Preparation method and application of modified activated carbon for recovering gold

Abstract

The invention discloses a preparation method and application of modified activated carbon for recovering gold and belongs to the fields of wet metallurgy and precious metal recovery. According to themethod, a modified activated carbon material is prepared under a certain condition by taking an activated carbon material as a matrix and thiourea as a modifier; and functional groups containing atomssuch as nitrogen, oxygen and sulfur are introduced to the surface of activated carbon, so that the properties on the surface of the material are changed, and [Au(S2O3)2]3-complex ions in a thiosulfate gold immersion solution are effectively adsorbed. By using the method disclosed by the invention, the defects that existing Prussian blue-like compound modified activated carbon is complex in preparation process and unstable in product structural performances and expensive modifiers and organic solvents are used by 2-mercaptophenylthiazole modified activated carbon are overcome; and the preparation method has the advantages such as simple preparation method, low price and environment friendliness.

Description

technical field [0001] The invention relates to a preparation method and application of modified activated carbon for gold recovery, belonging to the fields of hydrometallurgy and precious metal recovery. Background technique [0002] Because of its unique physical and chemical properties, gold plays a pivotal role in human production and life. Cyanide method has always been the main gold leaching technology for gold extraction, but highly toxic cyanide is easy to leak, and if it is not handled properly, it will cause serious damage to the environment and ecology. Therefore, the non-cyanide gold extraction technology has been developed; among them, the thiosulfate gold extraction technology is non-toxic, less polluting, low in cost, high in reaction selectivity, low in corrosiveness of the leachate, and easy to handle. The advantages of carbonaceous gold ore, copper-bearing gold ore and complex sulfur-bearing gold ore are considered to be the most promising alternative tech...

AI Technical Summary

Problems solved by technology

However, in the thiosulfate gold extraction process, the activated carbon on [Au(S 2 o 3 ) 2 ] 3- The complex ion adsorption capacity is extremely low, which may be attributed to the large volume, high charge, and low affinity of the gold thiosulfate complex ion to activated carbon, resulting in difficult adsorption.

[0003] In order to overcome the shortcoming of the low loading capacity of activated carbon, someone adds 1-2 times the amount of cyanide in the thiosulfate gold leaching solution, and [Au(S 2 o 3 ) 2 ] 3- Convert to [Au(CN) 2 ] - It can be effectively adsorbed by activated carbon. Although the effect of this method is good, it cannot avoid the highly toxic CN - Pollution

Patent CN 104549147 A loads Prussian blue-like compounds on the surface of activated carbon. Although some results have been achieved, the modification process is to deposit copper ferrocyanide on the surface of activated carbon, which is a physical modification and the modification process is complicated and has poor stability. Difficult to reproduce, not conducive to production

Patent CN 107215872 A adopts the impregnation method to load 2-mercaptobenzothiazole on activated carbon, which has a better adsorption effect on gold, but this method needs to use expensive modifiers and toxic organic solvents

In addition, strong alkaline solution will destroy the porous structure of activated carbon, resulting in a decrease in adsorption capacity.