Determination of the reaction mechanism of the calcium fluoride interaction with ammonium sulphate

Abstract

Production of ammonium hydrogen fluoride according to the traditional technology using concentrated sulfuric acid is associated with a number of technological difficulties. Considering this, an alternative option for producing ammonium hydrogen fluoride using ammonium sulphate, a by-product of the coke-chemical production has been proposed. Thermodynamic and differential-thermal analyzes of the reaction of the interaction of calcium fluoride with ammonium sulphate were carried out to establish the possibility of using ammonium sulphate as a reagent for the preparation of ammonium fluoride. According to the results of the analysis, the mechanism of the reaction of calcium fluoride with ammonium sulphate was established as the mixture was heated. It is established that there is ammonium sulphate decomposition in the beginning with formation of ammonium hydrosulphate, ammonia, sulfur trioxide and water. Then ammonium hydrosulphate, sulfur trioxide and water interact with calcium fluoride to form ammonium fluoride, fluoric hydrogen and calcium sulphate. Ammonia and fluoric hydrogen then can be also processed on ammonium fluoride. Thus, the possibility of using ammonium sulphate as a reagent for the production of ammonium fluoride from natural calcium fluoride has been established on the basis of the research conducted. The ammonium fluoride then can be processed to ammonium hydrogen fluoride. Thus, the reaction studied can serve as a chemical basis for an alternative technology for the production of ammonium hydrogen fluoride.