Whether you are a goldsmith, a jeweler or just an ordinary person who has some gold to melt, the first important step to take is to select the gold melting machine that will suit your purpose. Second, you must follow some safety procedures to avoid sustaining any injuries during the process.
Irrespective of your chosen gold melting method, you must pay serious attention to these safety tips while melting your gold:
- Always wear safety goggles to protect your face/eyes.
- Put on a pair of heat-resistant gloves.
- Wear a heavy apron.
- Never melt gold near something that can easily catch fire.
- Always chose a safe place in your house or shop to melt your gold.
- Use a flux such as the mixture of borax and sodium carbonate to remove impurities from the gold. These impurities could be some pieces of other precious metals like silver, copper or zinc.
4 Classifications of Gold Melting Method
A modern approach/method to melting gold is to use furnaces, and this article highlights the 4 main classifications of gold melting furnaces:
1. Using A Propane Torch: This gold melting method will melt a bar of gold within a few minutes. Put the gold in a crucible and place it on a fireproof surface. Bring the lighted torch to the gold and watch it melt in minutes. You can lower the melting temperature by adding borax to the gold beforehand. Focus the heat from the propane torch slowly and deliberately on the gold pieces. Do not do this in a hurry, or else you may blow up the gold pieces or crack the crucible. If you want more heat, you can use an oxy-acetylene torch instead of a propane torch. If you are melting some gold powder, make sure you supply the same amount of heat on the entire powder so as to get uniformly melt gold. Use a pair of strong tongs to pour the melted gold into the awaiting receptacle to form your desired, new shape.
2. Using Electric Gold Furnace
- Induction Gold Melting Furnace: The induction gold melting system is utilized in both high and low production levels, whether at the mining facilities, gold refining plants, or during gold wholesaling/retailing. This process is efficient because it is environmentally friendly (and largely considered to be a Green Technology). Therefore, it does not produce/release harmful emissions (pollutants) into the atmosphere, since the heating system is produced from the alternating magnetic current and directed into the SIC crucible or graphite. Other great advantages of induction furnace are that the heating is fast and homogenous melts can be obtained by frequently stirring the melting gold using the equipment’s electromagnetic system. Since it doesn’t require combustion or an arc, the induction furnace does not heat up the environment where the workers are; the only generated heat comes from the actual melts. The entire process of gold melting using induction furnace can be controlled, unlike other methods. At a certain controlled temperature, it is possible to obtain only the gold without losing other alloys or precious metals. And one sample of the cast gold represents the whole batch of melted gold. However, induction furnace is not mainly suitable for gold refining purpose, and the oxidization of other alloyed materials may occur during the melting procedures
- Resistance Furnace: The resistance furnace gold melting system is basically built for mining operations. It is more time-consuming when compared with the induction furnace system. However, it offers a wide range of temperatures, up to 1500 o C. Its temperature-controlling feature is automated. Resistance furnaces are well sealed, and this prevents heat from escaping from the vacuum created in the system. Resistance furnace also contains a gaseous medium that prevents oxidization and hardening of the gold sample someone is working on. But resistance furnace is not suitable for melting large quantity of gold—this type of furnace is built for small to mid-sized mining operations.
3. Use of 1,200-Watt Microwave Oven
A microwave oven is not only used for cooking purposes, but it is also a great gold melting method. It is advisable that you utilize a microwave that has no magnetron on its top, but rather on its back or side. You would need a gold melting kit or kiln to be placed inside the 1,200-Watt microwave oven. Then put the crucible that contains the gold bar, pieces or powder in the kiln. Do not forget to put a lid on the kiln. Adjust the microwave’s thermostat to 1,200 Watt to slowly melt the gold. For health reasons, do not use the microwave oven you have used to melt gold to cook food—the food may be contaminated.
The Comparison Table for the Three Types of Furnaces
|Item||Propane Torch||Induction Furnace||Resistance Furnace|
|Price performance||Higher||The highest||The lowest|
|Environmental friendliness||Less environmental friendly||The most environmental friendly||Less environmental friendly|
|Heating speed||A bit slower heating system
2kg gold is molten within 15mins nearly
2kg gold is molten within 3mins nearly
|The slowest heating system
2kg gold is molten within 20mins nearly
|Homogenous melts||Does not have electromagnetic stirring feature||The electromagnetic stirrers make it very easy to produce homogenous melts||Resistance furnace does not have electromagnetic stirring feature|
|Degree of productivity||Higher||The highest — because no warm up or cool down cycle needed. And the start-up time is surprisingly fast||Higher|
|Energy generation||Unclean energy through combustion is required||Clean/green energy generation through electromagnetism||Electric or slag generation|
|Energy consumption||Higher||The lowest||The highest|
|Moten metal stirring||No stirring function. it is by resistance heating transferring||The magnetic field will stir the molten metal to realize mixing alloy abundantly based on induction heating||No stirring function. it is by resistance heating transferring|
|Protection alarm||None||Over voltage warning, Over current warning, lack of water warning, phase loss warning, improper frequency warning||None|
|Working time||After 2-3 hours working, need 30 mins stop working for cooling||Theoretically, 24 hours continuous working||After 2-3 hours working, need 30 mins stop working for cooling|
The bulk of information presented in this article confirms the degree of usefulness of Induction Gold Melting Furnace as a great gold melting method. It can melt big amount of gold without experiencing any problem. Using induction furnace helps in saving some melting time, and because it has the capability of building up heat, it can rise to correspondingly high heat levels. As an environmentally friendly method, induction furnace does not produce smoke, pollutants, dust or any other kinds of harmful emissions. The machine does not need external cooling system because it has induction coils, water-cooling system, and induction power supply that constantly keep the coils of the furnace and its internal parts cool.
This is why induction gold melting furnace is very popular with gold miners because it provides unique opportunity to maximize production within a short period of time. When compared with the traditional gold melting method, induction furnace is cost-efficient, manageable, and peaceful to the environment.
On the other hand, Electric Arc Furnace is the opposite of what induction furnace stands for. Its heating system is powered by non-clean energy generation system—combustion, and it is practically non-environmental friendly. It takes a lot of time to start it and cool the system. And it costs a lot to make its procedures environmentally friendly.
However, resistance furnace comes between both induction furnace and electric arc furnace, but it does not possess the same sterling qualities of the induction furnace.