Deep impurity removal technology for coarse gold powder

Abstract

The invention provides a deep impurity removal technology for coarse gold powder, which comprises the following steps: putting the coarse gold powder into a chloridizing leaching reactor according to the liquid-solid ratio of (14-16):1, controlling the acidity of solution to be 3mol / L by adding industrial hydrochloric acid, and leaching by introducing chlorine after the temperature reaches 80-85 DEG C for 10-14 hours; then cooling, discharging and filtering, heating and boiling a filtrate and concentrating the volume to be 25% to 37.5% of the original volume, adding deionized water to the original volume after cooling, stirring for 30-60 minutes, standing for 2 hours and then discharging and filtering; and after hydrolysis, repeatedly operating steps of concentrating, deionized water adding, stirring, standing and filtering to remove impurities by hydrolysis, carrying out gold reduction after 2 to 3 times of hydrolysis treatment, and intensively storing hydrolysis residues. Through the process, the impurity content in the solution not subject to the gold reduction is effectively reduced, and especially the contents of Ag, Sb, Pb and Bi are decreased by 95% or so.

Description

technical field [0001] The invention relates to a hydrometallurgical process in the field of metallurgy, in particular to a coarse gold powder deep impurity removal technology for effectively removing most of the impurity elements such as silver and antimony in the coarse gold powder chlorination solution. Background technique [0002] At home and abroad, the fire process is often used to treat copper anode slime. Our company also successfully applied this process to production in 2000. The main process is to produce gold by electrolysis of coarse gold powder produced in the gold separation process. The principle process is copper anode slime sulfuric acid chemical roasting—acid leaching to separate copper—alkali leaching to separate tellurium—chlorination to separate gold—reduction of coarse gold powder—liquidation electrolysis—electrolysis of gold plate—boiling and washing to remove impurities. The requirements are high, especially the impurity element silver in the electr...

AI Technical Summary

Problems solved by technology

[0002] At home and abroad, the fire process is often used to treat copper anode slime. Our company also successfully applied this process to production in 2000. The main process is to produce gold by electrolysis of coarse gold powder produced in the gold separation process. The principle process is copper anode slime sulfuric acid chemical roasting—acid leaching to separate copper—alkali leaching to separate tellurium—chlorination to separate gold—reduction of coarse gold powder—liquidation electrolysis—electrolysis of gold plate—boiling and washing to remove impurities. The requirements are high, especially the impurity element silver in the electrolytic gold plate is difficult to control

Due to the sharp increase of impurity elements in copper raw materials in recent years, the quality of coarse gold powder produced in the roasting and leaching process of copper anode slime has declined significantly, mainly because the content of impurity elements such as silver, lead, antimony, and bismuth has increased, which eventually leads to electrolytic production. The quality of the gold products produced is difficult to meet the standard

For this reason, a new wet process was adopted to replace the electrolytic method to refine the crude gold powder. The quality of the gold powder produced still cannot meet the requirements of the national standard IC-Au99.99. Therefore, it is urgent to find a new process for the deep removal of impurities in coarse gold powder.