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Extraction method of silver

An extraction method and silver technology, which is applied in the field of gold and silver smelting, can solve the problems of harsh working environment, slow access speed, complicated operation, etc., and achieve the effects of good working conditions, fast response speed, and reduced procedures

Inactive Publication Date: 2009-11-04
宋裕华
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] Add NH to the water 3 ·H 2 O to achieve the leaching and dissolution of AgCl, the feeding speed is very slow, the time is long, the working environment is harsh, the operation is complicated, and the volume expands

Method used

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  • Extraction method of silver

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Embodiment 1

[0027] Slowly add the washed and filtered AgCl directly into N 2 h 4 ·H 2 O, stirring at the same time, until the white AgCl precipitation at the end of the reaction completely turns into gray silver powder, then add a few drops of N in excess 2 h 4 ·H 2 O, used to check whether the color of AgCl precipitated gray silver powder changes again, whether the reaction reaches the end point, and the fluffy silver powder precipitated. After filtering, washing and drying, it becomes qualified silver powder with a content of over 99.9%. The total silver recovery rate is greater than 99.5%, generally 500ml of N 2 h 4 ·H 2 O can reduce about 400g Ag.

[0028] 2AgCl+2N 2 h 4 ·H 2 O=2Ag+N 2 +2NH 4 Cl+2H 2 O+Q

[0029] The reaction process does not need to be heated, and the speed is slow at the beginning. The reaction is an exothermic reaction. When the temperature reaches about 60°C, the reaction speed is very fast. N 2 h 4 ·H 2 O cannot be added in one batch, otherwise...

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Abstract

The invention relates to the field of gold silver smelting technique, more particularly to an extraction method of silver. The inventive extraction method of silver comprises the following steps of: 1) directly and slowly adding N2H4.H2O into washed and filtered AgCl while agitating, with the reaction endpoint being complete change of white AgCl precipitates into gray silver powder; 2) then excessively adding several drops of or milliliter-grade N2H4.H2O in order to precipitate fluffy silver powder; 3) filtering, washing and drying the silver powder to generate qualified silver powder with the content reaching over 99.9%. The inventive extraction method of silver, without participation and production of ammonia in the process of reaction, does not cause respiratory system diseases, is beneficial for physical and mental health of operators, has good working conditions, outstanding environment, simple operation and fast reaction speed, shortens the time by about 3 / 4 compared with methods of ammonia leaching silver extraction and hydrazine hydrate sinking silver, does not bring about volume expansion, lessens investment of NH3.H2O, and saves procedures and investment on apparatus and materials.

Description

technical field [0001] The invention relates to the technical field of gold and silver smelting, in particular to a method for extracting silver. Background technique [0002] Silver extraction from AgCl adopts the method of leaching silver with ammonia and sinking silver with hydrazine hydrate, that is, AgCl is dissolved in ammonia water, and then the silver is reduced and replaced with hydrazine hydrate: [0003] [0004] 4〔Ag(NH 3 ) 2 〕Cl+N 2 h 4 ·H 2 O+Q=4Ag+N 2 +4NH 3 +4NH 4 Cl+H 2 o [0005] Note: Q in the above two formulas represents the heat supplied by heating. [0006] AgCl dissolved in NH 3 ·H 2 O formation [Ag(NH 3 ) 2 〕 + Not stable, when NH in solution 3 ·H 2 AgCl will re-precipitate when the O concentration decreases. [0007] Thanks to NH 3 ·H 2 NH in O 3 Extremely volatile, especially in the state of stirring and heating, so it is required to contain NH 3 12-24% high concentration NH 3 ·H 2 O. [0008] Add NH to the water 3 ·H ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22F9/24
Inventor 宋裕华刘建芳
Owner 宋裕华