Ion exchange resin method, ion exchange reaction of adsorption process

 

The process of adsorbing and recovering gold from a cyanide slurry using an ion exchange resin is referred to as the resin-in-pulp method (RIP method). Ion exchange resins consist of ionized groups capable of dissociating in solution. These groups can dissociate into two parts: one is a solid ion (denoted as R) that cannot be ion exchanged, and the other is a counter ion with the opposite charge of the fixed ion.

 

Cation exchange resins and anion exchange resins are classified based on the symbol of the counter ion charge in the ion exchange resin. In pulp cyanide leaching, gold exists in the form of the Au(CN)₂⁻ anion complex. Therefore, in the gold ion exchange resin method, only anion exchange resin is used. During the extraction of gold from the cyanide leaching slurry, the gold and silver cyanide complex ions dissolved in the resin and the slurry undergo the following ion exchange reaction through the adsorption mechanism of the ion pair:

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