You can melt scrap gold at home using a few specialised tools. Pure 24 carat gold has a melting point of 1,060 degrees C. Most gold is 14 carat, meaning it contains other metals as well as gold. Fine gold dust and flakes obtained from prospecting usually contain impurities and need to be mixed with a flux to help keep the particles from blowing away with the force of the torch. The flux also helps to pull out the impurities.
Put on protective gloves, eye goggles and a respirator mask.
Place your scrap gold in the dish part of the crucible. Sprinkle in a few pinches of borax and a few pinches of sodium carbonate and mix it all together with the gold. This will act as your flux.
Fire up the torch and carefully add the flame to the gold in the crucible. Proceed slowly, especially if you are trying to melt down fine gold flakes. Continue using the torch until all the gold melts. Use the crucible tongs to help break up any pieces that are taking a while to melt.
Pour the molten gold very carefully, using the tongs, into a brick- or bar-type mould. Allow it to set and cool before removing.
Never use ceramic crucibles because the torch added to the borax could cause the crucible to spring a leak, dangerously spewing molten gold everywhere.