Biohydrometallurgical Methods for Cobal and Nickel Recovery from Printed PC Motherboard

Poster presented at: The 22nd European Meeting on Environmental Chemistry (EMEC 22), 5 - 8 December,2022, Ljubljana, SloveniaAbstract: [https://cer.ihtm.bg.ac.rs/handle/123456789/5459

Biohydrometallurgical Methods for Cobal and Nickel Recovery from Printed PC Motherboard

E-waste is one of the fastest growing waste. Ewaste contains lots of valuable resources together with plenty of heavy metals and hazardous materials, which are considered both an attractive polymetallic secondary source and an environmental contaminant. Therefore, recycle of valuable metallic from them are necessary and compulsory in many developed/developing countries. The aim of our study was to investigate the potential of using the Acidithiobacillus sp. B2, to recovery Co and Ni from printed PC motherboard.Poster: [https://cer.ihtm.bg.ac.rs/handle/123456789/5460

The particle size distribution (PSD) as criteria for comparison of silver powders obtained by different methods of synthesis and by conditions of electrolysis

Silver powders produced by both electrochemical (galvanostatic (DC) and potentiostatic (POT) regimes of electrolysis) and chemical processes were examined by scanning electron microscope, and particle size distribution (PSD) of the obtained particles was done. In the DC regime, the current densities of -14.4 mA cm-2 for the nitrate (NIT; powder denoted with DC(NIT)) and -13.05 mA cm-2 for the ammonium (AM; DC(AM)) electrolytes were applied. In the POT regime, the used overpotentials were -90 mV (NIT(90)) and -150 mV (NIT(150)) for the nitrate, and -625 mV (AM(625)) and -925 mV (AM(925)) for the ammonium electrolytes. Reduction with hydrazine was used for chemical synthesis (powder denoted with HYD). On the basis of SEM and PSD analysis, Ag powders were grouped into three groups. In the first group DC(AM), AM(925) and HYD powders with the (8.4-8.9 %) volume ratios were placed. In the second group were AM(625) and DC(NIT) powders with the (6.5-6.6 %) volume ratios. NIT(90) and NIT(150) powders with the volume ratios of (5.2-5.7 %) made the third group. The obtained volume ratios were correlated with the morphology of synthesized particles in order to perceive advantages and lacks of powder production via electrochemical and chemical routes

Microbial solubilization of copper and zinc from polymetallic sulphide ore

The object of this study was to investigate the possibility of copper and zinc leaching from polymetallic sulphide ore from the Bobija deposit (Western Serbia) by Acidithiobacillus sp.B2. Iron-oxidizing Acidithiobacillus sp. B2 was isolated from copper sulphide mine wastewater (Lake Robule) in Bor, Serbia. The bacterium was identified by 16SrDNA oligonuckotide sequence. Leaching experiment by the shake flask testing technique was performed during a period of four weeks ata temperature of 28 °C. The percentage of Cu and Zn leached at the end of this experiment was 65% and 67% respectively. This study shows that iron-oxidizing Acidithiobacillus sp. B2 can have a very important role in the extraction of copper and zinc, from polymetallic sulphide ore from the Bobija deposit

JSCS–3824 +622.772:621.928.46 Original scientific paper Mesophilic leaching of copper sulphide sludge

Abstract: Copper was precipitated using a sodium sulphide solution as the precipitation agent from an acid solution containing 17 g/l copper and 350 g/l sulphuric acid. The particle size of nearly 1 µm in the sulphide sludge sample was detected by optical microscopy. Based on chemical and X-ray diffraction analyses, covellite was detected as the major sulphide mineral. The batch bioleach amenability test was performed at 32 °C on the Tk31 mine mesophilic mixed culture using a residence time of 28 days. The dissolution of copper sulphide by direct catalytic leaching of the sulphides with bacteria attached to the particles was found to be worthy, although a small quantity of ferrous ions had to be added to raise the activity of the bacteria and the redox potential of the culture medium. Throughout the 22-day period of the bioleach test, copper recovery based on residue analysis indicated a copper extraction of 95 %, with copper concentration in the bioleach solution of 15 g/l. The slope of the straight line tangential to the exponential part of the extraction curve gave a copper solubilisation rate of 1.1 g/l per day. This suggests that a copper extraction of 95 % for the period of bioleach test of 13.6 days may be attained in a three-stage bioreactor system

Construction of isotherms in solvent extraction of copper

The aim of this work is construction of equilibrium isotherms in solvent extraction. Technological parameters have been predicted for treatment of mine water by solvent extraction and electrowining. Two stages of extractions and one stage of stripping have been predicted for copper recovery by analyzing the equilibrium isotherms. The process was performed on mine water with 2,5 g/dm3 Cu2+, 3 g/dm Fe2+, pH 1,8, using 9 vol% LIX 984N in kerosene (organic solvent), with 95 and 98% stages efficiencies, respectively. This course produced an advanced electrolyte solution, suitable for electrowining and cathodic copper recovery, containing 51 g/dm3 Cu2+ and 160g/dm3 H2SO4 from a 30 g/dm3 Cu and 190 g/dm3 H2SO4

The particle size distribution (PSD) as criteria for comparison of silver powders obtained by different methods of synthesis and by conditions of electrolysis

Silver powders produced by both electrochemical (galvanostatic (DC) and potentiostatic (POT) regimes of electrolysis) and chemical processes were examined by scanning electron microscope, and particle size distribution (PSD) of the obtained particles was done. In the DC regime, the current densities of –14.4 mA cm-2 for the nitrate (NIT; powder denoted with DC(NIT)) and –13.05 mA cm-2 for the ammonium (AM; DC(AM)) electrolytes were applied. In the POT regime, the used overpotentials were –90 mV (NIT(90)) and –150 mV (NIT(150)) for the nitrate, and –625 mV (AM(625)) and –925 mV (AM(925)) for the ammonium electrolytes. Reduction with hydrazine was used for chemical synthesis (powder denoted with HYD). On the basis of SEM and PSD analysis, Ag powders were grouped into three groups. In the first group DC(AM), AM(925) and HYD powders with the (8.4–8.9 %) volume ratios were placed. In the second group were AM(625) and DC(NIT) powders with the (6.5–6.6 %) volume ratios. NIT(90) and NIT(150) powders with the volume ratios of (5.2–5.7 %) made the third group. The obtained volume ratios were correlated with the morphology of synthesized particles in order to perceive advantages and lacks of powder production via electrochemical and chemical routes