Item

Small-scale recovery of noble metals from jewellery wastes.

Potgieter, J.H.
Potgieter, S.S.
Mbaya, R.K.K.
Teodorovic, A.
Citations
Altmetric:
Abstract
This paper describes an investigation to separate and selectively recover silver, gold and platinum from jewellery and laboratory wastes, and produce technical grade material suitable for training purposes. Nitric acid was employed to dissolve and separate silver and other impurities from gold and platinum, which were then dissolved in aqua regia and precipitated selectively. The current work quantified the effects of temperature, stirring rate, leaching agent concentration and solid: liquid ratio on the recovery of the various noble metals and in summary yielded the optimum treatment conditions in each case. It was found that increased leaching reagent concentration (in the case of Ag), temperatures and stirring rates enhanced the recovery kinetics and optimum yield of the three noble metals. An increased liquid to solid ratio also enhanced the recovery of the silver. Recovery yields 97.1%, 99.9% and 99.4% for silver, gold and platinum, respectively, were obtained. The recovered silver, gold and platinum had purities of, respectively, 98.3%, 99.1% and 99.0%. A cost saving of approximately R10 000 per kilogram of scrap refined could be achieved by the in-house treatment of the waste, not to mention the time-saving benefit.
Description
Date
2004-11-01
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Research Projects
Organizational Units
Journal Issue
Keywords
Noble metals, silver, gold and platinum, Laboratory, Mining, jewellery waste
Citation
Embedded videos