New technology for extracting high-purity gold by adopting wet process

Abstract

The invention relates to a new technology for extracting high-purity gold by adopting a wet process, which comprises the following steps: melting gold in aqua regia; concentrating and removing nitrate; diluting and filtering; reducing and depositing; filtering and cleaning; and fusing ingot casting. In the step of reducing and depositing, SO2 is taken as a reducing agent; when the electric potential of the solution is 680-730mv, especially when the electric potential of the solution is 700mv, the introduction of reducing gas is stopped, so that the purity of the end product is kept above 99.999% and the once percent reduction of the product is higher. According to the new technology, the optimal reduction temperature is confirmed; when the reduction temperature is at 40-60 DEG C, optimal temperature is at 50 DEG C; and the reduction time is effectively shortened.

Description

technical field [0001] The invention relates to a new process for extracting high-purity gold by wet method. technical background [0002] With the advancement and development of science and technology, gold with a gold content of 99.99% can no longer meet the needs of special industries such as aerospace, and the production of high-purity gold with a gold content of 99.999% and above has attracted more and more attention. Due to its good market prospects, various enterprises Competing to study the production process of high-purity gold. On February 13, 2008, the State Intellectual Property Office announced the electrolysis production process with the publication number CN101122032A. High-purity gold is produced through steps such as gold-making electrolyte, electrolysis, and finished product treatment. This method has a long process flow and needs to maintain a high gold ion concentration. , the backlog of gold is serious, and chlorine gas may be generated at the anode at ...

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Problems solved by technology

On February 13, 2008, the State Intellectual Property Office announced the electrolysis production process with the publication number CN101122032A. High-purity gold is produced through steps such as gold-making electrolyte, electrolysis, and finished product treatment. This method has a long process flow and needs to maintain a high gold ion concentration. , the backlog of gold is serious, and chlorine gas may be generated at the anode at the same time, there are many factors affecting product quality, the pass rate is low, and it is difficult to apply it on a large scale in actual production; on November 4, 2009, the extraction production process with the publication number CN101570830A was announced, and passed by Wang Water dissolution, ether extraction, reduction and other steps produce high-purity gold. The reagent preparation process of this method is complicated, and ether has a low flash point, which is flammable and explosive. At the same time, due to the strong oxidation of the gold-dissolving precious liquid, ether is easily destroyed, and the extraction effect is difficult to guarantee. The reduction is over. Finally, the end point is to smell the irritating smell of SO2, which is difficult to control and causes great damage to the operator's body; the aqua regia method is one of the more commonly used methods for producing gold at present, but it has not been applied to the production of high-purity gold. Natural heating, the reaction end temperature can reach up to 90°C, the late reaction speed is obviously slower and the gold particles are thicker, and the quality is unstable. The reduction reaction end point is mostly observed with the naked eye.

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