DRY BENEFICIATION OF KYANITE ORES
A. I. Urvantsev
and I. D. Kashcheev
Translated from Novye Ogneupory, No. 6, pp. 10 – 12, June, 2013.
Original article submitted February 4, 2013.
The beneficiation of kyanite ores by a new dry technology is studied. Compared to the flotation method, the
method reduces energy consumption from 300 – 400 to 15 – 25 kWh/ton. Dry electroseparation has made it
possible to obtain concentrates with an Al
content of 59 – 60% while also producing pure quartz (“tail
Keywords: kyanite, beneficiation, energy efficiency, electroseparation.
Metastable minerals of the sillimanite group (andalusite,
sillimanite, and kyanite), having the general formula
and theoretical contents of Al
spectively equal to 62.9 and 37.1 mass %, are widely used as
an alumosilicate raw material in the refractories industry.
The volumes of andalusite, sillimanite, and kyanite increase
4, 8, and 16 – 18% during roasting. Thus, the first two miner-
als are used directly in refractories production, while kyanite
needs to undergo a preliminary roasting operation.
A large percentage of the deposits of metastable minerals
in the world are mined by opencast method. The average
content of the useful component in the ores is 10 – 15% and
the reserves total 1 million tons. The methods of benefici
ation that are used include crushing, classification, separa
tion based on density, and flotation (which is the most effec
tive method of obtaining high-quality concentrates). The
commercial product contains 56 – 59% Al
, 38 – 40%
, and less than 3% impurities.
The main producers of concentrates of minerals in the
sillimanite group are South Africa, the U. S., India, France,
and Brazil. In Russia, most of the kyanite reserves are lo
cated in the Urals and Karelia. The projected reserves of
kyanite in the Karabash deposit are estimated to be 10 mil
lion tons and have a mineral content ~25%. The total volume
of the ore is approximately 40 million tons.
By its very nature, wet beneficiation invariably entails
the consumption of large quantities of water, and subsequent
washing of the converter requires the use of heat to remove
the moisture. The use of water and fuel has an unavoidable
negative impact on the economics of the production process.
Thus, the elimination of wet beneficiation and its replace
ment by dry beneficiation is an important problem in the pro-
cessing of kyanite concentrate.
The main method employed in Russia for the benefici-
ation of kyanite ores is based on flotation and entails the use
of flotation reagents to remove sulfides in the initial part of
the process and subsequent flotation of kyanite from sulfide
flotation tailings. The reagents used in the sulfide flotation
are xanthogenate and aerofoil, while the reagent in the kyan-
ite flotation is sulfonate in an acid medium (in the presence
of sulfuric acid). The number of operations performed in sul-
fide flotation reaches six [1, pp. 203 – 207]. The flotation op-
eration is complicated by the presence of sulfides and graph
Flotation technology requires comminution to ~50% of
the –0.071 mm fraction, in addition to subsequent drying of
the kyanite concentrates from a moisture content in the range
15 – 20%. The tailings are not seen to have any value as pro
spective quartz products.
In a dry technology employing electroseparation,
comminution is carried out to ~50% of the –0.2 mm fraction
(100% of the –0.315 – 0.4 mm fraction). The sulfide and
graphite minerals are easily removed by corona-electrostatic
separation, while the dry quartz tailings become a commer
cial product for certain sectors of industry. The OOO
“Russkaya Korona” has developed a technology for the ben
eficiation of mineral resources - including kyanite ores -
through the use of cold drying and electroseparation . The
method makes it possible to reduce energy consumption in
the beneficiation process from the 300 – 400 kWh/ton crude
ore seen in flotation to 15 – 25 kWh/ton . The technology
does not use water, flotation reagents, or organic fuel, which
eliminates emissions of reagents and heat.
Refractories and Industrial Ceramics Vol. 54, No. 3, September, 2013
1083-4877/13/05403-0166 © 2013 Springer Science+Business Media New York
OOO “Russkaya Korona,” Ekaterinburg, Russia.
Ural Federal University, Ekaterinburg, Russia.