微孔刚玉的制备及其对铝镁浇注料性能的影响  

Preparation of micro-porous corundum and its effect on properties of Al_2O_3-MgO castables

作　　者：顾华志[1] 黄奥[1] 张美杰[1] 李正坤 马列鹰 杜博[1] 邹阳[1] 

机构地区：[1]武汉科技大学耐火材料与高温陶瓷国家重点实验室培育基地,湖北武汉430081 [2]江苏晶鑫高温材料有限公司,江苏扬州225265 [3]浙江自立股份有限公司,浙江上虞312300

出　　处：《耐火材料》2014年第1期9-12,17,共5页Refractories

基　　金：国家自然科学基金青年项目(51204126);国家"973"计划预研项目(2012CB722702);湖北省自然科学基金重点项目(2011CDA053)

摘　　要：在采用多孔介质模型进行微孔骨料孔径数值模拟设计的基础上，分别以α-Al2O3微粉、工业Al2O3细粉、α—Al2O3微粉＋CaCO3细粉为原料，通过湿磨工艺分别制备了三种微孔刚玉骨料A1、A2、A3，并分别以平均孔径约O．6μm的Al和A3两种微孔刚玉为骨料制成轻质铝镁浇注料，与采用板状刚玉骨料制备的普通铝镁浇注料进行了性能对比。结果表明：1）以α-Al2O3微粉、工业Al2O3细粉等为主要原料，在1800℃以上烧结可获得体积密度为3．1～3．5g·cm^-1、显气孔率约5％、闭口气孔率为8％～13％的微孔刚玉骨料，其800℃的热导率比板状刚玉的小；2）与普通铝镁浇注料相比，两种轻质铝镁浇注料的显气孔率较大，体积密度较小，1500℃处理后的强度较高，线变化率较小，在600和800℃时的热导率明显较小；3）与普通铝镁浇注料相比，含A1骨料的铝镁浇注料渗透指数偏大，含A3骨料的铝镁浇注料的侵蚀指数稍大，但渗透指数小。Based on the pore size design of micro-porous aggregate by numerical simulation applying porous media model, α-Al2O3 micropowder, industrial Al2O3 fine powder, α-Al2O3 micropowder ＋ CaCO3 fine powder were used as starting materials,respectively,the three micro-porous corundum aggregates named as A1 ,A2 and A3 were prepared by wet grinding process,and two lightweight Al2O3-MgO castables were prepared by selecting A1 or A3 with 0.6μm of average pore size as aggregate, then performances of castables with micro-porous corundum aggregates and castables with tabular corundum aggregates were compared. The results show that：（ 1 ） the micro-porous corundum aggregates with bulk density of 3.1-3.5 g · cm-3 ,apparent porosity of 5% ,closed porosity of 8%-13% ,and smaller thermal conductivity at 800℃ than tabular corundum,can be prepared by firing above 1 800 ℃; （2）compared with normal Al2O3-MgO castables,the two lightweight Al2O3-MgO castables have lower bulk density and higher apparent porosity; lower change rate in dimensions and higher strength firing at ：1 500 ℃;and lower thermal conductivity at 600 and 800℃; （3）compared with normal Al2O3-MgO castables,Al2O3-MgO castable with aggregate A1 has higher penetration index,and that with aggregate A3 has higher corrosion index and lower penetration index.

关 键 词：微孔刚玉骨料 铝镁浇注料 热导率 侵蚀指数 

分 类 号：TQ175[化学工程—硅酸盐工业]