Dry-type gunning material for steel refining furnace

Abstract

The invention relates to the field of fireproof materials for steel metallurgy, and in particular relates to a dry-type gunning material for a steel refining furnace. The dry-type gunning material comprises the following components in percentage by weight: 70 to 80 percent of magnesite, 5 to 20 percent of magnesium olive sand, 5 to 20 percent of magnesium-aluminum spinelle, 3 to 10 percent of mullite and 3 to 10 percent of adhesive, wherein the adhesive is a combination of one or any two or any three of industrial sodium tripolyphosphate, sodium hexametaphosphate and sodium metasilicate. The dry-type gunning material has the outstanding advantages of high adhesiveness, high adhesive rate, high sintering rate, high intensity, high steel erosion resistance and high slag iron erosion, and the service life of a gunned layer is prolonged; and furthermore, the raw materials are readily available and low in cost, so that the gunning efficiency can be effectively improved, and the steel refining cost is reduced.

Description

technical field [0001] The invention relates to the field of refractory materials for iron and steel metallurgy, in particular to a dry gunning material for repairing furnaces in steelmaking furnaces. Background technique [0002] In order to improve the smelting efficiency of steelmaking furnaces and shorten the time for lining repair and furnace repairing, since the 1980s, the online gunning technology of steelmaking furnaces has been promoted, and the demand for gunning materials is very large; at present, as steelmaking furnace gunning The main material of the material is magnesia, which has strong resistance to slag erosion, but its heap angle is small, the adhesion is poor, the strength of the gunning layer is low, and it is easy to peel off, which will cause the gunning layer to fail and pollute the molten steel. Initially, a single Magnesia is used as the gunning material, mainly considering the high refractoriness of magnesia, which can resist the erosion of high-te...

AI Technical Summary

Problems solved by technology

[0002] In order to improve the smelting efficiency of steelmaking furnaces and shorten the time for lining repair and furnace repairing, since the 1980s, the online gunning technology of steelmaking furnaces has been promoted, and the demand for gunning materials is very large; at present, as steelmaking furnace gunning The main material of the material is magnesia, which has strong resistance to slag erosion, but its heap angle is small, the adhesion is poor, the strength of the gunning layer is low, and it is easy to peel off, which will cause the gunning layer to fail and pollute the molten steel. Initially, a single Magnesia is used as the gunning material, mainly considering the high refractoriness of magnesia, which can resist the erosion of high-temperature steel slag, and at that time, fluorite and iron oxide were used as flux in steelmaking slag, and the magnesia gunning layer played a very important role. Good protective effect; with the promotion of gunning technology, the application of magnesia is increasing, and the price of magnesia is getting higher and higher; Chinese invention patent (application number 200910097752.3) discloses a gunning material for converter Formula, proposed to use magnesia olivine sand, dolomite plus burning accelerator and binder as gunning material, magnesia olivine sand has high refractoriness and stability, can replace part of magnesia, and magnesia olivine sand is resistant to steel slag SiO 2 The erosion ability of magnesia is stronger than that of magnesia. Therefore, magnesia olivine can be used as one of the components of gunning material; 2 ) is gradually replaced by bauxite (the main component is Al 2 o 3 · Fe 2 o 3 ) to replace Al in steelmaking slag 2 o 3 content increased, the gunning layer formed by a single gunning material composed of magnesia, magnesia olivine or both can resist Al in slag. 2 o 3 , SiO 2 The poor erosion ability of the gunning layer leads to low life of the gunning layer; in addition, the existing gunning layer composed of magnesia and forsterite has poor adhesion and low strength to the current magnesia-carbon refractories, which also causes the life of the gunning layer The main reason for low and low utilization rate of gunning material

[0003] To sum up, the current gunning material consisting of single magnesia or forsterite or both can no longer meet the requirements of steelmaking slag for furnace protection and repairing, and it is necessary to develop a new steelmaking furnace gunning material, which can improve the gunning layer’s resistance to Al in modern steelmaking slag 2 o 3 , SiO 2 The erosion ability of the gunning layer can improve the life of the gunning layer; at the same time, the adhesion of the gunning material to the furnace lining can be improved, thereby improving the life of the gunning layer and the utilization rate of the gunning material; Gunning material cost