用后镁钙砖制备镁钙质干式料

对AOD炉用后镁钙砖进行了分析发现,镁钙砖变质层的结构比原砖层更致密,而且用其原砖层和变质层再生的镁钙砂颗粒短时间放置后水化程度轻微。因此,以5～0.09 mm的原砖层再生镁钙砂和5～1 mm的变质层镁钙砂为骨料,≤0.074 mm的中档镁砂为细粉制备了镁钙质干式料,并测试了干式料经1 550℃3 h处理后的体积密度、抗折强度、耐压强度和加热永久线变化。结果表明:以用后镁钙砖原砖层和变质层部分为主要原料再生制备的镁钙质中间包干式料,其性能可满足中间包干式料的要求。

Preparation of magnesia-calcia dry mix from used MgO-CaO bricks

The analysis on the used MgO-CaO bricks in AOD furnace shows that the structure of the deteriorative layer is denser than the original layer and the magnesia-calcia clinker prepared with the deteriorative layer and the original layer hydrates slightly after a short time curing.Thus,magnesia-calcia dry mix was prepared using regenerated magnesia-calcia clinker from the original layer(5-0.09 mm) and that from the deteriorative layer(5-1 mm) as aggregates,and middle grade magnesia(≤0.074 mm) as fines.The bulk density,modulus of rupture,crushing strength,and permanent change in dimensions on heating of the dry mix fired at 1 550 ℃ for 3 h were tested.The results show that the magnesia-calcia dry mix prepared with the original layer and deteriorative layer of used MgO-CaO bricks can meet the requirement of tundish.