Research Of The No.1 Blast Furnace Multi-objective Optimal Model And The Energy Analysis Of Ore Beneficiation Process In JISCO

The question of energy,resource and environment is one of the worldwide questions that are payed much attention in 21st century. Iron and steel industry is energy and rescource intensive industry, and the energy consumption of that account for 13～14% of the total energy consumption in our country. Among the energy consumption of the iron and steel company, that of ironmaking process topped the list, accounting for 70% of the total energy consumption, and that of blast furnace accounted for 50%.The fossil fuel,such as coal, that consumpted in the process of blast furnace ironmaking,is the main source of CO2.Therefore, the research of energy conservation and emission reduction in the ironmaking by blast furnace, is very important for reducing the cost and improving the competitiveness.Based on the substance and energy conservation, a multiple objective optimal model of the No.1 blast furnace in JISCO has been established by using the method of linear programming, with the objective of energy, cost and the emission of CO2. By programming, the model has been optimized in the term of simple objective and multiple objective, to obtain the optimal results respectively. Comparing the optimal results and the real production data, the model has been verified. With the results of multiple objective for energy and cost, it can be concluded that the energy consumption reduces 65.64 kgce/t, and the cost reduces 137.37 RMB/t. By analyzing the influence of the factor,such as the coke ratio, the content of Si,sinter ore grade, and so on, to the energy consumption and the cost, some measures to saving energy and reducing emission has been proposed for the No.1 blast furnace in JISCO. The measures are improving the quality of the raw material and fuel, reducing the coke ratio, increasing the coal injection ratio and increasing the hot blast temperature, and so on.By analyzing the influence of the sinter ore grade to the energy consumption and cost of the blast furnace, it can be known that the sinter ore grade is on the low side, and the grade of ore put into furnace is only 52.5～53%, comparing with the ore grade of 60% in the domestic advanced company. That's because the Jingtieshan ore is refractory ore, so the iron ore concentrate grade is low. The grade of ore put into furnace is on the low side, and that influenced the energy consumption and economic benefit in a large extent. Therefore, according to the practical situation, in this thesis the energy consumption and grade of the two process, roasting-low intensity magnetic separation-flotation process and high intensity magnetic separation process,that used in the ore beneficiation process of JISCO has been analyzed. Some researches has been done for a new ore beneficiation process, which is rotary kiln roasting-high intensity magnetic separation process for the ore fines of 0-15mm. Then the influence of the new process to the energy consumption of ironmaking has been analyzed. The research results indicate that the energy consumption of the ore beneficiation process increases by 26.95kgce/t, and that of blast furnace ironmaking reduces by 31.31kgce/t after adding rotary kiln roasting for the ore fines of 0-15mm.That is to say, for the ironmaking system, the energy consumption reduces by 4.36kgce/t after adding rotary kiln roasting.