Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 11, pp. 1866−1870.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © V.Yu. Prokof’ev, P.B. Razgovorov, O.N. Zakharov, N.E. Gordina, 2011, published in Zhurnal Prikladnoi Khimii, 2011, Vol. 84,
No. 11, pp. 1780−1784.
OF SYSTEMS AND PROCESSES
Study of Pore Texture of Sorbents Based on Kaolin Clay
V. Yu. Prokof’ev, P. B. Razgovorov, O. N. Zakharov, and N. E. Gordina
Ivanovo State University of Chemistry and Technology, Ivanovo, Russia
Received June 29, 2010
Abstract—Acid modiﬁ cation of clay from the Veselovskoe deposit to obtain a sorbent with a developed pore
structure and low mechanical strength was studied. The compositions modiﬁ ed with liquid glass and the joint acid
and alkali treatment were considered.
Sorbents based on natural aluminosilicates (bentonite,
kaolin, etc.) [1, 2], which are often referred to as bleach-
ing earths, are widely used for ﬁ ne reﬁ nery of vegetable
oils. To increase the sorption capacity and selectivity, clay
materials are subjected to activation and modiﬁ cation,
chemical modiﬁ cation in particular. Typically, solutions
of alkalis and mineral acids are used for these purposes
[3–6], with strong mineral acids leading to the destruction
of the aluminosilicate structure. A more “soft” chemical
modiﬁ cation of kaolin clays with the use of weak organic
acids and sodium salts of weak mineral acids has been
suggested in [7–10], which largely retains the alumino-
silicate skeleton of kaolinite.
Aluminosilicate sorbents for oil reﬁ nement may be
used solely in the form of powders [1–7]. In this case, the
process proceeds in the periodic mode. The continuous oil
reﬁ ning process may be implemented only with granular
sorbents. Extruded sorbents based on modiﬁ ed clays from
the Veselovskoe and Malostupkinskoe deposits have been
studied in [10–12]. It was shown that granular aluminum
silicates provide the required treatment of vegetable oils
in a column apparatus.
It is known  that granular sorbent should have the
optimal texture and porosity, i.e., pore size distribution,
speciﬁ c surface area, and the mechanical strength of the
skeleton. This is especially true for reﬁ ning of oils, which
contain long-chain branches as concomitants.
The study is concerned with the pore structure of
extruded sorbents prepared from modiﬁ ed clay of the
We used for preparing a sorbent clay from the
Veselovskoe deposit (Donetsk region, Ukraine). The
average chemical composition in terms of oxides was
(wt %): SiO
0.63–0.87, СaO + MgO 1.45–1.77, K
О 0.34–0.61, and c.p.i. 9.5.
The X-ray diffraction analysis (DRON-3M diffrac-
-radiation) revealed kaolinite as major
crystalline phase, quartz, and minor amounts of montmo-
rillonite and hydromicas. By the data on the dispersion
analysis (Analysette-22 device), the fractional composi-
tion is as follows:
<1 1–5 5–15 15–30 >30
1.56 0.137 8.45 0.12 19.74
As modiﬁ ers of the above clay we used glacial acetic
acid (AA), a 20% NaOH solution, and liquid sodium glass
(LSG) with the silicate modulus 3.0.