Selection of refractory materials for core induction furnaces

The induction furnace is a device that converts electrical energy into heat energy by using the principle of electromagnetic field induction to heat and melt the metal charge. The structure and working principle of the core induction furnace are similar to the transformer. The primary winding is a multi-turn coil on the iron core, and the secondary winding is a closed metal melting groove. When the induction coil is connected to a variable current, its alternating magnetic flux causes an induced current to flow in the molten groove, causing the molten groove to heat and melt. The induction furnace is suitable for continuous operation because the induction furnace can only operate normally when the molten groove is closed.

Copper properties for refractory selection

The melting temperature of the core induction copper melting furnace is generally between 1200 and 1350 ° C (the melting point of copper is 960 ° C), and the temperature of the melting zone of the inductor is 1350 to 1450 ° C. Due to the low melting point of copper, the viscosity of the copper liquid is small (close to At a viscosity of 0.1 Pas in water, the density is very strong, and the infiltrated copper is easily oxidized, accompanied by volume expansion, resulting in loose structure of the lining, cracking and spalling, thereby reducing the service life of the lining. The following compatible refractory materials should be used.

Induction melting copper furnace throat: corundum-mullite castable: add appropriate amount of steel fiber to increase density and toughness and enhance resistance to spalling.

Inductor melting groove: The special corundum material is selected, the main mineral phase is mullite and corundum, and a stable network skeleton is formed. Considering the permeability of copper, Si C is added to improve the wetting property of the material.

In addition: the furnaces of different manufacturers use different conditions, so the life cycle is also different. The general time is between 6 months and 1 year and a half. Of course, through exploration and continuous improvement, it will achieve very good results.