Demineralized Water is obtained by distillation or ion exchange processes for medical or technical purposes. It run through active resin beds to remove metallic ions and filtered through a sub micron filter to remove suspended impurities. There are many forms of demineralized water. The differences of each form is primarily the conductivity or resistance of the water after demineralization.
Demineralizers are used to remove mineral ions from water. The process of demineralization is the same type of process used in a water softener, except that in the ion exchange process, all of ions, both negatively charged and positively charged, are removed. Demineralizers contain several beds of resins and are packaged in cartridges; the water that is obtained this way is free from both mineral anions and cations. Demineralizers will not remove organic matter or nonelectrolyte from water. These must be removed first by distillation. Demineralized water cannot be substituted for distilled water in every case.