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Method for preparing rare earth oxide powder by oxidizing and roasting rare earth mixture

A technology of rare earth mixtures and rare earth oxides, which is applied in the preparation/treatment of rare earth metal compounds, rare earth metal oxides/hydroxides, preparation of chlorides, etc. It is easy to operate, conducive to large-scale promotion and application, and achieves the effect of efficient utilization

Pending Publication Date: 2022-01-28
FUJIAN CHANGJIANG GOLDEN DRAGON RARE EARTH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In view of the disadvantages of high cost, poor quality and high environmental protection pressure of rare earth oxides in the prior art, the purpose of the present invention is to provide a method for preparing rare earth oxide powders by oxidizing and roasting rare earth mixtures

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Add 4.8kg yttrium cerium nitrate ((Y 0.9 Ce 0.1 )(NO 3 ) 3 ·6H 2 O, AR), and then heated to 275 ° C for 2 h. Measured precursor band 3.5H 2 O, the molar ratio of crystallization water to nitrate in the precursor is 0.3:1, then the roasted product is ball milled and sieved through a 250-mesh sieve, and the oversize is returned to the ball mill for crushing. The particle size of the precursor after crushing is 56um , the undersize is the precursor. Put this precursor into the roasting furnace, raise the temperature to 850°C, and let air in, the air humidity is 75-85%, and the air flow rate is 120L / min. After reacting for 3 hours, cooling down, the yttrium cerium oxide product with an average particle size of 0.86um can be obtained, the particle size is finer, and the particle size distribution is narrower, the purity is higher, the content of rare earth chloride is 40ppm, and the total amount of rare earth is greater than 99.5%.

Embodiment 2

[0033] Add 6.0kg yttrium cerium chloride ((Y 0.85 Ce 0.15 ) Cl 3 ·7H 2 O, AR), and then heated to 350 °C for 3.5 h. Precursor band 3H was measured 2 O, the molar ratio of crystallization water to chlorine in the precursor is 0.6:1, then the roasted product is crushed by ball milling, and sieved through a 300-mesh screen, and the oversize is returned to the ball mill for crushing. The particle size of the crushed precursor is 23um. The undersize is the precursor. Put this precursor into the roasting furnace, raise the temperature to 600°C, and let air in, the air humidity is 80-90%, and the air flow rate is 280L / min. After reacting for 2 hours, cooling down, the yttrium cerium oxide product with an average particle size of 0.42um can be obtained. The particle size distribution is relatively uniform and the purity is high. The rare earth chloride content is 43ppm and the total rare earth content is greater than 99.5%.

Embodiment 3

[0038] Add 4.8kg samarium gadolinium chloride ((Sm 0.9 Gd 0.1 ) Cl 3 ·6H 2 O, AR), and then heated to 350 °C for 5 h. Precursor band 3H was measured 2 O, the molar ratio of crystallization water to chlorine in the precursor is 0.5:1, then the roasted product is ball milled and sieved through a 250-mesh screen, and the oversize is returned to the ball mill for crushing. The particle size of the crushed precursor is 35um. The undersize is the precursor. Put this precursor into the roasting furnace, raise the temperature to 1060°C, and let air in, the air humidity is 85-95%, and the air flow rate is 350L / min. After reacting for 5 hours, cooling down, the samarium-gadolinium oxide product with an average particle size of 1.22um can be obtained, which has a high purity, a rare earth chloride content of 38ppm, and a total rare earth content of more than 99.5%.

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PUM

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Abstract

The invention relates to a method for preparing rare earth oxide powder by oxidizing and roasting a rare earth mixture, which comprises the following steps of: roasting the rare earth mixture containing rare earth chloride, nitrate or sulfate in an air atmosphere to obtain the rare earth oxide powder, wherein the roasting in the air atmosphere is divided into a first-stage roasting and a second-stage roasting, the first-stage roasting is to roast the rare earth mixture at 250-400 DEG C to obtain a precursor, the second-stage roasting is to roast the precursor by heating to 600-1200 DEG C, the air humidity is greater than 60%, and the rare earth oxide powder is obtained; the tail gas generated in the second-stage roasting is absorbed to obtain an inorganic acid by-product rare earth mixture. The method has the advantages of being simple in process, environmentally friendly, good in product performance and the like, and has a good industrial application prospect.

Description

technical field [0001] The invention belongs to the field of powder material preparation, and relates to a method for preparing rare earth oxide powder by oxidizing and roasting a rare earth mixture, in particular to a preparation method for high-purity rare earth oxide powder. Background technique [0002] China is currently the main producer of rare earths in the world, and more than 80% of rare earths are produced in China. In 2016, the output of rare earth smelting and separation products in China was 105,000 tons, accounting for about 88.2% of the world's total output. Rare earth oxide is the most important application form of rare earth, which is mainly used in high-performance catalytic materials, ultraviolet absorbing materials and luminescent materials and other fields. About 75% of the world's rare earths enter the consumption chain in the form of oxides. Therefore, for a long time, Chinese scientific and technological workers have devoted themselves to the resea...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F17/241C01F17/10C01B21/42C01B7/03
CPCC01F17/241C01F17/10C01B21/42C01B7/03C01P2006/80C01P2004/62
Inventor 李玉虎赵德森吴海洋李来超叶纪龙
Owner FUJIAN CHANGJIANG GOLDEN DRAGON RARE EARTH CO LTD
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