Method for recovering useful element from rare earth - transition metal alloy scrap

A recovery method and transition metal technology, applied in the direction of rare earth metal compounds, rare earth metal oxides/hydroxides, chemical instruments and methods, etc., can solve the problems that cannot be dealt with intact, the cost is difficult to process in large quantities, and the effect is not sufficient And other issues

Inactive Publication Date: 2005-08-17
SANTOKU CORP
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  • Summary
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  • Claims
  • Application Information

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Problems solved by technology

These methods leave iron in the solid phase in the form of iron hydroxide by blowing air, so compared with the above-mentioned (1) acid dissolution method, the amount of oxygen used is reduced, but the effect is not sufficient. In the case of massive solids, the pre-crushing process becomes indispensable
[0008] As mentioned above, the chemical separati

Method used

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  • Method for recovering useful element from rare earth - transition metal alloy scrap
  • Method for recovering useful element from rare earth - transition metal alloy scrap
  • Method for recovering useful element from rare earth - transition metal alloy scrap

Examples

Experimental program
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Effect test

Embodiment 1

[0055] The composition shown in Table 1 was mixed with 6 pieces of sludge containing powdery grinding debris (dry weight 119.7 g) was immersed in 500 ml of ammonium sulfate aqueous solution with a concentration of 0.8 mol / l. Next, oxidation treatment was performed at 70° C. for 30 hours while stirring and aerating, and precipitates of oxide powder were produced from the sludge. The oxide powder was isolated by filtration and dried to 192.5 g. A part thereof was collected and the composition was analyzed. Table 1 shows the results.

[0056] It is clear from Table 1 that at least 98% of the rare earth elements and at least 93% of Co in the sludge migrated to the obtained powder.

[0057] R in Table 1 and Table 2 represents a mixture of Nd, Pr, and Dy, and "Others" in Table 1 represents gas components such as oxygen, hydrogen, carbon, and sulfur.

[0058] Sludge sample (119.7g)

[0059]Next, an attempt was made to recover rare earth elements from the above powder ...

Embodiment 2

[0063] 350 g (dry weight 175 g) of sludge containing grinding debris derived from the production process of the rare earth-iron-boron sintered magnet having the same composition as in Example 1 was immersed in 500 ml of an aqueous solution of ammonium sulfate having a concentration of 0.2 mol / l. . Next, oxidation treatment was performed at 70° C. for 12 hours while stirring and aerating, and the generated oxide powder was filtered and separated. Next, the entire amount of the obtained oxide powder was dispersed in 200 ml of water, and a 5N aqueous solution of nitric acid was added dropwise while stirring and aerating. The temperature is maintained at 40-50°C. The pH gradually decreased from around 7 while the reaction proceeded, and the dropwise addition was terminated when the pH reached 3. The total dripping amount was 140 ml, and the time required was 8 hours. Next, the precipitate was filtered, and the obtained precipitate was washed with water. The filtrate and the wa...

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PUM

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Abstract

A method for recovering useful elements from a rare earth - transition metal alloy scrap, which comprises a step (A) of immersing the rare earth - transition metal alloy scrap in an aqueous solution of an ammonium salt of a mineral acid, a step (B) of passing a gas containing oxygen through said solution, to thereby oxidize the scrap and produce a precipitate comprising a powder containing oxides, hydroxides and the like as main components, a step (C) of separating said precipitate, and a step (D) of recovering rare earth elements from the separated precipitate. The method allows the economical and safe recovery of useful elements such as rare earth elements without the consumption of a large amount of acid and the need for the advance selection with respect to the form of a scrap or a preliminary crushing step.

Description

technical field [0001] The present invention relates to a method for recovering useful elements such as rare earth elements economically and safely from rare earth-transition metal alloy scraps. Background technique [0002] Representative products that are practically used in the field of rare earth-transition metal alloys include permanent magnets of rare earth-cobalt series and rare earth-iron-boron series. In particular, the latter has been remarkably increased in recent years because it exhibits excellent magnetic properties. The magnet usually contains about 30-35% by weight of rare earth elements such as Nd, Pr, and Dy, about 60-65% by weight of iron, 1-2% by weight of boron, and alloys (hereinafter sometimes referred to as Rare earth-iron-based alloys) as raw materials, crushed and then molded and sintered to make sintered magnets, or kneaded with resin and injection molded to make bonded magnets. [0003] In the case of using a rare earth-transition metal alloy to...

Claims

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Application Information

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IPC IPC(8): C01F17/206C22B7/00C22B59/00
CPCC01F17/0043C22B7/007C22B59/00C01F17/206Y02P10/20
Inventor 生赖浩横井英雄
Owner SANTOKU CORP
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