EBNER / Portfolio / Plants / High-priced potassium sulfate (SOP) from waste water

High-priced potassium sulfate (SOP) from waste water

(year 2005)

In 2005, EBNER was awarded the contract by a saline in Austria for the planning, supply and installation of a plant for the production of mainly high-purity potassium sulfate (SOP) from so-called mother liquor through a combined and patented circuit of cooling and evaporation crystallization.

The saline processes in the daily business raw brine to salable table salt or road salt in various process steps. The foreign substances being present in the raw brine, such as potassium or bromide, cannot be completely removed in the pre-purification processes. Sulfate ions are only partially eliminated according to their solubility. Therefore, these substances must be removed (elutriated) from the system during the evaporation and crystallization process in soluble form. In the case of this saline, this elutriated mother liquor was formerly discharged into the environment. Thanks to the plant designed by EBNER in association with a partner, from this mother liquor the well-marketable product potassium sulfate could now be produced in addition to the table salt.

This process is unique in the world and was realized in cooperation with K-UTEC from Sondershausen, Germany.

Among other things, the following process steps are applied in this case:

  1. Neutralization to set the pH-value
  2. Evaporation crystallization and extraction of sodium chloride
  3. Cooling crystallization and production of glaserite
  4. Conversion of sodium sulfate and potassium chloride to potassium sulfate
  5. Drying and storage of potassium sulfate

The customer is now able to generate high profit margins with the former waste product, which pollutes the environment. Due to the great satisfaction of the customer, EBNER later received a follow-up order for a plant regarding production of table salt.

Technical specifications of the plant:

  • Feed rate solution: 88 m3/h
  • Main ingredients solution: Na2SO4, NaCl, KCl
  • Water evaporation: 36 t/h
  • Production rate NaCl: 8,9 t/h
  • Production rate K2SO4: 2,5 t/h