Separation and Recovery of Nickel and Copper from Multi-Metal Electroplating Sludge by Co-Extracting and Selective Stripping

Abstract

N902 diluted with kerosene was used to co-extract copper and nickel from the ammoniac-carbonate leaching liquor of multi-metal electroplating sludge. The influence factors of the ammoniac-carbonate leaching and the extracting process on the recovery of copper and nickel were studied. The leaching rate of copper and nickel can reach to 90 % and the other metal ions are less leached under the optimal leaching condition. In order to optimize the extraction condition, the L9 (34) intersecting experiment of co-extraction of copper and nickel ions was tested. For a typical ammonium carbonate leaching solution containing Cu2+ 2.23 g/L, Ni2+ 3.31 g/L, Cr <0.02 g/L and pH 9.0-9.5, the optimal conditions of co-extraction, NH3 escape and selective stripping of nickel and copper were established. The percentage of extraction was more than 97.0 % for both copper and nickel, and the stripping percentages were 99.0 % and 99.3 % for copper and nickel, respectively. This study clearly demonstrates that N902 is suitable for the selective separation and recovery of copper and nickel from the multi-metal electroplating sludge in pure sulfate product as an extractant.