Demineralized water is used in applications that require low-salt or low conductivity. Some areas where this is an important factor are the power generation, food & beverage, electronics and pharmaceutical industries.


Demineralized water can be produced by passing water through ion exchange resins, which can be cationic or anionic, each of these has the ability to remove ions of different charge. The resins must be regenerated at the end of the exchange cycle, which depends on the ion concentration and the exchange capacity of the resins. Therefore, it is desirable to have an adequate pretreatment in order to maximize exchange cycles and minimize expenses due to chemical products. Some resins need to be regenerated with an acid or basic substance, while others can be regenerated with brine.


There are cases where the RO (Reverse Osmosis) process is enough to reach a demineralization degree suitable for most uses, because it is capable of removing over the 90% of the total salt content.

As a pretreatment for the ion exchange in Ultra-pure Water applications, RO represents an interesting alternative as it removes high salt contents and allows the exchange cycles to be longer even if the unit dimensions are kept constant. This means savings in operating expenses in return for a higher initial investment.