Sodium hexametaphosphate is hygroscopic and easily deliquesces in air, gradually transforming into sodium pyrophosphate and finally sodium orthophosphate, thus reducing its suppressive power. Therefore, when using sodium hexametaphosphate in a concentrator, it should be prepared and used on the same day.

In flotation, sodium hexametaphosphate (NaPO₃)₆ is commonly used. It can form complexes with Ca²⁺, Mg²⁺, and many other metal ions, thereby suppressing minerals containing these ions. It is a suppressor for apatite, calcite, barite, carbonaceous shale, and argillaceous gangue.

When using oleic acid to float cassiterite, sodium hexametaphosphate is commonly used to suppress calcium-containing minerals. Sodium hexametaphosphate is also commonly used to suppress feldspar, nepheline, kaolinite, and other gangue minerals when floating pyrochlore containing niobium, tantalum, and thorium, and zircon containing zirconium. It not only inhibits carbonate gangue, but also quartz and silicate minerals, and has a good dispersing effect on clay, so it is often used as a dispersant.