PRODUCTION OF GRANULAR AMMONIUM SULFATE

PURPOSE:To efficiently obtain granular ammonium sulfate having excellent hardness and shape as well as a large grain size, by concentrating and crystallizing an ammonium sulfate solution under specific condition. CONSTITUTION:Ammonium sulfate, having a small grain size and obtained by absorbing NH3...

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Bibliographic Details
Main Authors OGAWA SHIGENORI, AKIYAMA NAOYUKI, ITO TADASHI, NAKAMURA TAIZO
Format Patent
LanguageEnglish
Published 09.05.1988
Subjects
AMMONIA
CHEMISTRY
COMPOUNDS THEREOF
CYANOGEN
INORGANIC CHEMISTRY
METALLURGY
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Summary:PURPOSE:To efficiently obtain granular ammonium sulfate having excellent hardness and shape as well as a large grain size, by concentrating and crystallizing an ammonium sulfate solution under specific condition. CONSTITUTION:Ammonium sulfate, having a small grain size and obtained by absorbing NH3 in a coke oven in sulfuric acid, etc., is dissolved in water to c concentration close to the saturation value is charged into a crystallization vessel, e.g. continuous mixing crystallization type, etc., and a habit modifier, e.g. sulfamic acid, ammonium nitrate, etc., is added to give 1-10wt% concentration. The resultant solution is adjusted to pH 3.0-5.0 and 150-500wt% iron ion concentration and concentrated while stirring to operate the crystallization vessel under condition of 10-50wt% slurry concentration, 3-10hr slurry residence time and >50 deg.C under reduced pressure to afford the aimed hard and rounded granular ammonium sulfate having a large grain size.
Bibliography:Application Number: JP19860247570