反应时间等因素对尾矿砂酸蚀率的影响。结果显示,在无需搅拌的情况下,微波加热实验的最佳条件酸浓度5mol/L、液固比5.0mL/g都较传统水热法有优势,在反应时间上,微波加热15min就能达到传统水热法2～3h的效果。在酸蚀率相同的情况下,微波加热所用时间仅为传统水热法的1/6,而所用的酸浓度、液固比都较传统水热法小很多。先对尾矿砂直接微波辐照一段时间,然后再加入硫酸进行微波辐照加热溶解,能够促进尾矿砂的溶解,提高尾矿砂的酸蚀率。微波加热条件下,尾矿砂在硫酸浓度8mol/L、液固比5.0mL/g条件下无需搅拌,反应1h后,除透闪石没有完全溶解外,绝大部分的矿物被溶解。与传统加热方式相比,微波加热可显著提高尾矿砂酸溶解速率。

Dissolution of copper and nickel mine tailings in sulfuric acid heated with microwave

The sulfuric acid leaching process of tailings by using microwave was studied in this paper. The effects of sulfuric acid concentration, liquid to solid ratio and reaction time on the leaching ratio were also investigated. Without agitation, the optimum microwave heating conditions of sulfuric acid concentration 5.0 mol/L and liquid/solid ratio 5.0 mL/g are superior to those of water bathing heating. In addition, microwave heating for 15 man can yield the same effect as that of water bathing heating for 2--3 h. In addition, microwave heating for 1/6 reaction time of water bathing time can produce the same acid-leaching rate, with much lower sulfuric acid and liquid to solid ratio. The microwave heating of railings for some time followed by addition of sulfuric acid for leaching can be helpful to the dissolution of tailings and enhance the acid-leaching rate. Under the conditions of microwave heating of 1 h, sul- furic acid concentration 8.0 mol/L and liquid/solid ratio 5.0 mL/g, most of the minerals in tailings can be dissolved except tremolite. The results indicate that, compared with the traditional heating methods, microwave heating could greatly improve the acid-leaching rate of tailings.