This paper introduces in detail the uses,technical indexes,and the merits anddemerits of various methods of production as wel1 as the general equipmentand the development prospect of DRG,DLG,DEM and DOM.

• 本文详细介绍了“GRG”、“DLG”、“DEM”、“DOM”等产品的用途；主要技术指标、各种生产方案的优缺点以及生产所需要的一般设备和将来的发展方向.