Techonogy And Mechanism Of Improving Sintering Performance Of Fine-graded Specularite By Pre-briquetting

Abstract:With features such as high ferrous grade, few harmful impurities and relatively low price, a certain kind of imported specularite is stable and controllable specularite resources for a steel company in our country, adding large proportion of this pecularite is one of the measures to effectively reduce the cost of sintering. But the product quality indexes falls when a great amount of it added to sintering because of its poor granulating performance. But with fine granularity its sintering performance is poor. The existing ways of improving sintering performance for concentrate methods for enhanced sintering of specularite are not applicable for this kind of speculartite.In this paper, a new technology of improving sintering performance of this specularite by pre-briquetting was studied and developed. By this technology the sintering perfoamance was improved apparently. In conventional sintering, as the ratio of specularite increases from24%to36%, the permeability of the sinter layer drops9.81%, vertical sintering speed decreases11.16%as well as productivity decreases to1.24t·m-2·h-1from1.41t·m-2·h-1,tumbler index falls to65.01%from67.47%, fuel consumption rises2.82kg·t-1, the RI and RDI+3.15of sinter decline from82.31%and70.71%to80.76%and66.89%respectively. Under a36%ratio of specularite, the sintering improved technology by pre-molding improves the sintering bed permeability of25.91%, increases the vertical sintering speed of18.63%, enhances the productivity and tumbler index by0.32t·m-2·h-1and1.52%respectively, as the same time, brings the anthracite consumption down of2.00kg/t well the RI and RDI+3.15of sinter increase1.63and1.99pionts respectively.The specularite particles have dense and smooth surface, regular shape and unreasonable size distribution, result in the poor hydrophilia and granulating performance, the permeability of the sinter layer gets deteriora ted because of the intermediate grade and shed particles; the deformation temperature and softening temperature are bove1320℃and1400℃respectively in sintering basicity range of1.8-2.2, means poor assimilation performance and low ability of generating liquid phase that would affect the strength of sinter. The sintering-improved technology by pre-briquetting changes the specularite’s distribution in sintering layer, make it into larger particles and output in the way of enciled by liquid phase; with the permeability of sintering layer gets improved, the oxdizing atmosphere gets enhanced, and the binding phase of calcium ferrite increases, the strength and metallurgical performanceof sinter gets improved. The sintering-improved technology by pre-briquetting is an effective measure for improving sintering performance with high proportion specularite.