铝渣的烧结性能研究

以铬盐厂废弃的铝渣为原料,将其破碎,湿法球磨,烘干后以150 MPa压力压制成20 mm×10 mm的试样,然后经1 700℃煅烧3 h。按标准测定各试样的体积密度、显气孔率和吸水率。采用XRD检测煅烧前后铝渣中的物相组成;采用SEM观察试样的显微结构并结合能谱仪对微区成分进行分析。结果表明:经湿法球磨6 h后,铝渣的平均粒径由6.779μm降低到1.728μm,在1 700℃煅烧3 h可获得良好的烧结。烧结体主要物相为铬刚玉,其晶粒呈板片状结构,且晶粒间结合致密,部分晶粒已融合在一起,结合处的晶界已经消失,铬刚玉晶粒尺寸最大的可达15μm。

Sintering properties of alumina-containing slag

The specimens were prepared using alumina-containing slag derived from chromium salt production process.This alumina-containing slag was crushed,wet ball-milled,dried,then pressed into 20 mm×10 mm specimens under 150 MPa,and the specimens were calcined at 1 700 ℃ for 3 h.The apparent porosity,bulk density and water absorption of the specimens were determined.The phase compositions of alumina-containing slag before and after calcination were analyzed by XRD.The microstructure and spectrum composition were researched using SEM and EDS,respectively.The results show that after wet ball-milling for 6 h,the average particle size of the alumina-containing slag decreased from 6.779 μm to 1.728 μm and the specimens calcined at 1 700 ℃ for 3 h perform good sintering property.The main phase of the sintered specimens is tabular chrome corundum with strong bonding,and part of the chrome corundum grains are already fused together.The largest size of chrome corundum grains is up to 15 μm.