ABSTRACT
The main objective of the research group is the recovery of valuable metals (contained in PCB’s) such as Cu, Au, Ag, Pt, Pd, etc., by hydrometallurgical alternatives to the current ones used in mining.
One of the biggest difficulties that has encountered the research group is the lack of availability of an adequate, simple and reliable quantitative and qualitative determination technique of such metal values contained in the experimental technical solutions.
This paper presents the preliminary results obtained in carrying out various laboratory experiments aimed at building calibration curves and patterns to determine gold contents by UV/VIS absorption spectrophotometry technique. These experiments where carried on by dissolution of pure gold in an aqua regia solution (made with three parts of HCl per each of HNO3). Afterwards, the gold was extracted from the aqueous solution by an organic solvent (methyl-isobutyl-ketone or MIBK) and diluted solutions were analyzed with the spectrophotometer. Both direct absorbance spectra and second order derivative spectra were taken into consideration. Besides, it was evaluated the feasibility of applying this analysis technique on shredded samples of PCB’s.
The results showed that it is possible the construction of a standard curve using wavelengths around 332 nm and the analytical method is applicable to shredded electronic cards.
Keywords
Spectrophotometry; gold; E-waste; MIBK; calibration
