The gypsum is placed in a box which is then covered with a glass plate supplied with clay removing extra gypsum.
石膏被陈列在一个盖着玻璃盘子的盒子里，玻璃盘子上附带着从别的地方附带的粘土。
2
In this paper the characteristic of thermal process of clay castable refractories, the development of PVC expansion crack plate and its installment are introduced.