Refractory castable for molten iron pretreatment spray gun

Abstract

The invention discloses refractory castable for a molten iron pretreatment spray gun, which is mixed by castable base stock and a proper amount of additive. The castable base stock is composed of 30-40% of sintering zirconium mullite, 10-20% of flint clay, 20-30% of andalusite, 5-10% of compact corundum fine powder, 2-5% of alpha-Al2O3 micro powder, 5-8% of rho-Al2O3 micro powder, 3-7% of silicon micro powder, 1-4% of carborundum powder and 1.5-3% of pure calcium aluminate cement by weight percent. The additive takes the total weight M of the castable base stock as a metering reference and is composed of 1-5% of heat resistant steel fiber, 0-0.1% of polypropylene fibre, 0-0.5% of aluminium lactate, 0-0.5% of metallic aluminium powder, 0-0.15% of sodium tripolyphosphate and 0-0.5% of melamine in weight percent. The castable has favorable thermal shock stability performance, high-temperature mechanical strength and corrosion resistance. The spray gun bushing manufactured by the refractory castable can effectively prolong the service life of the spray gun.

Description

technical field [0001] The invention relates to the field of refractory materials for molten iron injection pretreatment before converter steelmaking, in particular to a refractory castable for torpedo tanks and molten iron pretreatment spray guns in molten iron tanks. Background technique [0002] Hot metal injection pretreatment is an important process in the modern metallurgical process, widely used in domestic and foreign iron and steel enterprises. The injection desulfurization outside the molten iron furnace is to use the spray gun inserted into the molten iron container about 250mm away from the bottom of the tank, and spray the desulfurizer into the molten iron through high-pressure carrier gas to increase the reaction contact area; through the vigorous stirring and mixing of jet kinetic energy, the reaction mass transfer rate is increased ; and through the frequent insertion and injection of the spray gun into the molten iron container that is constantly being deliv...

AI Technical Summary

Problems solved by technology

[0005] Although the aforementioned castables prolong the service life of the molten iron pretreatment spray gun to a certain extent, however, with the continuous improvement of the quality requirements of iron and steel products, the purity of molten iron injection pretreatment and the proportion of advanced pretreatment continue to increase. The pretreatment time of molten iron injection continues to prolong, and the spray gun wear, nozzle melting loss, thermal stress spalling and structural spalling continue to deteriorate, which reduces the actual use effect of the refractory castable technology of the above spray gun, resulting in a significant shortening of the service life of the spray gun. Intensified deterioration reduces the stirring, mixing and dispersing kinetic energy of the injection flow field, which further affects the production capacity of molten iron pretreatment equipment, the improvement of pretreatment efficiency and the reduction of production costs