Method for recycling palladium from palladium-contained waste catalyst

A waste catalyst and waste material technology, applied in the direction of improving process efficiency, can solve the problems of palladium scarce resource waste, complicated process flow, environmental pollution, etc., and achieve the goal of avoiding high energy consumption and environmental pollution, short process flow and high recovery rate Effect

Active Publication Date: 2018-10-12
CHONGQING UNIVERSITY OF SCIENCE AND TECHNOLOGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Such a traditional process not only has high energy consumption and complicated process, but more importantly, the recovery rate is low, which causes a serious waste of palladium, a scarce resource, and brings huge losses to the country. At the same time, there is serious environmental pollution.

Method used

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  • Method for recycling palladium from palladium-contained waste catalyst

Examples

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Comparison scheme
Effect test

Embodiment 1

[0023] In a 1000mL flask, add 100g of palladium-containing spent catalyst, add 300mL composite solution, the composite solution includes carbon tetrachloride, ethanol, methanol, petroleum ether, glacial acetic acid, carbon disulfide, chloroform and ether, each component in the composite solution is added The ratio is the same, wash 3 times, 30 minutes each time; after filtration, grind and crush the spent palladium-containing catalyst into a powder with a particle size of 20-200 mesh, add 100mL of hydrazine hydrate at 80°C, reduce for 30min, and Filtration, acid leaching the filter residue with 100mL aqua regia for 30min, then adding 30g of quicklime and 4g of zinc powder in turn, and then injecting hydrogen for 10min to obtain sponge palladium, finally boiling it, filtering to obtain refined palladium, and its recovery of palladium The rate reaches 99.4%.

Embodiment 2

[0025] In a 1000mL flask, add 100g of palladium-containing waste catalyst, add 300mL composite liquid and wash 3 times, each time for 25 minutes, the composite liquid includes carbon tetrachloride, ethanol, methyl alcohol, glacial acetic acid, carbon disulfide, chloroform and ether, the composite The addition ratio of each component in the liquid is the same; after filtration, the palladium-containing spent catalyst is ground and crushed, and 100 mL of sodium borohydride-methanol solution (40% by mass fraction) is added to reduce it for 30 min at 80 ° C. After filtration, The filter residue was acid-leached with 100mL aqua regia for 30min, then 30g of quicklime and 5g of tin powder were added successively, and the sponge palladium was obtained after introducing hydrogen gas for 10min. Finally, it was boiled and filtered to obtain refined palladium. The recovery rate of palladium reached 99.2%.

Embodiment 3

[0027] In the flask of 1000mL, add 100g to contain palladium waste catalyst, add 300mL composite liquid, described composite liquid comprises carbon tetrachloride, ethanol, methyl alcohol, carbon disulfide, chloroform and ether, and every kind of composition addition ratio is identical in the described composite liquid, Wash 3 times, 50 minutes each time; after filtration, grind and pulverize the spent palladium-containing catalyst, add 100mL formic acid at 80°C, reduce for 30min, filter, and acid-leach the filter residue with 100mL aqua regia for 30min, Then add 25g of quicklime and 6g of magnesium powder in turn, and then pass through hydrogen for 20 minutes to obtain sponge palladium, finally boil it, filter to obtain refined palladium, and the recovery rate of palladium reaches 99.3%.

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Abstract

The invention discloses a method for recycling palladium from a palladium-contained waste catalyst. The method comprises following steps that firstly, waste pre-treatment, wherein composite liquid isadopted for eluting the palladium-contained waste catalyst, filtering is carried out, and palladium-contained filter residue is obtained; secondly, palladium formation through palladium oxide reduction, wherein a reducing agent and the palladium-contained filter residue are used for having a reaction, the palladium oxide in the waste residue is reduced into elementary substance palladium; thirdly,acid soluble operation to obtain palladium ions, wherein organic acid haves a reaction with the elementary substance palladium, and an acid solution system existing in a palladium ion state is obtained; fourthly, replacement to obtain palladium, wherein a metal replacement method is adopted to carry out replacement on the palladium ions in the acid solution system, and sponge palladium is obtained; fifthly, palladium refining, wherein hydrogen is further used for reducing the metal palladium, and high-purity metal palladium is obtained. The organic composite liquid is used for eluting the palladium-contained waste catalyst, the problems of high energy consumption and environment pollution in the prior art are solved, the process flow is short, and the problems that in the current palladium recycling technology, energy consumption is high, and the recycling rate is low are solved.

Description

technical field [0001] The invention relates to a method for recovering palladium from spent palladium-containing catalysts, belongs to the field of recycling and utilization of precious metal secondary resources, and particularly relates to a metal palladium recovery method with mild reaction conditions, high recovery rate and low cost. Background technique [0002] As a rare and precious metal, palladium plays the role of catalyst in industrial production, such as plastic electroplating production process, fluoropiperidine, synthesis of toluene diisocyanate, and hydroprocessing of terephthalic acid, etc., all use palladium as a catalyst. Since palladium is a noble metal with scarce resources and high price, it is of great significance for how to recover palladium in deactivated catalysts. [0003] At present, the methods for recovering palladium from spent palladium-containing catalysts mainly include incineration and wet adsorption tower recovery methods. Most of these me...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B11/00C22B7/00
CPCC22B11/048Y02P10/20
Inventor 李敏
Owner CHONGQING UNIVERSITY OF SCIENCE AND TECHNOLOGY
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