Method and system for preparing cerium hydroxide

A cerium hydroxide, preparation system technology, applied in chemical instruments and methods, inorganic chemistry, rare earth metal compounds, etc., can solve the problems of inability to meet high-end quality requirements, difficult to filter cerium hydroxide, low purity of cerium hydroxide, etc. Easy to filter and dry, the solution is clear and transparent, and the price is low

Active Publication Date: 2014-07-09
江西金世纪新材料股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The methods for producing cerium hydroxide disclosed by CN87100620A, CN1075171A, CN1269327A, and CN1048239A all start from mixed rare earth feed liquid, and the obtained cerium hydroxide is difficult to filter and the product has low purity, which will entrain and wrap Na + , Mn 2+ , SO 4 2- and other rare earth impurities, etc., making the purity of cerium hydroxide obtained by these methods low
[0006] The preparation method of cerium hydroxide disclosed by CN1635169A can improve the quality grade of the product, but its product oxidation rate is on the low side, especially Cl hydroxide - High, low total, high nitrate
This cannot meet the high-end quality needs of domestic and foreign customers at all

Method used

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  • Method and system for preparing cerium hydroxide
  • Method and system for preparing cerium hydroxide

Examples

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preparation example Construction

[0063] Such as Figure 1-2 Shown, in one embodiment, the preparation method according to cerium hydroxide of the present invention comprises the following steps:

[0064] 1. Quantitatively put high-purity cerium carbonate 1 (>99.99%) into the reaction kettle 2, add nitric acid 3 to dissolve, pay attention to oil removal during the dissolution process, after the dissolution is complete, adjust the pH value to 4.5- 5.5 (for example, about 5), heat up, and carry out hydrolysis to remove impurities. The input ratio of high-purity cerium carbonate and nitric acid is about 1:3 by molar ratio.

[0065] 2. The hydrolyzed feed liquid (inject secondary water through the water injection port 4) adjusts the feed liquid concentration to 1-1.5M (for example, about 1), and puts it into the primary airtight filter tank 5 to filter (preferably, double-layer filter cloth with filter paper in between).

[0066] 3. The filtrate after the primary filtration enters the secondary airtight filter ...

example 1

[0093] Cerium carbonate with a purity of 4N is mixed with secondary water, dissolved in nitric acid, hydrolyzed, and configured to contain CeO 2 The feed liquid of about 170g / l is filtered for the second time, transferred to the storage tank with a precision filter pump for storage, and left to stand for about 15 days. Transfer the static material liquid into the precipitation reaction kettle, adjust the concentration to 0.2-0.4M with secondary water, and convert it to hydrogen peroxide with ammonia water to completely oxidize it, keep it at 100°C for one hour, soak it in 3-5N hot ammonia water, and then Wash twice with hot secondary water, drain and transfer to an oven, and dry at a constant temperature of 90-95°C for several hours (for example, 24 hours).

[0094] The cerium hydroxide sample obtained by this step has an oxidation rate of 99.9%, is easily soluble in nitric acid, the total amount is 90.5%, bright yellow powder, excellent fluidity, and generally non-rare earth ...

example 2

[0096] Cerium carbonate with a purity of 4N is mixed with secondary water, dissolved in nitric acid, hydrolyzed, and configured to contain CeO 2 The feed liquid of about 170g / l is filtered for the second time, transferred to the storage tank with a precision filter pump for storage, and left to stand for about 15 days. Transfer the static material liquid into the precipitation reaction kettle, adjust the concentration to 0.2-0.4M with secondary water, and convert it to hydrogen peroxide with ammonia water for complete oxidation, keep it at 100°C for one hour, and wash it directly with hot secondary water for 2-3 Then, drain and transfer to an oven, and dry at a constant temperature of 90-95°C for several hours (for example, 24 hours).

[0097] The cerium hydroxide sample obtained by this step has an oxidation rate of 99.9%, is easily soluble in nitric acid, the total amount is 90.5%, bright yellow powder, excellent fluidity, and generally non-rare earth impurities - 4 2- <10p...

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Abstract

The invention discloses a method for preparing cerium hydroxide. The method is characterized by comprising the following steps: dissolving cerous carbonate of which the purity is greater than 99.99% as a raw material by using nitric acid to obtain cerium nitrate feed liquid; carrying out hydrolysis to remove impurities in the dissolving process, and filtering for at least two times; filtering the obtained filtrate by using a precision filter, and transferring into a storage container to stand for a plurality of days, wherein the content of general non-rare earth impurities of the obtained cerium nitrate feed liquid is smaller than 5ppm; transforming the purified feed liquid into cerium hydroxide by taking ammonium hydroxide as a transforming agent and hydrogen peroxide as an oxidant; soaking and washing by strong alkalinity liquid to remove nitrate; filtering prepared cerium hydroxide; washing a filter cake by overheated secondary water, and pumping; putting the filtered material into an oven, and baking at 90-95 DEG C for a plurality of times, so as to obtain a cerium hydroxide product with over-high purity and ultra-high gross. According to the cerium hydroxide product prepared by the method, the nitrate content is smaller than 500ppm; the rate-earth purity is greater than 99.99%; the content of general non-rare earth impurities is smaller than 10ppm; the Cl<-> content is smaller than 10ppm; the SO4<2-> content is smaller than 10ppm; the oxidation rate is 98-99.9%; the oxide gross is greater than 90%.

Description

technical field [0001] The invention relates to a method and system for preparing ultra-high-purity and ultra-high-total cerium hydroxide, and belongs to the field of hydrometallurgy for rare earth production. Background technique [0002] Cerium hydroxide is an important industrial raw material. It is used as an additive for color TV fluorescent screens. It can change the toughness, strength and other optical properties of fluorescent glass. It can also be used to prepare ammonium cerium nitrate and many other uses. [0003] The international market has put forward higher and higher requirements for the quality of cerium hydroxide, for example: rare earth purity >99.99%, non-rare earth impurities generally <10ppm, CL - <10ppm, SO 4 2- <10ppm, nitrate <2000ppm, total oxides of cerium hydroxide >80%, good acid solubility, etc. [0004] However, in the prior art, the technology for producing cerium hydroxide is difficult to meet such high requirements. Es...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F17/00
Inventor 姜亚龙李常清詹海波陶利明张五国王文
Owner 江西金世纪新材料股份有限公司
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