The forming method of the intermediate frequency furnace lining can be roughly divided into four types according to the size of the crucible, such as mortar casting molding, pressure molding, furnace molding and masonry. The first two methods are mainly used to make small capacity (less than 100kg), and the latter two methods are suitable for the production of medium and large capacity.
1. Mortar casting method
This crucible molding method is suitable for the production of special refractory materials with a capacity of less than 25 kg, such as CaO, BeO, ZrO2, ThO2, Al2O3 and the like.
2, pressure molding method
The sand material to be produced is mixed uniformly according to different particle size ratios, and then placed in a pressure forming mold and subjected to pressure to form. The pressure forming method can be divided into two types: simple pressure forming and isostatic pressing.
a) Simple pressure forming is to load the sand into the cavity of the mold before pressing, and to form the slab blank by the up-and-down pressing of the upper and lower rams. The sand should contain a certain amount of moisture and additives or binders. After demolding, it can be used after drying and high-temperature sintering. It can also be placed in the inductor and sintered by molten steel temperature.
b) The cold isostatic pressing process is a powder metallurgy forming process that applies equal pressure to the entire surface of the object to be pressed. That is to say, the pressure at each point on the surface of the object to be pressed is exactly the same, so it is called isostatic pressing. Since the pressed object is not heated during the pressing process, it is also called cold isostatic pressing.
3, furnace molding method
In-furnace molding is a widely used crucible molding method. It is suitable for 坩埚 forming of different capacities. The in-furnace forming method is further divided into an artificial twist forming method and a mechanical vibration forming method.
4, masonry
The masonry method uses special refractory bricks to be built into the furnace. This method is suitable for hot charging large induction furnaces. More than 5 tons of enamel can be used. The advantage of this method of masonry is that the production time is short, the replacement is convenient, the machinery and core of the furnace are not required, and the prefabricated refractory brick can ensure the quality is stable and the baking time is reduced.
