A kind of 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 hydrometallurgy and precious metal recovery. The method of the present invention takes the activated carbon material as the matrix and uses thiourea as the modifying agent to prepare the modified activated carbon material under certain conditions; on the surface of the activated carbon, functional groups containing atoms such as nitrogen, oxygen, and sulfur are introduced, so that the surface of the material is properties change, [Au(S 2 o 3 ) 2 ] 3‑ Complex ions produced effective adsorption. The method of the invention overcomes the disadvantages of complex preparation process of the existing Prussian blue compound-modified activated carbon, unstable product structure and performance, and the use of expensive modifiers and organic solvents for the 2-mercaptophenylprophiazole-modified activated carbon, and has the advantages of simple preparation method and low price. Advantages such as low cost and environmental 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.