HIsmelt熔融还原主反应器能质流转模型构建与验证

 HIsmelt熔融还原炼铁工艺以铁矿粉和煤粉作为原料,流程中不需要烧结、球团和焦化,与高炉炼铁流程相比具有降碳减排等优势。明晰能质流转过程对HIsmelt熔融还原炼铁实际生产具有指导意义。基于物料平衡、热平衡方程,对输入和输出HIsmelt主反应器物质和能量进行平衡计算,建立能质流转模型,并结合FactSage中Equilib模块计算的各元素在渣铁两相间的质量分配比及实际生产数据对其进行修正。该模型可以计算原料和燃料成分、矿煤质量比、二次燃烧率、热风氧含量等参数对铁水温度、炉渣成分、热风量、煤气量等主要冶炼指标的影响。其次依据该模型,进行了物料平衡、热平衡计算,依据实际生产数据对模型计算结果进行了验证,结果表明该模型与实际生产数据契合度较高。探究了矿煤质量比对冶炼的影响,矿煤质量比为1.39～1.45时,矿煤质量比降低0.1,会使二次燃烧率降低0.23%,进而造成煤气化学能的利用率降低,同时需要更多的热风使煤粉燃烧,热风量和煤气产生量增加,可以通过适当提高热风氧含量以提高二次燃烧率并使煤气量降低来改善;矿煤质量比降低0.001,会使铁水温度升高3.76 ℃,有利于铁水后续的加工处理,但铁水温度升高使铁元素在铁液与渣中的比值降低,使炉渣FeO质量分数升高0.026%,增加铁损,可通过降低富氧热风喷吹量来降低铁的氧化量,从而降低铁损。

Construction and verification of energy and mass transfer model for HIsmelt smelting reduction main reactor

HIsmelt smelting reduction ironmaking process takes iron ore powder and coal powder as raw materials, and does not require sintering, pelletizing and coking in the process. Compared with the blast furnace ironmaking process, it has the advantages of carbon reduction and emission reduction. Clearing the process of energy and mass transfer has guiding significance for the actual production of HIsmelt smelting reduction ironmaking. Based on the material balance and heat balance equation, the material and energy balance of input and output HIsmelt main reactor were calculated, and the energy and mass transfer model was established. The model was corrected by mass distribution ratio of each element between slag and iron calculated by Equilib module in FactSage and the actual production data. The model could calculate the effects of raw material and fuel composition, mass ratio of iron ore to coal, secondary combustion rate, hot air oxygen content and other parameters on the main smelting indexes such as slag iron temperature, slag composition, hot air volume and gas volume. Secondly, based on the model, the material balance and heat balance were calculated. According to actual production data, the calculation results of model were verified, and the results show that the model was highly consistent with the actual production data. The effect of the mass ratio of iron ore to coal on smelting was studied. When the mass ratio of iron ore to coal is between 1.39 and 1.45, a reduction of 0.1 in the mass ratio of iron ore to coal will reduce the secondary combustion rate by 0.23%, resulting in a lower utilization rate of gas chemical energy, while more hot air is needed to make the pulverized coal burn, and the amount of hot air and gas production increases, which can be improved by appropriately increasing the oxygen content of the hot air to improve the secondary combustion rate and reduce the amount of gas. The decrease of the mass ratio of iron ore to coal by 0.001 increases the slag iron temperature by 3.76 ℃, which is conducive to the subsequent processing of molten iron. However, the increase in hot metal temperature reduces the ratio of elemental Fe in the iron and slag, which increases the mass percent of FeO of slag by 0.026% and increases the iron loss, which can be reduced by reducing the amount of oxygen-rich hot air blowing to reduce the amount of iron oxidation, thus reducing the iron loss.