The Research On Gushan Iron Ore By Reduction Roasting-magnetic Process

With the rapid development of Chinese iron and steel industry's rapid development, domestic iron ore resources becomes increasingly tense, and the dependence on the outside of iron ore is high. But Chinese iron ore resources has not been fully utilized because of difficult beneficiation. The increase of the dependence on iron ore imports has already become a major hidden peril of Chinese iron and steel industry's economic security. So it is urgent to rely on technological advances to maximize the use of existing domestic iron ore resources, raise the self-sufficiency rate of iron ore, and ease the pressure on iron ore imports, to ensure the sustained and steady development of the iron and steel industry. Magnetizing reduction is one of the most effective operations in the treatment of the refractory low-grade red irons ores, and in a rather long period, it is a most effective means of recycling utilization of refractory red iron ore in China. In this thesis, based on reduction roasting method, I take Gushan iron oxide ores for example to look for the technological means to develop and utilize the refractory iron ore such as Gushan iron ore.Through the analysis of the nature of the ore, the trial process of Crushin-Reduction Roasting-Magnetic was identified. In the experiment of Reduction Roasting-Magnetic Separation, the effects of index of iron concentrate such as types of reductants, reductant quantity, reduction time, reduction temperature, and so on, were studied. Meanwhile the effect of cooling conditions on the quality of roasted ores was researched. The optimal operating parameters for the concentrate of roasted ores with perfect iron grade and iron recovery were obtained. At the last, the mechanism of magnetization roasting was also discussed in this paper.Study shows that:when as the coal gas as a reductant, the optimal experimental conditions of Reduction Roasting-Magnetic are:roast temperature 600℃, roast time 15min, the index of iron concentrate high-intensity is iron grade 60% and iron recovery rate 98% through magnetic separation; While as the coal as a reductant, the optimal experimental conditions of Reduction Roasting-Magnetic are:reductant quantity 15%, roast temperature 800℃, roast time 15min, the index of iron concentrate high-intensity is iron grade 60% and iron recovery rate 98% through magnetic separation.With the method of XRD to analyze the concentrate,we can conclude that:when as the coal gas as a reductant, roast temperature 600℃, roast time 15min, magnetite in magnetic concentrate and the iron in the ferrite are all the highest numerical value. While as the coal as a reductant, reductant quantity 15%, roast temperature 800℃, roast time 15min, magnetite in magnetic concentrate and the iron in the ferrite which also the highest numerical value. Those testify that in the optimal experiment conditions, magnetite in magnetic concentrate and the iron in the ferrite are all the optimal datas.This paper studied systemically refractory low-grade red irons ores and achieved good experimental results. The technology will provide new technological routine for Gushan ore.