Method for recycling rare earth metal from waste fluorescent powder

A technology of rare earth metals and recycling methods, which is applied in the direction of improving process efficiency, etc., and can solve problems affecting continuous operation, dispersion of rare earth metals, and difficult elution of amphoteric metal impurities.

Active Publication Date: 2015-11-25
荆门格林循环电子废弃物处置有限公司
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  • Abstract
  • Description
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  • Application Information

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Problems solved by technology

[0004] Among them, in the method of alkali fusion-water washing and pH adjustment, hydrolysis and sedimentation, on the one hand, the amount of water used is relatively large, and on the other hand, the pH of the washing solution is difficult to control, which affects continuous operation. Too high pH of the solution promotes the dissolution and dispersion of some rare earth hydroxides. If the pH of the solution is too low, it is difficult to elut

Method used

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  • Method for recycling rare earth metal from waste fluorescent powder

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Effect test

Embodiment 1

[0045] S10. Add hydrochloric acid with a concentration of 6M to the raw material according to the ratio of solid-liquid volume ratio of 1:6, and stir and dissolve at 75°C; add saturated sodium chlorate solution according to the mass ratio of raw material to sodium chlorate of 1:0.3 . After 3 hours, extract the leaching solution by suction filtration, and test the leaching solution.

[0046] The results are as follows: in the leaching solution, yttrium is 12.81g / L, europium is 854mg / L, zinc is 19.97g / L, aluminum is 482.5mg / L, calcium is 620.5mg / L, lead is 484.0mg / L, and the leaching rate is higher than 99%.

[0047] S20, feed liquid ammonia into the leaching solution until the pH value of the solution is 8, during the process of adding liquid ammonia, the pH value of the solution increases, the rare earth metals and most of the non-rare earth metals form hydroxide precipitates, and the zinc and ammonia form a complex combined to generate soluble zinc ammonium complex ions; an...

Embodiment 2

[0054] S10, add hydrochloric acid with a concentration of 8M to the raw material according to the ratio of solid-liquid volume ratio of 1:8, and stir and dissolve at 60°C; add saturated sodium chlorate solution according to the mass ratio of raw material to sodium chlorate of 1:0.2 . After 2.5 hours, extract the leaching solution by suction filtration, and test the leaching solution.

[0055] The results are as follows: in the leaching solution, yttrium is 11.81g / L, europium is 824mg / L, zinc is 17.92g / L, aluminum is 445.5mg / L, calcium is 672.5mg / L, and lead is 520.0mg / L. The leaching rate is higher than 95%.

[0056] S20. Pass liquid ammonia into the leaching solution until the pH value of the solution is 9, and then filter to obtain a first filtrate and a first filter residue.

[0057] S30, adding 10% sodium hydroxide solution to the first filter residue obtained in S20 to dissolve, and adjusting the pH of the solution to 14, mixing and stirring for 3 hours and filtering to...

Embodiment 3

[0064] Add nitric acid with a concentration of 4M to the raw material according to the solid-liquid volume ratio of 1:5, and stir and dissolve at 85°C; add hydrogen peroxide according to the mass ratio of raw material to hydrogen peroxide at 1:0.4. After 3 hours, extract the leachate by suction filtration.

[0065] S20, feed liquid ammonia into the leaching solution until the pH value of the solution is 10, during the process of adding liquid ammonia, the pH value of the solution rises, the rare earth metals and most of the non-rare earth metals form hydroxide precipitates, and zinc and ammonia form a complex combined to generate soluble zinc ammonium complex ions; and then filtered to obtain the first filtrate and the first filter residue.

[0066] S30, add the first filter residue obtained in S20 to ultrapure water at a weight ratio of 1:2.5 for slurrying, then add 10% sodium hydroxide solution to the slurrying solution and control the pH to 13.5, mix and stir for 2.5 hours ...

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Abstract

The invention provides a method for recycling rare earth metal from waste fluorescent powder. The method includes the steps that the waste fluorescent powder is subjected to acidic leaching, and a leaching agent is obtained through filtration; the leaching agent is subjected to ammonia leaching processing, and a first filter residue and first filter liquor are obtained through filtration; the first filter residue is processed with alkali liquor, the solution pH is adjusted to be higher than 12.5, and a second filter residue and second filter liquor are obtained through filtration; the second filter residue is subjected to acid hydrolysis, the solution pH is adjusted to 3.5-4.5, then non-rare-earth metal precipitator is added for precipitation, and a third filter residue and third filter liquor are obtained through filtration; the third filter liquor is subjected to ammonium hydrocarbonate precipitation, and precipitate is taken; and the precipitate is roasted, and the rare earth metal oxide is prepared. According to the method for recycling rare earth metal from waste fluorescent powder, the rare earth metal in the waste fluorescent powder is extracted in an acidic leaching manner, the leaching rate reaches up to more than 99%. Zinc, aluminum and other non-rare-earth metal are removed from the leaching agent step by step, zinc and aluminum can be recycled step by step, and resource regeneration is achieved; and the technology can save energy and reduce emission, and is low in cost, reasonable and easy to implement.

Description

technical field [0001] The invention belongs to the technical field of metal resource recycling, and in particular relates to a method for recycling rare earth metals in waste fluorescent powder. Background technique [0002] Due to the preciousness and scarcity of rare earth resources, it has become more and more necessary to recover rare earth metals from discarded items. Phosphor powders that help to display in many discarded lighting appliances, computers, televisions, mobile phones and other products contain relatively large amounts of rare earth metals, so waste phosphor powders have gradually become an important raw material choice for rare earth metal recovery. [0003] However, the zinc and aluminum impurities generally contained in phosphor powder are much higher than the content of other non-rare earth metals. Therefore, the existing processes for rare earth extraction from waste phosphor powder need to achieve effective removal of zinc and aluminum impurities dur...

Claims

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Application Information

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IPC IPC(8): C22B7/00C22B59/00C22B19/30C22B21/00
CPCY02P10/20
Inventor 冯浩张云河苏陶贵郭苗苗王尝杨文翠
Owner 荆门格林循环电子废弃物处置有限公司
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