Back extraction solution prepared by extraction separation of washing organic matter of saponification wastewater by recycling rare earth and solution washing method

Abstract

The invention relates to a back extraction solution prepared by extraction separation of a washing organic matter of saponification wastewater by recycling rare earth and a solution washing method, belonging to the field of rare earth wet method hydrometallurgy. According to the requirement on purity of difficultly-extracted and easily-extracted elements by a rare earth extraction separation process and different ammonium chloride or sodium chloride media in a water phase in the process, the saponification wastewater is recycled and used as a washing organic matter water solution for preparing a back extraction solution and a washing solution, thus the wastewater discharge is lowered, the consumption of fresh water is reduced, the concentration of ammonium chloride or sodium chloride in the wastewater is improved, the energy consumption of concentrating and crystallizing as well as recycling the ammonium chloride or sodium chloride is decreased, the rare earth yield is improved and the organic matter loss is lowered.

Description

technical field [0001] The invention relates to a method for reusing rare earth to extract and separate saponification waste water for washing organic matter and preparing stripping liquid and lotion, and belongs to the field of rare earth hydrometallurgy. Background technique [0002] Rare earth extraction and separation using P 507 ,P 204 , naphthenic acid, etc. as the extraction agent, the saponification agent uses ammonia water, ammonium bicarbonate, sodium hydroxide, sodium carbonate, calcium oxide, magnesium oxide, and the saponified extraction agent enters the rare earth saponification section of the extraction and separation process to produce ammonium chloride , sodium chloride, calcium chloride, magnesium chloride wastewater, the salt content of these wastewaters is low, and a large amount of water needs to be evaporated to crystallize the recovered salt, which requires high energy consumption and large investment in equipment. [0003] The rare earth extraction ...

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Problems solved by technology

[0002] Rare earth extraction and separation using P 507 ,P 204 , naphthenic acid, etc. as the extraction agent, the saponification agent uses ammonia water, ammonium bicarbonate, sodium hydroxide, sodium carbonate, calcium oxide, magnesium oxide, and the saponified extraction agent enters the rare earth saponification section of the extraction and separation process to produce ammonium chloride , sodium chloride, calcium chloride, magnesium chloride wastewater, the salt content of these wastewaters is low, and a large amount of water needs to be evaporated to crystallize the recovered salt, which requires high energy consumption and large investment in equipment

[0003] The rare earth extraction and separation process uses fresh water to wash the organic matter. After washing the organic matter, the washing residue contains 0.5-3mol / L acidic aqueous solution. Since the amount of the washing residue is relatively large, except for dissolving mixed rare earth carbonate, the remaining part is discharged as waste water; Fresh water is used to prepare stripping liquid and washing liquid separately. The process consumes a large amount of fresh water and increases the amount of waste water discharge, resulting in low concentration of ammonium chloride or sodium chloride in waste water. Recover ammonium chloride or sodium chloride from waste water high energy consumption

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