ISSN 1070-4272, Russian Journal of Applied Chemistry, 2006, Vol. 79, No. 4, pp. 555!558. + Pleiades Publishing, Inc., 2006.
Original Russian Text + N. V. Sych, N. T. Kartel’, N. N. Tsyba, V. V. Strelko, A. D. Nikolaichuk, T. I. Mironyuk, 2006, published in Zhurnal Prikladnoi
Khimii, 2006, Vol. 79, No. 4, pp. 565!569.
AND ION-EXCHANGE PROCESSES
Porosity and Sorption Properties of Activated Carbons
Prepared from Anthracite by Steam!Air Activation
N. V. Sych, N. T. Kartel’, N. N. Tsyba, V. V. Strelko,
A. D. Nikolaichuk, and T. I. Mironyuk
Institute of Sorption and Problems of Endoecology, National Academy of Sciences of the Ukraine,
Received August 9, 2005; in final form, December 2005
Abstract-Fundamental aspects of the steam3air activation of anthracite from Donets coal fields were
studied. The effect of the flow rate of moistened air on the development of a porous structure and the sorption
properties of the adsorbents obtained were examined.
The intense development of sorption technologies
imposes increasingly stringent requirements to such
properties of adsorbents as high sorption capacity
determined by the pore structure, presence of surface
functional groups, and service characteristics associ-
ated with purity, abrasion resistance, and cost.
Fossil coals used as one of the main raw materials
for manufacturing carbon adsorbents for various pur-
poses largely satisfy these requirements [1, 2].
Among these coals, anthracite is one of the most
attractive raw materials owing to the high content
of carbon and low ash content, as well as to the high
mechanical strength of the final product, activated
At the same time, activation of anthracite to obtain
an adsorbing material encounters the problem of its
low reactivity in a high-temperature contact with
the conventionally used activating gases. This is due
to the high degree of metamorphism of this kind of
fossil coals (a strong change in the texture, structure,
and mineral composition under the action of tempera-
ture, pressure, and chemical activity of stratal solu-
tions). It is for this reason that an adsorbent with
a polymodal pore structure frequently cannot be pro-
duced by steam activation .
Of high importance in the technology of sorption
purification of liquids to remove inorganic and or-
ganic contaminations, recovery of precious metals
from solutions, and accumulation of process gases is
the possibility of controlling the pore structure.
In manufacture of activated carbons, the pore struc-
ture and properties are controlled by selecting the ac-
tivation method and the activating agent and by
varying the process duration and conditions.
The porous structure is rather frequently devel-
oped by chemical activation , which consists
in that coal is treated with carbonates, sulfates, hy-
droxides, sulfuric and phosphoric acids, and zinc
chloride, which release an activating gas (e.g., CO
) at high temperatures.
As a rule, chemical activation gives an adsorbent
with a sufficiently developed surface and comparative-
ly wide micropores. However, it is contaminated with
inorganic admixtures. Moreover, such a catalytic ac-
tivation impairs the mechanical strength of the final
product. Thus, the chemical activation is a technolog-
ically unjustified procedure: it complicates the process
of manufacture of activated coals because the process
is corrosive and it is necessary to wash carbon.
The authors made an attempt, as an alternative pro-
cedure for production of activated coals with a devel-
oped porous structure, to use activation with a com-
bined activating gas, humidified air.
The aim of the study was to examine kinetic as-
pects of the anthracite activation with a steam3air
mixture, specific features of the process of formation