Method of Dehydration,
Moulding, and Processing of Sludge from Thermal Power Plants
I. V. NIKOLAENKO
Ural Federal University named after the First President of Russia Boris Yeltsin, Yekaterinburg, Russia
E-mail: ibchem@uzsci.net
Keywords: sludge from thermal power plant, high molecular mass polymer, dehydration, microstructure, alumoferrite frame
Pages: 397-403
Abstract
The paper examines a facile and efficient method for
dehydration of sludge from chemical water treatment of the Surgut Thermal Power
Plant using a water-soluble powdered high molecular mass polymer i.e.
the sodium salt of carboxymethyl cellulose (Na-CMC), as an additive. The
integral mass loss and volume loss of samples vary within 70–80 % for 10–15
days when using this method. The optimum amount of the introduced binder is 3–5
% of the mass of the initial sample to obtain dense smooth shaped samples, as
established. The data of morphology, structure, phase composition, and particle
size in the initial and final products, and also in waste dehydration process
are given. Changes in the waste surface during the interaction with Na-CMC
accompanied by the formation of
hydroaluminate, hydrosulphoaluminate, and hydrosulphoalumoferrite particles
with a size of less than 300 nm were recorded. The particles generate a
primary alumoferrite frame of a hardening system of coagulation and
crystallization structures, as established in a more detailed study. During
dehydration and binding processes, it is suggested to dispose of the dry
product in the construction industry as an additive for manufacturing cements,
foam blocks, foam concretes, in mortars or producing plasters due to the
formation of the space frame of iron (III) and aluminium hydroxides. The
presence of small amounts of Na-CMC binder will make a positive contribution
since it is introduced to reduce setting time when manufacturing construction
materials. The results offer prospects for solving environmental issues related
to liberating overfilled sludge pits of the thermal power station.
DOI: 10.15372/CSD20170409
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