Regeneration salt

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Regeneration salt is specially granulated and highly purified sodium chloride used as a special salt for water softening systems . It is used to restore the ion exchanger's ability to absorb calcium and magnesium ions. These alkaline earth ions are removed from the water in order to lower the hardness of the water . During backwashing, they are displaced from the ion exchange resin by a high concentration of sodium ions.

In dishwashers , water is softened by means of ion exchangers in order to avoid deposits of lime soap and lime , which are particularly annoying on glasses and shiny cutlery . If the water is very soft, the regeneration process has to take place less often. Often, however, dishwashers automatically regenerate regularly without testing the need to regenerate. However, there are also machines which, if the water hardness is set accordingly, do not require salt for very soft water.

Table salt is unsuitable if it contains additives such as flow aids (such as magnesium chloride ), iodides or fluorides . Their cations impair the function of the ion exchanger over time. In addition, table salt does not have the right grain size. Conversely, regenerating salt could theoretically be used as table salt - but since different standards apply to the production than to the production of table salt, the manufacturers point out that regenerating salt is unsuitable for human consumption.

Essential criteria for the quality of regeneration salt are its solubility and speed of dissolution.

In Germany, regeneration salt must meet the purity requirements of DIN EN 973 Table 1: Type A and Table 3 in accordance with Section 11 of the 2001 Drinking Water Ordinance (as of November 2006).

Regeneration salt was exempt from the salt tax at the time of the salt tax (i.e. before 1993).

Individual evidence

  1. ↑ Georg Schwedt , Chemistry in everyday life for dummies, 1st edition - January 2010, Wiley-VCH, Weinheim, ISBN 978-3-527-70318-0
  2. ^ Stiftung Warentest, Test "Dishwashing Powder" , May 2011, p. 69, "Tips". Quote: "[...] only fill in designated regeneration salt. Table salt has trickle additives that can checkmate the softener. "
  3. ↑ List of treatment materials and disinfection processes according to § 11 Drinking Water Ordinance 2001 ( PDF ), published by the Federal Environment Agency. (164 kB)