刚果(金)曼甘塔尾矿中金赋存状态及综合回收技术

Gold Occurrence and Comprehensive Recovery Technology in Mangote Tailings, DRC

曼甘塔尾矿位于刚果(金)Mai-Ndombe地区,该尾矿平均含Au 9.9×10-6,具有较高的综合回收价值。为确定合理经济的综合回收方案,开展曼甘塔尾矿中金赋存状态研究,研究使用偏光显微镜、物相分析、扫描电镜及能谱分析等多种测试手段查明了曼甘塔尾矿中含金矿物的种类、赋存状态及与其他矿物的连生关系,并通过粒度筛析结合镜下统计结果确定了曼甘塔尾矿中自然金的嵌布粒度和解离度。结果表明:曼甘塔尾矿中的金主要以自然金形态赋存,多呈不规则状、粒状包裹于褐铁矿等矿物中,且嵌布粒度细小,解离度较低。结合工艺矿物学研究结果,确定了在入选磨矿细度-74μm占91%条件下,原矿筛分分级-螺旋溜槽重选的工艺流程,全流程在尾矿矿石含Au 9.9×10^-6条件下,重选获得总金精矿含Au 108.48×10^-6,Au回收率达到了67.34%,实现了曼甘塔尾矿有价金属的综合回收。

Mangote tailings is located in Mai-Ndombe area of Congo(DRC). The average Au content of Mangote tailings is 9.9×10-6, which has high comprehensive recovery value. In order to determine a reasonable and economical comprehensive recovery technological process, the gold occurrence state in Mangote tailings was studied. The occurrence states and association with other minerals of gold-bearing minerals in Mangote tailings were identified by polarizing microscope, phase analysis, scanning electron microscopy and energy spectrum analysis, and the grain size was determined. The size distribution and dissociation degree of natural gold in Mangote tailings were determined by degree sieving and microscopic statistics. The results show that gold in Mangote tailings mainly occurs in the form of natural gold, and most of them are irregular and granular encapsulated in limonite and other minerals, with fine particle size and low dissociation degree. Combining with the results of process mineralogy research, the process flow of screening and grading of raw ore and gravity separation of spiral chute was determined under the condition of grinding fineness of-74 micron accounting for 91%. Under the condition of Au 9.9×10^-6 in tailings, the total gold concentrate containing Au 108.48×10^-6 was obtained by gravity separation, and total Au recovery rate reached to 67.34%. The comprehensive recovery of valuable metals from MANGOTE tailings has been realized.