关键词：循环煤气 物料平衡 热平衡 冶炼性能
ABSTRACT:The research in the traditional production of blast furnace add 375 kg/t of coke and pulverized coal on the basis of 160 kg/t, by adding a certain amount of circulating gas (CO, H2 = 7:3) to replace the coal dust, the analysis of blast furnace, the change of the material balance and heat balance. Calculation formula of the author through the system, develop the material balance and heat balance, concluded in oxygen-enriched rate was 30%, the injection cycle gas volume of 890 m3/tFe conditions that can meet the needs of blast furnace smelting reductant and compound. The theory provide theoretical basis for smelting process scheme and opinion, has reached to reduce blast furnace fuel, reduce CO2 emissions and save smelting cost. At the same time, improve the performance of blast furnace, improve the utilization rate of carbon, hydrogen, and increase production of blast furnace. As a result, the flue gas recycling technology is adopted to the sustainable development of iron and steel industry has very important realistic meaning and far-reaching influence.
This study by changing the injection amount of gas, oxygen enrichment rate conditions, analysis of rich oxygen blowing cycle gas material balance and heat balance calculations, drawing related parameters change chart, summed up the injection in the blast furnace gas after heat energy utilization and change rule: under the certain oxygen enrichment rate, with the increment of blowing gas, theory burning temperature is reduced, its temperature range between 2060 ~ 2100 ℃, changed slightly; When blowing gas quantity is low, with the increase of injection quantity direct reduction degree of downward trend slowly, and when the larger injection quantity, with the increase of coal injection quantity direct reduction degree is lower too. When blowing gas quantity under certain conditions, with the increase of oxygen enrichment rate, iron smelting unit need air volume gradually decreased, but the extent of decrease with the increase of oxygen enrichment rate reduced. When oxygen enrichment rate lower than 10%, air volume decrease quickly; With the increase of oxygen enrichment rate, air volume decrease trend slowed.
The results show that the flue gas circulation technology feasibility is proved in theory. New technology and the traditional blast furnace smelting process between the process parameters of the comparison and analysis of the results can be seen that: Compared with the traditional blast furnace technology, new technology has obvious advantages in many aspects: circulation gas not only decrease the coke rate, lower the
fuel needed for smelting of pig iron cost 53.0 yuan/tFe, CO and H2 to make it into the blast furnace reducing atmosphere to enhance, improve smelting strength, reduce energy consumption, CO2 emissions, achieved the purpose of energy conservation and emissions reduction, and has broad application prospects.
Key words：Top gas recycling；Material balance；Heat balance；Metallurgical performance