Tar-Bonded Dolomite Refractory

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Tar-Bonded Dolomite Refractory

 

any of the materials formed by pressing calcined dolomite powder (grain size up to 6–8 mm) that has been mixed upon heating to 100°-120°C with 4–6 percent coal tar or pitch. Tar-bonded dolomite refractories have an apparent density of 2,800–2,900 kg/m3 and a compressive strength of 20–40 meganewtons/m2 (200–400 kilograms-force/cm2). They are resistant to basic slags. Additions of magnesite powder yield materials known as tar-bonded dolomite magnesite refractories. The free CaO present in large amounts in tar-bonded dolomite refractories is hydrated upon exposure to air. The resistance of the refractories to hydration increases after heat treatment at 300°-350°C in a reducing environment.

Tar-bonded dolomite refractories are used for lining oxygen converters; gaps in these converters are filled with a mixture known as tar-bonded dolomite substance, whose composition is analogous to that of the refractories. The refractories are sometimes used for lining electric arc steelmaking furnaces.

REFERENCE

Nepsha, A. V. Konverternye smolodolomitovye ogneupory. Moscow, 1967.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.