Hydrometallurgical Refining of High-grade Nickel Matte from Complex Platinum-Palladium Concentrates.

Taking the high-grade nickel matte obtained from the smelting and converting of Jinbaoshan platinum-palladium concentrates as the research object, a hydrometallurgical process of one-stage atmospheric pressure leaching followed by two-stage pressure leaching was used to study the leaching behavior of nickel, cobalt, copper, iron and sulfur, as well as the refining and enrichment of precious metals. The effects of leaching endpoint pH value, leaching temperature, liquid-solid ratio, oxygen partial pressure, reaction time, initial acidity and other factors were investigated. The results show that the control conditions for atmospheric pressure leaching are leaching temperature of 70 °C, leaching time of eight hours, liquid-solid ratio of 6, and the control conditions for the first stage pressure leaching are solution dosage of 500 mL (H2S04 10 g/L, Cu 3.19 g/L), liquid-solid ratio of 10, oxygen partial pressure of 0.2 MPa, leaching time of one hour, and reaction temperature of 150 °C. The control conditions for the second stage pressure leaching are solution dosage of 500 mL (H₂SO₄ 40 g/L), liquid-solid ratio of 10, reaction temperature of 180 °C, oxygen partial pressure of 0.1 MPa, and reaction time of two hours. The leaching rate of nickel and copper in high-grade nickel matte can reach more than 99%, and platinum and palladium are basically not eached, and the enrichment degree of total content of Au, Ag, Pt and Pd is more than 88 times. [ABSTRACT FROM AUTHOR]