Method for recovering palladium from waste palladium/alumina catalyst

A waste catalyst and alumina technology, which is applied in the field of palladium recovery, can solve problems such as complicated operation, and achieve the effects of simplifying the refining process, high recovery rate, and simplified process flow

Inactive Publication Date: 2014-12-24
KUNMING INST OF PRECIOUS METALS
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The chlorine gas method in hydrochloric acid, because the added chlorine gas cannot be completely absorbed,...

Method used

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  • Method for recovering palladium from waste palladium/alumina catalyst

Examples

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Embodiment 1

[0015] In Example 1, the spent palladium / alumina catalyst was roasted at 600°C for 1h, after cooling, it was finely ground to a particle size of -0.125mm, and 1000g of the finely ground material was weighed and mixed with 100g of iron powder, and added to the mass at a liquid-solid ratio of 5:1 In a sulfuric acid solution with a concentration of 30%, dissolve at a constant temperature of 80℃ for 2 hours; continue to slowly add sodium chlorate to the dissolution system to dissolve for 4 hours, after solid-liquid separation, a low-concentration palladium-containing solution is obtained; add to the low-concentration palladium-containing solution Sodium sulfide was stirred at a constant temperature of 80°C for 2 hours to completely precipitate palladium to obtain palladium sulfide. After solid-liquid separation, palladium sulfide was dissolved, separated, and refined to obtain sponge palladium with a purity of 99.95%. The recovery rate was 98.44%.

Embodiment 2

[0016] In Example 2, the spent palladium / alumina catalyst was roasted at 500°C for 2h. After cooling, it was finely ground to a particle size of -0.125mm. Weighed 1000g of finely ground material and mixed with 100g of aluminum powder, and added it to the mass at a liquid-solid ratio of 5:1 In a sulfuric acid solution with a concentration of 40%, stir and dissolve at a constant temperature of 80°C for 2h; continue to slowly pour chlorine into the dissolution system to dissolve for 2h, after solid-liquid separation, a low-concentration palladium-containing solution is obtained; add sulfur to the low-concentration palladium-containing solution Sodium was stirred at a constant temperature of 80°C for 2 hours to completely precipitate palladium to obtain palladium sulfide. After solid-liquid separation, palladium sulfide was purified by dissolving, separating, and refining to obtain sponge palladium with a purity of 99.95%, and the recovery rate was 98.56%.

Embodiment 3

[0017] Example 3, calcining the spent palladium / alumina catalyst at 500°C for 2h, after cooling, finely grind to a particle size of -0.125mm, weigh 1000g of finely ground material and mix with 100g of zinc powder, and add to the mass according to the liquid-solid ratio of 5:1 In a sulfuric acid solution with a concentration of 30%, stir and dissolve at 70°C for 3 hours; continue to slowly pass chlorine gas into the dissolution system to dissolve for 2 hours, after solid-liquid separation, a low-concentration palladium-containing solution is obtained; pass into the low-concentration palladium-containing solution Hydrogen sulfide gas was stirred at a constant temperature of 80°C for 2 hours to completely precipitate palladium to obtain palladium sulfide. After solid-liquid separation, palladium sulfide was dissolved, separated, and refined to obtain sponge palladium with a purity of 99.95%. The recovery rate was 98.32%. .

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Abstract

The invention discloses a method for recovering palladium from a waste palladium/alumina catalyst, which comprises the following steps: (1) roasting pretreatment; (2) material fine grinding; (3) acid dissolution activation by metal powder addition; (4) oxidization and dissolution of palladium; (5) vulcanization and precipitation; and (6) palladium refinement. In the step (3), the metal powder and acid react to generate H2, and the H2 reduces part of insoluble PdO in the waste catalyst into the metal Pd in the reaction process; no solid-liquid separation is needed between the step (3) and step (4), thereby implementing the palladium dissolution in one step; and the low-concentration palladium solution obtained in the step (5) is vulcanized and precipitated to obtain the high-grade palladium concentrate (palladium sulfide). The method can be used for recovering palladium from the waste palladium/alumina catalyst in petrochemical industry and fine chemical engineering industry. The recovery rate of the palladium is greater than 98%, and the purity of the palladium is 99.95%.

Description

Technical field [0001] The invention relates to a method for recovering palladium from a waste catalyst, in particular to a method for recovering palladium from a waste palladium / alumina catalyst. Background technique [0002] After long-term use, the catalytic activity will be weakened to lose activity and become a waste catalyst. However, the palladium content in palladium / alumina catalyst is relatively high, which has important recovery value. At present, there are many methods for recovering palladium from waste palladium / alumina catalyst. Generally, all methods are first to roast the palladium / alumina catalyst to remove surface carbon and organic matter, and then use corresponding methods to separate palladium and alumina, and then pass Refining to obtain palladium products. There are two main types of processes for recovering palladium from waste palladium / alumina catalysts. One is to selectively dissolve palladium by adding hydrochloric acid and an oxidizing agent to for...

Claims

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Application Information

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IPC IPC(8): C22B7/00C22B11/00
CPCY02P10/20
Inventor 董海刚赵家春周利民王亚雄童伟锋吴晓峰李博捷吴跃东杨海琼保思敏
Owner KUNMING INST OF PRECIOUS METALS
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