Russian Journal of Applied Chemistry, 2009, Vol. 82, No. 2, pp. 193−196.
Pleiades Publishing, Ltd., 2009.
Original Russian Text
D.R. Ruziev, U.M. Mirsaidov, Kh.S. Saﬁ ev, 2009, published in Zhurnal Prikladnoi Khimii, 2009, Vol. 82, No. 2, pp. 199−202.
AND INDUSTRIAL INORGANIC CHEMISTRY
Method for Synthesis of Sodium Aluminate by Caking Products
from the Mud Storage Area of Aluminum Plant
D. R. Ruziev, U. M. Mirsaidov, and Kh. S. Saﬁ ev
Nikitin Institute of Chemistry, Academy of Sciences of the Republic of Tajikistan, Dushanbe, Tajikistan
Received September 15, 2008
Abstract—Results obtained in a study of the topographic, layer-by-layer, chemical, and mineralogical composition
of products in the mud storage area of an aluminum plant and in an analysis of the kinetics and mechanism of
processes occurring in synthesis of sodium aluminate by the caking method are presented. It is shown that the
processing mode affects the yield of sodium aluminate in the cake and the coagulating properties of the resulting
Aluminum sulfate and iron chloride are for the most
part used as coagulants in natural water treatment.
The coagulating properties of these salts are due to the
formation of poorly soluble hydroxides upon hydrolysis
. Solutions of these salts are corrosive to ordinary
carbon steels. Therefore, special brands of stainless
steels and concretes should be used in their preparation,
transportation, and storage .
Aluminate solutions that can be used as an alkaline
coagulant are less corrosive, because hydrolysis of
aluminates is accompanied by release of hydroxide ions
and increase in pH in the course of time.
With account of this circumstance and of the necessity
for utilization of the industrial waste of Tajik aluminum
plant, a method for production of an alkaline coagulant
from the gas-treatment mud has been developed . The
method consists in high-temperature caking of the mud
and leaching of sodium aluminate from the cake.
A topological analysis of the mud for 48 samples taken
from 8 points of the mud storage area at depths of 0 to
100 cm demonstrated that the content of its components
widely ﬂ uctuates. For example, the content of water-
soluble salts in the mud may vary from 5 to 40 wt %.
Our present study was performed with an averaged
sample containing 30 ± 1 wt % water-soluble salts. We
varied the content of these salts in the mud by addition of
a sulfate-containing precipitate of soluble salts, formed
in evaporation and cooling of a solution from the mud
storage area . Depending on the composition of
the starting solution, the precipitate contained (wt %):
75.0–84.0 and NaF 3.5–15.0.
Fig. 1. Effect of (a) temperature T; (b) caking duration τ, min;
(c) content c
of water-soluble salts in the mud on the yield of
sodium aluminate in the cake, wt % .