Method for recycling and refining nickel and cadmium in solid hazardous wastes

Abstract

The invention discloses a method for recycling and refining nickel and cadmium in solid hazardous wastes. The method disclosed by the invention comprises the following steps: reducing semi-finished products by using a carbon-containing reducing agent, wherein the semi-finished products are nickel carbonate and cadmium carbonate which are generated during a treatment process of hazardous wastes containing heavy metals including nickel and cadmium and contain lots of nickel and cadmium and less magnesium, caecum and iron; then carrying out acid leaching; controlling the condition to ensure that cadmium oxide in the system is dissolved but the metallic nickel is not dissolved so as to realize separation of nickel and cadmium; melting the separated metallic nickel at the temperature of 1600 DEG C to form a nickel ingot product of which the grade is above 99%; putting a Cd<2+> solution obtained through dissolution into a workshop process and precipitating the solution by using sodium carbonate so as to obtain a CdCO3 product of which the purity is higher than 98%. The method disclosed by the invention can be used for greatly reducing energy consumption and environmental pollution and has the advantages of short process and easy control over conditions; substances contained in raw materials need not to be purified specially, a high-purity product can be obtained under the condition that the procedures are reduced; the reducing agent is selected conveniently according to local production conditions and is low in cost.

Description

technical field [0001] The invention relates to the technical field of heavy metal-containing hazardous waste treatment and metal recovery, in particular to a method for recovering and refining nickel and cadmium in solid hazardous waste. Background technique [0002] Nickel is a white ferromagnetic metal with the advantages of corrosion resistance, oxidation resistance, high mechanical strength and good ductility. It is widely used in metallurgy, chemical industry, petroleum, construction, machinery, transportation, spacecraft, instrumentation, light industry and other departments. It is an important raw material for manufacturing superalloys, special alloys and stainless steel. It is also used for casting coins and producing jewelry. and medical. Cadmium carbonate is widely used in production, and can be used as an intermediate for the manufacture of polyester, a flux for glass pigments, a catalyst for organic reactions, a plasticizer, a stabilizer for plastics, and a raw...

AI Technical Summary

Problems solved by technology

The extraction method not only has a long process flow, but also incomplete separation of nickel and cadmium, and a large amount of metal loss; when the process of separating NiO and CdO by acid leaching is used in industry, the conditions are not easy to control; in the emulsion liquid membrane method The matrix composition of the emulsion film is relatively complex, and the ammonia water component is volatile, which increases the cost of environmental treatment; the vacuum distillation method has high requirements for equipment, and leads to an increase in equipment maintenance costs

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