Method for preparing steel ladle or tundish covering agent by using boron slurry

Abstract

The invention relates to the technical field of steel metallurgy, and particularly relates to a method for preparing a steel ladle or a tundish covering agent by using boron slurry. The method comprises the steps of: dehydrating and drying the boron slurry in a gas furnace; converting Fe2O3 in the boron slurry into magnetic Fe3O4; reducing MnO into Mn; removing the Mn through magnetic separation; and adding a pre-melted mixture of CaO and Al2O3 so as to obtain a molten steel covering agent serving as a steel ladle or a tundish, or adding a small number of carbon materials for controlling the melting speed and the melting performance so as to obtain the covering agent. According to the method, waste boron slurry resources can be reused; the method has the advantages of being simple in preparation process, low in machining cost, eliminating harm of the boron slurry and reducing discharging of metallurgical waste; furthermore, the covering agent prepared by the method has high surface activity, good impurity absorption performance, good expandability and good effects of preventing molten steel from sucking air and being oxidized and preserving heat, has remarkable economic and social benefits and is deserved to popularization.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy, in particular to a method for preparing a ladle or tundish covering agent by utilizing boron mud. Background technique [0002] my country is rich in boron resources, with proven reserves exceeding 100 million tons (in B 2 o 3 However, the grade of most boron ores in my country is low, and most of them are mixed ores. After extracting borax by carbon-alkali method, a large amount of waste boron mud will be produced. Since boron, iron, magnesium, etc. in boron mud are all lean ores, The extraction cost is too high and the treatment process is complicated. At present, my country still lacks an industrialized method for the comprehensive utilization of waste boron mud with high added value. Water resources are seriously polluted; boron mud has accumulated nearly 100 million tons in my country, and the pollution and land occupation problems are becoming more and more serious. The co...

AI Technical Summary

Problems solved by technology

[0002] China is rich in boron resources, with proven reserves exceeding 100 million tons (calculated as B2O3 ), however, most of the boron ores in China are of low grade, and most of them are mixed ores. The cost is too high and the treatment process is complicated. At present, China still lacks an industrialized method for realizing high value-added comprehensive utilization of waste boron mud. It has been treated as waste slag accumulation, which not only occupies a lot of land resources, but also has a large amount of open-air accumulation of boron mud. Soil and water Resources are seriously polluted; the accumulated boron mud in China is nearly 100 million tons, and the pollution and land occupation problems are becoming more and more serious. The comprehensive utilization of boron mud needs to be solved urgently

[0003]The main purpose of the ladle covering agent is to isolate the molten steel from the air, to avoid the inhalation and oxidation of the molten steel and to have a certain heat preservation effect. The basic components of the covering agent in the prior art are CaO, SiO2, Al2O3, MgO, Fe2O3, coke powder, etc., such as Chinese invention patents (application numbers 01105402.6, 200410084336.7, 200510023196.7), etc., all propose ladle covering agents composed of different proportions of the above materials; at present, these covering agents are basically composed of lime, silica, Wollastonite, corundum powder, magnesia and other single minerals are mixed and prepared, and the production cost is high, and these mineral resources are non-renewable resources, which are getting less and less, so the raw material cost and processing and manufacturing cost of the covering agent are increased.

[0004]The main composition of boron mud powder after dehydration is: MgO 24~40%, SiO2 20~35%, B2 O3 2~4%, Al2O3 2~4%, Fe2 O3 2~4%, CaO 2-10%, of which CaO, MgO, SiO2, Al2O3, B2O3, etc. are all important components in the covering agent, so it can be considered to treat boron mud as the main raw material of the covering agent; Iron oxide, phosphate and sulfide in boron mud are regarded as the main harmful substances used as ladle or tundish covering agent. With the development of society, the quality of steel is getting higher and higher, and boron mud must be specially treated and added with other components. The element can be used for ladle or tundish covering agent only after component adjustment, and search the prior art, do not find relevant reports on how to process boron mud and use it as ladle or tundish covering agent