semi-compounded molding sand是什么意思

用法例句

The oxidized layer at the EAF bottom surface,which is made by MgO-CaO-Fe_2O_3 synthetic sand is disappeared and reproduced successively during operation.

ＭｇＯ－ＣａＯ－Ｆｅ_２Ｏ_３合成砂构筑的电炉炉底，表面形成的氧化层不断地消失和再生，体现了陶瓷结合相进入主晶相和形成高熔点矿物的结构特征，从而实现长寿命炉底。