Recovering gold chloride from used solutions
For the chemistry experts among us, Has anyone tried, been successful, or know the techniques for recovering gold chloride from previously used toning solutions. In my case, I use gold chloride mixed with distilled water and sodium thiosulphate (common photographic fixer) for gilding daguerreotypes. I have been saving my used gilding solutions so that one day I could attempt to recover some of the unused gold, in the hopes of reusing it again for additional gilding. That day has come, seeing as I now have several gallons of used solution waiting for recovery or disposal. The gold chloride I use is reagent grade HAuCl4 and only a gram of it is used in a quart of mixed solution. Any recommendations, website referrals, etc. are welcome. I have not yet done any Google searches, thinking I would first post the query here, in the hopes someone had already been successful in recovering the gold from their toning solutions. I want to be able to do this myself, as there is not enough gold in the solution (thus not cost effective) to pay someone else to recover it. Thanks in advance, Rob McElroy Contemporary daguerreotypist Buffalo, NY |