You are hereExamples - Case Studies of plants with resins recovery systems
Examples - Case Studies of plants with resins recovery systems
The experiences of some plants with resins are described in this part. One of the limitations in the application of resins is the lack of knowledge on chemical aspects, and the popularity offered by activated carbon in the treatment of solutions and pulps from cyanidation.
3.1 Mintek Pilot Plant.: The plant is located in Randburg (South Africa). Mintek is a pioneer on the study and treatment of resins for the gold extraction from cyanidation processes. In the plant were employed strong base resins and weak base resins in different trials, and the eluant tested most the time was zinc cyanide which gives recoveries over 90%, and few tests with sodium hydroxide when the tested weak base resins.
The conditions tested in the plant during many trials were as follows: the pulp feed to the plant contained about 50% solids, resin per stage 5%, resin flowrate 50 per cent of stage inventory per day, and residence time of pulp per stage 40 minutes. The RIP pilot trials were run to demonstrate the chemical, rather than the physical performance of resins for gold recovery.
Pulp/resin separation was done using wedgewire screens with air to keep the pulp moving across the screen, efficiencies for resin screening were about 60 m3 of pulp per hour per square meter of screen. Even more promising results were achieved with sieve bends. [11,12]
The loaded strong base resins were eluted with a zinc cyanide solution containing 25 to 30 g/t and a slight excess of cyanide, and the gold rich solution was sent to an electrochemical cell in which gold was removed by deposition onto graphite granules. The flowsheet for the Mintek pilot plant is shown in Figure 10.
