Prospects for Using Boron in Metallurgy. Report 1

Abstract

Based on literature and our own data, the effect of boron on the characteristics of all stages of metallurgical processes (from sintering, smelting of cast iron and ferroalloys, to steel production) and on the properties of the resulting slag and metal was studied. To intensify hardening of the pellets at the stage of liquid-phase sintering and to improve their metallurgical properties, it is sufficient to have 0.20–0.35% of boron oxide in them. According to laboratory studies, the presence of boron oxide in pellets increases their compressive strength by 1.5–1.7 times and hot strength by 3–4 times. While studying the mechanism and kinetics of sulfur removal, it was shown that the presence of boric anhydride significantly intensifies processes of ±pellets desulfurization. Their intensive progress goes to the zones of lower temperatures of 1050–1100°C. To increase the sinter strength characteristics, it is possible to add B2O3 to the charge. The introduction of 0.44% of B2O3 does not affect the sinter abrasion. The content of fines (0–5 mm) in comparison with the base sample is reduced by 1.5 times. The use of boron pellets in blast-furnace smelting makes it possible to increase the basicity of the final slag from 1.10 to 1.16. In this regard, the sulfur distribution coefficient increases from 48 to 74. The sulfur content in cast iron decreases by 0.005%. The possibility of using boron and its compounds to improve the technical and economic indicators of production and pellet quality, sinter and cast iron is shown on the base of the presented theoretical, laboratory-experimental and industrial data.