Ion exchange resins, that are semi-selective for gold, have been extensively used for gold recovery from cyanide leach processes in the former USSR. Despite forward looking statements by researchers and technology vendors, there have been very few applications in Western plants. Historically, the difference in economic drivers, relative availability and application experience of resins and activated carbon may explain the different approach in the two markets. However, many of the early Western studies comparing resins and carbon were over simplified, ignoring issues like differences in pulp density and adsorbent particle sizing. There is some ongoing interest in application of resins in the former USSR but using medium base resins that allow simpler single stage cyanide elution rather than multistage elution, including thiourea, and requiring titanium columns for corrosion resistance.
Conventional strong base anion exchange resins as used for uranium RIP or gold recovery from thiosulfate solution are unsuitable for cyanide solutions. Strong base gold selective (Minix/ Dow XZ 91419) resin is used at Penjom in Malaysia and Gedabek, Azerbaijan. Gold selective medium/strong base guanidine based AuRIX 100 resin is used to treat high grade solutions in Gekko intensive leach systems, while medium base Purogold S992 is used in some Russian plants.
This paper analyses the factors that have allowed successful application of resin at a number of plants and some of the issues that need to be considered in choosing resin for a particular application.
Ben Strong presented this paper at ALTA 2017. Organised by ALTA Metallurgical Services, ALTA 2017 is the 22nd year of one of the world’s premier annual metallurgical events. The conference is an annual gathering of the global Nickel, Cobalt, Copper, Uranium-REE and Gold-PM industries and features highly focused programs, topical forums and presentations by key international speakers. Held over eight days in Perth, it comprises three technical conferences, three practically-oriented short courses, social functions and an international trade exhibition. Visit conference website.