Recovery of precious metals by an electrochemical deposition method.
Conversion of soluble precious metals into a solid form for further reuse was studied by using an electrochemical deposition approach. It was found that the metal recovery followed a first-order reaction kinetics. The distance between the electrodes had no much impact on the recovery, while higher mixing led to faster kinetics. The presence of humic acid (HA) with lower concentration (<20mg l (-1)) did not have impact on the recovery. When its concentration was increased to 50 mg l (-1), it decreased the metal reduction. Presence of ethylene diamine tetraacetic acid (EDTA) and ionic strength slightly reduced the copper recovery rate. Around 50% removal of for HA and EDTA was achieved. In the competing environment, metal recovery was in the following order: silver>lead>copper. X-ray photoelectron spectroscopic and scanning electronic microscopic analysis of the reduced metals demonstrated that the depositions were composed of mainly elemental metals together with their oxides which were due to the oxidation.
Paul Chen
J
J
Department of Chemical and Biomolecular Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore. jchen.enve97@gtalumni.org
Lim
L L
LL
D002614:Chelating Agents / Q000737:chemistry; D003247:Conservation of Natural Resources; D003300:Copper / Q000737:chemistry / Q000302:isolation & purification*; D004492:Edetic Acid / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D006812:Humic Substances; D007700:Kinetics; D007854:Lead / Q000737:chemistry / Q000302:isolation & purification*; D009994:Osmolar Concentration; D010084:Oxidation-Reduction; D012834:Silver / Q000737:chemistry / Q000302:isolation & purification*
D002614:Chelating Agents; D006812:Humic Substances; D007854:Lead; D012834:Silver; D003300:Copper; D004492:Edetic Acid