The gold-adsorbing properties of silica sand(quartz) were examined. Silica sand was found to adsorbsignificant amounts of gold cyanide, and infra-red tests showedthe presence of Au(CN)_2~- on the surface. The results obtainedfrom a fire-assay showed that the gold adsorbed onto the silica,and did not merely attach physically to the surface. Thermaltreatment modified the silanol groups on the surface of the silica,which made it practically inert towards gold adsorption.
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