| 摘要 |
PURPOSE:To improve high temperature strength by making spinel to constitute the matrix of the grain boundary of periclase crystal having respectively specified weight composition, bulk density, apparent porosity and average crystalline size. CONSTITUTION:With an Mg compound having a composition of >=97.0wt.% MgO, <=1.5wt.% CaO, <=0.2wt.% B2O3 and <=1.0wt.% remainder components on ignition base, a prescribed amount of an Al compound such as Al2O3 or Al(OH)3 having <=100mum particle size and >=99% purity is admixed and the resultant mixture is calcined, subsequently granulated or molded and then burnt. Thereby the objective coarse crystalline magnesia clinker having a composition of >=85.0wt.% MgO, <=1.5wt.% CaO, <=1.7wt.% (CaO + SiO2), <=0.2wt.% Fe2O3, 1.5-15wt.% Al2O3 and <=0.2wt.% B2O3 on oxide base, >=3.1g/cm<3> bulk density, <=5% apparent porosity, >=80mum average crystal size of periclase, >=10wt.% ratio of number of periclase crystal grains having >=125mum grain size to total number of periclase crystal grains and the matrix composed of spinel of the grain boundary of the periclase crystal is obtained. |
