Batching Optimization Of Siderite Smelting Reduction And Semi-industrial Experiment Exploration

With the rapid development of Chinese economy, iron ore and other non-renewableresources are becoming shortage, therefore, improving the efficient utilization oflow-grade ore becomes more and more important. China has large reserves of siderite,but the grade is lower, and ore dressing is very difficult, so it cannot be used for theblast furnace ironmaking, which results in low utilization of siderite, thus it is verysignificant to explore a new approach to efficiently use siderite. At present, there aretwo kinds of main non-blast furnace ironmaking technology: direct reductionironmaking at low temperature and smelting reduction ironmaking at high temperature.This paper intends to combine the two processes together to exploit a new ironmakingtechnology of low temperature pre-reduction and high temperature smelting reduction,which is carried out through reforming suspended preheating precalcining rotary kilncement system.In this paper, Xinjiang siderite was selected as raw material, and the influencefactors and the reaction rules of smelting reduction ironmaking has been studiedsystematically. Combined with the phase diagram, basicity, lime factor, alumina silicaratio and other ingredients ratio value were presented, which were used to theoreticallyguide the burden of the smelting reduction ironmaking experiments. The effects oflimestone and calcium fluoride on smelting reduction temperature, yielding rate of ironand slag-iron separation were studied. The effects of different fluxing agent content onsoftening temperature, smelting temperature and flowing temperature of the hightemperature melts were also studied. Finally, the effects of different burden on the slagmineral composition were analyzed. Based on laboratory research, the semi-industrial ironmaking process and the equipment were optimized, and subsequently thesemi-industrial ironmaking experiment was explored.The results show that, with the reduction temperature increasing, the slag-ironseparation effect become more evident, and the iron yield rate reaches the maximum at1550?. With the holding time increasing, the iron yield rate tends to increase, but it haslittle change when the holding time is over90min. The iron yield rate is easy to beeffected significantly by the limestone content, and with limestone content increasing, itfirst increases and then decreases gradually. When the limestone content reaches7%,the iron yield rate reaches the maximum of92.2%. CaF2can effectively decrease thesmelting temperature of siderite, and with CaF2content increasing, the softeningtemperature has little change, but the hemispheric temperature and the flow temperaturedrop greatly, and the iron yield rate first increases and then decreases. B2O3candecrease the beginning softening temperature obviously, but it has a little effect on thehalf ball temperature, moreover it has little effect on the fluid temperature. The burdenscheme is obtained through the laboratory research. According to the previous semi-industrialtest, the process and equipments are modified, thus the new ironmaking process can berealized to carry out successly.