A global leader in Soda Ash

Solvay is a global leader in Soda Solvay® sodium carbonate production, using two different processes: the traditional Solvay ammonia process and the refining of a primary source of sodium carbonate, natural Trona (or sesquicarbonate).

Soda Ash industrial process

Soda Ash-process-Solvay-bicarbonate


Soda Ash natural trona Process


What is Soda Ash?

Commonly named “Soda”, the Soda Ash is known as Sodium carbonate, Na2CO3. Its CAS registry number is 497-19-8 and its Harmonized System (HS) code is 283 620.

Sodium Carbonate or Natural Soda Ash (based on Trona) are present in a wide range of applications. They are already well-known for their effectiveness in flux for glass and flux for silicate. Moreover, they are also playing another role: a chemical that can substitute caustic soda and increase PH.


In which consumer markets is Soda Solvay® usually present?

  • Glass Industry – Raw material for melting and flux agent to reduce the melting point of silica (and consequently reduces energy consumption) 
  • Detergents – Alkaline support, grease removal (sapinification effect), water softening
  • Chemical Industry – Acting as a strong base (increases pH) with a softer effect compared to caustic soda
  • Metallurgical processes – Desulfurization of pig iron, flux agent for mineral extraction, production of Lithium Carbonate …  
  • Pulp & Paper - Can substitute caustic soda
  • Supplement in pharma – High purity carbonate IPH is used as an Active Pharmaceutical Ingredient (API) to enable tabletting  (effervescent tablets)
Soda Ash website


Solvay is available in two different grades

Soda Solvay® is available in dense and light grades to meet its customers’ specifications in accordance with all applicable safety, health and environmental standards.


The dense grade has a bulk density of ~1 t per m3 and a Particle-Median-Diameter (D50) of 300 to 500 microns.  

Soda Ash Dense is the grade preferred for glass manufacture because its granular properties make it widely dust-free and reduce the risks of segregation during transport and handling.

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The light grade has a bulk density of ~0,5 t per m3. The D50 of approximately 100 microns is very well suited for detergent and chemical applications.

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A pharmaceutical grade of sodium carbonate anhydrous is also available. It is produced in a dedicated production facility in Dombasle (France).

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Why do we speak about the “Solvay process”?

We speak about the “Solvay process” because in the 1860s, Ernest Solvay invented a new soda ash process using ammonia as processing agent - enabling CO2 to substitute Chlorine at the Sodium atom (also called "ammonia process"). This process replaced the previous Leblanc process as Solvay process is much less impactful for the environment.  We still use today this process to produce synthetic soda ash. The other synthetic route is the Hou process developed in China where ammonia is not recycled but sold as a byproduct: ammonium chloride.

Soda Solvay® is shipped to more than 90 countries

…using and developing every form of transport at hand. 


transportation soda ash solvay


Whereas our seven plants produce high and constant quality products, Solvay's global supply chain capability benefits from multiple sourcing opportunities, a wide network of local warehouses and historical partners to give an even better service to its customers, both across Europe, the USA, and, specifically in many export destinations.

Soda Ash Bicarbonate plants -worldwide-2019-with legend



Our actions for Sustainable Development

In line with the Solvay Group commitments, we constantly work on developing manufacturing excellence and energy efficiency programs to minimize our environmental footprint by reducing, for example, our greenhouse emissions and energy consumption. Over 2014-2018, our CO2  emissions have decreased by 8%.

We have also developed an energy transition roadmap to reduce the use of fossil fuels in our plants and develop clean energy production for our needs.

A few examples of projects: 

The Rosignano plant in Italy

The investment in a new energy- efficient gas turbine at our soda ash plant in Rosignano, Italy

With this investment, Solvay secured the plant’s current production capacity and long-term competitiveness on local and export markets while using less energy and providing co-generation electricity (lowest COemission for fuel generated electricity) to the Italian grid.

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RDF Power Plant at Bernburg site

The modernization of our cogeneration unit in Bernburg

In 2018, Solvay invested €48 million for the modernization of its cogeneration unit to maintain its current production capacity, decrease CO2 intensity and provide the German grid with a back-up based on co-generated electricity.

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Plant Rheinberg, Germany

Biomass In Rheinberg plant 

In 2019, Solvay invested in a new biomass boiler at its soda ash plant in Rheinberg, Germany, a decision that will cut the site’s CO₂ emissions by more than 30% (190 kt/year) while at the same time improving its competitiveness.

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The installation of solar panels in Walcourt, Belgium

Solvay developed a solar panels project in its Belgium limestone quarry, to increase the use of renewable energy for the site. With a surface of 1.4 ha, this photovoltaic farm is one of the largest solar energy installations in Belgium.

Algal biomass cells

The use of biomass for co-firing with coal in Rheinberg and Dombasle

Solvay uses biomass for co-firing with coal in the boilers of the plants, to reduce the use of coal, which consequently reduce CO2 emissions

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Solvay core value : safety

Safety is our core value and people protection is an integral part of the way we conduct our business. Thanks to our Safety Excellence Program, we are especially cautious to regularly review our process and monitor it on a daily basis so that every person producing, delivering or using our products do not take any risk. To that end, we regularly organize Safety Days, safety leadership courses and life saving rules training sessions.


Our relationships with communities

We are engaged in many societal actions that focus on Science, Youth, Employability & Education, Environment and Solidarity. Our goal is to facilitate the involvement of our teams in community projects. Discover some of our societal actions: