Shoutingtoe
New member
- Joined
- Apr 27, 2018
- Messages
- 4
Hello, I am new to refining but I have been studying for a long time to get started. My project is to start with sluice concentrates sourced from an underground gold vein rich with gold and silver but mixed with pyrite. I started by mechanical separation with a blue bowl set up. this yields gold mixed with pyrite. I take this pyrite/gold mixture and roast at 1,000 degrees F for about an hour. Then I take the roasted material and smelt it with hank chapman flux + thinner and pour into a conical mold. At the tip of the cone I get what appears to be a gold/silver alloy that is slightly brittle. Next I take this metal cone, melt and pour into water to form shot. I take the shot and dissolve with nitric acid. (This is where my problems started) For the first run it seemed to be going well until I decided to crush the remaining slag and add to the reaction in an attempt to recover any remaining pm that didn't collect in the smelting process. This resulted in a thick gelatinous formation that pretty much stopped the reaction(my best guess is something to do with the silica in the flux). I attempted to thin this the gelatin with water and recover the remaining shot with a spoon. I then rinsed the recovered shot and started it in a separate nitric reaction. After the reaction died down I filtered out the remaining solids assuming it was mostly gold. I then incinerated the filter paper containing the solids and poured pre-mixed AR over them. I got an active reaction with red fumes. Once this reaction died down I added urea to neutralize the remaining nitric (I know now that I should have added the nitric to the HCL as needed to prevent excess nitric in the mix). When I added urea to the AR it just sank to the bottom and took a while to dissolve. I expected a head of foam as it reacted with the nitric like some videos I have seen but this did not happen. A stannous Chloride test was negative for gold in the solution but I assumed that I made the test solution wrong as I have no means to test it with a known gold containing solution at this time. I then filtered through several passes and then added sodium bisulfite and it just clumped up and collected on the bottom of the beaker. No foam or anything. I added a little heat (it was about 60 degrees outside) and it dissolved with stirring but dropped no gold. I am stumped at this point. I don't know where my gold is hiding. My next move is to make fresh stannous chloride and dissolve about 0.5g of 18k gold I have sitting around in AR then test the stannous solution to confirm it works. Then I plan to test all my solutions to see if I have gold in any of them. If this doesn't work the only place I can figure it may be is in a filter paper or in the thick gel/nitric mess holding the undissolved flux that I spooned out the remaining shot pieces from. I will definitely not be adding the crushed flux to the next batch!
Sorry this is so long but I tried to be as thorough as possible. Any suggestions as to where I went wrong or what I should try would be greatly appreciated. Thank you for your time. Also I have a concern that I may have accidentally created an explosive with the nitric acid and the gel that formed. Any thoughts on that?
Sorry this is so long but I tried to be as thorough as possible. Any suggestions as to where I went wrong or what I should try would be greatly appreciated. Thank you for your time. Also I have a concern that I may have accidentally created an explosive with the nitric acid and the gel that formed. Any thoughts on that?