Induction Melting Furnaces
An induction furnace operates by utilizing electrical energy to generate heat through the process of induction heating within the metal. It functions by channeling induction power into the furnace via a coil constructed from hollow copper tubing. This action generates an electromagnetic field that permeates the conductive metal placed within the furnace, prompting an electric current to circulate within the metal itself. As a result, heat is produced internally, efficiently melting the metal. While certain surfaces of the furnace might reach temperatures high enough to pose a risk of burns, the induction method directly heats the metal charge rather than the furnace itself, making induction melting a distinctively efficient process.
Induction heating is recognized as an environmentally friendly technology because it produces no harmful emissions, thanks to the generation of heat through an alternating magnetic current directed into a graphite crucible. Additionally, this method offers several benefits for gold casting, such as rapid heating times and frequency stirring, which results in more uniform melts. Moreover, induction melting technology maintains a cooler surrounding environment for the operator, as the only heat produced is directly from the melting process itself.
Traditional Gold Melting
The conventional method of melting gold, originating from the early days of the gold rush, continues to be practiced in various regions worldwide, particularly in areas with limited access to modern gold melting technologies or machinery. This process involves melting the gold in an open crucible using a gas furnace, which can significantly raise the temperature of the surrounding environment where the melting occurs. The primary disadvantages of this traditional gold melting approach include the need for a substantial workforce, its negative impact on the environment, the potential loss of some gold during the process, and the inability to prevent oxidation and other forms of degradation that could compromise the quality of the gold.
| Traditional Melting Methods | Metro Gold Melting Machines |
| First melting usually takes as long as 30 to 45 minutes. | In Metro melting machine, once the power is switched ON, melting process starts immediately, there’s no warmup required. |
| In this method, the coil gets heated first & then the heating of crucible takes place followed by the metal heating, which results in loss of heat and metal. | Metro melting machine creates heat in the metal by inducing low voltage high current electrical energy in the metal to be melted with help of temperature sensor and graphite crucible gets heated evenly from all sides. The metals start melting, there’s no direct heat on the metal hence there’s no melting loss. Hence Metro machine is known as Energy Saving Flameless Furnace. Benefit of 40% IT depreciation. |
| Due to the heat loss the power consumption is always more. | Due to less melting time, melting process is faster, and saves energy. |
| Because of no stirring effect the metal does not properly melt. At the time of pouring of the ready metal it is found that he metal oxides also come out with the finished metal creating as improper metal stock or rod. | Due to 100% accurate temperature control, there’s no metal loss and mixing is homogeneous. Crucible is made of pure graphite and melted metals does not stick to the sides of the crucible wall and can be easily transferred into a mould. |
| As there is no water circulation the temperature of the workshop unit remains hot for very long time. | Chilling unit is an additional accessory which keeps the induction unit cool and melting unit can be operated continuously for 8 hrs without any breakdown. |
| There is no auto stirring and the metal is stirred with the help of a carbon rod. The metal sticks to the carbon rod leading to loss of metal and also mixture of carbon with metal. | Automatic mixing and stirring is the key feature in metro melting machine which results in homogeneous mixing of metals and hence no melting loss. And gives better jewellery quality and finishing. |
| As there is no stirring effect, there is additional of copper and silver in gold (99.99%) it is not in uniform micro structure. | Due to automatic temperature control and stirring, results in 100% homogeneous mixing of alloys |
| Due to second melting process the heat is excessively spread out so it is very difficult to put metal in the form of dust or scrap in the crucible. | In Metro machine, heat transfers evenly to all sides of the crucibles resulting in no melting loss. It is also user friendly and easy to operate. |