THE INVESTIGATION OF GRINDABILITY OF REFRACTORY WASTES
IN THEIR RECYCLING
A. Dilek Cuhadaroglu
and E. Kara
Translated from Novye Ogneupory, No. 6, pp. 14 – 23, June 2015.
Original article submitted January 26, 2015.
The ceramic industry is one that stands out in the use of industrial tailings, replacing pure raw materials by
some of these materials. Refractory wastes are ground and used in certain proportions in refractory produc-
tion. This study is aimed at determining the grindability of recycling of refractory wastes and their kinetic be-
havior. The breakage behaviors were determined experimentally by using the mono-size fraction technique.
The mono-size samples of –2360 + 1700 mm, –1180 + 850 mm, and –425 + 300 mm were ground batchwise
for the selected periods to determine the Si. At the end of each grinding period, using the material at different
mono-size groups, we determined theparticle size distributions and breakage behaviors of the products. De-
pending on the grinding periods in both of the mills, energy consumption and d80 values of grinding products
obtained by various grinding periods were determined. It was found that as the size group decreases, the
breakage speed decreases in the ball mill and increases in the stirred mill. An increase in the grinding period
results in an increase in energy consumption, but there is no significant change in d80 size in grinding of re-
fractory waste in the ball mill. However, it was found that d80 size decreases significantly with increasing
grinding period in the stirred mill.
Keywords: Grindability of refractory wastes, specific rate of breakage, stirred mill and ball mill, reuse of in-
Natural resources have been diminishing rapidly due to
the rise in the world’s population and changes in consump-
tion habits. Thus humanity has to use natural resources effi-
ciently by recycling qualified wastes. Recycling is an impor-
tant investment in the long term and it provides energy sav-
ings by decreasing the number of processes in material pro-
duction; reduction in the amount of waste material thus re-
duces negative environmental effects, ultimately requiring
less waste sites and energy for transportation and storage.
A firebrick factory in the Zonguldak Basin, depending on
the market demand, produces four different products: fire-
brick, monolithic refractors, forging mortar, and masonry
mortar. Depending on the product group, certain proportions
of ground refractory wastes are added into raw materials
such as silica, bauxite, fireclay, kieselguhr, binding clay, etc.
These refractory wastes are the ones stored as refractory
wastes from the renewal of refractory bricks used in kilns,
chimneys, etc. of various national facilities, and they are ob-
tained from the relevant factories.
The grinding cost of these refractory wastes has a high
share among the total production cost. In industrial plants,
grinding is where energy is used most extensively and least
efficiently. In particular, when the particle size gets finer, the
energy consumed increases excessively since the resistance
of particles towards breakage increases. There have been
many studies on grinding for the determination of the en-
ergy — size reduction relationship. Importantly, an attempt
has been made to find a method to obtain the most efficient
size reduction by using the least amount of energy [1 – 5].
In this study, breakage behaviors and grindability charac
teristics of these refractory wastes in laboratory scale vertical
Refractories and Industrial Ceramics Vol. 56, No. 3, September, 2015
1083-4877/15/05603-0236 © 2015 Springer Science+Business Media New York
Mining Engineering Department, Bulent Ecevit University,
67100 Zonguldak, Turkey.
Gökçebey M. M. Çanakçi Vocational School of Higher Educa
tion, Bulent Ecevit University, 67100 Zonguldak, Turkey.