Improved sponge cadmium replacement process

Abstract

The embodiment of the invention discloses an improved sponge cadmium replacement process, and relates to the technical field of nonferrous metallurgy. The process comprises the following steps of: putting cadmium liquid into a reaction tank; weighing concentrated sulfuric acid and zinc powder for later use, wherein the amount of the concentrated sulfuric acid is 2.5-3.5 percent of the cadmium content in the cadmium liquid, and the amount of the zinc powder is 58-60 percent of the cadmium content in the cadmium liquid; and under a stirring condition, adding a part of concentrated sulfuric acidinto the cadmium liquid to adjust the acidity of the solution until the pH value is 2.5-2.7, and synchronously, uniformly and continuously adding the zinc powder and the residual concentrated sulfuricacid for replacement reaction, and performing solid-liquid separation after the replacement reaction is finished to obtain sponge cadmium and filtrate with the cadmium content of 0.5-1 g/L. Accordingto the improved sponge cadmium replacement process disclosed by the embodiment of the invention, the usage amount of the concentrated sulfuric acid and the zinc powder is obviously reduced, the replacement reaction can be stably performed by adopting a process of synchronously adding the zinc powder and the sulfuric acid, a trace amount of arsenic in the solution is prevented from escaping, and safety production is facilitated.

Description

technical field [0001] The embodiment of the present invention relates to the technical field of non-ferrous metal metallurgy, in particular to an improved sponge cadmium replacement process. Background technique [0002] Cadmium is a non-ferrous heavy metal, soft, ductile, and easily oxidized on the surface. It is widely used in cadmium plating, manufacturing alloys, pigments, plastic stabilizers, batteries, etc. 90% of cadmium-containing raw materials come from lead-zinc smelting, and sometimes metal cadmium is extracted from waste nickel-cadmium batteries. [0003] The copper cadmium slag produced in the purification process of zinc hydrometallurgy and the cadmium-containing smoke produced by pyrometallurgy zinc are the initial raw materials for the production of cadmium. The combined method consisting of wet method and fire method is the cadmium extraction process adopted by most smelters. Its main process includes: leaching, purification, replacement, briquette smeltin...

AI Technical Summary

Problems solved by technology

[0005] For this reason, the embodiment of the present invention provides an improved sponge cadmium replacement process to solve the problems of high sulfuric acid consumption, high zinc powder consumption, and long replacement time in the existing sponge cadmium replacement process.