Fast neutralization and treatment of drinking water and swimming pool water.

High purity semi-calcined dolomite for calcite contactors

Semidol is a semi-calcined dolomite qualified to EN 1017 for the treatment of drinking water, desalination permeate and water in swimming pools.  

It can also be used for the deacidification of water and for reducing iron, manganese, and silicate levels in water. 

The benefits of Semidol

  • Premium-quality, high purity material
  • Protects water pipes and fittings from corrosion
  • Mineral enhancement of the water with both calcium and magnesium
  • Behaves neutrally when in contact with other similar materials
  • Conforms to EN1017
  • Qualified as Type A product to EN 1017 for use within drinking water applications 
  • Ideal for use in calcite contactors.

Not all products are registered for use in all markets. Check with your local Omya representative or email for more information.

Your questions answered

Semidol is a premium quality product made from pure dolomite that has undergone a specific thermal degradation process. 


Its homogenous raw material and high-quality technical processing ensure that the material quality is always consistent, resulting in a 99% pure product.  

 Semidol removes aggressive carbonic acid from the water, which helps to protect water pipes and fittings from corrosion.  

Semidol enhances the water with both calcium and magnesium minerals whilst at the same time increasing the pH of the water for a stabilized and healthy water quality.  


It also reduces the content of iron, manganese and silicates in the water. 

Semidol is highly efficient, converting only 0.78g of carbon dioxide per gram of filter material. As a result, it has a very low consumption rate and is very cost-efficient. 

The Omyaqua range includes Omyaqua, Omyaqua Boost, Omyaqua Pure, Omyaqua Dol, and Semidol. 

Water treatment consultancies

We offer technical support to customers, from the assessment of site-specific issues to the recommendation and implementation of proven solutions.

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