Refractrory materials are those materials, which retain their stability at high temperatures. ASTM C71 refractories defined as „non-metallic materials with chemical and physical properties, allowing them to use for such structures, systems or components which are exposed to conditions above 500 °C“.

   Refractories must be chemically and physically stable at high temperatures. Depending on the environment should be resistant to thermal shock, chemically inert or have a specific range of thermal conduktivity and coefficient of thermal expansion.

  Aluminium oxides (Al2O3
is one of the most important materials used  for manufacturing refractories. Some applications require a special refractories. One of them is silicon carbide, which is used in very difficult conditions.



Refractory producer, refractory special-shape and refractory-cement our company delivers:

a. aluminium oxides Al2O3 in various fractions and packaging

b. silicon carbide SiC


c. composite refractories: in such proportions and mixed fractions SiC and Al2O3

d. chromium oxide Cr2O3


Use of refractory materials

production of iron and steel

70 %


ceramic industry

6 %

industry of non-ferous metals

3 %


glass industry

   4 %

cement industry

7 %


chemical industry

4 %


6 %




Chromium oxide Cr2O3

enlarged 1000 x

Chromium oxide Cr2O3 is very resistant to high temperatures, the temperature of  melting is 2275 ° C, it is  important refractories, which is used among others in the productions of special refractory  bricks. They are made from either pure chromium oxide   or is supplemented by other more refractory materials, especially silicon carbide SiC or aluminium oxide Al2O3. 

Chromium oxide Cr2O3

Silicon carbide (SiC)
2730 °C

Aluminium oxide (Al2O3)


2072 °C

Chromium oxide (Cr2O3)







KOLTEX COLOR, s.r.o.      2013