USE OF SPENT MOLDING SAND
IN THE PRODUCTION OF REFRACTORIES
Z. G. Ponomarenko,
A. L. Rechneva,
F. L. Kapustin,
I. D. Kashcheev,
V. A. Perepelitsyn,
and A. A. Ponomarenko
Translated from Novye Ogneupory, No. 4, pp. 10 – 12, April, 2016.
Original article submitted February 2, 2016.
The composition and products of reclamation of spent molding sand made of quartz sand and a pulverized
fraction and the potential for its use as a component of a raw mixture of silica brick articles are considered. Re
sults of laboratory and commercial tests employing the technology used in the production of silica brick for
coke ovens and the determination of the properties of articles produced from the addition of products from the
reclamation of “burnt Earth” are presented.
Keywords: spent molding sand, foundry sand, products of reclamation, composition, properties, technology,
Molding mixtures consisting chiefly of quartz sand and
binding components, such as bentonite, water glass, and oth-
ers, are used in machine construction and metallurgical en-
terprises for the fabrication of casting molds. Depending on
the weight of the articles, the flow rate of the molding sand
ranges from 5 to 13 t per ton prefabricated casting. After the
casting has been produced, the mold is dismantled and the
spent molding sand (“burnt Earth”) is sent to the dumping
grounds . Machine construction enterprises alone have
now accumulated several tens of millions of tons of burnt
Earth at dumping grounds.
One possible way of recycling spent molding sand is
through reclamation, a process that consists in extraction of
quartz sand from the molding sand for the purpose of reuse.
Reclamation of spent molding sand by a dry method com
prises crushing of the fragments, magnetic separation of the
metallic inclusions, screening with simultaneous dedusting
of the sand, and removal of the binder. The pulverized frac
tion is not used and is instead brought to a dumping ground,
which contaminates the environment. At the same time, ac
cording to the estimates of specialists, the products of the
reclamation of spent molding sand possess sufficiently good
indicators of chemical and granular composition so that they
may be used as siliciferous component of raw mixes of Port
land cement clinker as well as in compounds of binder of ar-
tificial soil mixtures and asphalt concrete.
In the present study we wish to investigate whether it is
possible to use spent molding sand formed in the plant of AO
Sukholozh Mechanical Foundry (Sverdlovsk district) in the
production of silica refractory. The following method of rec-
lamation of spent molding sand is employed at the enterprise.
Fragments of spent molding sand are pulverized by crushing.
Metallic inclusions are removed from the crushed mass on a
conveyor belt by means of a magnet and the fragments are
then fed to a drum grinder through which air is blown by an
exhaust fan. The pulverized fraction of the spent molding
sand is removed from the grinder by a flow of air, collected
in a bag filter, and removed to a dumping ground. The sand
thus formed is drained from the mill at a rate of at least 50%
of the total mass of the spent molding sand and used as a
The properties and composition of the products created
in reclamation of spent molding sand are presented in Tables
1 and 2. The pulverized fraction is characterized by its spe
cific surface, which is determined by the method of air per
meability to be 163 m
/kg. From Table 2 it follows that the
chemical composition of the spent molding sand is repre
sented basically by silicon oxide, though its pulverized frac
tion contains more oxides of aluminum and iron, though less
quartz oxide. The content of quartz in the sand and in the pul
verized fraction is 94.3 and 88.5%, respectively.
Refractories and Industrial Ceramics Vol. 57, No. 2, July, 2016
1083-4877/16/05702-0132 © 2016 Springer Science+Business Media New York
OAO DINUR, Pervoural’sk, Russia.
FGAOU VPO Ural State University, Yekaterinburg, Russia.