Brine saturation depends on NaCl feedstock quality. This system is embedded in the plant. Agitated vertical saturator are used in case of pre-purified NaCl, while horizontal pots are used for raw salt. Saturators design allows an easy slurry removal. Beside standard treatment with carbonate and caustic soda, saturated brine can be further treated to eliminate specific impurities contained in the raw salt (e.g. aluminum, Iodine, bromine, sulphates ect...). Conventional or lamellar decanters can be used before filtration. For some specific and very special cases, in order to optimize the output stream purity, floatation separation may replace the usual decantation.