Method for recycling copper, nickel, chromium, zinc and iron from plating sludge

Abstract

The invention relates to a method for recycling copper, nickel, chromium, zinc and iron from plating sludge, belonging to the technical field of chemical engineering and metallurgy. The method comprises the following steps: acid leaching, vulcanizing for separation and enrichment, hot-pressure leaching, extracting for separation, hot-press oxidizing chromium, purifying chromium solution, extracting ferric chloride and the like. The method has obvious advantages of strong adaptability to different kinds of plating sludge, high utilization of metal resources, high value-added content of product,less process waste residue, thorough deintoxication and the like.

Description

technical field [0001] The invention relates to the technical field of metallurgy and chemical industry, in particular to the technology of recovering metal from electroplating sludge. Background technique [0002] Electroplating sludge is a solid waste that has been neutralized from waste water in the electronics, electroplating, and circuit board surface treatment industries. It has been listed as hazardous waste by the state. Electroplating sludge has a high water content; the particles are fine and muddy; the composition is complex and contains a variety of heavy metal elements such as copper, zinc, nickel, chromium, etc.; metals are mostly endowed in the state of hydroxide, oxide, carbonate, etc. Therefore, the comprehensive utilization of electroplating sludge brings considerable difficulty. Therefore, the current common disposal methods for electroplating sludge are landfill, incineration, solidification, etc., and some of them are directly stacked in the open air. ...

AI Technical Summary

Problems solved by technology

Due to its leaching toxicity, it is easy to pollute surface water or groundwater

[0003] In order to reduce pollution, there are also researches on resource utilization of electroplating sludge. The methods include pyro-reduction smelting and wet chemical separation and recovery, etc., but the overall technical level is not high, and there are the following defects: (1) The scale is small and the process disposal chain is not Integrity, low comprehensive utilization rate, if the production waste residue and waste water are not properly disposed of, it is easy to cause secondary pollution

(2) The treatment process is simple, and the adaptability to raw materials is poor. Only those with higher copper and nickel content can be selected for recycling.

(3) Most of them can only produce crude products, and the economic benefits are low

As far as the properties and characteristics of electroplating sludge are concerned, the following problems should be solved to achieve a more ideal comprehensive utilization effect: (1) Adaptability to raw materials

Since the electroplating sludge comes from different manufacturers, the composition is complex, and the content of main metals and impurities fluctuates in a large range, which brings great difficulties to the process selection

(2) The comprehensive utilization rate of metal resources is not high

Due to technical factors, some available resources are not fully utilized, and are lost in waste slag or wastewater due to low metal recovery rate, which can easily cause secondary pollution

(3) Economic issues: Wet treatment often results in high production costs due to long process and low metal recovery rate