I've been refining as a hobbyist for 5+ years. I usually just do my work outside when the weather is nice but recently have wanted a small set up in my garage. So I devised my bucket scrubber!
It's a small scale scrubber for occasional use in my garage and I have been using with decent results. I'm in the process of updating the vacuum to a more potent suction source since I just used a cordless vac to start. The whole thing can be built for approximately $80-$100 and maybe even less depending on what you have on hand. The basics - I used a 5 gallon bucket, cordless vac, 100 PSI water pump, tubing and some misc PVC pipe. I took advantage of nitrogen dioxide's solubility in water by using a spray/mist nozzle to introduce to the gas being sucked into the bucket by the vacuum source. For the water, I fill the bottom of the bucket and this is used both a source and collection reservoir. Once I'm completed with the reactions - I neutralize the scrubber bucket contents to a pH of 8-10, which is safe for the material to be dumped down the drain.
Note.....I refine gold and silver in small quantities (ex. I use between 200 - 400 ml of HNO3 per batch) so this would need to be magnified for larger scale use.
It's a small scale scrubber for occasional use in my garage and I have been using with decent results. I'm in the process of updating the vacuum to a more potent suction source since I just used a cordless vac to start. The whole thing can be built for approximately $80-$100 and maybe even less depending on what you have on hand. The basics - I used a 5 gallon bucket, cordless vac, 100 PSI water pump, tubing and some misc PVC pipe. I took advantage of nitrogen dioxide's solubility in water by using a spray/mist nozzle to introduce to the gas being sucked into the bucket by the vacuum source. For the water, I fill the bottom of the bucket and this is used both a source and collection reservoir. Once I'm completed with the reactions - I neutralize the scrubber bucket contents to a pH of 8-10, which is safe for the material to be dumped down the drain.
Note.....I refine gold and silver in small quantities (ex. I use between 200 - 400 ml of HNO3 per batch) so this would need to be magnified for larger scale use.