Adsorption of copper on manganese nodule residue obtained from NH3¯SO2 leaching

Manganese nodules occurring in beds of many of the worldʹs oceans contain valuable metals such as Cu, Co, Ni, Mn, Zn, etc. in the form of oxides/oxy-hydroxides. Many processes have been developed worldwide to extract metal values from manganese nodules. A process based on NH3¯SO2 leaching has been developed at RRL, Bhubaneswar to recover Cu, Ni, Co and Zn. The process generates a large amount of residue. Studies were undertaken to examine the possibility of adsorption of heavy metal ions on this residue. Adsorption of copper on polymetallic nodule (PMN) leach residue was examined using synthetic copper sulfate solution. Adsorption was pH dependent and was maximum at pH between 4.0 and 5.0. The material was found to be a good adsorbent and its loading capacity was higher than activated charcoal.