Method for comprehensively recovering rare earth elements and fluorine element in a bastnaesite treatment process

A method for recovering rare earth elements and fluorine element in a bastnaesite treatment process, wherein the method comprises:

• oxidation roasting bastnaesite to obtain a roasted mixture, and leaching the roasted mixture with hydrochloric acid,
• adding a roasting promoter to the bastnaesite during the oxidation roasting;
• and
• adding a catalytic leaching promoter to the mixture during the leaching with hydrochloric acid;
• obtaining a rare earth chloride solution containing little cerium element and a cerium-rich residue containing the fluorine element;
• and
• separating and recovering rare earth fluorides from the cerium-rich residue;
• wherein the catalytic leaching promoter is at least one selected from the group consisting of magnesium sulfate, ammonium sulfate, a rare earth sulfate, ammonium ceric nitrate, cerium(IV) nitrate, aluminum nitrate, aluminum chloride, aluminum sulfate, sodium fluoride, potassium fluoride, ammonium fluoride and aluminum fluoride;
• or
• the method for recovering rare earth elements and fluorine element in a bastnaesite treatment process, comprising:
• oxidation roasting bastnaesite to obtain a roasted mixture, and leaching the roasted mixture with hydrochloric acid,
• adding a catalytic leaching promoter to the mixture during the leaching with hydrochloric acid;
• obtaining a rare earth chloride solution containing little cerium element and a cerium-rich residue containing the fluorine element;
• and
• separating and recovering rare earth fluorides from the cerium-rich residue;
• wherein the catalytic leaching promoter is at least one selected from the group consisting of magnesium sulfate, ammonium sulfate, a rare earth sulfate, ammonium ceric nitrate, cerium(IV) nitrate, aluminum nitrate, aluminum chloride, aluminum sulfate, sodium fluoride, potassium fluoride, ammonium fluoride and aluminum fluoride.