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U.S. Department of Energy
Office of Scientific and Technical Information

Recovery of calcium fluoride from phosphate operation waste water

Patent ·
OSTI ID:5602389
Calcium fluroide is produced from pond waters resulting from phosphoric acid processing by treating the pond waters with calcium carbonate and/or calcium oxide in two stages to precipitate out the major part of the fluorine values from the waters as calcium fluoride. After removal of the calcium fluoride the filtrate is treated with calcium oxide to remove a substantial portion of the remaining fluorine values as calcium fluoride. After removal of these calcium fluoride solids, the filtrate is treated with another charge of calcium oxide to produce dicalcium phosphate (dical) which is separated from the aqueous phase. The aqueous phase is treated with an additional charge of calcium oxide to remove a substantial portion of the solids from the aqueous phase leaving waters that can be discharged as waste or recycled as process water.
Assignee:
Occidental Chemical Co.
Patent Number(s):
US 4171342
OSTI ID:
5602389
Country of Publication:
United States
Language:
English