Liquid phase collecting method in superfine metal powder preparation process

Abstract

The invention discloses a liquid phase collecting method in a superfine metal powder preparation process, and relates to the technical field of powder preparation. Superfine metal powder is obtained through a wet cooling method by adopting a cooling system composed of a condensation chamber, a spraying head, a collecting tank, a centrifugal machine and a centrifugal pump. The wet cooling method comprises the following steps that 1, circulating cooling water is prepared from a corrosion inhibitor and water; 2, the circulating cooling water is added into the cooling system to be subjected to self-circulation for 30 min; 3, the spraying head and the centrifugal pump are started, and the circulating cooling water enters the condensation chamber and exchanges heat with metal steam to form a powder solution; 4, the powder solution is collected through a collecting tank, and solid-liquid separation is carried out in the centrifugal machine; and 5, the centrifugal machine collects solids, and liquid enters circulation through the centrifugal pump. According to the liquid phase collecting method, organic citric acid is adopted as the corrosion inhibitor, so that metal salt compounds are effectively prevented from being generated in the cooling treatment of the superfine metal powder, and the purity of the superfine metal powder is remarkably improved.

Description

technical field [0001] The present application relates to the technical field of powder preparation, in particular to a liquid phase collection method in the preparation process of ultrafine metal powder. Background technique [0002] In the ultrafine metal powder production process used in the MLCC industry, evaporation, condensation, and physical vapor collection (PVD) methods are usually used to produce ultrafine metal powder. The process of condensation and collection of powder usually adopts gas dry cooling and collection. Nitrogen gas is used as the cooling medium, and the metal vapor is cooled by nitrogen gas, and the metal powder is collected after crystallization. In the production process of copper, silver, tin, iron, nickel and other metal powders with high thermal conductivity, the gas cooling speed is slow and the temperature is high. The collected powder particles adhere to each other to form connected particles, resulting in powder sphericity Low, poor dispe...

AI Technical Summary

Problems solved by technology

The increase of the oxygen content in the copper powder leads to the increase of the sintering temperature and the decrease of the capacitance value in the capacitor manufacturing process

The change of the specific surface area of ​​copper powder affects the change of film density in the copper powder slurrying process and affects the performance of capacitors

[0004] At the same time, traditional inorganic antioxidants often contain metal ions such as sodium, phosphorus, etc., which are easy to react in aqueous solution and produce precipitates. It is difficult to remove the above-mentioned metal ions in the subsequent process, resulting in excessive metal elements in the product, affecting quality

[0005] Therefore, in the existing production process of ultra-fine metal powder, the problems of powder particle conjoining, agglomeration and oxidative corrosion in the cooling and collection process of the ultra-fine metal powder are caused, which in turn leads to the change of the specific surface area of ​​the powder and the metal Elements exceed the standard, which seriously affects the quality of ultrafine metal powder and needs to be improved

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