Abstract 1. A CONTINUOUS PROCESS FOR THE PREPARATION OF ALKALI METAL DIHYDROGEN PHOSPHATES AND PHOSPHORIC ACID AND THE REMOVAL OF FLUORINE VALUES FROM PHOSPHATE ROCK, COMPRISING THE STEPS OF REACTING PHOSPHATE ROCK WITH SUFFICIENT PHOSPHORIC ACID TO EFFECT SUBSTANTIALLY COMPLETE REACTION WITH THE CALCIUM IN THE ROCK IN A FIRST STAGE AT A TEMPERATURE OF ABOUT 40-110*C. TO FORM A MONOCALCIUM PHOSPHATE MIXTURE, REACTING THIS MIXTURE IN A SECOND STAGE AT A TEMPERATURE OF ABOUT 40-110*C. WITH A STOICHIOMETRIC AMOUNT OR SLIGHT EXCESS OF AN AQUEOUS SOLUTION CONTAINING A SULPHATE OF THE FORMULA R2SO4 WHEREIN R IS ALKALI METAL OR ONE R IS HYDROGEN AND THE OTHER R IS ALKYL METAL, TO FORM A REACTING SLURRY OF PHOSPHORIC ACID, ALKALI METAL DIHYDRGEN PHOSPHATE AND GYPSUM, SEPARATING A SOLID GYPSUM CAKE FROM THE SYSTEM TO PROVIDE A RESULTING SOLUTION CONTAINING PHOSPHORIC ACID AND ALKALI METAL DIHYDROGEN PHOSPHATE, DIVIDING THE RESULTING SOLUTION INTO TWO PORTIONS, REACTING ONE PORTION WITH AN ALKALI METAL SULFATE SALT SOLUTION, WHEREIN SAID ALKALI METAL SALT IS OF THE FORMULA R2SO4, WHERE R IS AS DESCRIBED ABOVE, USING A SUFFICIENT AMOUNT OF SAID ONE PORTION OF RESULTING SOLUTION TO NEUTRALIZE ANY SULFURIC ACID PRESENT IN THE SYSTEM, AND FORM A MIXTURE OF PHOSPHORIC ACID AND ALKALI METAL SULFATE OR BISULFATE, SEPARATING THE SOLID WHICH COMPRISES A SLURRY OF SULFATE SOLIDS AND PHOSPHORIC ACID LIQUID, RECYCLING AT LEAST A PORTION OF THE PHOSPHORIC ACID LIQUID TO THE FIRST STAGE PHOSPHATE ROCK REACTION AND RRECYCLING AT LEAST A PORTION OF THE SULFATE SOLIDS TO THE SECOND STAGE FOR REACTION WITH THE MONOCALCIUM PHOSPHATE MIXTURE, CONTACTING THE SECOND PORTION OF THE RESULTING SOLUTION WITH A LOWER ALKYL ALCOHOL, LOWER ALKYL KETONE OR MIXTURE THEREOF TO DISSOLVE THE PHOSPHORIC ACID PRESENT AND PRECIPITATE THE SOLID ALKALI METAL DIHYDROGEN PHOSPHATE PRODUCT AND RECOVERING THE SOLID PRODUCT.
A CONTINUOUS PROCESS FOR THE PREPARATION OF ALKALI METAL DIHYDROGEN PHOSPHATES AND PHOSPHORIC ACID AND THE REMOVAL OF FLUORINE VALUES FROM PHOSPHATE ROCK, COMPRISING THE STEPS OF REACTING PHOSPHATE ROCK WITH SUFFICIENT PHOSPHORIC ACID TO EFFECT SUBSTANTIALLY COMPLETE REACTION WITH THE CALCIUM IN THE ROCK IN A FIRST STAGE AT A TEMPERATURE OF ABOUT 40-110*C. TO FORM A MONOCALCIUM PHOSPHATE MIXTURE, REACTING THIS MIXTURE IN A SECOND STAGE AT A TEMPERATURE OF ABOUT 40-110*C. WITH A STOICHIOMETRIC AMOUNT OR SLIGHT EXCESS OF AN AQUEOUS SOLUTION CONTAINING A SULPHATE OF THE FORMULA R2SO4 WHEREIN R IS ALKALI METAL OR ONE R IS HYDROGEN AND THE OTHER R IS ALKYL METAL, TO FORM A REACTING SLURRY OF PHOSPHORIC ACID, ALKALI METAL DIHYDRGEN PHOSPHATE AND GYPSUM, SEPARATING A SOLID GYPSUM CAKE FROM THE SYSTEM TO PROVIDE A RESULTING SOLUTION CONTAINING PHOSPHORIC ACID AND ALKALI METAL DIHYDROGEN PHOSPHATE, DIVIDING THE RESULTING SOLUTION INTO TWO PORTIONS, REACTING