Manufacture of dicalcium phosphate, dihydrate

Claim 1

IN THE PROCESS FOR THE MANUFACTURE OF DICALCIUM PHOSPHATE DIHYDRATE BY REACTING FEED COMPOUNDS COMPRISING (A) AT LEAST ONE CALCIUM SALT SELECTED FROM THE GROUP CONSISTING OF AQUEOUS CALCIUM HYDROXIDE, AQUEOUS CALCIUM CARBONATE, AQUEOUS CALCIUM CHLORIDE AND AQUEOUS CALCIUM NITRATE, (B) AT LEAST ONE PHOSPHORIC ACID COMPOUND SELECTED FROM THE GROUP CONSISTING OF PHOSPHORIC ACID, AQUEOUS ALKALI METAL PHOSPHATE AND AQUEOUS AMMONIUM PHOSPHATE AND (C) WHEN THE CALCIUM SALT (A) IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF CALCIUM CHLORIDE AND CALCIUM NITRATE, AT LEAST ONE BASIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL AND AMMONIUM HYDROXIDES AND CARBONATES IN THE PRESENCE OF WATER AT A TEMPERATURE BELOW 70* C., THE IMPROVEMENT WHICH COMPRISES SIMULTANEOUSLY INTRODUCING INTO A REACTION ZONE THE CALCIUM SALT AND THE PHOSPHORIC ACID COMPOUND TO FORM A REACTION MIXTURE, REACTING THE CALCIUM SALT AND THE PHOSPHORIC ACID COMPOUND BY RAPIDLY AND INTIMATELY MIXING THEM, ADJUSTING THE REACTION MIXTURE TO A PH-VALUE WITHIN THE RANGE OF 2.0 AND 6.0 AND MAINTAINING THE PH-VALUE DURING SUBSTANTIALLY THE ENTIRE REACTION BY SUPPLYING THE FEED COMPOUNDS SUCH THAT THE PHVALUE IS MAINTAINED, WHEREBY A HIGHER PH-VALUE WITHIN THE PH-RANGE PRODUCES DICALCIUM PHOSPHATE DIHYDRATE HAVING A SMALLER GRAIN SIZE AND A LOWER PH-VALUE WITHIN THE PH-RANGE PRODUCES DICALCIUM PHOSPHATE DIHYDRATE HAVING A LARGER GRAIN SIZE, AFTER ALL OF SAID PHOSPHORIC ACID COMPOUND HAS BEEN INTRODUCED, ADDING THE BALANCE OF THE FEED COMPOUNDS OTHER THAN THE PHOSPHORIC ACID COMPOUND WHILE INCREASING THE PH-VALUE ADJUSTED AND SEPARATING THE DICALCIUM PHOSPHATE DIHYDRATE FROM LIQUID MATTER ACCOMPANYING IT.