In many industries, such as textile, steel, paper, and petrochemicals, the required process water must often be fully demineralized. This is termed to be the process of removing salts and minerals from the source to make it suitable for its end user.

These are commonly achieved through Ion exchange systems where ions like calcium, magnesium are displaced by another active ion. Softeners and mixed bed plants are examples of this process.

The main considerations for demineralization operation are operating economics, quality and reliability of resin performance, and minimizing environmental costs. The primary variables in determining the operating economics are costs associated with regeneration, waste neutralization and disposal, as well as, resin replacement and disposal.