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GÓRKAL 70

Description

GÓRKAL 70 is a hydraulic binder with high Al₂O₃ content (69–71%), developed specifically for the refractory industry. It is a chemically pure cement without additives or modifiers, minimizing the risk of adverse interactions with other mix components. The white color of the product extends its use in building chemistry formulations, while the extremely high refractoriness (≥158 sP) and short setting time make it the preferred choice for critical refractory products.

Documentation

GÓRKAL 70

Advantages

  • Exceptionally high alumina content (69–71%) – ensures maximum refractoriness and resistance to high-temperature deformation.
  • Chemical purity and absence of additives – white color and minimal impurity levels (Fe₂O₃ <0.3%, Na₂O+K₂O <0.5%) eliminate contamination and side reactions in mixes, which is particularly important for building chemistry and “clean” refractories.
  • Highest refractoriness in the GÓRKAL range (≥158 sP) – allows the cement to be used in extremely hot zones of thermal units.
  • Short and controlled setting time (initial ≥160 min, final ≤240 min) – ensures a fast production cycle for items without compromising forming quality.
  • High mechanical strength (over 30 MPa after 24 hours) – combined with a dense structure, ensures the longevity of refractory products.
  • Versatility – suitable for both refractory products (shaped, monolithic, insulating) and building chemistry formulations where color and purity are important.

Technical Specifications

ParameterValue
Chemical composition (typical values)Al₂O₃ 69–71%, CaO 28–30%, SiO₂ <0.5%, Fe₂O₃ <0.3%, Na₂O+K₂O <0.5%
Principal mineralogical phaseCA, CA₂
Secondary phasesC₁₂A₇, αA
Specific surface (Blaine)4000–4500 cm²/g
Refractoriness≥ 158 sP (Seger cone)
Density3.0 g/cm³
Bulk density1.1 g/cm³
Initial setting time≥ 160 minutes
Final setting time≤ 240 minutes
Cold crushing strength after 6 h> 5 MPa
Cold crushing strength after 24 h> 30 MPa
Shelf life in dry conditionsup to 12 months

Note: characteristics determined by internal methods based on EN-196. Exact values may vary within specification limits.

Applications

  • A wide range of refractory products: shaped refractories, monolithic linings, shotcrete mixes, insulating and structural concretes.
  • Building chemistry: dry mixes, repair compounds where a white or light shade and absence of impurities are required.
  • High-temperature zones of metallurgical, glass-melting, and ceramic furnaces.
  • Production of heat-resistant items operating at temperatures up to 158 sP (Seger cone).
  • Special hydraulically hardening concretes for aggressive environments with high purity requirements.

Packaging

GÓRKAL 70 aluminous cement is packed in multi-layer 25/50 kg bags or 1 t big bags, providing protection against moisture. Exact weight and packaging type to be confirmed upon order.

FAQ

GÓRKAL 70 contains the highest amount of Al₂O₃ (69–71%) and minimal impurities, providing the highest refractoriness (≥158 sP) and chemical purity. Unlike GÓRKAL 40 and 50+, it contains no additives, has a white color, and is aimed at the most demanding refractory and construction mixes.

Because it contains no modifying additives and has exceptionally low levels of iron oxides (<0.3%) and alkalis (<0.5%). This minimizes the risk of uncontrolled reactions with other components and ensures property stability in any formulations.

The white color indicates high raw material purity and the absence of coloring oxides (iron, manganese). This makes GÓRKAL 70 in demand in building chemistry, where the shade of the final product matters, as well as in refractories in contact with melts where contamination is unacceptable.

Initial setting begins no earlier than 160 minutes, and final setting occurs no later than 240 minutes. This is a shorter interval compared to GÓRKAL 50+, which speeds up the production cycle of items.

When stored in dry conditions, the shelf life is up to 12 months. Avoid contact with moisture.