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A method for recovering rare earth elements from waste rare earth grinding materials

A technology for grinding materials and rare earth elements, applied in the direction of improving process efficiency, can solve problems such as acid gas environmental pollution, and achieve the effect of reducing pollution and reducing dosage

Inactive Publication Date: 2011-12-28
BAOTOU XINYUAN RARE EARCH HI TECH NEW MATERIAL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when sulfuric acid is roasted at high temperature, part of it is directly volatilized into the atmosphere, and part of it is decomposed into SO 3 The formation of acid gas will cause serious pollution to the environment

Method used

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  • A method for recovering rare earth elements from waste rare earth grinding materials
  • A method for recovering rare earth elements from waste rare earth grinding materials
  • A method for recovering rare earth elements from waste rare earth grinding materials

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] 2 tons of waste polishing material mixture, TREO=17wt%, add 280 kilograms of industrial sulfuric acid of 92wt%, 50 kilograms of industrial pure ammonium chloride, 85 kilograms of magnesium sulfates, fully stir, put into iron sagger at 350 ℃ and burn 2 hours, Cool down to room temperature, take it out, mechanically crush it to 80 mesh, put it in 20m 3 FRP water immersion tank, add 12m 3 Water, start stirring and soaking in water for 40 minutes, add 50 kg of magnesium oxide to adjust the pH value to 2.5-3, plate and frame filter, filter cake with 3m 3 Wash once with water, and put the lotion into the water immersion solution. It was measured that REO=4.8wt% in the filter cake (after drying at 110°C) after washing with water, and REO=19.5g / L in the soaking liquid.

[0036] The above water immersion liquid is used as the feed liquid for solvent extraction. Specific process parameters: organic phase PC-88A, 1.5 mole, kerosene as diluent, sodium hydroxide saponification, sa...

Embodiment 2

[0047] 2 tons of waste polishing material mixture, TREO=26wt%, add 400 kilograms of industrial sulfuric acid of 92wt%, 80 kilograms of industrial pure ammonium chloride, 130 kilograms of magnesium sulfates, fully stir, put into iron sagger at 380 ℃ and burn 2 hours, All the other steps are with embodiment 1.

[0048] Rare earth yield: 689 kg of dry slag was obtained through the above process, and the total amount of rare earth in the slag was 4.2wt%, so the rare earth in the slag was 28.93 kg, and the yield was 94.4%.

[0049] The quality index of stripping solution (rare earth chloride solution) is as follows:

[0050] Table 4. quality index (g / L) of rare earth chloride solution)

[0051] REO

La 2 o 3 / REO

CeO 2 / REO

PR 6 o 11 / REO

Nd 2 o 3 / REO

253.8

62.1

182.3

5.4

0.6

Fe 2 o 3

CaO

MgO

PbO

0.015

0.056

0.006

0.0011

[0052] The quality indicat...

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Abstract

The invention relates to a method for recovering rare earth elements from waste rare earth grinding materials, which is characterized in that a ternary mixture of ammonium chloride, magnesium sulfate and sulfuric acid is used as a decomposing agent, subjected to low-temperature roasting and water immersion, and solvent extraction to prepare mixed rare earth chlorides, and then Liquid-liquid cascade extraction and separation prepares 99.95-99.99% rare earth oxides. The process greatly reduces the consumption of sulfuric acid, reduces the environmental pollution caused by roasting tail gas, and the total yield of rare earth is greater than 90%. At the same time, the mixed rare earth chlorides prepared by extraction can also directly prepare rare earth grinding materials.

Description

technical field [0001] The invention relates to a method for recovering rare earth elements from waste rare earth grinding materials, and belongs to the field of repurification and utilization of rare earth elements recovered from used waste rare earth grinding materials. Background technique [0002] Cerium-containing rare earth polishing materials are widely used in the polishing of optical lenses, liquid crystal displays, tablet computers, mobile phone panels, and glass substrates for hard disks due to their advantages of fast polishing speed, smoothness, and high flatness. In 2010, the global consumption of rare earth polishing materials reached 30,000 tons. Among them, the amount used in mainland China is 22,000 tons. Total rare earth (TREO) of rare earth polishing powder > 86wt%, CeO 2 / TREO>55%; La 2 o 3 / TREO=28-36%; Pr 6 o 11 / TREO=4-7%; F=4-7.5%. When the rare earth polishing powder is used, it should be adjusted into a slurry with water at first, and ...

Claims

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Application Information

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IPC IPC(8): C22B7/00C22B59/00
CPCY02P10/20
Inventor 冀代雨张存瑞冀代明郝喜平
Owner BAOTOU XINYUAN RARE EARCH HI TECH NEW MATERIAL