EFFECT OF HEATING UNIT LINING WARM-UP REGIMES
AND REFRACTORY STORAGE DURATION ON REFRACTORY LINING LIFE
V. V. Slovikovskii
and A. V. Gulyaeva
Translated from Novye Ogneupory, No. 6, pp. 9 – 13, June 2015.
Original article submitted November 24, 2014.
Measures are developed for improving heating unit (converter) lining life. This task is resolved by studying
the mechanism of heating unit lining breakdown during heating and cooling, changes in thermophysical prop
erties of refractories of different composition, and also refractories impregnated with copper-nickel matte.
Lining drying and heating schedules are studied. Measures developed on the basis of results obtained with
proving under industrial conditions make it possible to increase converter lining life by 25 – 30% without spe
cial material consumption.
Keywords: temperature regime, thermal stresses, thermal shock, dinas refractory, chromite-periclase refrac-
Lining refractory wear in intermittently operating high-
temperature metallurgical units (converters, Waelz kilns, ro-
tary furnaces, steel-pouring ladles, etc.) during service oc-
curs mainly by spalling as a result of occurrence of thermal
stresses within a lining. During start-up of converters without
prior lining warm-up the size of lining spalling due to initial
thermal shock reaches 150 mm.
Traditional refractory lay-up within nonferrous metal
lurgy intermittently operating high-temperature units using
dry refractory powders in joints in ineffective, since it exhib
its corresponding mechanical properties. During operation
dry powder rises to the surface as a result of low-density and
absence of adhesion with a lining, and molten reagents pene
trate into exposed joints.
During cooling of a slag and matte melt, which has re
placed dry powder on floating away, due to a considerable
linear thermal expansion coefficient there is an increase in
volume, causing internal stresses within a lining. These re
peated cyclic stresses lead to rapid lining breakdown during
each cycle. Simultaneously with filling of lining joints with
slag and matte the lining working surface is impregnated
with melt to a depth of 30 – 100 mm, as a result of which
zones forms within a refractory. During lining heating and
cooling thermal stresses arise at the boundary of these zones
(Fig. 1), and in a number of cases exceeding refractory
Refractories and Industrial Ceramics Vol. 56, No. 3, September, 2015
1083-4877/15/05603-0225 © 2015 Springer Science+Business Media New York
Ural Federal University, Ekaterinburg, Russia.
Fig. 1. Stress s — strain e dependence in chrome-magnesite refrac
tory before and after service: I ) refractory before service; II ) least
changed refractory zone; III ) refractory transition and working
zone. Specimen test temperature sown on curves.