A method for the production of a coarse-grained ammonium sulfate - product by crystallization and plant for carrying out the method

摘要

A process for the continuous production of a coarse-grained ammonium sulfate - product (grain size d ’ in the region of 2,0 – 3,0 mm, in particular 2,3 – 2,5 mm) by crystallization of ammonium sulfate - solution in a according to the dtb - principle operated crystallization stage, in which a suspension of mother liquor and ammonium sulfate - crystals in the case of evaporation of water is constantly circulated in an internal circuit, and in the upper region of the continuously from a sedimentation zone a clarified partial flow of solution in an external circuit, to the resolution of the solids contained therein and then heated again as a clear solution in the lower region of the crystallization stage is returned, vapors are drawn off from the head of the crystallization stage, new ammonium sulfate - solution to be fed from outside and from the lower region of the crystallization stage, a suspension stream with the coarse-grained ammonium sulfate - product is drawn off, characterised in that from the sedimentation zone as a further partial stream is a finely crystal suspension stream off, and without any previous resolution of the contained solids content in the internal circuit is returned to the crystallization stage.