Explosion-proof Performance And Application Research Of High-performance Corundum-spinel Castable

With the development of modern industry for the increasing demand for thequality of steel, high performance corundum-spinel castables are becoming more andmore widely used in big ladles. The addition of powder or superfine powder incorundum-spinel castables has improved its using performance, but also improvedensity and block the pores, so water vapor cannot be discharged easily in the heatingbaking process, which leads to the drop of explosion-proof performance, prolongs ladlebaking time, affects the ladle turnaround and increases cost caused by baking, especiallyfor the overall construction or large prefabricated parts.In this paper, using tabular corundum aggregate and powder, magnesia powder,78spinel powder, α-Al2O3powder, pure calcium aluminate cement as main startingmaterials.By adding appropriate explosion-proof agents in corundum-spinel castablesand studying on the baking process of castables, their explosion-proof performance hasbeen improved as more as possible without influencing other properties of castablessobviously. And Making reasonable baking system in order to shorten the time of ladlebaking. The main research works are as follows:(1) By adding aluminum powder, organic fiber, AC and aluminum lactate intocastables respectively, effects of explosion-proof agents on explosion-proofperformance of corundum-spinel castables have been studied. The results show that:when the amount of explosion-proof agent is not too much, strength, BP, and corrosionresistance to slag of castables won’t dropped too much either; Adding aluminum powderis the most effective way to improve the explosion-proof performance ofcorundum-spinel castables, however, too much aluminum powder will cause greatdamage to the matrix structure of castables; Organic fiber will seriously affect the flowproperties of castables, and for thicker castables or longer baking time, organic fiber onimprovement of explosion-proof performance will be more apparent; When the amountof AC climbed to0.12%, the explosion-proof performance of castables can be improved obviously, but its excess will produce more irritating gas NH3, which limits its use;Adding of aluminum lactate can improve room temperature strength of castablesobviously, but its improvement of explosion-proof performance of castable is limitted,and at the same time, the flow property of castables is largely damaged.(2) By reducing the amount of explosion-proof agents and using compoundexplosion-proof agents, effects of compound explosion-proof agent on properties ofcorundum-spinel castables have been studied. The results show that: Throughcompound using of explosion-proof agents with less amount, the explosion-proofperformance of castables can be largedly improved without damaging other propertiesobviously. The sample with compound explosion-proof agents of0.06%aluminumpowder,0.03%organic fiber and0.05%aluminum lactate have the best explosion-proofperformance, and explosion-proof temperature has climbed to900℃; When thecastables has contained aluminum powder, the adding of AC cannot further improve theexplosion-proof performance of it; On the basis of compound using of aluminumpowder and organic fiber, a little using of aluminum lactate will make theexplosion-proof performance of castables further improved largedly.(3)The main explosion reason of corundum-spinel castables during bakingprocess is the high steam pressure caused by blocked discharging of free water, andstructured water is much less,so discharging of structured water won’t lead to explosivedamage of castables. For the actual concrete baking, baking temperature can rise to200℃or higher quickly, and insulate for1~2h, then continuous heat slowly with a speed of25~35℃/h. In this way, the baking time can be used effectively, and the explosions ofcastables caused by the sudden increase of internal steam pressure or thermal shock canalso be prevented.