Rare earth fluoride molten salt electrolysis slag treatment method

Abstract

The invention discloses a rare earth fluoride molten salt electrolysis slag treatment method. The rare earth fluoride molten salt electrolysis slag treatment method comprises the following steps thatball milling is carried out on rare earth molten salt electrolytic slag to a certain particle size; the electrolytic slag obtained after ball milling is subjected to magnetic separation, and magneticseparation tailings and magnetic separation concentrates are obtained; the magnetic separation tailings and concentrated sulfuric acid are mixed to make a heating reaction, and curing residues and HFgas (preparing an HF solution with water absorption) are obtained; the sulfuric acid curing residues are leached with water, and water leaching liquid is obtained; and the water leaching liquid obtained in the fourth step is subjected to fluoride precipitation with the HF solution obtained in the step three, and a rare earth fluoride product is obtained after liquid-solid separation is carried. The rare earth fluoride molten salt electrolysis slag treatment method is environment-friendly and economical, and solves the problem about separation of molten salt electrolysis slag rare earth and fluorine; meanwhile, the fluorine is finally recycled into a reaction system to react with rare earth to form precipitate, and green production and high-efficiency recovery of rare earth and iron from rare earth molten salt electrolysis slag are realized.

Description

technical field [0001] The invention relates to a comprehensive recovery and utilization treatment technology of rare earth waste residue in the rare earth smelting industry. More specifically, the present invention relates to the recycling of fluorine in rare earth fluoride molten salt slag and the recovery method of rare earth and iron. Background technique [0002] At present, the equipment for the production of rare earth metals or alloys in my country is a 3000 A electrolytic cell mainly operated by hand. Therefore, during the production operations of rare earth metals out of the furnace, replacement of anodes, regular furnace cleaning, and furnace dismantling, there are many non-rare earth impurities. Accumulated in the rare earth molten salt, the generation of waste rare earth molten salt is unavoidable. There are many types of these waste rare earth molten salts, and the degree of contamination by impurities is also quite different. During the molten salt electrolys...

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Problems solved by technology

[0004] The purpose of the present invention is to provide an environmentally friendly and economical method for treating fluoride rare earth molten salt electrolytic slag. Aiming at many problems faced by defluorination and extraction of rare earth from rare earth molten salt electrolytic slag, a magnetic separation-sulfuric acid aging-water immersion method is proposed. The method of rare earth precipitation by HF circulation is used to deal with the process idea of ​​rare earth molten salt electrolytic slag, which solves the problem of separation of rare earth and fluorine in molten salt electrolytic slag. The green production and high-efficiency recovery of rare earth and iron provide a technical basis for the recovery and utilization of molten salt electrolytic slag

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