Process for precipitating readily filterable rare earth hydroxides

Claim 1

IN A METHOD OF PRECIPITATING RARE EARTH HYDROXIDES FROM A SOLUTION OF RARE EARTH CHLORIDES, THE IMPROVEMENT IN THE PRECIPITATION OF MORE EASILY FILTRABLE PRECIPITATES WHICH COMPRISES REACTING AN AQUEOUS SOLUTION OF A MIXTURE OF RARE EARTH CHLORIDES AT A TEMPERATURE BETWEEN 25* AND 50*C. WITH AN AQUEOUS SOLUTION CONTAINING AN ALKALINE PRECIPITATING AGENT SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL AND AMMONIUM HYDROXIDES AND ALSO CONTAINING IN SOLUTION AN ALIPHATIC CARBOXYLIC ACID OF LESS THAN FOUR CARBON ATOMS IN AN AMOUNT EQUIVALENT IN NORMALITY TO 5-15% OF THE CONCENTRATION OF SAID ALKALINE PRECIPITATING AGENT IN NORMALITY, WHEREBY SAID RARE EARTHS ARE PRECIPITATED AS HYDROXIDES IN TEH FORM OF A DENSE, READILY FILTERABLE PRECIPITATE.