IMPROVED PROCESS FOR THE RECOVERY OF NON-FERROUS METALS FRM ACIDIC HYDROMETALLURGICAL LEACH LIQUORS WITH A CHELATE EXCHANGE RESIN

摘要

The recovery of non-ferrous transition metals such as copper and nickel from acidic hydrometallurgical leach liquors with a 2-picolylamine chelate exchange resin is improved by the in situ reduction of Fe+3 present in the leach liquor with a water soluble reducing agent during the resin loading cycle. The chelate resin functions not only as a selective sorbent for the desired metal values, but also as a catalyst for the in situ reduction of Fe+3 to Fe+2. A suitable reducing agent such as SO2 or HCHO is fed into the chelate resin column with the leach liquor. When the loading cycle is completed, regeneration with sulfuric acid gives an enriched eluent with a high non-ferrous metal:Fe ratio. For example, using SO2 with a copper leach liquor feed, subsequent regeneration at about 70 DEG C gives better than 90 percent recovery of the copper as a highly enriched copper sulfate solution with a Cu:Fe ratio of about 10,000.