Study On Lining Refractories Of Torpedo Cars In Baosteel

Since March 1998, dephosphorization, desulphurization and desiliconization were carried out in 76 torpedo cars in Baosteel, which aggravated the corrosion of the lining refractories, made the campaign life reduce from 1200 heats to 850 heats, i.e. reduced 30%, interrupt the regular trouble shooting, endangered regular producing process.In this paper, the corrosive mechanism of refractories in different part of torpedo cars when hot metal pretreatment was carried out was analyzed, and then the analyzed direction of the lining refractories of torpedo cars was confirmed, the effect of the composition, additions on oxidation resistance, corrosion resistance and thermal shock resistance of the refractories was studied, the conclusions were listed as following:(1) The oxidation resistance and high temperature strength of the unsintered Al2O3-SiC-C brick with metal antioxidant, special antioxidant and special addition were improved.(2) The binding strength of graphite was improved by the addition of special addition in the unsintered Al2O3-SiC-C brick, and then the high temperature strength was improved, the coefficient of thermal expansion and Young's modulus were decreased.(3) The corrosion resistance of the unsintered Al2O3-SiC-C brick was increased by special antioxidant and special addition.(4) For the purpose of elongation the service life of the unsintered Al2O3-SiC-C brick, the brick should be high carbon, low SiO2 and proper SiC.From the study in this paper, the using effect of the refractories was list as following:(1) The development that the sintered Al2O3-C brick was used in cylinder top of torpedo cars, and the unsintered Al2O3-SiC-C brick was used in other parts broke the routine that the unsintered Al2O3-SiC-C brick was used in all of the torpedo cars, and the problems that the oxidization in earlier applied stage, spalling and back oxidization of the unsintered Al2O3-SiC-C brick were solved.(2) The refractories of each part in torpedo cars were comparably corroded, i.e. the residual refractories of each part in the torpedo cars were almost near by application of sintered Al2O3-C brick in cylinder top of torpedo cars, and the unsintered Al2O3-SiC-C brick in other parts. The medium maintenance and the consumption of refractories were decreased.(3) The average campaign life of torpedo cars was increased by more than 300 heats, the consumption of refractories was decreased.