Recovery of nickel and cobalt from laterite leach tailings through resin-in-pulp scavenging and selective ammoniacal elution

In the hydrometallurgical processing of nickel laterite ore, a significant amount of dissolved nickel and cobalt can be lost to neutralized tailings slurry during counter current decantation. Resin-in-pulp (RIP) scavenging using ion exchange resin functionalized with iminodiacetic acid (IDA) has been proposed as an effective way to recover lost metal value. However, the tendency of this resin to co-load impurities makes integration of metal value back into the plant challenging. In this paper, the application of bis-picolylamine functionalized resin to RIP scavenging is explored. Both types of resin load the valuable metals effectively but bis-picolylamine functionalized resin has a much lower affinity for unwanted impurities. After loading, selective elution of nickel and cobalt from the new resin was carried out using an ammonia based eluent. The resultant eluate was high in nickel and cobalt with ppm levels of impurities, making it appropriate for downstream integration in existing nickel/cobalt refineries.