The modified mill is suitable for changing the crystal structure of gypsum powder. Increase the strength of gypsum powder. The modified mill is divided into needle mill and ball mill.

The ball mill is one of the grinding equipment. In the production of mineral processing, the material can be directly sent to smelting after crushing, screening, and most ores must also be ground to 0.1-0.074 mm or even finer, so that useful minerals to achieve monomer dissociation, and after sorting can be sent to smelting, grinding operation is an important process in the production of mineral processing. The effect of fine grinding is better than that of coarse grinding, when fine grinding, generally the granularity of the ore is not greater than 25 mm, and the most suitable granularity of the ore is below 6 mm. Ball mill is widely used in metal and non-metal mines, building materials, gypsum and other industrial sectors grinding all kinds of ore and rock operations. High yield, small footprint, durable. Loud noise, high energy consumption, not easy to maintain. The needle grinding has the advantages of low noise, high efficiency and easy maintenance.