Experimental Research on Enrichment of Precious Metals from Lead Matte by Nitric Acid Leaching

2017 3rd International Conference on Energy, Environment and Materials Science

能源学;生态环境科学;材料科学

Fan, Xingxiang^1 ; Yang, Kunbin^2 ; Tan, Chunmei^2

Faculty of Metallurgical Material, Kunming Metallurgy College, Kunming, Yunnan

650033, China^1

Yunnan Copper Co., Ltd, Kunming, Yunnan

650102, China^2

关键词: Ball milling time;    Direct leaching;    Enrichment ratio;    Experimental research;    Leaching rates;    Nitric acid leaching;    Optimal process;    Phase and element composition;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/94/1/012124/pdf
DOI  :  10.1088/1755-1315/94/1/012124

来源: IOP

【 摘 要 】

Based on the phase and element composition of lead matte, this paper presents an enrichment process of precious metals by selective leaching of base metals of Pb and Cu from lead matte with nitric acid. The effects of nitric acid dosage, leaching time, leaching temperature, liquid-solid ratio on the leaching rate of lead and copper were also discussed in detail. Through the experiments, the optimal process data were obtained as follows: nitric acid dosage 1.54 times the weight of lead matte, leaching time 3h, leaching temperature 75°C, and liquid-solid ratio 4:1. Under this condition, the slag rate was 33.20%, Pb/Cu leaching rates were 91.14% and 89.99%, Au and Ag contents in the leaching residue were 10.54 g/t, Ag 2693.95 g/t, respectively; and the enrichment ratio of precious metals up to 3.01 times. The effect of milling of lead matte on Pb/Cu leaching rate was also investigated while keeping the leaching condition constant. Experiments show Pb/Cu leaching rates were up to 97.46% and 96.73% and the slag rate was 30.16%, Pb/Cu content in residues were 4.58% and 1.29%, respectively, when ball milling time was 30 min. Compared with direct leaching, Pb/Cu leaching rate increased by 6.32% and 6.74%, the enrichment ratio increased by 0.31 times. It was proved that ball milling of lead matte was helpful to improve Pb/Cu leaching rate.