Overview of SSS

The concentrated sodium sulphate solution is contacted with a causticizing agent, converting the sodium sulphate solution to a sodium hydroxide solution. The sulphates are converted to a solid sulphate concentrate.

If required, the generated caustic stream is concentrated to a desired concentration by distilling off excess water. It can then be reused in the upstream process or sold into the market.

The solid sulphate concentrate is separated from the caustic solution. After drying, it is thermally regenerated with a reducing agent to again form the causticizing agent, which is contacted with incoming sodium sulphate.

In the thermal process where the causticizing agent is produced, the sulphates are converted to gaseous sulphur dioxide. This sulphur dioxide is in turn converted to sulphuric acid. This sulphuric acid can be marketed or reused upstream.