A METALLURGICAL PROCESS FOR IRON-RICH MONAZITE RARE EARTH ORE OR CONCENTRATE

摘要

THE PRESENT INVENTION RELATES TO A METALLURGICAL PROCESS FOR IRON-RICH MONAZITE ORE OR CONCENTRATE, IN PARTICULAR COMPRISES THE FOLLOWING STEPS: MIXING IRON-RICH MONAZITE RARE EARTH ORE OR CONCENTRATE CONTAINING 8-40% IRON WITH CONCENTRATED SULPHURIC ACID AND FEEDING THE MIXTURE INTO A CALCINING KILN; CALCINING AT 231-600°C, WHEREIN RARE EARTH REACTS WITH SULPHURIC ACID TO PRODUCE RARE EARTH SULPHATE WHICH DISSOLVES IN WATER OR A SOLUTION WITH A H⁺ CONCENTRATION LESS THAN 1.5MOL/L, AND IRON IS TRANSFORMED INTO AT LEAST ONE OF IRON SULPHATE, IRON PHOSPHATE AND IRON PYROPHOSPHATE; LEACHING THE CALCINED ORE WITH WATER OR A SOLUTION WITH A H⁺ CONCENTRATION LESS THAN 1.5MOL/L AND FILTERING TO OBTAIN A SOLUTION OF RARE EARTH SULPHATE CONTAINING IRON AND P; NEUTRALIZING THE SOLUTION TO RECOVER IRON AND P AND TO OBTAIN PURE SOLUTION OF RARE EARTH SULPHATE; PRODUCING INDIVIDUAL OR MIXED RARE EARTH COMPOUND BY SOLVENT EXTRACTION FROM THE PURE SOLUTION DIRECTLY, OR PRODUCING MIXED RARE EARTH CARBONATE BY PRECIPITATION. THE PROCESS COULD AVOID THE INFLUENCE OF IRON ON THE EXTRACTION RARE EARTH. THE PROCESS IS SIMPLE, CONTINUOUS, EASY TO CONTROL, LOW CONSUMPTION OF CHEMICAL RAW MATERIALS, HIGH RARE EARTH RECOVERY AND SUITABLE FOR LARGE-SCALE PRODUCTION.