Resin adsorption mechanism (3)

Although the above two results indicate a difference between the specific values ​​of the preferred strong base group content, both of them prove that the resin used for gold extraction should be a bifunctional resin, and the strong base group content has some kind The preferred range is very clear. And the difference between the two may mean that the composition of the solution used in the two sets of experiments is significantly different: for solutions with low bismuth metal content and relatively high gold content, it is advantageous to have a high base group content in the resin, so that the resin The gold capacity is higher and the adsorption amount of the base metal is not too high; on the contrary, when the gold content is low and the base metal content is much higher (such as the test and results of the former Soviet Union mentioned above), the bifunctional resin with high adsorption selectivity should be selected, among which The low base group content and comprehensive index are favorable for the adsorption of gold AM-2 resin, which is the best one of the bifunctional gold extraction resins at that time.
The characteristics of anion exchange resins for the adsorption of gold from cyanide or slurry by the tests of the former Soviet Union, South Africa and China are shown in Table 4.

A comparative adsorption test was conducted on a weakly basic phenolic resin A7, a bifunctional resin IRA-93 and a strongly basic quaternary amine resin A101DU in a manually prepared cyanide solution of pH=11. The results are shown in Table 5. It can be seen from the table that the total exchange capacity of the three resins is the largest with A101DU and the smallest with A7; the selectivity to gold is best with IRA-93, and A7 is the smallest, they conclude that: a bifunctional group containing a certain amount of quaternary amine groups Weakly basic resin is currently the best gold extraction resin.