Experimental Study On Coal Gasification Kinetics In Coal - Based Melting Reduction Ironmaking Process

There are very rich resources of high-phosphorus iron ores in Yunnan Province, and the total reserves of high-phosphorus iron ores in Huimin and Luoci are over2billion tons. But, these resources cannot be consumed by the traditional blast furnace process due to the high content of phosphorus. Besides, because there are some shortcomings of the iron ore, such as rich in crystallization wate、weak magnetism and low flotation, the quality of these ores cannot be improved by physical mineral processing. Considering the local resources and energy situation in Yunnan, the non-blast furnace ironmaking technology can be developed which directly utilize iron ore power and coal as raw materials. Coal gasification is an important process which is included in direct smelting reduction and coal-based direct reduction. In order to investigate the dynamics and reaction mechanisms of coal gasification of high-phosphorus during the coal-based reduction process, mathematical modeling and experiments are utilized in this paper to investigate the dynamics of coal gasification during the smelting reduction process of iron ore powders of Huimin. And the structure morphology, contents and dynamic behavior during the coal gasification of smelting reduction of iron ore powders are investigated, which can be used as a reference of coals gasification.In this paper, the thermal gravimetric analysis method is used to investigate the coal pyrolysis and gasification in the reduction process of coal-iron in the temperature range of50℃to1400℃.Firstly, STA449F3TGA was used to obtain the TG-DSC curve of smelting reduction of coal-based in iron ore powders. And the reaction rules of coal in different phases during the smelting reduction process can be investigated based on the analysis to the trend of peak and change of up and down. Secondly, several special temperatures during the smelting reduction process of coal-based of high-phosphorus are selected to do expanded experiment of high-phosphorus iron in vertical furnace. After analyzing the phase structure and content in different phases, the reaction process of coal gasification and kinetic behavior of coal-based smelting reduction in iron ores can be investigated. Finally,an apparent reaction kinetic model can be established based on the integral method of thermal analysis dynamics. According to the kinetic model, the parameters of Ea, lnA and kinetic mechanism function f(a) can be obtained. To do a fitting figure of ln[g(α)/T2)] and1/T,12functions of reaction mechanism in pyrolysis process and15functions of reaction mechanism in gasification process are investigated. The optimum function of reaction mechanism can be obtained based on fitting figure. And then a formula of kinetic model can be established, that is...