Extraction of copper from copper slag: Mineralogical insights, physical beneficiation and bioleaching studies


Panda S. , Mishra S., Rao D. S. , Pradhan N., Mohapatra U., Angadi S., ...More

KOREAN JOURNAL OF CHEMICAL ENGINEERING, vol.32, no.4, pp.667-676, 2015 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 32 Issue: 4
  • Publication Date: 2015
  • Doi Number: 10.1007/s11814-014-0298-6
  • Title of Journal : KOREAN JOURNAL OF CHEMICAL ENGINEERING
  • Page Numbers: pp.667-676
  • Keywords: Copper Slag, Characterization, Microscope, Physical Beneficiation, Bioleaching, BALL MILL SPILLAGE, ACIDITHIOBACILLUS-FERROOXIDANS, HEAVY-METALS, CONVERTER SLAG, FLY-ASH, RED MUD, RECOVERY, CHALCOPYRITE, BACTERIA, CEMENT

Abstract

Copper slag was subjected to in-depth mineralogical characterization by integrated instrumental techniques and evaluated for the efficacy of physical beneficiation and mixed meso-acidophilic bioleaching tests towards recovery of copper. Point-to-point mineral chemistry of the copper slag is discussed in detail to give better insight into the association of copper in slag. Characterization studies of the representative sample revealed the presence of fayalite and magnetite along with metallic copper disseminated within the iron and silicate phases. Physical beneficiation of the feed slag (similar to 0.6% Cu) in a 2 L working volume flotation cell using sodium isopropyl xanthate resulted in Cu beneficiation up to 2-4% and final recovery within 42-46%. On the other hand, a mixed meso-acidophilic bacterial consortium comprised of a group of iron and/or sulfur oxidizing bacteria resulted in enhanced recovery of Cu (similar to 92-96%) from the slag sample. SEM characterization of the bioleached slag residue also showed massive coagulated texture with severe weathered structures. FE-SEM elemental mapping with EDS analysis indicated that the bioleached residues were devoid of copper.