RickRag
Active member
Hi guys,
My previous posts were in regard to difficulties cementing Pd and Pt using copper bus bar stock from chloride solutions from which all gold had been dropped. I kept geting a positive SnCl reaction that has become another topic for others to discuss regarding electromotive potentials etc. of specific ion valences in the presence of Sn.
In reference to my original issue, I appeared to have solved my cementation problem by heating the AR solution containing Pd and maybe Pt having dropped to gold using SMB. In some instances, a LOT of SMB due to an excess of NO3 left in solution from the nitric. Anyway, I ended up with a lot of solution (8L) that was reluctant to cement the values at room temperature suing an air bubbler for agitation. Accordingly, after getting a suitable result with simple heating of the AR, I discarded the initial spent solution and proceeded to heat 2L portions from the origianl reluctant 8L. I was also using a rather thin copper plate rather than the thicker bus bar. The 2L sample did appear to have some cementation occur even thoug the solution was mostly barren. The problem I am inquiring about now is that in addition to the solution cementing values it also formed a white-ish precipitate after heating. This precipitate was rather flocculent as it took up the blee color of the copper in solution easily. Is this CuSO4? I am filtering the precipitate and cemented values as we speak but would like to dissolve the white precipitate so it doesn't contaminate what littel Pd may have been cemented. I haven't tried to dissolve it in anything yet so I am waiting for the answer to this post before proceeding. A little help would be appreciated.
Rick
My previous posts were in regard to difficulties cementing Pd and Pt using copper bus bar stock from chloride solutions from which all gold had been dropped. I kept geting a positive SnCl reaction that has become another topic for others to discuss regarding electromotive potentials etc. of specific ion valences in the presence of Sn.
In reference to my original issue, I appeared to have solved my cementation problem by heating the AR solution containing Pd and maybe Pt having dropped to gold using SMB. In some instances, a LOT of SMB due to an excess of NO3 left in solution from the nitric. Anyway, I ended up with a lot of solution (8L) that was reluctant to cement the values at room temperature suing an air bubbler for agitation. Accordingly, after getting a suitable result with simple heating of the AR, I discarded the initial spent solution and proceeded to heat 2L portions from the origianl reluctant 8L. I was also using a rather thin copper plate rather than the thicker bus bar. The 2L sample did appear to have some cementation occur even thoug the solution was mostly barren. The problem I am inquiring about now is that in addition to the solution cementing values it also formed a white-ish precipitate after heating. This precipitate was rather flocculent as it took up the blee color of the copper in solution easily. Is this CuSO4? I am filtering the precipitate and cemented values as we speak but would like to dissolve the white precipitate so it doesn't contaminate what littel Pd may have been cemented. I haven't tried to dissolve it in anything yet so I am waiting for the answer to this post before proceeding. A little help would be appreciated.
Rick
