gypsum powder machine The big sized gypsum stones are crushed into granules which are less than 25mm by the crusher. After storing and conveying, they will be conveyed into mill for grinding.Then they will be classified through a analytical engine. The qualified powder will be conveyed to the calciner for calcination, while the unqualified one will return to the mill for further grinding until it is qualified. The calcined gypsum powder (it¡¯s usually called Plaster of Paris) will be stored in the finished product silo for the preparation of plasterboard raw material or directly packing and transport to the customer;s site. There are two types of the gypsum powder productionline. One uses the direct burning calciner (it is usually used in the small capacity line, such as 20000 or 30000 tons per year), the other uses the fluidized bed furnace (it fits for all the capacity of the gypsum powder line. This style is very popular in the gypsum powder industry.). Use 40 feet container to transport.