A method for resource utilization of waste nickel-cadmium batteries

Abstract

The invention provides a method for recycling a waste nickel-cadmium cell. The method comprises the following steps: mixing the waste nickel-cadmium cell material, an HCl solution and a compound to obtain a metal ionic mixed solution, wherein the compound is tartaric acid and / or sodium tartrate; regulating pH to be 4-7; filtering to obtain a pre-treated solution; regulating the pH of the pre-treated solution to be 8-11; filtering to obtain cadmium hydroxide and filtrate; regulating the pH of the filtrate to be 5-7; mixing with calcium nitrate; reacting to obtain a nickel nitrate solution and calcium tartrate; and regulating the pH of the nickel nitrate solution to be 7-12 to obtain nickelous hydroxide. According to the method, a recovery device used in the method is simple, and convenientto operate; the nickel and cadmium are separated and recovered based on different pH; the method is simple; the recovery rate and the purity are high; general agents are adopted; tartaric acid or sodium tartrate are recyclable, so that the cost is low; toxic agents such as sulfide are not used, so that secondary pollution is not caused; tartaric acid or sodium tartrate is capable of increasing themetal dissolution speed and rate.

Description

technical field [0001] The invention relates to the technical field of cadmium-nickel separation by hydrometallurgy, in particular to a method for resource utilization of waste cadmium-nickel batteries. Background technique [0002] Due to the excellent performance and wide application of cadmium-nickel batteries, waste cadmium-nickel batteries contain a large amount of toxic heavy metals cadmium and nickel, which will cause great harm if they enter the environment without treatment. Long-term consumption of cadmium-lead-contaminated vegetables, rice, and groundwater can cause renal tubular damage, rickets, and itai disease. Short-term excessive intake of cadmium can cause toxic pulmonary edema, dyspnea, and acute kidney failure. Excessive intake of nickel can lead to serious diseases such as lung cancer, leukemia, asthma, and urinary stones. The combination of nickel with chloride ions, sulfide ions, and carbonyl groups is more toxic, which can cause central circulation and...

AI Technical Summary

Problems solved by technology

Among them, the methods used in hydrometallurgy are: (1) Ammonium salt leaching method: first roast nickel-cadmium battery waste, and then use ammonium nitrate solution to separate and recycle the ammonium nitrate solution. This method has low cost and no secondary pollution, but its recovery Rate is only 20-30%

(2) Fluidized bed electrolysis method: metal copper particles are used as the cathode to reduce metal ions at the cathode, but due to the difficulty in manufacturing granular cathodes, it has not yet been put into industrial application

The recovery rate of this method can reach more than 99%, but it is expensive and not suitable for industrial application

(4) Sulfide precipitation method: Dissolve the cadmium-nickel battery waste with acid, feed hydrogen sulfide to precipitate cadmium sulfide, and the filtrate is concentrated and cooled to make the nickel ions form NiSO 4 ·6H 2 O crystals are precipitated, the separation rate of this method is high and the cost is low, but H 2 S smell foul, pollute the atmosphere

[0004] Technologies such as pyrometallurgy, biometallurgy and mechanical recycling have the problems of complex equipment, high cost, and low purity of recovered metals

Existing wet recycling of waste batteries often involves complex processes and high reagent consumption