Separating Gold And Silver Dore Bars With Nitric Acid

Separating Gold And Silver Dore Bars With Nitric Acid

A dore bar is the metal that comes from the slag that has been fired and cooled.

  1. Place dore bar into a crucible.
  2. Fire in a furnace or oven. When using a muffle furnace, fire on high.
    It is ready when the metal is melted and looks like honey with no lumps in it.
  3. Pour quickly into a five-gallon bucket of cold tap water to form small BBs.
  4. Remove BBs from the water and place in a Pyrex container.
  5. Add 3 parts distilled water to 1 part nitric acid to the container.
  6. Place on stove or hot plate and simmer until only the gold is showing.
  7. Add a very small amount of nitric acid to check if all of the metals, except the gold are in solution.
    If the acid does not bubble around the gold, the metals are in solution.
  8. Add 10 parts distilled water.
  9. Filter the gold out of the container through a plastic strainer, or a funnel lined with a filter. The gold will be clean.
    DO NOT DISCARD THE SOLUTION AT THIS POINT BUT SET IT ASIDE – IT HAS YOUR SILVER IN IT.
  10. Let the filter and gold dry and put them into a crucible.
  11. Light the filter with a match and burn it.
  12. Cover the burned filter and gold completely over with borax.
  13. Place the crucible in a furnace or oven. When using a muffle furnace, fire on high.
    Gold fires at 1950 degrees F.
    The gold should lay flat and look like honey with no lumps in it when it is ready.
  14. Quickly pour gold into a mold and let it set in the crucible until it has cooled.
  15. Remove the gold and clean with warm water and soap.
  16. Drop a small amount of un-iodized table salt into the acid solution.
    If there is silver present, you’ll find a white substance that looks like cottage cheese.
    This is silver chloride.
  17. Filter off the silver chloride by putting the solution through a plastic strainer or funnel lined with a filter.
  18. Rinse the filter with the silver chloride in it 2 or 3 times with water.
  19. Dry the filter and silver chloride.
  20. Burn the filter by putting it into a clay crucible and lighting a match to it.
  21. Cover the silver and burned filter with soda ash.
  22. Place crucible in a furnace or oven and heat to 2100 degrees F. heat until silver is liquid, looking like honey and having no lumps in it.
  23. Quickly pour into a mold or let it set in the crucible until the silver has cooled.
  24. Remove the silver and wash it with soap and water.
  25. Add ¼ cup lime juice to the left over solution to neutralize it and dispose of it immediately.

Warning