Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 8, pp. 1192−1196.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © T.N. Lugovitskaya, K.N. Bolatbaev, S.S. Naboichenko, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 8, pp. 1253−1257.
OF SYSTEMS AND PROCESSES
Study of Surface Phenomena at Phase Boundaries
in the Presence of Lignosulfonates
T. N. Lugovitskaya
, K. N. Bolatbaev
, and S. S. Naboichenko
Northern-Kazakhstan State University, Petropavlovsk, Kazakhstan
Ural Federal University named after the ﬁ rst President of Russia B. N. Yeltsin, Yekaterinburg, Russia
Received June 26, 2012
Abstract—Surface activity and fundamental aspects of the wetting effect of three varieties of lignosulfonates with
different compositions toward elementary sulfur and sphalerite were determined by a set of physicochemical studies.
The ability of a number of surfactants to eliminate
the screening effect of molten elementary sulfur opened
up prospects for implementation of high-temperature
modes and intensiﬁ cation of autoclave processes.
Technical-grade lignosulfonates (LSs) have found
application in hydrometallurgy as surfactants. Despite
that LSs have been comparatively long used in autoclave
leaching, good parameters of technological processes
could not be reached so far with these compounds. This
is due to the instability of the functional characteristics
of technical-grade LSs, differences in their chemical
compositions and molecular masses, and lack of reliable
evidence about their surface-active, wetting, dispersing,
and stabilizing properties.
We present in this communication results of our
studies of the surface activity of lignosulfonates with
different compositions at LS solution–air and LS
)–air phase boundaries in neutral and
We found fundamental aspects of surface phenomena
involving LSs by determining the surface tensions of
solutions at the interface with air, wetting angles at the
)–LS solution–air interfaces, and characteristics
of cohesive and adhesive interaction in the bulk and at
In our study, we used technical-grade LS sample no.
1 with a weighted-average molecular mass of 16 900
and two molecular-mass-fractionated samples: low-
molecular LS no. 2 (M
= 9250) and high-molecular LS
no. 3 (M
= 46 300). The elemental compositions of the
sample are listed in Table 1. The chemical composition
and physicochemical properties of solutions of all
LSs (acid-base, associative-dissociative, and redox
transformations in solution) were described in [1, 2].
The effect of the molecular-mass composition,
quantitative content of LSs (c
= 0.001–1.50 g dm
and electrolyte additions (c
= 0.1–10 g dm
on surface-tension characteristics of lignosulfonate
solutions was determined by the method of capillary
rise of the level of a liquid . The wetting angles of
lignosulfonate-containing solutions on the surface of
elementary sulfur and sphalerite were measured by
the spreading-drop method . The surface quality of
elementary sulfur deposited onto an object glass by
melting and subsequent crystallization was evaluated
by the roughness parameter RZ by a computerized
micro-optical method . The wetting of sphalerite by
LS solutions was studied using monomineral samples
subjected to preliminary polishing and washing.
Characteristics of the intermolecular interaction in
solutions and at phase boundaries between an LS solution