EnglishPolish

GÓRKAL 80

Description

GÓRKAL 80 is a high-alumina hydraulic binder with an Al₂O₃ content of 79–82%, designed to offer maximum refractoriness and satisfactory mechanical properties. It is a chemically pure cement without additives, capable of performing in reducing atmospheres. The product is in the launch phase; manufacturer’s feedback is welcome. Its exceptionally high alumina content and ultra-fine grinding (specific surface >8000 cm²/g) make it a specialized material for the most extreme thermal conditions.

Documentation

GÓRKAL 80

Advantages

  • Record alumina content (79–82%) and refractoriness above 173 sP – enables use in temperature zones inaccessible to conventional aluminous cements.
  • Chemical purity (Fe₂O₃ <0.2%, total alkalis <0.7%) – eliminates contamination and side reactions, and combined with the high Al₂O₃ level, ensures stability in reducing gas atmospheres (CO, H₂, etc.).
  • Ultra-high specific surface (>8000 cm²/g) – the ultra-fine grinding ensures enhanced reactivity and dense particle packing, improving formability and monolithicity of low-cement refractories.
  • Accelerated setting (initial >120 min, final <360 min) – the relatively short cycle enables faster transition to drying and firing of products.
  • Sufficient mechanical strength (CCS 24 h >20 MPa) – despite the ultra-high alumina content, the cement provides the load-bearing capacity required for most refractory structures.
  • Specialization in reducing atmospheres – operates stably where many refractory binders degrade due to oxide reduction.

Technical Specifications

ParameterValue
Chemical composition (typical values)Al₂O₃ 79–82%, CaO <20%, SiO₂ <0.4%, Fe₂O₃ <0.2%, Na₂O+K₂O <0.7%
Principal mineralogical phaseCA, CA₂, αAl₂O₃
Secondary phasesC₁₂A₇
Specific surface (Blaine)>8000 cm²/g
Refractoriness>173 sP (Seger cone)
Initial setting time>120 minutes
Final setting time<360 minutes
Cold crushing strength after 6 h>6 MPa
Cold crushing strength after 24 h>20 MPa
Shelf life in dry conditionsup to 6 months

Note: Exact characteristic values ​​may vary within the specification limits.

Applications

  • Linings of thermal units with reducing gas atmospheres (blast furnaces, coke ovens, synthesis reactors, graphitization furnaces).
  • Production of high-purity corundum and mullite refractories.
  • Manufacture of shaped products and monolithic castables intended for long-term service at temperatures above 1700 °C.
  • Special hydraulically hardening concretes for chemically aggressive and high-temperature environments where absolute binder purity is required.

Packaging

GÓRKAL 80 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 80 contains even more alumina (79–82% vs 69–71%) and has a significantly higher specific surface (>8000 cm²/g vs 4000–4500 cm²/g). This results in higher refractoriness (>173 sP) and the ability to work in reducing atmospheres where GÓRKAL 70 may not always be suitable.

The ultra-fine grinding (>8000 cm²/g) is designed for maximum reactivity and dense particle packing in the refractory. It improves sintering, reduces porosity, and enhances the strength of the structure after firing, despite the moderate initial strength of the cement stone.

Yes, it is specifically developed for such conditions. Low iron oxide and alkali content prevents the formation of low-melting phases and degradation under CO, H₂, and other reducing gases.

Due to the ultra-high fineness and purity, the cement is more reactive and absorbs moisture from the air faster. If stored in dry conditions, it retains its properties for 6 months, after which it is recommended to check its activity.

Cold crushing strength after 6 hours exceeds 6 MPa, and after 24 hours it is over 20 MPa. These values are sufficient for most refractory structures, especially considering subsequent sintering and strength gain at high temperatures.