| 摘要 |
PROBLEM TO BE SOLVED: To diminish unevenness in pH of a solid processing agent at the time of granulation with a fluidized bed granulator by keeping powdery-granular bodies in a specified temp. range during granulation and specifying the temp. of sucked air. SOLUTION: When powdery-granular bodies contg. at least a thiosulfate and an alkali carbonate are kept in a fluidized state with sucked air and spray granulation is carried out using bound water, the powdery-granular bodies are kept at 30-60οC during the granulation and the temp. of the sucked air is regulated to <=65 deg.C. The thiosulfate is preferably ammonium thiosulfate, sodium thiosulfate or potassium thiosulfate. The alkali carbonate is preferably potassium carbonate or sodium carbonate. The powdery-granular bodies are powder, crystals, granules or a mixture of them. The granules are obtd. by granulating powder or fine crystals and have 53-2,830μm diameter. The pref. wt. average particle diameter of the resultant granular solid processing agent is 200-600μm.
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