Comprehensive furnace protecting method for steelmaking convertor furnace

Abstract

The invention belongs to the field of steel smelting and particularly relates to a comprehensive furnace protecting method for a steelmaking convertor furnace. Light-roasted dolomite and raw dolomite are selected as splashed slag materials, and a ratio of the splashed slag materials to adding amount of lime is 1 to 1, 25-35kg / t each. Light-roasted magnesium balls which are high in price and are extremely great in waste residue amount and a modifier are cancelled, and the furnace is protected by adopting a three-in-one combination furnace protecting method of curing the furnace by formed slag, protecting the furnace by splashed slag and cushioning furnace by left slag. On the basis of the conventional splashed slag furnace protecting process, the comprehensive furnace protecting method disclosed by the invention properly lowers application conditions of the splashed slag furnace protecting technology, and adopts the method of adjusting measures to local conditions and replacing to satisfy needs of the splashed slag furnace protecting process according to practical production conditions of each steel plant, so that effects of the furnace protecting by splashed slag are brought into play to the greatest extent, manual tiling and fettling by a great shovel are completely cancelled, fettling materials are lowered to be lowest, and therefore, cost decreasing and benefit increasing of the steel plant realize maximization. The comprehensive furnace protecting method is perfection and supplementation of the conventional splashed slag furnace protecting process, so that the comprehensive furnace protecting method is more universal, and therefore, more than half steel mills in China are benefited.

Description

technical field [0001] The invention belongs to the field of iron and steel smelting, and in particular relates to a comprehensive furnace protection method for a converter used in steelmaking. Background technique [0002] The technology of slag splashing for converter originated in the United States and was introduced to my country in 1994. It has a history of 20 years of development. At present, more than half of the steel mills in my country have adopted this technology and received good results. [0003] The principle of this technology is to spray nitrogen at a certain pressure and flow rate into the furnace after tapping, spray the residual slag in the furnace on the inner wall of the furnace lining, use waste, turn waste into treasure, and protect the furnace lining bricks so that they do not touch Molten steel and steel slag are basically not corroded by high temperature and slag. The smelting process of the lower furnace is carried out on the slag sprayed on the up...

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Problems solved by technology

[0004] However, the reason why this technology has been popularized and applied for 20 years is that nearly half of the steel mills (thousands) in my country have not yet adopted it or the use effect is not good. The main reason is that the relevant requirements required by this technology Equipment conditions (nitrogen working pressure must be greater than 10 kg), raw materials and final slag composition conditions (slag materials must use expensive slagging magnesium balls and modifiers, magnesium oxide, calcium oxide, silicon dioxide, There are strict regulations on total iron and alkalinity), and the process temperature drop conditions are relatively high (the tapping temperature should not exceed 1700 degrees for starting pouring, and the continuous pouring temperature should not exceed 1680 degrees), the production and equipment conditions of many small and medium-sized steel mills have not reached If the series of strict requirements necessary for furnace protection by slag splashing are not met, the furnace protection by slag splashing has to be abandoned, and more manual shovels are used to repair the furnace with "three meals a day" to repair the furnace with bricks, which is labor-intensive, time-consuming, and material-intensive. , low production efficiency

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