INDUSTRIAL WATER PRODUCTION BY UTILIZATION OF A REVERSE-OSMOSIS AND AN EVAPORATION PLANT

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.