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A method for preparing high-purity rare earth oxide by using composite precipitant

A composite precipitant and rare earth oxidation technology, which is applied in the preparation/treatment of rare earth metal compounds, rare earth metal oxides/hydroxides, etc., can solve the problems of large consumption of precipitants, easy to leak, and affect production efficiency

Active Publication Date: 2021-09-14
GANZHOU NONFERROUS METALLURGICAL RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, using sodium carbonate or sodium bicarbonate as a precipitating agent is easy to form amorphous precipitation, contains a large amount of water and impurities, is difficult to filter and wash, and the product purity is low; especially when sodium carbonate precipitates, it is difficult to control, and it is easy to generate local over-alkali Oxidation of rare earth to form a paste-like product, poor crystallinity, long crystallization conversion time, longer aging time, Na + , Cl - It is not easy to wash, and it is easy to cause the impurities in the oxide to exceed the standard; sodium bicarbonate as a precipitant will produce a large amount of CO 2 The consumption of gas and precipitant is large, the utilization rate is low, and it is easy to leak, which will affect the production efficiency

Method used

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  • A method for preparing high-purity rare earth oxide by using composite precipitant
  • A method for preparing high-purity rare earth oxide by using composite precipitant
  • A method for preparing high-purity rare earth oxide by using composite precipitant

Examples

Experimental program
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Effect test

Embodiment 1

[0041] First add 200mL deionized water to the 15L keg, add 100g lanthanum carbonate seed crystals, prepare 3728mL lanthanum chloride feed liquid, REO concentration is 100g / L, 5950mL composite precipitant solution (195g sodium bicarbonate+485g sodium carbonate , mNaHCO 3 :mNa 2 CO 3 =0.4:1), the concentration is 114.3g / L, and the temperature is 20°C. Under appropriate stirring conditions, first add the lanthanum chloride feed solution until the pH value of the feed solution in the container is less than 4, and then control the flow rate of the lanthanum chloride feed solution The flow rate ratio of the precipitant and the precipitant is about 1:2, and the flow between the two should be properly adjusted to control the pH range of the precipitation process to be 4 to 5.5 until the solution is added, and the final pH value is 6.5 to 7.5, then stop stirring and let it stand for a while. After 2 hours, filter with suction, wash the precipitate with deionized water to obtain rare ...

Embodiment 2

[0043] First add 200mL deionized water to the 15L keg, add 100g lanthanum carbonate seed crystals, prepare 3728mL lanthanum chloride feed liquid, REO concentration is 100g / L, 5950mL composite precipitant solution (108g sodium bicarbonate+540g sodium carbonate , mNaHCO 3 :mNa 2 CO 3 =0.2:1), the concentration is 108.9g / L, and the temperature is 20°C. Under proper stirring conditions, first add the lanthanum chloride feed solution until the pH value of the feed solution in the container is less than 4, and then control the flow rate of the lanthanum chloride feed solution The flow rate ratio of the precipitant and the precipitant is about 1:2. Properly adjust the flow between the two, and control the pH range of the precipitation process to be 4-5.5 until the solution is added, and the final pH value is 6.5-7.5. Stop stirring and age for 2 hours. Filtrate with suction, wash the precipitate with deionized water to obtain rare earth carbonate, and finally burn at 850°C for 2 hou...

Embodiment 3

[0045] Get 8.4kg sodium bicarbonate and 41.9kg sodium carbonate (mNaHCO 3 :mNa 2 CO 3 =0.2:1) was dissolved in a 1000L liquid mixing tank, added 370L water to prepare a composite precipitant, the concentration was 135g / L, put it into a high-level storage tank for subsequent use, prepared lanthanum chloride feed solution 350L, and its REO concentration was measured to be 131.9 g / L, the initial pH value is 1.8. Pre-add deionized water in the precipitation tank to cover the stirring paddle, add 10kg of lanthanum carbonate seed crystals, start stirring, first add the lanthanum chloride feed solution until the pH value of the feed solution in the precipitation tank is less than 4, then add the lanthanum chloride feed solution and Composite precipitant solution, properly adjust the flow between the two, control the pH range of the precipitation process to be 4 to 5.5, until the feed liquid is added, the end point pH is 6.5 to 7.5, stop stirring, age for 2 hours, filter with suctio...

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Abstract

The invention relates to the technical field of rare earth hydrometallurgy, and provides a method for preparing high-purity rare earth oxide by using a composite precipitant. In the present invention, the seed crystal is first added to the reactor, and then the rare earth chloride feed liquid and the composite precipitant solution are added to carry out precipitation reaction, and then aging, liquid-solid separation and washing are carried out in sequence, and the obtained rare earth carbonate is burned to obtain high-purity oxidation Rare earth; the composite precipitation agent used in the present invention includes sodium bicarbonate and sodium carbonate, and the mass ratio of sodium bicarbonate and sodium carbonate is 0.2~10:1. The present invention uses a composite precipitant to precipitate rare earth chloride, which can comprehensively utilize the advantages of sodium bicarbonate and sodium carbonate, reduce the generation of carbon dioxide during sodium bicarbonate precipitation, reduce the risk of bubbles escaping into the tank, and prevent sodium carbonate from being too alkaline to Rare earth hydroxide is produced as a pasty product, and rare earth carbonate with good crystallinity, stable crystal form, narrow particle size distribution and low impurity content is prepared. The high-purity rare earth oxide obtained after burning is better than the national standard.

Description

technical field [0001] The invention relates to the technical field of rare earth hydrometallurgy, in particular to a method for preparing high-purity rare earth oxide by using a composite precipitant. Background technique [0002] Rare earth elements are widely used in petroleum, chemical industry, metallurgy, textile, ceramics, glass, permanent magnet materials and other fields, and with the advancement of science and technology, the value of rare earth oxides will increase. The preparation method of rare earth oxide is generally to add a precipitant to the rare earth solution, and then burn the precipitated rare earth compound to obtain the rare earth oxide. In order to produce rare earth oxides with high purity, it is necessary to precipitate rare earth compounds with good crystallinity, stable crystal form, narrow particle size distribution and low impurity content during the rare earth precipitation process. At present, rare earth precipitation usually adopts the oxal...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01F17/206C01F17/10
CPCC01P2006/80C01P2004/03C01P2004/61C01P2002/72C01F17/206
Inventor 张积锴陈东英周洁英赖兰萍陈后兴洪侃王明
Owner GANZHOU NONFERROUS METALLURGICAL RES INST