Claims
- 1. A process for preparing dicalcium phosphate dihydrate having improved monofluorophosphate compatibility comprising the steps of:
- (a) reacting a slaked lime slurry with phosphoric acid to form a monocalcium phosphate solution;
- (b) adding to said solution additional slaked lime slurry and pyrophosphoric acid in amounts sufficient to form a dicalcium phosphate dihydrate slurry having a pH ranging from above about 2.2 to below 4.7; and
- (c) separating said dicalcium phosphate dihydrate from said slurry.
- 2. The process of claim 1 wherein the amount of pyrophosphoric acid added ranges from about 0.1% to about 1.0% by weight of dicalcium phosphate dihydrate to be produced.
- 3. The process of claim 1 wherein said pH ranges from above about 3.3 up to below 4.7.
- 4. The process of claim 1 wherein said pH ranges from above about 2.2 up to about 3.3.
Parent Case Info
This is a continuation of application Ser. No. 336,214 filed Dec. 31, 1981, abandoned.
US Referenced Citations (4)
Continuations (1)
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Number |
Date |
Country |
Parent |
336214 |
Dec 1981 |
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