Refractory castable for desulfurization stirrer

Abstract

The invention discloses a refractory castable for a desulfurization stirrer, which is prepared by mixing a castable base material and a proper amount of additives, wherein the castable base material comprises the following components in percentage by weight: 26-33% of sintered zirconium mullite, 26-35% of common fused mullite, 5-9% of flint clay, 4-7% of kyanite, 5-10% of superfine bauxite chamotte, 3-5% of fine silicon powder, 3-5% of fine alpha-Al2O3 powder, 5-8% of fine rho-Al2O3 powder, 1.5-3.5% of pure calcium aluminate cement and 1.5-3.5% of dense fine alundum powder. The additives comprise three or more of 1-2% of heat-proof steel fiber, 0-0.15% of polypropylene fiber, 0-0.5% of metallic aluminum powder, 0-0.3% of sodium tripolyphosphate and 0-0.5% of melamine based on the weight of the castable base material. The refractory castable has the advantages of good performance, low cost and wide sources of raw materials. Compared with the prior art, the refractory castable can enable the average service life of KR desulfurization stirrers to be improved by more than 100 times.

Description

technical field [0001] The invention belongs to a refractory material for desulfurization pretreatment of molten iron in a molten iron tank, in particular to a refractory castable for a desulfurization agitator. Background technique [0002] At present, the desulfurization agitator used in the external stirring desulfurization of the molten iron furnace before the converter steelmaking in the surrounding metallurgical enterprises is composed of a stirring metal core and a refractory lining. Among them, the refractory materials for the lining body of the agitator are all mullite refractory castables. Taking the KR hot metal desulfurization mixer in the second steelmaking plant of Wuhan Iron and Steel (Group) Company as an example, it can be seen from its production regulations that the main component of the refractory castable used is Al 2 o 3 ≥60%, SiO 2 It accounts for 30-35%; its physical properties are: compressive strength 110℃×24h≥24Mpa, 1500℃×3h≥60Mpa, bulk density ...

AI Technical Summary

Problems solved by technology

Due to the serious problem of high-temperature oxidation of steel fibers, it is restricted from fully exerting its effects on improving the strength of castables and thermal shock stability, resulting in serious thermal shock cracking and crack peeling of the working lining of agitator castables; in addition, due to The sintering temperature of silicon carbide material is high, and the addition of a high proportion is not conducive to the improvement of the mechanical properties of the castable and the densification of the castable at high temperature treatment, resulting in the penetration of high-temperature melt and the deterioration of the structure, causing the structural peeling of the working lining of the castable

Based on the above reasons, the above-mentioned existing technical solutions ultimately affect the improvement effect of the castable and the further improvement of the service life of the agitator