Process of co-production and technological modification of melamine and urea

The off-gas from melamine plants is recovered with the co-production technology used in Zhongyuan Dahua Group Ltd.of Henan Province.The urea plant in existing process is modified,some new urea equipments with a capacity of 110 kt/a has been added,and urea hydrolyzer,with OAT hydrolyzer,carbomate solution recovery unit and urea melting unit added simultaneously.All these units are linked together while operated independently.By this kind of co-production technology of urea plants and melamine plants,the production cost of melamine can be reduced,meanwhile the up-to-standard pollutants discharge ensured.