Demineralization process was introduced years back for the removal of mineral salts from water. It used the ion exchange process for the same. The resultant water is free of dissolved minerals. The processes that can be followed for demineralising water are distillation, deionization, membrane filtration, electrodyalisis, etc. De-mineralization technology is an afformed method of water treatment. The mineral ions and anions that are removed from the water by Demineralised Water Plants are cations of sodium, iron, copper, calcium, chloride, sulphate, nitrate, etc. The mineral free water is produced on the principles of ion exchange, degasification, and polishing.