PURPOSE: To manufacture lead oxide granules with superior wear resistance and fluidity by a chemically granulating means by calcining coarse cubic system particles of basic lead nitrate obtd. by reacting Pb2O and NH4NO3 in an aqueous medium under specified conditions.
CONSTITUTION: Pb2O of ≤10μm particle size and 0.2W2.0 times as much NH4 NO3 as Pb2O by mol an mixed in an aqueous medium to prepare an aqueous slurry, and by heating the slurry at ≥50°C for 1W10hr, liberated NH3 is expelled to adjust the slurry to 4.0W10.0pH. This slurry is then allowed to stand to crystallize coarse cubic system particles of basic lead nitrate having ≥0.05mm length in side. The particles are separated from the mother liquor, washed, dried, and calcined at 400W500°C in an oxygen-contg. atmosphere to form Pb3O4 of cubic shape. This Pb3O4 is further calcined at 600W650°C to form Pb2O3 of cubic shape.
Takai, Kiyoshi
Shoji, Masashi
Sugawara, Hiroshi
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