Study On The Technique Of Simultaneous Conditioning Of Upper And Lower Parts Of Blast Furnace

Based on the practice of iron-making in Jiuquan Iron & Steel Group Co., the influences of simultaneous conditioning of upper and lower parts on blast furnace iron-making were studied. It was considered as the kernel technique for blast furnace. Every new technique which be put into practice all depends on accurately combination with simultaneous conditioning of upper and lower parts measures.According to the experimental simulation results and the testing analysis of burden distribution in the furnace roof, it was found that certain rules should be followed under the conditions of Jiuquan blast furnace equipments and raw materials. Adjustment measures of the upper part should comply with the basic principle of separate and multi梤ing burden distribution, and the kernel of adjustment measures of lower part should be matching with the simultaneous conditioning of upper and lower parts. Under the precondition of fully-open tuyeres, high blast kinetic energy should be employed and combined with the techniques, such as: short-tuyere, coal injection and rich oxygen. A proposal was offered for forbidding to block the tuyeres over a long period of time, so that regular blast furnace shape and steady work condition of furnace hearth could be obtained. In the process of furnace operating, as long as the guideline "upper part being steady and lower part being active" be ensured, the effect of multi-ring burden distribution would go into effect.After the proposed measures being put into practice, such as: fully-opened tuyere working and multi-ring burden distribution on the basis of separate charge and heavy burden, working condition of furnace hearth became uniform gradually and the gas-flow distribution of the upper furnace went into stable state. The long-term stable and in regular sequence furnace goal was achieved. The realization of increasing production and reducing coke was accelerated. The operating level of Jiuquan blast furnace reached the highlight level in the history. Till the end of 2002, coke ratio fell to 430kg/t.Fe, coal ratio reached to 100kg/t.Fe. Remarkable economic benefits were obtained.From the theorical analysis and the practice, under present metallurgical condition of Jiuquan, some directions should be followed. For 1# BF(1800m3), the optimized burden weight is 48ton, blast kinetic energy 110~130KJ/s; For 2# BF(1000m3), the optimized burden weight is 28ton, blast kinetic energy 80?0KJ/S.