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FAQ

FAQ (frequently asked questions) related to industrial heat, foundry, aluminium and refractory products.
  • CORUNDUM FORMATION

    Corundum formation and its subsequent destruction of the furnace lining can be a constant worry to the maintenance department. The picture below is all too common of a reality in a typical Aluminium Foundry. The following conditions facilitate corundum formation: • Excessive free silica in the ref ...

  • Raw Materials from Steel Industry

      About 70% of all Refractory Products are used un the steel industry. Raw materials are more & more expensive and scarce. For this reason Refractory Manufactures find difficult to control the price of their products. All of this take us in two topics of study: 1.- Recycling of raw material ...

  • Why slag may appear adhered to the lining?

    The slag adhered to the silicon lining carries an inefficient running of the furnace. It can be low or high melting point. Low melting point. When the furnace works at low temperatures silicon oxide is formed and it sticks to the walls of the lining as: Si metal + O2 > SiO2 slag High melting poin ...

  • Why does Zn appear against the mica during the demolition of the lining?

    The presence of Zn in the demolition is associated with its presence in the used load and with the incorrect melting of the same one in the furnace of induction. The Zn  volatilizes at 919 ºC going from solid form (of galvanic sheets) to gas. In gas form it penetrates in the pores of the lining an ...

  • What is the difference between acid and boric oxide?

    Boric acid is the hydrated form (it contains water) of boric oxide (anhydrous form or free water). Boric acid H3BO3 at low temperature (less than 150ºC) decomposes to boric oxide (B2O3) and water (H2O) representing approximately 44% by weight. This means thta when we have 10 kg of boric acid in a l ...

  • At what temperature should I sinter a silicon lining?

    It is recommended to sinter the lining 50ºC above the working temperature. Keep this temperature for 1 hour and strain. Never use the furnace at full power until after the first 3 - 5 strains. ...

  • Why does the lining appear pale pink or reddish colour?

    Normally  it is associated with traces of elements accompanying quartzite. What can happen? Nothing. What to do? Nothing. To know it is enough.     ...

  • Why do small black balls appear in the lining when it is demolished?

    Carbon monoxide produced of the oxidation of the carbon of the metal spreads across the porous zones of the silicon lining where it dissociates itself depositing coal. 2C metal + O2 (air) >2 CO (gas) > C + O2 What can happen? It does not have effect on the refractoriness of the mass. However, ...

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