关键词: 菱镁矿, 转炉, 镁质修补料, 使用寿命, 烧结时间

Abstract: To further improve their properties,based on the formulation of 93 mass% fused magnesia (5-3,3-1,≤1 and ≤0.088 mm),5 mass% SiO₂ micropowder,2 mass% sodium metasilicate nonahydrate,and extra 0.15 mass% superplasticizer SD-80,the environment-friendly water-based magnesia repair mixes for converters were prepared by replacing the ≤0.088 mm fused magnesia fines in the equal amount with high-quality natural magnesite powder from southern Liaoning (0,1%,2%,3%,4%,5%,6%,7%,8%,and 9%,by mass).The effects of the natural magnesite addition on the fluidity,the bulk density,the apparent porosity,the mechanical properties,and the slag resistance of the repair mixes were studied.The results show that:(1)the introduction of natural magnesite powder has no obvious effect on the fluidity of the repair mixes and the bulk density and the apparent porosity of the samples dried at 110 ℃ for 24 h;(2)the samples fired at 1 500 ℃ for 3 h have significantly improved bulk density,cold strength,hot modulus of rupture,slag resistance and other properties,achieving the best performance with 4%-5% natural magnesite powder;(3)the application test proves that the sample with 5% natural magnesite powder has long service life and the shortest sintering time;under the same smelting conditions,the service life of the sample increases by 100% and the sintering time shortens by 70% compared with the traditional asphalt bonded magnesia carbon repair mixes,which is the most ideal technical scheme.

Key words: magnesite, converter, magnesia repair mix, service life, sintering time