Kieserite granulating process.

摘要

Pelleting of kieserite comprises: (a) rolling a mixt. (which is pre-moistened or is moistened during the rolling process) of (i) kieserite with an av. particle size of 0.3-0.5 mm, (ii) at least 20% of very fine ground kieserite with an av. particle size of 0.02-0.04 mm, and (iii) recovered material from recycled defective grains, on a granulation plate in the presence of granulation auxiliaries; (b) sieving; (c) taking out the saleable grain fraction, and recycling defective grains (opt. after comminution). The granulation auxiliary is 0.7-3.0% (based on Hs amt. of components (i) and (ii) only) alkali hydroxide in the form of a soln. The resulting total mixt. is jetted onto the granulation plate with magnesium sulphate. The pellets which are removed from the plate are cooled to 30 oC and subjected to a maturation process.