Process for the production of magnesium hydroxide

Claim 1

PROCESS FOR THE PRODUCTION OF MAGNESIUM HYDROXIDE FROM A COOLED MOTHER LIQUOR CONTAINING A MAGNESIUM SALT AND AN AMMONIUM SALT IN AMOUNTS CORRESPONDING TO THE RESIDUE AFTER COOLING, WHICH COMPRISES INTRODUCING THE MOTOR LIQUOR CONTAINING SAID MAGNESIUM AND AMMONIIM SALTS SIMULTANEOUSLY WITH AN EXCESS OF AMMONIA INTO A FURTHER PORTION OF MOTHER LIQUOR, PRECIPITATING MAGNESIUM HYDROXIDE, STOPPING SAID PRECIPITATION WHEN ABOUT 66% OF THE THEORETICAL AMOUNT OF MAGNESIUM HYDROXIDE HAS BEEN PRECIPITATED, FILTERING OFF THE PRECIPITATED MAGNESIUM HYDROXIDE, EXPELLING EXCESS AMMONIA FROM THE RESULTING LIQUOR, THEN ADDING THERETO A SOLID MAGNESIUM SALT OF SAME IDENTITY AS THE MAGNESIUM SALT CONTAINED IN SAID STARTING MOTHER LIQUOR IN AN AMOUNT IN EXCESS OF THE AMMONIIM SALTS PRESENT IN SAID MOTHER LIQUOR, PRECIPITATING AN AMMONIUM-MAGNESIUM DOUBLE SALT, COOLING THE MIXTURE AND SEPARATING SAID DOUBLE SALT AND RECYCLING SAID MOTHER LIQUOR TO SAID FURTHER PORTION OF LIQUOR.