Salt for industrial products?

What purpose is salt used for industrial application? Majority of seaborne traded salt is being consumed at “chlor-alkali” (CA) plants. Process of CA plants is put purified salt brine into electrolyzer unit, run electricity and produce chlorine from anode and sodium hydroxide (NaOH, caustic soda) with hydrogen gas from cathode side. Although there are many diversified chlorine downstream products, largest application is polyvinyl chloride (PVC) that you have seen gray and white color pipes used for water piping. Caustic soda has also various applications and one of major application is used at refinery of bauxite to alumina, intermediate product before making aluminium. Most interesting and challenge part of this business is that CA plants always produce both chlorine and caustic soda together but market demand for both product moves independently. ​