Remove Gold from Circuit Boards
If you’ve opened an electronic device before, such as radios, televisions, or even your old cellphone, you’ve seen their inner workings. Ever noticed those shiny gold-colored parts on the circuit boards? Those bright pieces of metal are, in fact, gold. Gold is used on electronic circuit boards because of its excellent conductive properties and because it doesn’t corrode or rust over time. If you still have any of those circuit boards lying around, have a bit of fun and mine them for gold.
Contents
Steps
Removing Gold Using Nitric Acid
- Get protective gear. Be sure to wear a face mask, safety glasses, and industrial gloves. Chemicals and acids can irritate or even burn through your skin. Fumes from burning acids can also hurt your eyes and cause nausea when inhaled.
- Purchase concentrated nitric acid. Nitric acid is a clear liquid chemical commonly used for various industrial, steel, and wood works. You can purchase nitric acid from industrial or chemical shops.
- In some states and countries, however, you might be prohibited from buying nitric acid or you might have to meet certain standards before you’re allowed to purchase it. Check with your local authorities before purchasing.
- Put your circuit boards in a glass container. The container should preferably be Pyrex glassware or the kind that can withstand extreme heat.
- Break the circuit boards into smaller pieces before you put them in the glass container.
- Do not use plastic containers as the acid might burn right through it.
- Pour the concentrated nitric acid into the glass container with the circuit boards. As you put the acid in, burning fumes will start to come out of the container, so make sure you’re wearing protective gear.
- Stir the mixture using a glass rod until the contents become fluid in form. Since gold requires stronger chemicals to be dissolved, the nitric acid will melt all the plastic and metal parts of the circuit board without harming the gold bits.
- Drain the nitric acid from the mixture. Use a filter to separate the solid parts from the liquid.
- Pick out the unmelted parts. These parts will have the gold. Some plastic may still be attached to the gold, so you need to separate these little bits off the gold yourself. Be sure to use industrial strength gloves when you do so.
Removing Gold Using Fire
- Get protective gear. Be sure to wear a face mask, safety glasses, and industrial gloves to avoid breathing in the fumes released by the burning plastic. Use steel tongs to turn over the burning circuit boards.
- Get a metal bin or tray, and put the circuit boards into it. Break the boards into smaller pieces so they burn faster.
- Light the boards on fire. Pour a bit of gasoline over the pieces to put the pieces on fire. Turn the burning pieces over using steel tongs, and wait until the boards are burnt black.
- Put out the fire. Allow the pieces to cool down a little—just warm enough so you can touch them, but not too cooled down that the plastic hardens again.
- Break off the pieces of plastic attached to the gold parts. The burning process should have made the board materials brittle and easy to break.
- To be safe, wear protective gloves when breaking off the plastic.
Warnings
- Burning plastics can cause severe lung and environmental hazards, so do the process with extreme caution and consideration for others.
- Handle acids and chemicals with extreme care. Do not ever touch them with your bare hands to avoid severe chemical burns.
- Use acids and chemicals in a well-ventilated area to avoid inhaling the fumes.
- Dispose of the chemicals properly. Take the used acid to recycling plants.
- Take the burned plastic remains of the board to recycling plants in your area to dispose of waste properly.
