HUANG Xu, ZHANG Jianliang, XU Runsheng, ZHANG Kaijun, WANG Yanmin, ZHU Jinfeng, YE Lian, YU Yang
In order to study the influence of decarburization rate of circulating gas on the smelting process, a mathematical model was established based on the process of gas circulating oxygen blast furnace. The effects of different decarburization rates such as 100%, 98%, 96%, 94%, 92% and 90% of circulating gas on theoretical combustion temperature, coke ratio, direct reduction degree, gas distribution and carbon emission were analyzed. The results show that the theoretical combustion temperature increases by about 14-15 ℃, the coke ratio increases by about 1.46 kg/t, and the direct reduction degree increases with the decrease of 1% decarburization rate. The amount of gas in the hearth increased by about 2.47 m3/t, the amount of gas in the bosh and just entering the furnace body increased by about 2.60 m3/t, and the amount of gas in the top of the furnace increased by about 0.18 m3/t. As the decarbonization rate decreases, carbon emissions gradually increase. For every 1% reduction in decarburization rate, the total carbon emissions increase by about 1.01 m3/t. The carbon consumption in the internal area of the blast furnace, including the total carbon consumption per ton of iron into the furnace, direct reduction carbon consumption, desulfurization carbon consumption, and melting loss reaction carbon consumption, all showed an increasing trend. The carbon content of combustion in front of the tuyere showed a decreasing trend, and the carbon content of molten iron remained unchanged.
