THEORY AND PRACTICAL USE OF MODULAR-POURING
ELECTRIC FURNACES FOR FIRING VERMICULITE
A. I. Nizhegorodov
Translated from Novye Ogneupory, No. 8, pp. 34 – 38, August, 2015.
Original article submitted May 19, 2015.
Results are presented from theoretical and experimental studies of modular-pouring electric furnaces. The
process of the absorption of heat energy by vermiculite was examined and the optical-geometric parameters of
the firing modules were determined. Efficient values were found for the temperature and duration of the firing
of vermiculite concentrates. It is shown that the existing modular-pouring electric furnaces can be improved
and new, energy-saving furnaces of this type can be developed.
Keywords: vermiculite, modular-pouring electric furnace, heat assimilation, thermal radiation, firing module,
furnace efficiency, unit energy content of the firing operation.
Products based on expanded vermiculite occupy an im-
portant place among the wide range of refractory materials
that are made. They have good heat-insulating properties
thanks to their porous layered structure, which allows them
to be used to line different types of high-temperature equip-
ment. Vermiculite is also an effective heat-insulating mate-
rial and serves as a porous filler for lightweight concretes. It
can be used to prepare dry mixes, including mixes with fire-
protection properties. Vermiculite is employed in the acous
tic insulation of buildings, the casting of steel, and other ap
plications [1, 2].
The idea of creating a modular-pouring electric furnace
for firing vermiculite was conceived in 2003 [2 – 4], and re
finements were made to the original concept during the ensu
ing decade of practical use of such furnaces. Improvements
were made to the furnaces on the basis of results obtained not
only from their operation but also studies of analytical mod
els of their working processes.
The goals of the studies were to analyze the process by
which heat energy is absorbed by vermiculite, determine the
optical-geometric parameters of the firing modules, find effi
cient temperature-time regimes for the firing operation, and
determine the efficiency and unit energy content of the firing
Modular-pouring electric furnaces can be used as a basis
for the construction of small production units designed to ob
tain different fractions of high-quality expanded products
from vermiculite concentrates (including concentrates that
have already undergone preliminary beneficiation) and con-
glomerates with a high content of inert material .
Figure 1 shows a block diagram of the process of obtain-
ing an expanded product from high-purity concentrates with
a vermiculite content of 94 – 96%. Charging the raw material
into the furnace in different fractions makes it possible to ob
tain vermiculite of any desired granulometric composition. If
Refractories and Industrial Ceramics Vol. 56, No. 4, November, 2015
1083-4877/15/05604-0361 © 2015 Springer Science+Business Media New York
Irkutsk National Research Technical University, Irkutsk, Russia.
Fig. 1. Block diagram of the process of obtaining expanded vermic