Casting industry is a typical high energy consumption, high pollution enterprises, the task of energy saving and emission reduction is very difficult, the service life of the lining can guarantee the normal production of the electric furnace has a great impact, Anaejie through the production practice, according to the characteristics of the electric furnace knotting material to master the material selection, batching, knotting, baking and sintering process, And in the use of electric furnace smelting process to do daily maintenance of the furnace lining, to improve its service life is very important.

Acid lining material The working condition of induction furnace lining is very bad. In the process of use is in a series of complex physical and chemical changes interwoven conditions to work, to withstand the melting process of 1550~1580℃ high temperature action, when the pig iron, scrap steel, alloy material on the lining of the violent impact and collision, melting electromagnetic stirring caused by the metal liquid on the lining of the strong scouring effect, slag on the lining of the chemical erosion effect, The intermittent operation causes the temperature of the lining to change, such as chill and heat, so that the lining cracks, local erosion, spalling, etc. The acid lining material causes the penetration of metal liquid and leads to the failure of the lining. It can be seen that the furnace lining refractory should have the following properties:

(1) High enough refractoriness. The operating temperature of the furnace lining is generally lower than that of the molten metal. However, taking into account the requirements for the life of the furnace lining, it is necessary to consider the occasional or frequent overtemperature of the molten pool and the molten groove, the fluidity of the cast iron is good, the use of materials with low refractoriness and softening temperature in the cast iron induction furnace is not good for production, as the refractory material for the production of cast iron products, the refractoriness should reach 1650~1700℃, and the softening temperature should be higher than 1700℃.

(2) The coefficient of thermal expansion is small, and the volume should be relatively stable with the change of temperature, without severe expansion and contraction.

(3) Good chemical stability, the chemical stability of the material and the life of the lining have a close relationship, the lining material should have at low temperature not hydrolysis differentiation, at high temperature should not be easy to decompose and reduce, in the melting process should not be easy to form a low melting point with the slag material. It is not easy to react with metal solution, solvent and slag.

(4) Acid lining material has high mechanical properties. When the temperature in the furnace is low, it can withstand the impact of the charge, and when the metal is in a high temperature melting state, it should be able to withstand the static pressure of the metal liquid and the strong electromagnetic stirring effect, and wear resistance and corrosion resistance under the long-term erosion of the metal liquid.

(5) Good insulation performance. Furnace lining should not conduct electricity at high temperature, otherwise there will be leakage and short circuit, resulting in safety and equipment accidents.

(6) The construction performance of the material is good, the repair and sintering performance is good, and the furnace building and maintenance are convenient.

(7) No harmful impurities such as iron oxide and low melting point minerals.

Silica sand is an acid lining material, its low price, a wide range of sources, in 600~800℃ to basically complete its expansion change, at this temperature above the volume change is small, thermal stability and resistance to iron leakage performance is good, can adapt to intermittent operation. In addition, the load softening temperature of silica sand is close to its refractoriness, and the high temperature mechanical strength is higher. The main technical conditions of silica sand for lining knotting: the main component of silica sand is silicon oxide, the higher its content, the higher the refractoriness of the lining, so it is currently widely used acid lining knotting material.