Process for comprehensively recovering arsenic, copper and bismuth from copper-bismuth slags

Abstract

The invention relates to a process for comprehensively recovering arsenic, copper and bismuth from copper-bismuth slags. The process for comprehensively recovering the arsenic, the copper and the bismuth from the copper-bismuth slags comprises the following steps of carrying out oxygen pressure leaching on the copper-bismuth slags in a sulfuric acid system by taking the copper-bismuth slags generated by sulfuration fractional precipitation of copper-bismuth-containing acidic waste liquid generated by acid production from copper smelting flue gas as a research object, then adding the copper-bismuth slags into the leaching slurry, replacing arsenic sulfide in the copper-bismuth slags with copper sulfate in the slurry, reducing pentavalent arsenic into trivalent arsenic by the copper-bismuth slags, and filtering to obtain a trivalent arsenic solution and a slag phase; evaporating, concentrating, cooling and crystallizing the trivalent arsenic solution to obtain a white arsenic product; adding sodium chlorate and hydrochloric acid into the slag phase under a normal pressure condition to leach the copper and the bismuth, firstly adding a dilute alkali solution into leachate to carry out hydrolysis reaction so as to generate bismuth oxychloride, carrying out solid-liquid separation, and adding solid alkali into filtrate to neutralize the solution so as to recover copper; and returning leaching residues to a lead smelting system to recover the lead, and returning hydrolysate to the leaching procedure of copper and bismuth. The process for comprehensively recovering the arsenic, the copper and the bismuth from the copper-bismuth slags provided by the invention is short in technological process, economical, applicable, free of pollution and low in energy consumption, and efficient separation and comprehensive recovery of the arsenic, the copper and the bismuth are achieved.

Description

technical field [0001] The invention belongs to the technical field of resource waste recycling, in particular to a comprehensive recovery process for arsenic, copper and bismuth in copper-bismuth slag. Background technique [0002] A large amount of sulfur-containing flue gas produced by pyrometallurgy of copper is mainly used to prepare sulfuric acid. A large amount of dirty acid wastewater generated after flue gas washing in the acid production process contains about 10-30 mg / L of metal rhenium, 600-800 mg / L of copper, and 500 mg / L of bismuth. ~1000 mg / L, arsenic 13~20g / L, copper, bismuth, arsenic are precipitated first through potential controlled sulfidation precipitation, and then rhenium is precipitated, and copper, bismuth, arsenic and rhenium are separated by step-by-step precipitation, and the rhenium is realized Enrichment. A large amount of copper, bismuth and arsenic slag are produced in the process of precipitation of copper, bismuth and arsenic. At present, c...

AI Technical Summary

Problems solved by technology

The copper, bismuth, and arsenic precipitation process produces a large amount of copper, bismuth and arsenic slag. At present, copper is recovered by remelting, and arsenic and bismuth have been circulating in the system in a closed circuit, which not only increases the equipment load, but also increases the concentration of arsenic and bismuth in the copper electrolyte. , which seriously affects the quality of cathode copper

In addition, when copper-bismuth slag is treated by pyrotechnics alone, the smelting slag contains high bismuth, the separation of arsenic and bismuth is not complete, the direct recovery rate of bismuth refining is low, and the environmental pollution is large

In the wet treatment process, the copper sulfate replacement method, alkali leaching method, oxygen pressure leaching method and ferric sulfate method can all achieve the removal of arsenic and the enrichment of copper and bismuth, but the copper sulfate replacement method consumes a lot of copper powder and costs high

The alkaline leaching method consumes a lot of alkali and is difficult to recycle. The alkaline leaching solution needs to go through an oxidation-reduction process to prepare arsenic products with low environmental risks.

The ferric sulfate method is complex and costly, and the iron in the prepared arsenic trioxide tends to exceed the standard, making it difficult to meet the purity requirements

Using oxygen pressure leaching-sulfur dioxide / sodium sulfite reduction process to treat copper bismuth slag can obtain arsenic trioxide with better quality, but the whole process returns more materials, and the ratio of arsenic entering the final product is relatively low