Influence of fluxing additives on aluminothermic synthesis of aluminum borides

Abstract

In the article, the influence of fluxing additives on the kinetics of the process and the yield of the alloy is investigated. It has been proven that the use of fluoride salts, in particular CaF2, in an amount from 15.0 to 18.0% contributes to an increase in the burning rate of the charge, the formation of mobile liquid slags that improve phase separation; at 6.7-8.0%, the maximum yield of the alloy occurs. The features of the use of fluxing additives in aluminothermic processes, the dependences of the charge burning rate based on the B₂O₃-Al system on the amount of flux were determined. The choice of a flux and the determination of its optimal amount, which provides the necessary physicochemical properties of the slag melt, which contributes to the formation of an ingot of aluminum borides, more complete phase separation, were carried out, experiments were carried out using: calcium oxide, fluorspar, potassium chlorides, potassium tetrafluoroborate in various combinations. The effectiveness of using potassium tetrafluoroborate as a fluxing additive mixed with fluorspar to increase the yield of the alloy and increase the boron content in it is analyzed.