THE DANGERS OF AQUA REGIA:  When adding aqua regia to ore, there can be use a red gas given off; THIS RED GAS CAN KILL Sometimes the ore will bubble over, so watch it carefully. Use the aqua regia in an open area and it to the ore very slowly.

Aqua regia cannot be boiled or simmered in the house or where it is not well ventilated. This can cause serious illness or KILL YOU! Use a vent hood with an exhaust fan or simmer in the open.

Hydrochloric acid is very dangerous. It can burn to the bone and is extremely painful. In most cases, it has burned before you know it.

Nitric acid can be absorbed through the skin, causing nitric acid poisoning, which makes you very ill. WEAR RUBBER GLOVES!

Aqua regia, nitric acid and hydrochloric acid can kill if swallowed.

Always wear rubber gloves, plastic safety glasses and a plastic or rubber apron.

Aqua regia can ruin your clothes and shoes.

Equipment Used

  • Breaker, coming ware or Pyrex container.
  • Hot plate or camping stove.
  • Wooden or plastic spoon for stirring. A glass rod can be used.
  • Squeeze bottle, such as a soap bottle, containing distilled water for washing the beaker.
  • Ash-free or coffee filter. An Ash-free filter is best, but it costs more and is harder to find.
  • A plastic funnel or strainer to use with the filter.A bottle or beaker to filter the liquid into.

Ingredients Used

  • Gold or finely powdered ore.
  • Hydrochloric acid.
  • Nitric acid.
  • Formic acid.
  • Sodium sulfite or sodium bisulfite.
  • Tap water and distilled water.
  • Un-iodized Salt.

How To Use Aqua Regia To Purify Gold

  1. Place your gold or finely powdered ore in a Pyrex container breaker.
  2. Mix 1 part nitric acid to 3 parts hydrochloric acid in a separate glass or plastic container. When mixing the acids together, use great caution!
  3. Add the acid mixture, very slowly, to the Pyrex container or beaker containing the ore.
  4. On stove or hot plate, simmer until the gold is in solution and nitric acid is boiled off. It will look like maple syrup and be a yellowish to orange color.
  5. To make sure all the nitric acid has been boiled off, add a small amount of formic acid. If nitric acid is present, a reddish brown gas will be given off. Add hydrochloric acid, if necessary, to keep the material covered with liquid. Continue simmering until the nitric acid is gone.
  6. Filter off any solids that are not in solution through a plastic strainer or funnel lined with a filter. Neutralize this material with lime juice and discard.
  7. Add to the liquid solution an equal amount of water.
  8. Drop a small amount of un-iodized table salt into the mixture to check for silver. If silver is present, a white substance will fall to the bottom of the container. This is silver chloride Continue dropping small amounts of salt in until the silver chloride stops falling.
  9. Filter off the silver chloride through a plastic strainer or funnel lined with an ash-free or coffee filter.
    DO NOT DISPOSE OF THE ACID SOLUTION-SET IT ASIDE!
  10. Rinse the filter containing silver chloride with water.
  11. Dry the filter and silver chloride with water.
  12. Place the filter and silver chloride in a clay crucible and burn the filter by lighting a match to it.
  13. Cover the silver chloride and burned filter with soda ash.
  14. Place the crucible in a furnace or oven and heat to a temperature of 2100 degrees F until the silver is a smooth honey-like liquid with no lumps in it.
  15. Immediately Pour the silver into a mold or let it set in the crucible until it is good.
  16. Remove the silver and wash with soap and water.
  17. Take the sodium that you set aside (see step 9) and a little sodium sulfite. The gold will start to fall. Continue to add the sodium sulfite until the gold stops falling. You should see black specks that look like pepper. This is gold sulfide.
  18. Filter off the gold sulfide through a plastic strainer or funnel lined with a filter.
  19. Rinse the filter containing gold sulfide with water.
  20. Dry the filter containing gold sulfide.
  21. Put the filter and gold sulfide into a clay crucible and burn the filter by lighting a match to it.
  22. Cover the gold sulfide and burned filter with borax and place the crucible in a furnace or oven and heat to 1950 degrees F until the gold is a smooth, honey-like liquid with no lumps in it.
  23. Immediately, pour the gold into a mold or let it set in the crucible until it is cool.
  24. Remove the gold and wash with soap and water.
  25. Add ¼ cup lime juice to the acid mixture to neutralize it and dispose of it immediately.

Warning