Removal and recovery of platinum group metals through anode slimes of moebius electrolysis

Annual primary gold production in the last decade has been within the range of 2500 to 2800 tons per year while the sectoral distribution of annual consumption has been 4-5% electronics (coating scart plugs, foil production, solar collectors for artificial satellites etc.), 8-10% ingot stocks (kilobars, large-bars) and 85-88% jewellery (jewellery and ornaments). These distribution statistics show that the main field of use that introduces gold into global circulation is jewellery. The largest loop of gold circulation on a global level rises from resales by users for liquidifying gold assets for profit at times of rising unit prices or for emergency cash, or reselling ornaments when they fall out of fashion. For example, the amount of gold delivered to the three major refineries and forty two unregistered businesses in Istanbul's Grand Bazaar in the form of operation residue (recycling) or re-melted scrap (wedge) is over 5 tons per day. In other words, every year ca. 1500 tons of gold is refined in Istanbul alone. The amount of refined silver is around 4000 tons. The Platinum Group Metals (PGM) remaining in gold and silver as it commercially changes hands are subject to dispute due to inadequate technical procedures that work either in favor of the seller or the client. 5‰ copper and/or silver may be present legitimately in 24 carat gold corresponding to 995‰. However, the only method of analysis in use for gold trade is cupellation and it fails to detect platinum, ruthenium, rhodium, osmium, iridium metals (except palladium) as they do not dissolve in nitric acid and therefore behave like gold through this analysis. Consequently, they are only noticed when they form "blisters" on the surface due to segregation during pure ingot casting. It is possible to remove and recover PGM from gold and silver by designing the right processes for their refining. Silver especially is a perfect collector fo platinum group metals, and also the easiest metal to extract platinum group metals off of. Moebius Silver Refining Electrolysis is the most effective method for preventing PGM from infusing into gold and silver. Within the scope of this study, this method was applied, on spilled silver bullions in anode form and with varying PGM content from different process phases of a noble metal refinery in Istanbul. Throughout the electrolysis procedure chemical extraction and recovery of the PGM from accumulating anode sludge and characterization of the products were performed. The characterization of raw slimes and synthesized powders were carried out by stereo microscope (SM), X-ray diffraction spectrometer (XRD), scanning electron microscope (SEM) and energy-dispersive X-ray spectrometer (EDS) function of SEM. The analysis solutions were performed in atomic absorption spectrometer (AAS).