Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for recovering silver from silver catalyst

A technology of silver catalyst and silver powder, which is applied in the field of silver recovery, can solve the problems of high price of reducing agent hydrazine hydrate, high reduction cost, and difficult treatment, and achieves low reagent cost, convenient operation, and omission of filtration operation.

Inactive Publication Date: 2019-05-21
BEIJING RESEARCH INSTITUTE OF CHEMICAL ENGINEERING AND METALLURGY
View PDF5 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The reduction of silver chloride with hydrazine hydrate in the ammonia water system is a traditional reduction process. The reduction mother liquor is ammonia-containing wastewater, which is difficult to treat. The high price of the reducing agent hydrazine hydrate makes the reduction cost relatively high.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for recovering silver from silver catalyst
  • Method for recovering silver from silver catalyst

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] A method for recovering silver from silver catalyst, comprising the following steps:

[0027] S1: first crush the waste silver catalyst, and the particle size after crushing is controlled at 0.074-3.2mm;

[0028] S2: Place the waste silver catalyst crushed by S1 in an enamel kettle to dissolve silver with nitric acid; the nitric acid used is dilute nitric acid with a concentration of 5% to 30%, and the dilution water used is treated with reverse osmosis or ion exchange resin The final deionized water to reduce the impact of chloride ions in the water on the dissolution of silver; the solid-to-liquid ratio (weight to volume ratio) of spent silver catalyst to dilute nitric acid is 1:2 to 1:6, and the temperature is 50°C to 90°C. ℃, the time is 30min~150min; after the nitric acid dissolves the silver, the leaching residue is washed by 2-stage countercurrent leaching and 3-stage countercurrent washing;

[0029] S3: After the silver-containing solution in S2 is inspected an...

Embodiment 2

[0034] 1000g of Ag-Al2O3 waste catalyst containing 16.7% of Ag was crushed to -3.2mm, and the crushed silver catalyst was placed in a 3-liter beaker. Preparation 3000ml concentration is 15% nitric acid, and used water is purified water. Pour the prepared nitric acid into the beaker filled with the silver catalyst, the pouring amount is based on just submerging the silver catalyst. Heat the beaker to 85°C in a water bath, stir and turn it occasionally with a glass rod, pour out the leaching solution after reacting for 60 minutes, repeat this until the 3000ml prepared nitric acid solution is used up, combine the obtained leaching solution after inspection and filtration, and take it for chlorination Sodium immersion silver. Use 3000ml of pure water to wash the leached slag, and the amount poured each time is based on the amount just submerged in the silver catalyst. Heat the beaker to 50°C in a water bath, stir and turn it occasionally with a glass rod, pour out the leaching s...

Embodiment 3

[0042]A method for recovering silver from silver catalyst, comprising the following steps:

[0043] S1: first crush the waste silver catalyst, and the particle size after crushing is controlled at 0.074mm;

[0044] S2: Place the waste silver catalyst crushed by S1 in an enamel kettle to dissolve silver with nitric acid; the nitric acid used is dilute nitric acid with a concentration of 5% to 30%, and the dilution water used is treated with reverse osmosis or ion exchange resin The final deionized water is used to reduce the impact of chloride ions in the water on the dissolution of silver; the solid-to-liquid ratio (ratio of weight to volume) of spent silver catalyst to dilute nitric acid is 1:2, the temperature is 50°C, and the time is 30min; After nitric acid dissolves silver, the leaching residue is washed by 2-stage countercurrent leaching and 3-stage countercurrent washing;

[0045] S3: After the silver-containing solution in S2 is inspected and filtered, sodium chloride...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention provides a method for recovering silver from a silver-containing waste catalyst of petrochemical engineering. The method is suitable for recovering silver from the silver-containing waste catalyst of which a carrier belongs to aluminum oxide or silicon oxide. The process route of the method is shown as follows: the waste silver catalyst, crushing, nitric acid leaching, sodium chloride silver precipitation, iron plate replacement, melting and ingot casting and a metal silver ingot product. The method is concise in process, low in recovery cost and high in metal recovery rate. Thesilver leaching rate is greater than 99.5%. The silver recovery rate is greater than 99.3%. The purity of the silver ingot is greater than or equal to 99.95%.

Description

technical field [0001] The invention belongs to the field of silver recovery, in particular to a method for recovering silver from a silver catalyst. Background technique [0002] Silver is one of the precious metals, precious metal resources are scarce, the content in the earth's crust is only 0.001-0.01g / t, the price is expensive, in addition to having extremely important economic value, it is also very important in the process of modern technology and industrial development the use of. Noble metals have excellent catalytic properties. In the chemical industry, especially in the petrochemical industry, petroleum refining industry, medicine and energy industries, catalysts containing noble metals, such as platinum, palladium, and silver, are widely used. As far as silver is concerned, silver can be used as an active component of various oxidation reaction catalysts in petrochemical industry, especially as a catalyst in the production process of ethylene oxide to ethylene o...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C22B7/00C22B11/00
CPCY02P10/20
Inventor 杨志平
Owner BEIJING RESEARCH INSTITUTE OF CHEMICAL ENGINEERING AND METALLURGY