ITALIMPIANTI has realized the steel making plant in Woljsky (on 1989),
situated in the Volgograd area between the Caspian Sea and the Black
Sea, with a steel output of 150,000 t/y from scrap, 720,000 t/y of sea
mless pipes, and 210,000 t/y of blooms. In the ambit of the operation
system of water necessary for the production cycles, for ancillary equ
ipments and in compliance with the former USSR rules, it has been chos
en a treatment system to bring to ''zero'' the waste water discharge f
rom the steel plant complex. In this point of view, the ''conventional
'' treatment stages of the make-up recycling water and steam generator
s feeding is as follows: flow rate 300 m(3)/h, softening line, gravity
sand filters, two lines of demiwater production for two different pur
poses, final storage, and sand filter backwash treatment and sludge de
watering lines. A ''non-conventional'' process is added to the previou
s one to treat different effluents of backwashing water of resins used
for the demineralizing system for which the following scheme is fores
een: flow rate max. 600 m(3)/d, neutralization, and two lines of RO ha
ving each three stages in series. The aim of this treatment plant is t
o produce industrial water with characteristics as above mentioned. Th
e concentrated makes up the feeding of a multi-nash evaporator with a
production of mixed crystals and condensate used as industrial water.