ONE PORTION WITH AN ALKALI METAL SULFATE SALT SOLUTION, WHEREIN SAID ALKALI METAL SALT IS OF THE FORMULA R2SO4, WHERE R IS AS DESCRIBED ABOVE, USING A SUFFICIENT AMOUNT OF SAID ONE PORTION OF RESULTING SOLUTION TO NEUTRALIZE ANY SULFURIC ACID PRESENT IN THE SYSTEM, AND FORM A MIXTURE OF PHOSPHORIC ACID AND ALKALI METAL SULFATE OR BISULFATE, SEPARATING THE SOLID WHICH COMPRISES A SLURRY OF SULFATE SOLIDS AND PHOSPHORIC ACID LIQUID, RECYCLING AT LEAST A PORTION OF THE PHOSPHORIC ACID LIQUID TO THE FIRST STAGE PHOSPHATE ROCK REACTION AND RRECYCLING AT LEAST A PORTION OF THE SULFATE SOLIDS TO THE SECOND STAGE FOR REACTION WITH THE MONOCALCIUM PHOSPHATE MIXTURE, CONTACTING THE SECOND PORTION OF THE RESULTING SOLUTION WITH A LOWER ALKYL ALCOHOL, LOWER ALKYL KETONE OR MIXTURE THEREOF TO DISSOLVE THE PHOSPHORIC ACID PRESENT AND PRECIPITATE THE SOLID ALKALI METAL DIHYDROGEN PHOSPHATE PRODUCT AND RECOVERING THE SOLID PRODUCT.
Claim 2
Dependent Claim
301 words
A CONTINUOUS PROCESS FOR THE PREPARATION OF ALKALI METAL DIHYDROGEN PHOSPHATES AND PHOSPHORIC ACID AND THE REMOVAL OF FLUORINE VALUES FROM PHOSPHATE ROCK, COMPRISING THE STEPS OF REACTING PHOSPHATE ROCK WITH SUFFICIENT PHOSPHORIC ACID TO EFFECT SUBSTANTIALLY COMPLETE REACTION WITH THE CALCIUM IN THE ROCK IN A FIRST STAGE AT A TEMPERATURE OF ABOUT 40-110*C. TO FORM A MONOCALCIUM PHOSPHATE MIXTURE, REACTING THIS MIXTURE IN A SECOND STAGE AT A TEMPERATURE OF ABOUT 40-110*C. WITH A STOICHIOMETRIC AMOUNT OR SLIGHT EXCESS OF AN AQUEOUS SOLUTION CONTAINING A SULPHATE OF THE FORMULA R2SO4 WHEREIN R IS ALKALI METAL OR ONE R IS HYDROGEN AND THE OTHER R IS ALKYL METAL, TO FORM A REACTING SLURRY OF PHOSPHORIC ACID, ALKALI METAL DIHYDRGEN PHOSPHATE AND GYPSUM, SEPARATING A SOLID GYPSUM CAKE FROM THE SYSTEM TO PROVIDE A RESULTING SOLUTION CONTAINING PHOSPHORIC ACID AND ALKALI METAL DIHYDROGEN PHOSPHATE, DIVIDING THE RESULTING SOLUTION INTO TWO PORTIONS, REACTING ONE PORTION WITH AN ALKALI METAL SULFATE SALT SOLUTION, WHEREIN SAID ALKALI METAL SALT IS OF THE FORMULA R2SO4, WHERE R IS AS DESCRIBED ABOVE, USING A SUFFICIENT AMOUNT OF SAID ONE PORTION OF RESULTING SOLUTION TO NEUTRALIZE ANY SULFURIC ACID PRESENT IN THE SYSTEM, AND FORM A MIXTURE OF PHOSPHORIC ACID AND ALKALI METAL SULFATE OR BISULFATE, SEPARATING THE SOLID WHICH COMPRISES A SLURRY OF SULFATE SOLIDS AND PHOSPHORIC ACID LIQUID, RECYCLING AT LEAST A PORTION OF THE PHOSPHORIC ACID LIQUID TO THE FIRST STAGE PHOSPHATE ROCK REACTION AND RRECYCLING AT LEAST A PORTION OF THE SULFATE SOLIDS TO THE SECOND STAGE FOR REACTION WITH THE MONOCALCIUM PHOSPHATE MIXTURE, CONTACTING THE SECOND PORTION OF THE RESULTING SOLUTION WITH A LOWER ALKYL ALCOHOL, LOWER ALKYL KETONE OR MIXTURE THEREOF TO DISSOLVE THE PHOSPHORIC ACID PRESENT AND PRECIPITATE THE SOLID ALKALI METAL DIHYDROGEN PHOSPHATE PRODUCT AND RECOVERING THE SOLID PRODUCT.