PRODUCTION OF ALUMINUM FLUORIDE FROM FLUOROSILICIC ACID AND HYDRATED ALUMINUM OXIDES

The main objective of this work is to determine the possibility of obtaining aluminum fluoride from fluorosilicic acid, a waste product of wet-process phosphoric acid production, and hydrated aluminum oxide, which can be obtained by acid or acid-salt processing of Kola nepheline concentrate. The article presents a study on obtaining hydrated aluminum oxide from nepheline concentrate by hydrosulfate processing and determining the X-ray phase and chemical composition of the obtained sample. It is shown that hydrated aluminum oxide has amorphous structure with a tendency to exhibit crystallizing phase reflexes, as well as an increased content of ammonium sulfate impurity. A study was conducted on obtaining aluminum fluoride from aluminum hydroxide in order to develop a comparison sample. A study was conducted on obtaining aluminum fluoride from hydrated aluminum oxide under process parameters similar to those used in industrial production. X-ray phase and chemical analysis of the developed samples was performed. It is shown that the comparison sample obtained from aluminum hydroxide corresponds to the highest grade of aluminum fluoride. It is identified that when using hydrated aluminum oxide, it is possible to obtain aluminum fluoride from fluorosilicate acid. It is shown that aluminum fluoride obtained from hydrated aluminum oxide has a deviation from the first grade in the sulfate impurities content. A method for improving hydrated aluminum oxide technology to reduce the content of ammonium sulfate impurities is proposed. A method for improving aluminum fluoride from hydrated aluminum oxide technology is proposed to reduce the content of free Al2O3 and increase the main component content. The possibility of using hydrated aluminum oxide as a substitute for aluminum hydroxide grade GD18 in the aluminum fluoride production is confirmed. For citation: Morozkov A.V., Norov A.M. Production of aluminum fluoride from fluorosilicic acid and hydrated aluminum oxides. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2025. V. 68. N 5. P. 56-63. DOI: 10.6060/ivkkt.20256805.6f.