Oxalate monodisperse ultra-fine powder and preparation method thereof

Abstract

The invention discloses a monodisperse superfine powder and the preparation method, relating to the preparation of monodisperse nickel and cobaltous oxalate powder. In the water solution of soluble salt of nickel or cobaltic, alkali is added according to 50-100 percent of stoichiometric proportion, and is hydrolyzed to achieve Ni(OH) 2 or Co(OH)2 gel; then C2O42- is added according to a proper stoichiometric proportion to make the remained Ni2+ or Co2+ ion to generate the corresponding oxalate nucleus; finally, under the condition of constant pH value, oxalic acid is added to make all the Ni(OH)2 or Co(OH)2 gel to generate oxalate precipitation; grain nucleation is separated from the growth stage, and the growth is kept under controlled supersaturation, and the quantity of crystal nucleuses can be controlled by regulating the temperature and other conditions. The prepared powder grain is in rhomboid column form, and has the advantages that the granularity is at nanometer-micron level, has monodispersion, is free of agglomeration, etc.

Description

technical field [0001] The invention relates to a nickel oxalate or cobalt oxalate powder and a preparation method thereof. Background technique [0002] Ultrafine (micron and submicron) nickel, cobalt metal or oxide powders are widely used in cemented carbide, battery materials, electronic materials, catalysts and other fields, and are an important class of non-ferrous metal functional powder materials. There are many preparation methods, among which, the oxalate precipitation of nickel and cobalt is used as an intermediate product, and then heated and converted into metal or oxide powder under conditions such as controlled temperature and atmosphere, which is one of the most important methods. a wide range of applications. This kind of nickel, cobalt metal and oxide powder prepared by further heating and converting with oxalate precipitation as the precursor, its final powder shape, particle size and distribution are determined by the precursor, that is, the oxalate powde...

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Problems solved by technology

Its two, in order to maintain higher production efficiency, the solution concentration that industrial production adopts is bigger, is generally higher than 0.5mol / L, and in this case, no matter what kind of feeding method is adopted, it is impossible to ensure that the solution concentration in the reaction system is high. The degree of supersaturation is uniform. Therefore, in the process of precipitation formation, the steps of nucleation, growth, and agglomeration cannot be effectively controlled, and it is impossible to prepare oxalate powder with a narrow particle size distribution.

Third, during the preparation process, the agglomeration of powder particles is serious, making the particles coarse and the particle size distribution is very wide. The prepared nickel and cobalt oxalate are difficult to obtain about 1 micron and narrow particle size distribution during further heating transformation. Nickel, Cobalt Metal and Oxide Powders

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