Method 1: melting gold
1, put gold jewelry or gold nuggets in the crucible. Most crucibles are made of graphite, so they can withstand the high temperature of melting contents.
2. Place the crucible on a fireproof surface.
Aim the torch at the gold. Aim the flame at the gold until it is completely melted.
4. Pick up the crucible with the crucible pliers.
5. Divide the gold into small pieces and wait for the gold to solidify. This is called "making small balls". If you want to extract a small amount of gold, such as rings, then you don't have to go through this step, just melt it directly.
Method 2: Add aqua regia.
1, select the appropriate container. Every ounce needs fine gold, and you need to prepare a container with a capacity of at least 300 ml.
You can use a larger plastic bucket or a glass pot.
2. Wear protective tools. Wear a pair of rubber gloves to protect your hands from strong acid. Remember to wear gloves before touching any chemicals mentioned in this tutorial.
Wear a rubber apron to protect your clothes.
Wear goggles to protect your eyes.
You can consider wearing a mask to avoid inhaling harmful gases.
3. Place the container outdoors with good ventilation. In the process of treatment, the gas produced by this strong acid is likely to be very harmful and dangerous.
Every ounce of gold put into the container needs to be poured with 30 ml of nitric acid. Let nitric acid react with gold for 30 minutes.
5. Every ounce of gold needs120ml hydrochloric acid. Leave it overnight for reaction until all the generated gas is exhausted.
6. Pour the acid into another larger container. Never pour out small pieces of gold with acid, otherwise it may damage the gold.
The acid should be ruby green. If the color is cloudy, then you should filter the acid with a Brinell filter funnel.
Method 3: Add urea and precipitant.
1, add 946 ml of water, and add 453 g of urea to the water. Continue heating until boiling.
2. Slowly add the mixture of urea and water into the acid. When water and urea are added, the acid bubbles. Be sure to move slowly to prevent bubbles generated by strong acid from overflowing the container.
Neutralize nitric acid with water and urea, but do not neutralize hydrochloric acid in the mixture.
3. According to the instructions provided by the manufacturer, add the selective precipitant of gold into 946 ml of boiling water. Usually, every time 1 ounce (about 28g) of gold is refined, 1 ounce of precipitant is added.
Don't put your face near the open container, because the smell is heavy and pungent.
4. Slowly add the solution mixed with precipitant. The acid will turn brown like mud, which is actually caused by separated gold particles.
Wait for 30 minutes for the precipitant to give full play to gold.
Method 4: Test the acid used to dissolve gold.
1, put the stirring rod into the acid solution.
2. Drop a drop of solution at the end of the paper towel.
3. Drop a drop of precious metal test solution on it. If this turns purple, you need to give the precipitant more time to precipitate, and then pour out the acid.
4. After separating the acid from the dissolved gold, immediately pour the acid into a clean container. At this time, the acid should be amber, and there should be a muddy substance at the bottom of the container.
Don't throw away the dirty things, they are all pure gold.
Method 5: Wash gold.
1. Add tap water to the remaining turbid substances in the container and stir to precipitate the turbid substances.
2. Pour the water into the acid container.
3. Wash the clay gold with water for 3 to 4 times, and then pour off the excess water.
4. Wash gold with ammonia water. You will see white fog on the surface of muddy gold. Be sure to protect your eyes and don't inhale gas.
5. Wash off the ammonia on the gold with distilled water.
6. Pour the turbid gold into a big beaker, and pour out all the remaining distilled water, so that there is only gold in the beaker.