I’ll start by saying thank you to anyone in advance who might be able to help me make sense of this mess I’ve created… I’m certain I am not the first newbie to show up on a refining forum with a messy soup and no idea what to do next. Below I will describe how and what lead me up to this point.This started with two separate solutions that I mixed together and boiled down to a concentrate.
Solution one came from a bit over 300 grams of 10k-18k white gold where the gold was inquarted to 25%. The first issue arose here where I had one stubborn ring that didn’t want to melt along with the rest but now had gold stuck to it so I just left it in and went on to the nitric boils. A total of four nitric acid boils were used in attempt to remove the base metals and silver from solution. My next problem arose here where much of the gold disintegrated and a fair amount went colloidal. Also, that ring that wouldn’t melt was still hanging around with only small pieces of it appearing to have dissolved away in the nitric and it still had chunks of inquarted gold alloyed to the sides of it. This is when I started thinking the ring must have been platinum or palladium, and not the stainless steel or tungsten that I assumed it to be during the melt process. Yes, all of my nitric books were a deeply saturated green up until this point, but I expected that because all of this gold was white gold and most of it was vintage to antique, so I already assumed I’d be dealing with a fair amount of PGMs here. Attempts to filter proved to be extremely difficult and I decided to turn the solution into aqua Regia even though it was still an obvious green color. I precipitated out the gold using smb without issue and after multiple washings and another refining in ar, the majority of gold was clean and accounted for. What I was left with is was a few green solutions that I boiled down into a deep green, verging on black, concentrate. Once allowed to cool cubic crystals had formed across the bottom of the beaker. I separated the remaining dark green solution from the crystals and washed them with distilled water. They were pretty white and grew in the same sort of cubic way that bismuth does. I tested the concentrate solution with stannous chloride on a piece of filter paper and it returned a greenish-brown indication. I added some nitric to the white crystals and the resulting solution immediately turned yellow with some of them appearing to disintegrate but not fully dissolving. I tested this yellow solution with stannous and got a weak orange result. I took one of the crystals, now yellow due to the nitric addition, and placed it on a watch glass. I added a few ml of distilled water to it at a time to get it dissolved which it eventually appeared to do, or at least form a suspension, which was a weak milky white. I added a few ml of stannous chloride to this and it turned a weak brown color. In the mean time I took a few pieces of clean copper pipe and placed them in the dark green solution in attempt to cement out any PGMs in there. Over the course of a couple of hours the solution went from deep, dark green, to a very very deep brown color with no obvious metals cementing out of solution and accumulating on the bottom. Ugh.
Solution 2 was 120 grams of unknown dental scrap I had acquired years ago and didn’t know the composition of other than presumably not gold as it was sold to me as not gold but possibly containing platinum. The only testing I did on it at the time was submerging the scrap in weak hydrogen peroxide and noticing a weak bubbling coming off of the submerged metal at room temperature. I did not further testing and when I recently came across it, it was recklessly tossed into an ar solution which caused it to dissolve. I wish I could remember more about this reaction but I didn’t take notes and I forgot most of it. I do remember the solution appearing to be a deep green color. Cleaned copper fittings were added and the solution turned a deep brown color, exactly like the first solution. A stannous test showed a light brown-to-green result. I diluted the solution with distilled water and a bunch of white precipitate came crashing out and the resulting solution went from a deep brown color to a deep green (but transparent) solution. I didn’t know what this was or how to handle it so I boiled the solution back down, the scary white crystals went away, and the resulting solution was back to being a deep, deep brown color, with no possibility of light transmitting through it. After allowing the solution to cool overnight, crystals had formed at the bottom of the beaker and the solution was back to being very deep and dark green. the crystals were small, very hard, and as clear as glass. I added water and threw the solution back up on the heat to make the scary crystals go away.
Yesterday was cleanup day because I needed my glassware back that had been commandeered by countless little side quests in this gold refining journey and I took all of the solutions that I assumed had PGMs in them and put them all together in one large beaker and boiled them all down into a concentrate. The resulting photos were taken this morning. It appears I have managed to cement some metal out of solution on the copper that stayed with the solutions through the boiling yesterday. The cemented metal appears to be grayish like silver so I’m now assuming that was silver chloride that came crashing out of solution 2 when it was diluted with distilled water, I was unaware silver could remain in solution with hydrochloric acid but the resulting cemented metal is not dark like I assume a PGM would be. I also managed to grow one heck a of scary looking crystal. My immediate reaction was to want to throw some distilled water on it and get it up on the heat to make it go away but I reasoned that continuing to run from my problems is not getting me the results I want and I just need to ask for help at this point. So… with a hanging head and my tail between my legs I am here to humbly ask for any help I can get on figuring out how I recover the PGMs from this God forsaken soup I’ve created..
