Method for preparing superfine nickel powder by direct reduction

Abstract

The invention relates to a process for preparing metal powder and provides a method for superfine nickel powder by direct reduction. The method comprises the following steps: drying and dehydrating nickel chloride crystals serving as a nickel source to obtain absolute nickel chloride; and performing a reduction reaction by using hydrogen at 230 to 700 DEG C in a protective gas to obtain the superfine nickel powder. In the preparation method, the absolute nickel chloride crystals are reduced directly to form the nickel powder. As the synthesis of a precursor (such as the nickel carbonate or nickel oxalate in the conventional wet-method process) is not required in the solid-phase direct reduction method, working procedures are saved and process cost is reduced greatly; and meanwhile, almostno waste water is discharged, so the method is favorable for environment protection. In addition, the absolute nickel chloride crystals are used as a nickel raw material to undergo a reaction in a hydrogen reducing atmosphere, so the source of carbon is reduced, the carbon content of the final product is reduced, and the low-carbon and environment-protection requirements are met.

Description

technical field [0001] The invention belongs to metal powder preparation technology, in particular to a method for preparing superfine nickel powder through direct reduction of solid phase method. Background technique [0002] At present, as a metal powder material, ultrafine nickel powder has gradually replaced gold, silver, etc. Precious metals are used in catalyst materials, electrode materials and hard alloys. For example, current electrode materials mostly use ultra-fine nickel powder as raw material to prepare lithium nickelate composite electrode materials. [0003] Ultrafine nickel powder has a variety of preparation methods, including nickel carbonyl thermal decomposition method, evaporation-condensation method, alloy method, gas reduction method, electrolysis method, mechanical pulverization method and liquid phase reduction method, etc. Among these methods, the liquid phase reduction method has become an important method for the preparation of ultrafine nickel p...

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Problems solved by technology

In addition, there are some nickel powders produced by the carbonylation method, generally called carbonyl nickel powders, such as Canadian Inco nickel carbonyl powders, including T255, T123 and other series products. The raw materials of these carbonyl nickel powder products also contain carbon. Meet the current low-carbon environmental protection requirements

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