Insertion Of Insulator Research Articles

Tests of dunites from the Iovsk Deposits in production and in use in thermal insulation inserts

Thermal-insulation inserts manufactured on the basis of unfired Iovsk dunite had the same properties as those made from fired Solov'evogorsk dunite and met the requirements of TU 14-8-357-80 with amendments 1 and 2. No burning of the insert was observed and the surface of the head part of the casts was clean and even. The range of the shrinkage defects in the slabs of the experimental and standard casts was virtually identical and was ≤7%. The average value of the leading-edge trim in the case of the experimental and standard casts was virtually identical (9.99 and 10.09%, respectively). The same was also noted for the additional shrinkage segregation and the degree of chemcial nonuniformity at the level of the leading-edge trim.

Kytlym dunites as material for the production of heat-insulation inserts

The thermophysical and physicomechanical properties of heat-insulation inserts produced from magnesium-silicate materials (dunites) are not inferior to those of inserts produced from quartz sand. The quality of the head metal of the ingots (after the pickup and fins are stripped) depends on the degree of serpentinization of the original rock, i.e., the starting material for the inserts. Among the materials investigated the best indices were those of the dunites of the Kytlym massif (Iovsk body), which proved to be a high-quality raw material for the production of heat insulation inserts. The dunite reserves of the Kytlym deposits will be conclusively established and confirmed in the near future and will be used widely in the metallurgical and machine-construction industries.

The thermophysical properties of heat insulation inserts

The investigation showed that the thermal conductivity of inserts intended for heating the feeder part of the ingot varies considerably, notably at 600–900°C.

Developing drying cycles for heat-insulating inserts

By increasing the velocity and temperature of the heat carrier and also by arranging an excess pressure at the exit from the drier it is possible to intensify the drying of heat insulation inserts by a factor of 3.2.