Preparation method of ammonium chloroplatinate

Abstract

The invention relates to a preparation method of ammonium chloroplatinate, and the preparation method comprises the following steps of: (1) adding dilute acid to platinum, carrying out cooking washing for 10-60 minutes, and then filtering and washing to obtain refined platinum; (2) adding a hydrochloric acid and perchloric acid solution to the refined platinum, introducing chlorine, and heating the platinum to be completely dissolved to obtain a mixed solution; (3) slowly evaporating the mixed solution into a viscous state, adding hydrochloric acid and oxydol to the mixed solution, continuously slowly evaporating to dryness, and then adding distilled water to obtain a chloroplatinic acid solution; (4) adding the distilled water to ammonium chloride, and heating and dissolving to obtain an ammonium chloride solution; and (5) slowly adding a thermal ammonium chloride solution to the chloroplatinic acid solution to obtain deposits, and filtering, washing and drying the deposits to obtain ammonium chloroplatinate. The prepared ammonium chloroplatinate is mainly used for industrially preparing the noble metal catalyst, the noble metal electroplated layer and the platinized asbestos and can also be used for analytical chemistry.

Description

technical field [0001] The invention specifically relates to a preparation method of ammonium chloroplatinate, which belongs to the field of inorganic compounds. Background technique [0002] Chloroplatinic acid is mainly used in the industry to prepare precious metal catalysts, precious metal electroplating layers and platinum asbestos, and can also be used to precipitate alkaloids, and to test potassium and ammonium ions in analytical chemistry. However, chloroplatinic acid is easy to weather in the air, has a low melting point and unstable crystal form. Its above-mentioned characteristics determine that chloroplatinic acid is not conducive to storage and transportation. In fact, chloroplatinic acid mainly uses its chloroplatinic acid radical in use. Ions, so it is usually necessary to convert chloroplatinic acid into stable ammonium chloroplatinate to facilitate its storage, transportation and use. [0003] In the current technology, aqua regia is used to dissolve platin...

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Problems solved by technology

[0004] In the above-mentioned technology, after aqua regia dissolves metal platinum, there is still excess nitric acid in the reaction system. In order to ensure the purity of the obtained product, it is necessary to carry out nitrate removal to remove nitrate radicals. During the nitrate removal process, the solution needs to be continuously heated to make the The nitric acid in the aqua regia is converted into nitrogen oxide gas and escapes. At the same time, hydrochloric acid is added dropwise to the solution to supplement the hydrochloric acid lost due to heating. The nitrogen oxide and hydrogen chloride gas released during this process have strong oxidizing properties. Acidic, discharged into the atmosphere will cause serious harm to the environment, even if it is not discharged into the atmosphere, it is difficult to separate and recycle when collected, which is not conducive to environmental protection

[0005] In addition, in the process of preparing the chloroplatinic acid solution, the platinum ion is unstable, and it is easy to decompose into chloroplatinous acid when the local temperature is overheated, so that the amount of chloroplatinic acid will be reduced, resulting in the prepared ammonium chloroplatinate The amount is reduced, and the purity of ammonium chloroplatinate is reduced

[0006] In the above technology, after the ammonium chloroplatinate is initially obtained, the ammonium chloroplatinate solution is further purified by a cation exchange resin, and the cations in the ammonium chloroplatinate solution are exchanged by the cation exchange resin, thereby removing the ammonium chloroplatinate cationic impurities in the solution, but the anionic impurities therein have not been removed, so that the obtained ammonium chloroplatinate still contains impurities, and the purity is not high