刚玉砖抗高磷鲕状赤铁矿还原物料的侵蚀与渗透研究

摘要

The paper aims at investigating whether corundum bricks can be used for the bottom of the direct reduction furnace of high phosphorus oolitic hematite.The reducing materials including high phosphorus oolitic hematite,bitumite,Ca(OH)2 and Na2 CO3 at a mass ratio of 1 0.15 0.15 0.03 were mixed and pressed into carbon containing cylindrical specimens with the size of 15 mm ×20 mm.The specimens were placed on the corundum bricks and reduced in a high temperature tube furnace at 1 200 ℃ for 40,60, 80,140 and 220 min,respectively.The corrosion resistance and penetration resistance of corundum bricks to high phosphorus oolitic hematite reducing materials were analyzed with XRD,SEM and EDS.I t shows that the reducing slag formed in the reduction process corrodes the surface of corundum bricks to form a product layer of anorthite and hercynite,retarding the further corrosion of the reducing slag;the reducing slag which has penetrated into the interior of the brick goes through the gaps between the particles and generates anorthite and hercynite,filling the gaps and hindering the reducing slag penetration.%为考察刚玉砖是否适用于高磷鲕状赤铁矿直接还原的炉底，将还原物料高磷鲕状赤铁矿、烟煤、Ca（OH）2和 Na2 CO3按质量比为10．150．150．03混匀后压制成15 mm ×20 mm 的含碳圆柱试样，置于刚玉砖上，一起放入高温管式炉内分别于1200℃保温40、60、80、140和220 min 进行还原试验，采用 XRD、SEM及EDS 研究了刚玉砖抗高磷鲕状赤铁矿还原物料的侵蚀与渗透行为。结果表明：还原物料在还原过程中形成的还原渣侵蚀刚玉砖表面而形成钙长石和铁尖晶石产物层，抑制了还原渣的侵蚀；而已渗透至砖内的还原渣，在向砖内部扩散迁移过程中生成钙长石和铁尖晶石，起到填充与堵塞孔缝的作用，阻碍了还原渣的渗透。