Industrial production gold separation

Recovery of noble metals, from such raw materials, requires individual approach to each material and application of selective methods for their removal. Moreover, separation of noble metals, particularly platinum metals and gold from geological samples, industrial products and S)mthetic mixtures along with other elements, is a problem of significant importance nowadays. 

Hydrochloric acid was known in Europe during the Middle Ages under the name of spirits of salt. The industrial production of this acid developed as a by-product of the manufacture of alkalis, notably of calcium carbonate. Nitric acid was utilized by Albert le Grand to separate gold from silver. Lavoisier showed that nitric acid contained hydrogen and nitrogen. Industrial manufacturing commenced in the nineteenth century, by diverse methods which allowed lower and lower costs. 

The interest of using fine-pore thin-film ceramic or metal membranes for isotope separation (e.g. uranium) is still apparent even after years of production practice [Miszenti and Nannetti, 1975 Sumitomo Electric Industry, 1981]. Isotopes other than uranium, such as those of Ar or Ne [Isomura, et al., 1969 Fain and Brown, 1974], can also be separated by gaseous diffusion. The membrane materials having been successfully tested for these specific applications include alumina, glass and gold. 

Based on the above considerations effect of gold nanoparticles loading in polydimethyl siloxane matrix was examined for the separation of CO/CO2, CO/CH4 and CO2/CH4. The above gas mixtures are the product of syngas reaction and their separation is of great significance to industrial application in natural gas purification. PDMS have received considerable attention as potential membrane material for gas separation because of their high intrinsic permeability to gases and vapors. 

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