Production of ferroboron by using redesigned ESR process called electroslag melting for alloying by reductions (ESMAR)

Abstract

Ferroboron is produced economically for decades by the carbothermic process. However, the carbon content of ferroboron, is above 0.5% as a result of the carbothermic process, which adversely affects the properties of permanent magnets. On the other hand, the requirement of aluminium for reduction of iron ore in the aluminothermic process increases the production costs. In this study, ESR process was redesigned for the production of ferroboron to take advantages of the process. In this study, a new process was developed with the name of Electroslag Melting for Alloying by Reduction (ESMAR) by using the advantages of ESR process and the feasibility of ferroboron production by using this process was investigated. Since the steel ingot in the ESMAR process will be used as a consumable electrode, the iron content of the ferroboron to be produced can be obtained from these ingots without the use of iron ore, thus eliminating the need for aluminium for iron ore reduction. The boron content of ferroboron will be obtained by reducing the boron oxide in the slag with aluminum. At the end of the experiments, ferroboron products containing different ratios of boron and residual aluminum (15.23% B and 1.19% Al; 18.39% B and 5.44% Al) were obtained. These products are of commercial quality. Since this new process did not require Al for the reduction of iron ore, the consumption of Al decreased by 3.37 grams per gram of boron. As a result, it was found out that the ESMAR Process is a suitable method for ferroboron production and that the process can be improved by optimization of process parameters.