Recovery and purification of vitamin b12

Claim 1

THE PROCESS WHICH COMPRISES ADDING TO AN AQUEOUS SOLUTION OF IMPURE VITAMIN B12 MATERIAL, SAID AQUEOUS SOLUTION CONTAINING FROM ABOUT 0.1 TO 100 GAMMAS OF VITAMIN B12 PER ML. AND SAID AQUEOUS SOLUTION HAVING A PH OF FROM ABOUT 1 TO ABOUT 10 INCLUSIVE AND HAVING TEMPERATURE OF FROM ABOUT 0* C. TO ABOUT 80* C., A QUANTITY OF A WATER-SOLUBLE SALT OF A WATER-INSOLUBLE CARBOXYLIC ACID, SAID QUANTITY OF WATER-SOLUBLE SALT BEING FROM ABOUT 0.005 TO ABOUT 0.5 GRAM PER ML. OF SAID AQUEOUS SOLUTION, SAID CARBOXYLIC ACID BEING A BENZENE CARBOXYLIC ACID HAVING NOT MORE THAN TWO CARBOXYL GROUPS, NOT MORE THAN TWELVE CARBON ATOMS AND CONTAINING A BENZENE RING, AND SAID CARBOXYLIC ACID BEING A SOLID IN THE PRESENCE OF WATER AT TEMPERATURES BELOW ABOUT 80* C., TREATING THE RESULTING SOLUTION WITH SUFFICIENT MINERAL ACID TO RESULT IN THE PRECIPITATION OF FREE INSOLUBLE CARBOXYLIC ACID, SEPARATING THE RESULTING SOLID PRECIPITATE, CONTACTING SAID PRECIPITATE WITH A COMBINATION OF AN AQUEOUS SOLVENT AND A WATER-IMMISCIBLE ORGANIC LIQUID, SAID ORGANIC LIQUID BEING A SOLVENT FOR SAID CARBOXYLIC ACID BUT A NON-SOLVENT FOR VITAMIN B12 MATERIALS, AND SEPARATING THE TWO PHASES WHEREBY AN AQUEOUS SOLUTION OF PURIFIED VITAMIN B12 MATERIAL IS OBTAINED.