Method for separating and extracting iron and nickel from iron and nickel leaching agent

Abstract

The invention discloses a method for separating and extracting iron and nickel from an iron and nickel leaching agent. According to the method, after pH adjusting is conducted on waste water, firstlyferrous oxalate and a nickel sulfate solution are obtained by oxalic acid precipitating for deironing, and ferric oxide is obtained after the ferrous oxalate is roasted; and a nickel plate is obtainedby nickel electrodeposition after ion exchange and deep deironing are further conducted on the nickel sulfate solution, a solution generated by nickel electrodeposition is processed by electrodialysis, and then fresh water is reused. According to the technology, the problem of depth separating of the high-concentration iron and nickel leaching agent is solved, closed cycle is formed in the wholeprocess, sulfuric acid and water resources are recycled, the technological operation cost is low, ferrous oxide with the purity being greater than 99.5% is obtained by extracting and producing the iron, the nickel plate with the purity being greater than 99.995% is obtained by extracting and producing the nickel, the resource utilization rate is high, the product purity is good, the economic benefits are excellent, waste gas, the waste water and waste residue are not discharged in the whole process, and secondary pollution is avoided.

Description

technical field [0001] The invention belongs to the field of advanced treatment of wastewater, in particular to a method for separating and extracting iron and nickel from iron and nickel leachate. Background technique [0002] For high-concentration iron and nickel leaching solutions, extraction, ion exchange and hydrolysis precipitation are usually used in industry to separate and extract iron and nickel. The commonly used extraction agents in the extraction method are P204 and P507. P204 and P507 have good ability to extract nickel, but they will also extract a part of iron while extracting nickel, and iron is also difficult to back-extract from the loaded organic phase with sulfuric acid. It can only be back-extracted with hydrochloric acid, and the concentration of hydrochloric acid must reach more than 4mol / L, and the acid consumption is huge; for high-concentration iron and nickel leaching solutions, when using ion exchange technology to separate iron and nickel, the ...

AI Technical Summary

Problems solved by technology

The commonly used extraction agents in the extraction method are P204 and P507. P204 and P507 have good ability to extract nickel, but they will also extract a part of iron while extracting nickel, and iron is also difficult to back-extract from the loaded organic phase with sulfuric acid. It can only be back-extracted with hydrochloric acid, and the concentration of hydrochloric acid must reach more than 4mol / L, and the acid consumption is huge; for high-concentration iron and nickel leaching solutions, when using ion exchange technology to separate iron and nickel, the first stage does not meet the standard, and multi-stage exchange columns are required. The amount of resin is large, the investment is expensive, and there are shortcomings such as competitive adsorption of iron and nickel, which cannot be separated and purified in depth; the method of hydrolysis will introduce Na into the system + Other impurities, poor product purity

Images