Classification and quality requirements of crucible for induction melting furnace
1, Classification of crucibles: there are three kinds of induction furnace crucibles according to materials, alkaline crucible, acidic crucible and neutral crucible. The most widely used binder is boric acid.
The functions of boric acid in the manufacture of acidic (quartz sand) or alkaline (magnesia) crucibles are as follows:
1) Reduce the sintering temperature.
2) Promote the formation of spinel.
3) Reduces the volume change rate of the crucible.
According to the manufacturing methods, there are three manufacturing methods for crucibles: prefabricated shaped crucibles outside the furnace, shaped crucibles inside the furnace and masonry crucibles.
2, Quality requirements of crucible: the main requirements for crucible refractories are:
1) High refractory and high temperature structural strength.
2) Good resistance to quench and heat.
3) Good slag resistance.
4) That thermal conductivity is as low as possible.
5) Insulation performance.
6) No pollution, no harm, low volatility, strong hydration resistance and low cost.