Services

A demineralization plant is a water treatment facility designed to remove dissolved mineral salts and ions, such as calcium, magnesium, sodium, chloride, sulfate, and bicarbonate, from water to produce high-purity or deionized water. This process is primarily achieved through ion exchange resins in a staged sequence involving cation and anion exchange.

Design and Process

• The demineralization process typically employs two main ion exchange columns: one with a strong acid cation resin that replaces mineral cations (e.g., Ca2+, Mg2+, Na+) with hydrogen ions (H+), and another with a strong base anion resin that replaces anions (e.g., Cl−, SO4²−, HCO3−) with hydroxyl ions (OH−).

• The H+ and OH− ions released combine to form pure water (H2O), effectively removing dissolved salts.

• Sometimes a mixed-bed unit, containing a mixture of both cation and anion resins, is used after the dual beds for further polishing to produce ultrapure water.

• Pre-treatment steps such as filtration or clarification often precede the ion exchange process to remove suspended solids and protect resin beds.

• Regeneration of exhausted resins involves chemical treatments with acid (for cation resins) and caustic (for anion resins) solutions to restore ion exchange capacity.

• Additional units like degassers may be included to remove dissolved gases such as CO2, and ultrafiltration systems may be used for colloidal silica removal.

Applications and Uses

• Providing high-purity water for boilers and steam generation in power plants, preventing scale formation and corrosion.

• Supplying ultrapure water for pharmaceutical manufacturing, electronics, and semiconductor industries.

• Producing process water for industrial applications requiring minimal dissolved solids.

• Used in laboratories and medical facilities for controlled water quality.

• Essential for industries requiring water free from mineral contaminants to protect equipment and product quality.