Rapid preparation method of chloroiridic acid

Abstract

The invention discloses a rapid preparation method of chloroiridic acid. The method comprises the following steps: firstly, adding iridium powder and hydrochloric acid into a reaction still, introducing chlorine into the reaction still and reacting under certain conditions; after the reaction is ended, adding concentrated hydrochloric acid into the reaction still, removing free chlorine from the reaction liquid, and filtering after the chlorine is removed to obtain filtrate and filtrate residues, wherein trivalent iridium and tetravalent iridium exist in the filtrate; secondly, taking the filtrate as a raw material and carrying out oxidation reaction on the filtrate and nitric acid; after the reaction is ended, oxidizing the trivalent iridium in the filtrate into the tetravalent iridium toobtain a chloroiridic acid solution; finally, concentrating acid on the chloroiridic acid solution to obtain a chloroiridic acid product. Compared with the prior art, the rapid preparation method ofthe chloroiridic acid, disclosed by the invention, has the advantages of short process flow, simple operation, high processing capacity, no possibility of introducing impurity ions, good operating environment and the like; the iridium powder can be quickly prepared into the chloroiridic acid; in addition, the rapid preparation method has the characteristics of high efficiency, low cost, greennessand environment friendliness.

Description

technical field [0001] The invention belongs to the technical field of preparation of rare metal chemicals, and in particular relates to a rapid preparation method of chloroiridic acid. Background technique [0002] Chloroiridic acid is one of the most common compounds of the element iridium. It is the initial raw material for the synthesis of other iridium-containing compounds and the preparation of iridium-containing catalysts. Iridium-containing compounds and iridium-containing catalysts are widely used in petrochemical, organic synthesis, anode coating and other fields . [0003] Iridium is a silver-white precious metal with considerable ductility, with a melting point of 2410±40°C, a boiling point of 4130°C, and a density of 22.42g / cm 3 , has extremely high corrosion resistance. Usually the form of commercial iridium is powder, namely iridium powder. [0004] The key step in preparing chloroiridic acid and other iridium-containing compounds is to dissolve elemental i...

AI Technical Summary

Problems solved by technology

This method has the following disadvantages: ① "High temperature chlorination roasting or alkali fusion roasting-water leaching or acid leaching" prepares chloroiridate solution and introduces K + or Na + Impurity ions; ② Use ammonium chloride to precipitate iridium to remove K + or Na + ions, and ammonium ions are brought in; ③ It is necessary to wash the ammonium chloroiridate precipitate many times before the K + or Na + The ions are reduced to a certain level, and the impurity ions introduced from the outside cannot be completely removed; ④The process is long, the operation is complicated, the processing volume is small, the cost is high, and the metal loss is large

This method has the following problems: 1. the roasting temperature is higher, 200°C to 300°C higher than the method reported in patent CN 107758752 A and the method widely used in production, which requires higher equipment and higher energy consumption; 2. iridium hydroxide is heated by hydrochloric acid Acidification generates chloroiridic acid expression principle is unreasonable, and hydroxide and hydrochloric acid take place neutralization reaction, should generate chloride by principle, do not see inventor to elaborate further; 3. alkali solution neutralization process still introduces a large amount of impurity cations (as sodium to system) ions), which cannot be completely removed by simply washing the hydroxide; ④Small processing capacity, long process and complicated operation

The main disadvantages of this method are: ①The processing capacity is very small, which is not suitable for industrial production; ②The electrolysis process cannot be carried out in a sealed environment, and the volatilization of hydrogen chloride and the chlorine gas produced by the anode lead to an extremely harsh operating environment

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