Preparation method of small-FSSS high-looseness-ratio cobalt powder

Abstract

The invention discloses a preparation method of small-FSSS high-looseness-ratio cobalt powder. The preparation method comprises the specific steps of 1, synthetising cobalt powder precursor cobalt carbonate; 2, calcining the cobalt powder precursor cobalt carbonate obtained in the step 1 to obtain tricobalt tetraoxide; 3, conducting stepped reduction on the tricobalt tetraoxide obtained in the step 2 to obtain a cobalt powder intermediate body; and 4, crushing the cobalt powder intermediate body obtained in the step 3, screening the crushed cobalt powder intermediate body to remove iron, and obtaining the small-FSSS high-looseness-ratio cobalt powder. According to preparation method, by optimizing equipment and technological conditions, the cobalt powder precursor is dried through a tray drier, and the situation that big and small particle tailing and multimodal distribution occur to the particle size of cobalt carbonate due to cyclone drying is avoided; the cobalt carbonate is calcined into the tricobalt tetraoxide through a rotary kiln, the sphericity of cobalt carbonate is maintained, and thus, after reduction, the cobalt powder has the high looseness ratio; a 15-tube furnace isadopted for reduction to prevent incomplete reduction caused by low hydrogen partial pressure; and moreover, the tricobalt tetraoxide is successfully reduced at ultralow temperature, so that the small-particle and high-looseness-ratio cobalt powder with the good fluidity is obtained.

Description

technical field [0001] The invention belongs to the technical field of metal material preparation, and in particular relates to a method for preparing cobalt powder with small FSSS and high loose ratio. Background technique [0002] Cobalt powder has a wide range of application fields, mainly used in cemented carbide, catalysis, electronic devices, special tools, magnetic materials, batteries and hydrogen storage alloy electrodes and other fields. In the field of cemented carbide and diamond tools, ultrafine cobalt powder is used as a binder. The production of cemented carbide and diamond tools in my country is huge, so a large amount of ultra-fine cobalt powder will be needed. [0003] At present, there are many methods for preparing cobalt powder at home and abroad. Such as oxide, oxalate hydrogen reduction method, oxalate thermal decomposition method, high pressure water spray method, electrolysis method, polyol method, microemulsion method, high pressure hydrogen reduc...

AI Technical Summary

Problems solved by technology

With the expansion of the application field of Co powder, many old processes can no longer meet the requirements of powder properties

[0004] In some fields, such as cemented carbide, the cobalt powder needs to be spherical and the finer the particle size, the better. Ultrafine spherical cobalt powder (FSSS particle size less than 1 micron) can be larger in the production of low-cobalt ultrafine cemented carbide. The wet grinding time of the mixture is shortened, and the dispersibility of the ultrafine spherical cobalt powder in the mixture is better than that of the dendritic cobalt powder, and the composition of the micro-area of ​​the mixture is more uniform. In addition, the ultrafine spherical cobalt powder can be uniform Dispersed between carbides, so that the binder phase is more evenly distributed in the hard phase, which effectively compensates for the uneven distribution of cobalt phase due to low cobalt when producing ultra-fine low-cobalt cemented carbide with general dendritic cobalt powder However, problems such as cobalt pools and micropores are generated, which improves the bending strength of the alloy; while the cobalt powder prepared by the prior art cannot meet the high-porosity ratio while achieving a small particle size

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