Refractorie mixes and mortas



♦ According to application method

  • Castable mixes for patching and trowelling
  • Castable mixes applied by vibration
  • Self-levelling castable mixes


♦ According to binder system

  • Castable mixes with cement, traditional
  • Low cement castable mixes                   
  • Ultra low cement castable mixes
  • No cement castable mixes








Raw Materials


♦Metacast-K95, -K97, -K97af

♦Metacast-K95/MA, -K97/MA, -K97/MAc

  • Based on tabular alumina and MA-spinel, 92-97% Al2O3
  • Suitable for application areas with molten steel contact
  • Hot/cold all kinds of repairs
  • Low porosity, high strength properties


♦Metacast-B80, -B82, -B82st, -B86c

  • Based on high quality bauxite, 80-85% Al2O3
  • Tundish permanent lining and high temperature furnance areas
  • Metacast-B82st includes stainless steel fibers (10-20 kg/m3)


Low Cement

Castable Mixes


♦Low CaO value due to decrease in cement ratio (1.5%>CaO>1.0%)

♦Decrease in water demand for mixing

♦Castable mixed with water remains workable for a longer period

♦Initial setting of castable starts at temperatures over 15°C

♦High strength properties remain the same till working temperatures

♦Well designed particle size distribution, low porosity and high strength due to less CaO and water content

♦Application areas:

  • Steel ladle working lining areas
  • Tundish permanent lining
  • Blast furnance runner
  • Linings of reheating furnances



(1) Storing of raw materials


  • Castable mixes are packed dry in
    humidity-proof bags of 25kg or 50kg.

  • Shelf-life is approximately 6 months
    under dry and rost-proof conditions
    of storing.

  • The best way to store castables is in
    a ventilated,closed area with room
    tenperature of approximately 20°C.

  • Unproper storing conditions detoriate
    performance of castable mix at
    application area.



(2) Mixing

  • The castable is preferably mixed
    in an intensive mixer.

  • Horizontal pan type, with pallets
    and preferably agitators give best
    results in mixing.

  • Considering a possible segregation
    of the grains, mixing should start dry.
    The whole content of the castable bag
    is to be poured into the mixer.

  • Only the quantity of castable to
    be applied at given period should be
    mixed with water.

  • Minimum and maximum water
    quantity to be added is mentioned
    in using instructions.




Water demand and consistency


  • Water quality for mixing should be drinkable, clear, no odor,
    co color. Mud, sugar, grease and particles should not be present
    in water.

  • Ph value for water should be between 7,0-7,5 and never
    less than 7,0. Hardness should be over 2.0°d.

  • Water temperature of 15-20°C improves consistency and
    casting properties.

  • Mixing should start with the lowest water addition ratio.
    Depending on consistency of the castable, water content can be
    increased till to upper limit value.

  • In order to determine consistency some castable is shaped
    as a ball in hand.

  • Mixing time is mentioned in using instructions. If mixing time is
    hold short, a good mixing is not achieved. If mixing is longer than
    required than the castable may get warm and set early.




(3) casting into mould under vibration


  • Castable mixes are shaped in stationary steel or wooden templates or moulds. Mould surface shoud
    be greased before application.

  • Immediately after casting the mix it is compacted by vibration with use of external or submerged shakers.

  • Submerged vibrators compact the castable by quickly inserting in the castable and slow withdrawal movement.
    In case if the vibrator is withdrawn quickly there may occur gaps in the castable and if it is held for a long time
    than twister may occur.

  • Vibrators are driven with electricity or compressed air.

  • Choice of vibration frequency may influence coarse/fine grain segregation in the castable. Increasing frequency
    may prevent fine grains moving towards mould surfaces.



Vibration equipment


Submerged vibrators Exrernal vibrators
Compressed air type external vibrators Quick connection parts for external vibrators


(4)  Setting of castable and demoulding


  • Binding time of dense castable mixes is around 
    2-3 hours depending on environmental conditions,
    water added and type of raw material.

  • Depending on wall thickness, room temperature
    and material type, it is possible to remove template
    or mould after 6 to 12 hours. In contructions like roof
    this period should at least be doubled.

  • After demoulding the material should be airdried at
    least for 24 hours.

  • Lining to be cast can be structurally strengthened
    by suitable anchors. They should be placed with
    a disance of approximately 30cm to each other and
    the length to be 2/3 of the lining thickness. Generally,
    Y-shape anchors are prefered.




(5) Drying


  • Water in refractory lining may be present in following states;
♦ Free water, inside the pores,
♦ Physically bonded water, inside tiny channels,
♦ Chemically bonded water by hydration,
♦ Hidrate pouch shaped physical/chemical bonded water
  • Drying by heat generally consist of two steps;
♦ Phase change of waterinto steam
♦ Escape of steam by diffusion and flow
  • Drying curve to e applied is given in using instructions of castable mix.

  • Rapid drying may cause explotion due to sudden increase in steam pressure inside the materials.

  • Special additives in dense castables for thick linings may help easier escape of water and risk
    of explosion in reduced.



  • Design and application
    of high technology castable mixes


  • Right material choice by determination
    of user expectations and application areas


  • Always cooperate with the user in
    production, sales and application...