A procedure for processing of pregnant leach solution (PLS) produced from a chalcopyrite-ore bio-heap: CuO Nano-powder fabrication

The present research work describes a facile and industrial-friendly procedure for producing high quality CuO nano-powder from a PLS of a low-grade chalcopyrite-ore bioleaching. The PLS containing lower than about 1gCu/L (obtained from the ore bioleaching) was used as the feed for the procedure in which firstly the iron and other impurities was removed from the PLS, and next the pure copper–ammonia complex was selectively formed from the PLS. Then, the complex was transformed to the precursor (Copper Hydroxide Sulfate Hydrate (Cu2.5(OH)3(SO4)·(H2O)2)) at the room temperature. Finally, the precursor was dried at 60°C overnight to obtain pure CuO nano-powder (average crystalline size of about 19nm). The results were confirmed by the characterization analyses: XRD, SEM/EDS, elemental mapping, TEM, FTIR, chemical analyses, and XRF. [Display omitted] •Solvent extraction-Electro-Winning (SX-EW) process has tremendous problems.•A process was developed to be a viable alternative to the conventional SX-EW.•Low-concentrated Pregnant Leach Solutions (PLS) were the subject of this process.•CuO nano-powder (19nm) was successfully fabricated from the bio-processing PLS.