Sulzer-escher Wyss Ag

Ube Industries, Inc.

Sulzer-escher Wyss Limited

Robert Winkler

Shinjiro Yokota

Siro Sala

Takayuki Kobayashi

Yakayuki Kobayashi

A high pressure evaporation vessel which is operated at a predeterminate pressure above atmospheric pressure, is connected to a low pressure expansion vessel which is operated at a predeterminate pressure below the pressure prevailing in the high pressure evaporation vessel, through a U-shaped siphon tube. The U-shaped siphon tube contains a liquid column absorbing the pressure difference existing between the high pressure evaporation vessel and the low pressure expansion vessel.

Apparatus for preparing high-concentration alkali

Method and apparatus for preparing high-concentration alkali

The invention relates to the treatment of brine and more particularly the treatment of the brine elutriate drawn off after evaporation of the brine at an elevated temperature to separate some of the sodium chloride thereon. The crude brine normally contains sodium sulphate and potassium chloride, sometimes to relatively high levels, and the invention is directed primarily at the separation out of these salts. To achieve this, the brine elutriate is cooled, in chamber (12) whereby an NaCl--/KCl--/Na.sub.2 SO.sub.4 -- salt mixture is separated off by crystallization. The remaining parent solution can be returned to the evaporation stage (10), without disturbing the equalized balance of the secondary salts in the brine to be processed. The NaCl present in the salt mixture can be recovered by deposition with refrigerated water and separation of the Na.sub.2 SO.sub.4.

Treatment of brine elutriate

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Wallisellen, Switzerland

Robert Winkler