Method for comprehensively recycling rare earth oxalate precipitate waste liquid

A technology of oxalic acid precipitation and waste liquid, applied in the field of rare earth, can solve the problem of reducing the evaporation temperature of dilute acid, and achieve the effects of less acid gas leakage, prolonging service life, and reducing processing and operating costs

Inactive Publication Date: 2011-01-05
江西明达功能材料有限责任公司
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  • Abstract
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  • Application Information

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Problems solved by technology

[0007] The present invention adopts the method of vacuum evaporation. By controlling the appropriate vacuum degree, the boiling point of the material is lowered, and the evaporation temperature of dilute acid is lowered, so that the evaporati

Method used

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  • Method for comprehensively recycling rare earth oxalate precipitate waste liquid
  • Method for comprehensively recycling rare earth oxalate precipitate waste liquid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] will contain C HCl =1.88mol / L, C 草酸 =15.1g / L, 4m of dysprosium oxalate precipitation waste liquid of REO=0.77g / L 3 join 5m 3 After heating to 50°C in a jacketed enamel reaction tank, evaporate and concentrate under the condition of -0.08Mpa (table) and gradually heat up to a maximum of 95°C to evaporate and recover hydrochloric acid; when the volume of waste liquid is concentrated to 8%, stop evaporation; concentrate The remaining liquid is filtered while it is hot at 70°C. After recovering dysprosium oxalate, the filtrate is cooled and crystallized to recover oxalic acid; the residual liquid after recovering oxalic acid is incorporated into the next evaporation and concentrated. Total recovered C HCl =1.74mol / L hydrochloric acid 3.68m 3 , the recovery rate of hydrochloric acid is 85.15%; 50kg of oxalic acid is recovered, and the recovery rate of oxalic acid is 88.78%; the recovered dysprosium oxalate is equivalent to REO 3.02kg, and the recovery rate of dysprosium ...

Embodiment 2

[0029] will contain C HCl =0.86mol / L, C 草酸 =10.6g / L, REO=0.71g / L praseodymium neodymium oxalate precipitation waste liquid 4m 3 join 5m 3 After heating to 50°C in a jacketed enamel reaction tank, evaporate and concentrate under the condition of -0.03MPa (table) and gradually heat up to a maximum of 105°C to recover hydrochloric acid by evaporation; when the volume of waste liquid is concentrated to 5%, stop evaporation; after concentration The remaining solution is filtered while hot at 95°C, and after recovering praseodymium and neodymium oxalate, the filtrate is cooled and crystallized to recover oxalic acid; the residual solution after recovering oxalic acid is incorporated into the next evaporation and concentration. Total recovered C HCl =0.82mol / L hydrochloric acid 3.8m 3 , the recovery rate of hydrochloric acid is 90.58%; 32kg of oxalic acid is recovered, and the recovery rate of oxalic acid is 75.47%; the recovery rate of praseodymium neodymium oxalate is equivalen...

Embodiment 3

[0031] will contain C HCl =2.44mol / L, C 草酸 =28.3g / L, yttrium europium oxalate precipitation waste liquid 4m of REO=0.83g / L 3 join 5m 3 After heating to 50°C in the enamel reaction tank, evaporate and recover hydrochloric acid under the conditions of -0.01MPa (table) and 50°C. When the waste liquid volume is concentrated to 30%, stop evaporation; the concentrated residual liquid is filtered while hot at 50°C After recovering yttrium and europium oxalate, the filtrate is cooled and crystallized to recover oxalic acid; the raffinate after recovery of oxalic acid is incorporated into the next evaporation and concentration. Total recovered C HCl =2.04mol / L hydrochloric acid 3.76m 3 , the recovery rate of hydrochloric acid is 78.59%; 53kg of oxalic acid is recovered, and the recovery rate of oxalic acid is 46.8%; 2.13kg of yttrium europium oxalate (calculated as REO) is recovered, and the recovery rate of yttrium europium oxalate is 64.16%; The index of impurity content in ", t...

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Abstract

The invention relates to a method for comprehensively recycling rare earth oxalate precipitate waste liquid, which is characterized by treating and comprehensively recycling the waste water of rare earth oxalate precipitate mother liquid according to the characteristics of oxalic acid and oxalate rare earth in a hydrochloric acid system and based on the principle of the common evaporation of hydrogen chloride and water. The separation and recovery of the hydrochloric acid, the hydrochloric acid and the oxalic acid are realized by a method of vacuum evaporation, condensation, filtration, and cooling crystallization. The method of the invention has the advantages that: many types of rare earth oxalate precipitate waste liquid can be processed; a process is simple; the generation of acidic waste water and environment pollution is reduced and the hydrochloric acid, the oxalic acid and rare earth are recycled at the same time; and wastes are comprehensively recycled and good economical and social benefit is created simultaneously.

Description

technical field [0001] The invention relates to a method for comprehensive recovery and utilization of rare earth oxalic acid precipitation waste liquid, belonging to the technical field of rare earth. Background technique [0002] In the rare earth production process, the separated and purified rare earth feed liquid (usually rare earth chloride feed liquid) is often precipitated with oxalic acid, and the rare earth oxalate precipitate is burned to obtain rare earth products. The above process produces rare earth oxalic acid precipitation waste liquid, which is mainly a mixed solution composed of hydrochloric acid, oxalic acid and rare earth oxalate. The waste liquid contains hydrochloric acid, oxalic acid and a small amount of oxalic acid rare earth and non-rare earth impurities such as iron and aluminum. It has the characteristics of large amount of waste liquid, high acidity, strong corrosion, low concentration of valuable elements and toxicity. Discharge will cause ser...

Claims

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Application Information

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IPC IPC(8): C22B7/00C22B59/00
Inventor 蔡志双刘钧云龚斌王功秒谢楠
Owner 江西明达功能材料有限责任公司
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