Method for recovering and preparing basic zinc carbonate from waste zinc-containing anti-corrosion coatings

Abstract

The invention discloses a method for recycling and preparing basic zinc carbonate from waste zinc-containing anticorrosive paint. The method for recycling and preparing basic zinc carbonate from wastezinc-containing anticorrosive paint comprises the following process steps of (1) wet ball-milling, specifically, zinc-containing anticorrosive paint and water are mixed and then delivered into a ballmill for wet grinding, so that granular raw materials with the mesh number not smaller than 30 are prepared; (2) leaching, specifically, the granular raw materials and a reaction solution are mixed according to the weight ratio of 1:5-6, agitation leaching is conducted, sulfuric acid with the concentration of 98% is added, the pH at the later stage of leaching is controlled to 1.5-2.5, filter pressing is conducted, and filtrate with the iron concentration not over 10g / L is obtained and delivered into an iron and manganese removal agitation tank; (3) stage-by-stage removal of iron and manganese impurities; and (4) preparation of the basic zinc carbonate through deposition. According to the method for recycling and preparing basic zinc carbonate from waste zinc-containing anticorrosive paint, through the process sequentially including wet ball-milling, direct leaching, stage-by-stage impurity removal and deposition for preparation, qualified basic zinc carbonate can be prepared. The process is simple, and energy consumption is low.

Description

technical field [0001] The invention relates to a treatment technology for zinc-containing anticorrosion coatings, in particular to a method for recovering and preparing basic zinc carbonate from waste zinc-containing anticorrosion coatings. Background technique [0002] Zinc has excellent corrosion protection performance for steel. Zinc-rich primer uses zinc powder as a filler for heavy-duty anti-corrosion coatings. The main reason is that the potential of zinc metal is lower than that of iron, which has a cathodic protection effect. The anti-rust mechanism is the zinc-rich primer. cathodic protection. As the name suggests, zinc-rich primers have a high content of zinc dust, which can be as high as 90% by weight. [0003] Zinc has a lower boiling point of 906.97°C. Zinc pyrometallurgy uses this characteristic of zinc to reduce its oxide to metallic zinc with a reducing agent. After the gaseous metallic zinc volatilizes, it condenses to obtain solid metallic zinc, thereby ...

AI Technical Summary

Problems solved by technology

However, the equipment used in the extraction is relatively large, the price of the extraction agent is relatively high, and the energy consumption of electrowinning is relatively large.