Neutral Refractory

• Refractory materials for intermediate frequency furnaces are divided into alkaline, neutral and acid refractories according to chemical minerals.
• In general, the main raw materials of common furnace lining materials include quartz matrix, and furnace lining materials based on the mixture of quartz sand materials have high purity of raw materials, reasonable material ratio, enhanced corrosion resistance of molten iron, strong cold and heat resistance, high softness, and impact resistance. It has strong properties, high softening temperature under load, high compressive strength at high temperature, high flexural strength at high temperature and good slag resistance, especially suitable for intermittent operation of large medium frequency induction furnaces.
• The quality of raw materials requires high requirements, select raw materials, ensure high purity of raw materials, and ensure stable product quality.

Characteristics Of Neutral Refractories

Refractories that are not easy to react significantly with alkaline or acidic slag at high temperatures are called neutral refractories, or amphoteric refractories. Neutral refractories are mainly composed of alumina, chromium oxide or carbon. From the point of view of neutral refractories, clay refractory products have good thermal stability and slag resistance, and are widely used. Almost all kinds of thermal equipment use clay bricks more or less.

Scope Of Application

• All steel grades including high temperature alloys (stainless, duplex etc)
• Iron and its alloys (Ni-hard, Ni-resist etc)
• Copper and copper alloys
• Aluminium and aluminium alloys

The medium frequency induction melting furnace lining has high refractory temperature, good corrosion resistance to alkaline, neutral and weakly acidic slag, and has a long service life and high cost performance.

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↔  Swipe left and right 

Refractory Selection For Melting Different Products

• Depending on the volume of the furnace and the metal properties of the smelted metal, the composition of the refractory material we use will also be different, and the type of refractory material corresponding to different smelting materials.
• Certain factors affecting lining life restrict the selection of the most suitable lining structure. Metal movement, erosion due to stirring forces in the induction furnace may cause the lining to peel off. Spalling can occur anywhere, but is most likely to occur at the bottom of the side walls and at the molten metal line near the top of the furnace. Generally, higher temperature and power will lead to increased corrosion. The power is increased, and the stirring action is more powerful.
• The first choice of the shape and size of the lining can be recommended by Shennai Power Equipment Co., Ltd. to obtain the desired power and the best lining life. When melting malleable iron at high temperature, the lining can be slightly thickened (if the upper wall is excessively corroded) and/or the taper of the lining splices or continuous lining can be increased if the lower wall is excessively corroded to prolong the lining life.

• After laying mica paper or asbestos cloth on the furnace bottom and furnace wall, add refractory material to the furnace bottom and knot the furnace bottom.
• After knotting the bottom of the furnace, use a ruler to measure the thickness of about 25mm-30mm.
• Place the crucible mold, find the center of the mold, and ensure that the mold is placed horizontally on the refractory material at the bottom of the furnace.
• Fixed mold, which can be fixed by external fixing bracket or wedge.
• Add refractory material to the outer circle of the mold.
• The furnace wall is knotted, the material thickness is about 100mm. Use a fork and a shovel to level it, and degas it six times. Use a flat head to ram the side wall material six times to obtain the maximum density. After loosening the surface of the refractory material with a fork , and then add the next layer, continue construction until the furnace top.

Other Materials

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