Thermal Analysis in Examination of Reduction of Blast Furnace Pellets

This paper presents applications of thermal analysis to observe the course of reduction of acidic pellets, metallurgical substances whose reducibility and strength are basic parameters of use in blast furnace processes. Both parameters depend on the mineral composition of the samples. The investigations included determination of the chemical and phase compositions of the initial samples and reduction products. Research was conducted on acidic pellets from Połtawa (Poland), applied in the T. Sendzimir Steelworks (Poland), in comparison with pellets from Brazil, Canada and Lebedyn (Russia). This revised version was published online in August 2006 with corrections to the Cover Date.     

Thermal Analysis in Examinations of Reduction of Mixtures of Acidic Pellets and High-basicity Sinters

The aim of this work was to investigate the application of mixtures of high-basicity sinters and acidic pellets in blast furnace charges. The ratio of high-basicity sinter and pellets depends on the nature and basicity of the latter, and is established in order to secure desired properties of the slag and sufficient reducibility and mechanical strength of the furnace charge. Such a composition of the charge leads to a considerable cost decrease related to coke saving, the elimination of fluxes and a decrease in air pollution. Examinations of phase composition and physicochemical properties of the sinters and pellets as separate materials were carried out. The effect of the mineral composition of sinters with a basicity of 1.7–2.0 on the reducibility was determined. Sinters of different basicities (CaO/SiO₂=1.7; 2.0) mixed with pellets from Poltawawere reduced in a CO/CO₂ gas mixture. The reduction process was followed by thermal analysis. This revised version was published online in July 2006 with corrections to the Cover Date.     

Application of thermal analysis to study of phase composition changes in blast furnace sinters

Application of thermal analysis to determine a quantity portion of iron oxides in symmetric blast furnace sinters is presented. In the multicomponent sample, calcium ferrites and many silicate phases beside doped iron oxides phases were observed. The dependence of sinter phase composition from basicity and relation with physicochemical properties is defined.