| With the crude steel yield in China increasing rapidly these recent years, the source of iron ore tends to become increasingly strained, and the import dependence of iron ore remains extraordinary high for several years. In order to improve the blast furnace output, to enhance the product properties and to decrease the production cost, many kinds of iron ore with different property and quality has been used in China steel enterprises, which result in the unstable iron ore sinter performance. Based on the practical iron ore resource distribution of Chongqing Iron and Steel Co. Ltd. (CISC), the basic characteristics of raw materials, the granulation property of sintering blend and the physical and metallurgical properties of iron ore sinter have been investigated, the relative mechanism during the blend granulating and the high temperature sintering has been also studied by experimental research and theoretical analyse. The investigation results have certain theoretical contributions and practical significance for the iron ore resource utilization efficiency, the sinter property improvement and the iron ore sintering theory enrichment.In this study, the basic characteristics of the raw materials were investigated firstly, including the chemical composition, the size distribution and specific area, the moisture absorption capacity and the thermal change during the heating process. According to the Lagergren first order rate equation, a macro dynamics model of water absorbing of iron ore fines were established and the water mass transfer coefficient were obtained. The Australia iron ore fines are the classical hematite, which contents crystal water and carbonate and have obvious loss when it was heated; the Australia iron ore fines have the largest moisture capacity and homogeneous size distribution, there are more particles greater than 0.7mm and the particles between 0.2 to 0.7mm contains 20%, which have the negative influence to the granulation effect; The Australia iron ore have the larhest specific area and the diameter and the volume of micropore, which is the classical porous particles and easy to absorb water; The Australia iron ore have the largest moisture capacity and water mass transfer coefficient, which can improve the granulation efficiency.The conclusion of the study of mixture granulation are as follows:â‘ with the water content increases, the small size particles decreases; When the blend contens 50% gtain with size grater than 10mm, 30% with 5-8mm, 10% with 8-10mm and 10% with other size, the green ball bed have the best permeability.â‘¡With the water input increases, the content of 3-8mm size changes with the trend of the curve with the classical curve of reverse V.â‘¢An adapted water content corresponding to the best granulation effect.â‘£A linear realation exist between the adapted water content and the moisture capacity. The conclusion of the iron ore sintering experiment are as follows:â‘ Accorrding to the test of the iron ore sinter physical properties, 11 group of mixture ratio are chosen to conduct the reproducibility test.â‘¡The metallurgical properties of the samples were measured and the 18# and the 30# with cold set pellet added were selected as the best one.â‘¢When the Australia iron ore mix ratio is 55%, the sinter retain the best properties.â‘£The adding of cold set pellet can improve the sinter physical properties such as the Tumbler strength, abrasion index and Shatter strength.The Factsage software were used to calculate the mass of the liquid phase of the sitering of iron ore, the theoretical fuel ratio and the isothermal line for the liquid phase SFCA. The influence of the content Al2O3 and MgO on the liquid phase generating were conducted, the calculated result shows that it is reliable to use the Factsage software to proceed the theoretical computation of the sintering, which can instruct the suitable fuel addition an the rational mixture ratio to get the good sinter property.This assignment brings forward the calculation model of accumulation heat and fuel distribution along the bed. Mathematical model of accumulation heat in sinter layers is founded and Matlab program is compiled. It is subject to the sintering materials of Chongqing Iron and Steel Corp. The heat balance and auto accumulation heat of layers is calculated in the sintering process. The result of the best fuel distribution model is achieved after sintering experiment validated. All of this make heat of layer distribute reasonably and sinter layers remain high temperature stability, achieve the result of high-quality, high-yield, low fuel consumption sintering. Figure which is via to model calculation shows that, heat accumulation quantity in lower layers is gradually increased. Dividing the bed into 3 layers, the ratio of upper, middle and lower bed's heat accumulation is 1:1.08:1.13. Resulted from sintering pot test for the best segregate feed of fuel, it was shown that when the upper bed is 5.2%, the middle bed is 3.1%,the lower bed is 2.7%.The innovative research works are as follows: The dynamic classification diagram was obtained by the classification model. It realized the dynamic classification of iron ore in CISC. The impacts of mixture properties on the properties of sinter ore were studied via single factor analysis and range analysis. Influence of the carbon mixture ratio is more significant than that of other mixture properties on the properties of sinter ore in addition to reducibility. Basicity and temperature were propitious to the production of liquid-phase.The appropriate amount of carbon mixture ratio could be determined on the base of relationship between amount of liquid-phase and temperature. The results showed that the applications of model are benefit for guiding experiments and production.
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