The Cause of the Problems and Solving Measures in Molten Iron Pretreatment

摘要

This paper analizes the mechanism of problems existing in desilication, dephosphorization and desulfurization process, and propose the corresponding solutions in order to solve these problems constraining process development and affecting the efficiency. Practice has proved that it is an effective way using green scientific solutions to restrain foam in desilication, prevent blocking guns in dephosphorization and deslagging in desulfurization process. With the market competition continues to intensify, pressure of manufacturing costs in enterprise is adding increasingly. Molten iron pretreatment technology mainly including desilication, dephosphorization and desulfurization process has been developped rapidly. In particular, steel production is expanding rapidly in the "Eleventh Five-Year" period. In this context, New molten iron pretreatment process technology developed one after another in order to maintain high efficiency, high-quality, low-cost smelting with high-yield. The pretreatment of molten iron furnace has become an important part in the process of iron and steel metallurgy. In recent decades, in order to establish its own steel position and to meet the increasing demands of users, TISCO has established a special clean steel smelting process: molten iron pretreatment - converter - molten steel in secondary refining. The current annual processing capacity of this smelting process has reached 7 million tons, handling close to 100%, and it meets the production needs of low sulfur and ultra low sulfur (the target upper limit is less than 10 × 10~(-6)) varieties of high value-added steel such as Stainless Steel, cold rolled silicon steel, hot rolled high strength and toughness steels, and so on. At the same time, molten iron pretreatment also plays an important role in improving productivity, cost savings and adapting to the raw materials change in market, and so on. However, "three off" process in pretreatment often appears negative issues affecting the production anterograde and operating efficiency, such as foam, back to the phosphorus, back to the sulfur, high iron loss and taking the red smoke, and so on. Such associated problems may be small, if it is unscientific processed, production rhythm of the post-step process and unit costs will be seriously impacted.