Pigments Based on Thermally Treated Iron-Containing Slimes
, L. S. Eshchenko
, and V. A. Salonikov
Vilnius Gediminas Technical University, Vilnius, Lithuania
State Technological University, Minsk, Belarus
Received April 16, 2009
Abstract―The effect exerted by chemical and phase composition on the color characteristics of the products
of a heat treatment of slime obtained at purification of model wastewaters containing prescribed amount of
zinc(II), nickel(II), copper(II), and chromium(III) compounds using ferroferrihydrosol was studied. The
dependence of pigment properties of the products of the heat treatment of slimes on the concentration of metal
compounds in them was determined.
INORGANIC SYNTHESIS AND INDUSTRIAL
ISSN 1070-4272, Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 3, pp. 390–394. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © D. Budilovskis, L.S. Eshchenko, V.A. Salonikov, 2010, published in Zhurnal Prikladnoi Khimii, 2010, Vol. 83, No. 3, pp. 391–395.
The treatment of wastewaters with ferroferri-
hydrosol (FFH) [aqueous suspension of iron(II) and
iron(III) oxohydrates] to remove heavy metal ions
yields slime containing high concentration of iron
compounds. This makes it possible to obtain iron oxide
pigments on its basis [1–3]. The slime contains metal
compounds, main of them are zinc(II), nickel(II), cop-
per(II), and chromium(III) compounds. Their
concentration may reach 10 wt % and higher.
As known, a majority of 3d-metal ions are chromo-
phores. The presence of even minor amounts of them
can affect color shadow of pigments. This property is
used in a so-called structural modification of pigment
materials [4, 5].
The previous studies showed that cations present in
slime not only affect the color characteristics of the
heat-treatment products, but also change their phase
composition, dispersion, and properties . According
to , other than hepatite crystalline phases in the
thermally treated slime are associated with the forma-
tion of interstitial and substitutional solutions with
participation of metal ions present in them. The
formation of the above phases at the thermal treatment
of slime affects the properties of the obtained products,
in particular, their color characteristics. Data on the
color and paint technical characteristics of the
thermally treated slime containing a number of metal
chromophores are virtually lacking, which essentially
impedes their estimate as pigments.
Therefore, the study is concerned with the com-
position, color, and paint technical characteristics of
the products of the thermal treatment of slimes
obtained at treatment with FFH of model wastewaters
containing prescribed amount of zinc(II), nickel(II),
copper(II), and chromium(III) compounds.
Model wastewaters with prescribed concentration
of zinc(II), nickel(II), copper(II), and chromium(III)
compounds and their treatment FFH were performed,
according to the method described in . The slimes
thus obtained were dried at 200°С to constant mass
and then heat-treated within 200–900°С. The con-
centration of main components in slime and thermal
treatment products was determined by the known
procedures of chemical analysis . The phase
composition of thermal treatment products was studied
on a “Bruker” AXS 08 Advance diffratometer (Germany).
The color characteristics of pigments were determined
on a SF-18 spectrophotometer (“B” radiation source).
The paint technical characteristics of pigments
(covering power, oil number) were determined by the
standard procedures .
The chemical composition of slimes obtained at
treatment of model wastewaters with FFH and heat-
treated at 200°С to constant mass is given in Table 1.
In slime, as in FFH, the iron(II) compounds are major.
The total concentration in slime of zinc, chromium,