Sinter Blend Research Articles

Multi-objective intelligent coordinating optimization blending system based on qualitative and quantitative synthetic model

A multi-objective intelligent coordinating optimization strategy based on qualitative and quantitative synthetic model for Pb-Zn sintering blending process was proposed to obtain optimal mixture ratio. The mechanism and neural network quantitative models for predicting compositions and rule models for expert reasoning were constructed based on statistical data and empirical knowledge. An expert reasoning method based on these models were proposed to solve blending optimization problem, including multi-objective optimization for the first blending process and area optimization for the second blending process, and to determine optimal mixture ratio which will meet the requirement of intelligent coordination. The results show that the qualified rates of agglomerate Pb, Zn and S compositions are increased by 7.1%, 6.5% and 6.9%, respectively, and the fluctuation of sintering permeability is reduced by 7.0%, which effectively stabilizes the agglomerate compositions and the permeability.

The Effect of Marra Mamba Ore Addition on the Granulation Characteristics of Pisolite Based and Hematite Based Sinter Blends

The granulation characteristics of two quite different sinter blends have been studied. One comprises a significant proportion of pisolite ore, and the other is dominated by hematite ores. The effect on granulation of adding a significant proportion of West Angelas, a Marra Mamba type ore, into both blends is also studied. The relationship between blend moisture content and green permeability is measured, as is the size distribution of the granulated blends at different moisture contents. It is clear that when West Angelas ore displaces a denser, less porous ore type in a sinter blend, additional granulation moisture must be added to ensure optimal granulation performance. A petrographic study of granule morphology at different blend moisture contents is reported, with particular reference to the features of the adhering layer. The important role of ultrafines, particularly the -50 μm ‘superfine’ fraction, in the granulation process is discussed. The variations in mineralogical and textural characteristics of West Angelas ore with size are presented. It is proposed that the mineralogical and textural characteristics of the superfine particles are an important factor in the granulation performance of an ore or a blend of ores.

Fundamental investigations of differences in bonding mechanisms in iron ore sinter formed from magnetite concentrates and hematite ores

Whilst increasing amounts of imported hematite ores are being added with the magnetite concentrates that dominate sinter blends in the People's Republic of China, little is known about the fundamental behaviour of magnetite concentrates during sintering compared to hematite ores. Compacted tablets of fluxed magnetite, magnetite–hematite and hematite concentrates and ores were fired under simulated sintering conditions in the laboratory to establish the fundamental differences in sintering behaviour, mineralogy and bonding mechanisms between magnetite concentrates and hematite ores. Sinter made from magnetite concentrates (<10% hematite) relies on the formation of a network of fused magnetite–magnetite grains (diffusional bonding) and high temperatures (1350–1370 °C) to obtain satisfactory sinter tumble strength. Magnetite–hematite concentrate mixtures, with <45% hematite, behave during sintering like magnetite concentrates. The large phase field for Magnetite+Liquid under typical sintering compositions and temperatures was found to prevent all but minor formation of Ca-ferrites via hematite from low-basicity (<2.0) sinter blends dominated by magnetite concentrates. In contrast, hematite ores with high (>2.0) effective basicity are able to form a high tumble strength sinter matrix composed of a network of abundant calcium ferrites (e.g. SFCA, SFCA I) below 1300 °C.