mikemrtwin
Member
- Joined
- Dec 31, 2020
- Messages
- 11
Hello, I have refined a bunch of gold jewelry. Towards the end of the traditional refining I found it to be heavily contaminated with selenium. About 0.455%
I was suggested to use sodium hydroxide to keep the selenium in solution while the gold precipitated. Reading more into the topic it states that it has to be done at boiling temperatures but that statement meant that it will drop out as sodium selenide. I did experiment with it and I noticed that the gold would drop out first prior to hitting a pH 2. I did two experiments with oxalic acid and sodium hydroxide and just sodium hydroxide. At the end of the oxalic and sodium hydroxide test pink residue was coming out. I'm assuming this is sodium selenide and the remaining oxalic acid dropping out again.
I still find that the gold sample is testing high in selenium. During the testing the reaction between the gold bearing solution and sodium hydroxide was very violent. Can anyone clarify on the proper procedure? Would anyone be interested in refining the selenium out for a small portion of the gold and let me know there procedure?
I was suggested to use sodium hydroxide to keep the selenium in solution while the gold precipitated. Reading more into the topic it states that it has to be done at boiling temperatures but that statement meant that it will drop out as sodium selenide. I did experiment with it and I noticed that the gold would drop out first prior to hitting a pH 2. I did two experiments with oxalic acid and sodium hydroxide and just sodium hydroxide. At the end of the oxalic and sodium hydroxide test pink residue was coming out. I'm assuming this is sodium selenide and the remaining oxalic acid dropping out again.
I still find that the gold sample is testing high in selenium. During the testing the reaction between the gold bearing solution and sodium hydroxide was very violent. Can anyone clarify on the proper procedure? Would anyone be interested in refining the selenium out for a small portion of the gold and let me know there procedure?