Fluorapatite (Ca5F(PO4)3) → Calcium Hydroxide

Participants

Reaction Steps

A fluid bed reactor unit of the type illustrated in the drawing, having a bed diameter of 10 feet, operates on a feed of about 60 TPH (short tons per hour) of phosphate rock calcines having particle sizes up to -4 mesh. The hot calcines are introduced tnto the fluid bed reactor unit at a temperature of about 500°-600° C (932°-1112° F). The calcines contain about 10-15 % by weight, of CaO. Cooling water is sprayed on the fluidized bed at the rate of 20-30 GPH (Gallons Per Hour) and a fluidizing air stream is introduced through the windbox of the fluid bed reactor at ambient temperature. An additional quantity of water is introduced through a conduit which supplies a plurality of nozzles positioned within the fluidized bed and just above the level of the constriction plate of the fluid bed reactor at the rate of 10-15 GPH. About 55 TPH of beneficiated phosphate rock product is produced at a temperature of about 160°-170° C (320° -338° F) and about 5 TPH of calcium hydroxide having an average particle size of up to -65 mesh is elutriated by the fluidizing gas and obtained as separated waste or by-product. The slaking reaction transforms about 85% of the CaO to calcium hydroxide, and the separation which occurs in the fluid bed reactor is effective to separate about 75% of the calcium hydroxide from the phosphate rock calcines.

Provenance & Evidence