| Different granulometric compositions with the particle
sizes less than 0.3 mm, less than 0.05 mm, and in the
ranges 0.5-1.6 mm, 1.6-3.0 mm, 3.0-5.0 mm and 5.0-8.0
mm were taken to prepare pitch bonded dolomite bricks.
The composition with finer fractions to an extent of 70
weight percent with 45% of less than 0.3 mm grade, 10%
of less than 0.5 mm grade and 15% of 0.5-1.6 mm grade
gave a bulk density of 2.94 gm.cm-3, cold crushing_strength
of 822 kg.cm-2
, a retained carbon content of 3.44%, apparent
porosity of 13.0 and modulus of rupture at 300°C 7.7
kg.cm-2
• The· campaign life of -LD converter was found to
increase from 148 heats to 230 heats with this optimum
composition. An addition of a maximum of 3% graphite
further improved the properties, raising the BD to 2.96
gm.cm-3, CCS to 832 kg.cm-2, RC to 4.5% and MOR at
3oo•c to 8.6 kg.cm-1 and reduced the po_rosity to 12.7%. It
is expected to .give a higher campaign life of the converter. |
