2015-Sustainable Industrial Processing Summit
SIPS 2015 Volume 7: Ionic Liquids & Energy Production
| Editors: | Kongoli F, Gaune-Escard M, Mauntz M, Rubinstein J, Dodds H.L. |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2015 |
| Pages: | 310 pages |
| ISBN: | 978-1-987820-30-0 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Copper Extraction from Copper Sulfide by Electro-Reduction in Molten Borax
Levent Kartal1; Guldem Kartal Sireli2; Servet Timur1;1ISTANBUL TECHNICAL UNIVERSITY, Istanbul, Turkey; 2ISTANBUL TECHNICAL UNIVERSITY (ITU), istanbul, Turkey;
Type of Paper: Regular
Id Paper: 147
Topic: 13
Abstract:
In this study, a new environmentally-friendly salt electrolyte was applied for the extraction of copper from Cu2S (white metal- containing approximately 78 wt.% Cu), supplied from KBI Black Sea Copper Works Inc. The effects of process parameters, namely current density and time on the cathodic current efficiency and copper yield were systematically investigated. The molten salt electrolysis was performed at a constant temperature of 1200 °C in a borax electrolyte at current densities ranging from 100 to 800 mA/cm2 for periods of 15 to 60 minutes. The highest cathodic current efficiency (Iii) calculated according to Faraday's Law was found as 40.8% at 600 mA/cm2 for 15 minutes. It was seen that the increase in process time does not have any significant influence on the value of current efficiency (Iii). However, the yield of copper was raised to 79.58% after longer process time; for instance, 38 g Cu was recovered from 60 g Cu2S at 400 mA/cm2 in 1 hour. The cell potential values were increased with increasing current density and measured as 5.6 V at 800 mA/cm2. The specific energy consumption was reached up to 5.8 kWh/kg at 600 mA/cm2. The analyses revealed that the extracted copper had 97.3 wt. % of purity with minor amounts of lead, zinc, iron. The mechanism of copper extraction from Cu2S was suggested with possible reactions. The scanning electron microscopy and energy dispersive spectrometry (SEM-EDS) inspections confirmed the condensed sulphur and zinc oxide formations on the cold part of the system, i.e. graphite crucible and anode.
Keywords:
Copper; Electrolysis; Environment; Industry; Metals; Moltensalt; Processing; Technology;References:
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