The heating methods of materials in the two crucibles are different.
Quartz crucible is more resistant to high temperature than graphite crucible. The maximum temperature of intermediate frequency smelting furnace is 2600 ℃, which is matched with quartz crucible; The maximum temperature of high-frequency smelting furnace is 1600 ℃, which is matched with graphite crucible.
The heating methods of materials in the two crucibles are different. There is no resistance in quartz. When the medium frequency current passes through, the metal materials in the quartz crucible generate induction heat, while the quartz crucible does not generate heat. It is suitable for smelting iron, aluminum, stainless steel, platinum, gold, palladium, etc; There is resistance in the graphite. When the high-frequency current passes through, the graphite crucible heats the metal materials through its own induction heating, and can smelt gold, silver, copper, alloy, K-gold, etc.
Quartz crucible can be used alone, but graphite crucible should be used with quartz jacket, because graphite will be oxidized. The quality of graphite crucible is related to its good material and density. A good graphite crucible has uniform oxidation, is not easy to eat gold, and causes low production loss; Poor graphite is oxidized unevenly, which will eat materials and cause high loss. If graphite is oxidized, it is easy to thin or even crack. Therefore, when using graphite crucible, you must put on a quartz crucible jacket, which plays a protective role.
By understanding the difference between quartz crucible and graphite crucible, we can better and more accurately select crucible when smelting metal.