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Method for recycling waste rare earth polishing powder and rare earth polishing liquid

A rare earth polishing powder and rare earth polishing technology, which is applied in the field of rare earth polishing liquid, can solve the problems of polluting the surrounding environment, waste of rare earth resources, and low recycling rate, and achieve the effects of resource saving, easy operation, and high cutting rate

Active Publication Date: 2015-02-25
包头中科雨航抛光材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The commercially available polishing powder is divided into two categories according to the content of CeO2, one is CeO2≥80%, the other is CeO2≤65%. At present, most of the relevant factories in my country use about 65% of the powder, which is discarded as waste after use, which not only causes a waste of rare earth resources, but also pollutes the environment.
[0004] There are many ways to separate cerium from mixed rare earth oxides. For example, Chinese patent CN1194060C discloses "preparation method of regenerated rare earth polishing powder", which adopts " Sulfuric acid method", its technology is outdated, its recycling rate is low, its energy consumption is high, and it seriously pollutes the surrounding environment
CN101353178B discloses a method for recovering rare earth hydroxides or oxides, wherein strong acid and hydrogen peroxide are used, but it needs to use oxalate or carbonate, the process steps are more, the water consumption and energy consumption are high, and the prepared The ratio of trivalent cerium oxides in rare earth oxides is relatively high, resulting in low quality of recovered rare earth oxides as raw materials for rare earth polishing fluids

Method used

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  • Method for recycling waste rare earth polishing powder and rare earth polishing liquid
  • Method for recycling waste rare earth polishing powder and rare earth polishing liquid
  • Method for recycling waste rare earth polishing powder and rare earth polishing liquid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Get 40 grams of ground waste polishing powder, the ingredients of which are shown in Table 1, place the ground waste polishing powder in a beaker, add 120 milliliters of nitric acid solution with a concentration of 63 wt%, stir at 80 ° C, and pass through a pipe to the bottom of the solution, gradually add H 2 o 2 15 mL of hydrogen peroxide with a volume concentration of 30% to obtain a solution containing rare earth elements, and then remove insoluble substances; continue stirring and add ammonia (NH 3 :H 2 O=1:1) adjust the pH to 5.5, heat to 55°C, add 10mL of H 2 o 2 Hydrogen peroxide with volume concentration of 30%, add 1.0 g Ce(OH) 4 Then heated to 80°C, stirred and left for 10 hours, washed the precipitate with water until neutral, filtered, dried to obtain hydroxide; then roasted at 950°C for 3 hours, and sieved to obtain rare earth particles with a particle size of less than 2 μm Oxides, the composition of the rare earth oxides is shown in Table 1.

Embodiment 2

[0039] Take 40 grams of ground waste polishing powder, the ingredients of which are shown in Table 1, place the ground waste polishing powder in a beaker, add 130 milliliters of nitric acid solution with a concentration of 63 wt%, stir at 60 ° C, and pass through a pipe to the bottom of the solution, gradually add H 2 o 2 18 mL of hydrogen peroxide with a volume concentration of 30% was obtained to obtain a solution containing rare earth elements, and then the insoluble substances were removed; then continue to stir and add ammonia (NH 3 :H 2O=1:1) adjust the pH value to 6.0, heat to 50°C, add 8 mLH 2 o 2 Hydrogen peroxide with volume concentration of 30%, add 1.0 g Ce(OH) 4 Then heated to 80°C, stirred and left for 8 hours, washed the precipitate with water until neutral, filtered, dried to obtain hydroxide; then roasted at 900°C for 3 hours, and sieved to obtain rare earth particles with a particle size of less than 2 μm Oxides, the composition of the rare earth oxides ...

Embodiment 3

[0045] This embodiment relates to the surface treatment of nano-scale ceria powder, which comprises the following steps

[0046] (1) Add a modifier whose mass is 10wt% of nano-sized ceria powder into deionized water, and stir for 15 minutes at a stirring speed of 800~1000 rpm to form the first system with a concentration of 2.0wt%;

[0047] (2) Disperse the nano-sized ceria powder and acryloyloxyethyltrimethylammonium chloride with a mass of 8wt% of the nano-sized ceria powder in a The second system is obtained in the glycidyl methacrylate; the quality of the glycidyl methacrylate is 3.0 times the quality of the nano-sized cerium dioxide powder;

[0048] (3) Add the second system obtained in step (2) to the first system obtained in step (1), stir at a stirring speed of 1800~2000 rpm for 25 min to obtain a mixed solution, and transfer it to the reactor, N 2 Under the protection of the atmosphere, add dilauroyl peroxide with 0.5wt% glycidyl methacrylate mass under continuous s...

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Abstract

The invention relates to a method for recycling waste rare earth polishing powder. The method comprises the following steps: mixing waste rare earth polishing powder with nitric acid, and adding hydrogen peroxide to the bottom of a liquid; heating to dissolve the waste rare earth polishing powder, so as to obtain a liquid containing a rare-earth element; adding ammonium hydroxide to the obtained liquid containing the rare-earth element and adjusting the pH value to be 5.0-6.0; adding hydrogen peroxide under a heating condition, and then adding a little of suspension liquid of Ce(OH)4; stirring and standing to obtain a rare earth hydroxide sediment; and roasting to obtain a rare earth oxide, and then grinding the rare earth oxide until the particle size is smaller than 2 microns. The rare-earth polishing liquid prepared from the rare earth oxide recycled by the method can be applied to high-precision grinding and polishing processes of glass, sapphire, resin lenses and semiconductor substrates, and has the advantages of high polishing efficiency, high polishing accuracy and high cutting rate.

Description

technical field [0001] The invention relates to the technical field of surface polishing treatment, more specifically, the invention relates to a method for recycling waste rare earth polishing powder and a rare earth polishing liquid. Background technique [0002] Rare earth oxides have a wide range of uses, one of which is as an efficient and high-quality polishing material for glass or semiconductor wafers. In recent years, the domestic demand alone is more than 35,000 tons per year, resulting in a large amount of waste rare earth polishing powder. [0003] The rare earth polishing powder used in the polishing liquid is a mixed light rare earth oxide, the main component is CeO 2 , La 2 o 3 , Pr 6 o 11 ,Nd 2 o 3 wait. Polishing performance of polishing powder and CeO 2 content are closely related. Commercially available polishing powder according to CeO 2 The content is divided into two categories, one is CeO 2 ≥80%, the other type is CeO 2 ≤65%. At present, m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09G1/02
CPCC09G1/02
Inventor 张海龙王用堂张磊
Owner 包头中科雨航抛光材料有限公司
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