Washing Soda Production Using Solvay Process - WorldOfChemicals

Interesting facts about Soda ash / Washing soda / Sodium carbonate

What is soda ash?

What is washing soda?

What is the chemical name of soda ash and washing soda?

Sodium carbonate is the chemical name for soda ash and washing soda. Major source of soda ash is trona ore. Sodium carbonate occurs naturally in arid regions. It is found in the form of deposits on locations where lakes evaporate. Sodium carbonate is one of the most basic industrial chemicals. It is found in large natural deposits and is mined in Wyoming.

Deposits of sodium carbonate are found in large quantities in different regions of the world but major locations include United States, China, Botswana, Uganda, Kenya, Mexico, Peru, India, Egypt, South Africa and Turkey. It is found both as extensive beds of sodium minerals and as sodium-rich waters (brines).

The principal applications of sodium carbonate are in the manufacture of glass and the production of chemicals. It is also used in processing wood pulp to make paper, in making soaps and detergents, in refining aluminum, in water softening, and in many other applications.

It can help remove alcohol and grease stains from clothing, as well as calcifications in everything from coffee pots and espresso makers to boilers and hot water heaters.

Soda ash can also be used to increase the alkalinity in swimming pools, helping to ensure the proper pH balance of the water. It can be used in dying to help the dye bond to the fabric effectively. Photographers also use a sodium carbonate solution as part of the photo development process.


Washing soda has significant economic importance because of its applications in manufacturing glass, chemicals, paper, detergents and many other products. It has been used since ancient times.

Sodium carbonate is having characteristics like white, anhydrous, powdered or granular material. Soda ash is an alkali that has a high ph in concentrated solutions. It can irritate the eyes, respiratory tract and skin. It should not be ingested. Soda ash is made in three important grades – light grade, intermediate grade, and dense grade.


Anhydrous sodium carbonate loses weight when heated

Na2CO3(solid) → Na2O (solid) + CO2 (gas)

Sodium carbonate although readily soluble in water and it reaches maximum solubility at the relatively low temperature of 35.4oC.

How to transport soda ash?

Light and dense soda ash are normally packaged in plastic or polyethylene lined bags, multiwall paper bags. Covered hopper cars with bottom discharge are the most common rail cars used for bulk soda ash.

Sodium carbonate is a fragile, crystalline product subject to breakage from conveying equipment. Soda ash generates micron-sized particles that require high-efficiency collectors.

Soda ash is usually stored in the warehouse for a short time. It can be stored in bulk as a pile on the floor and reclaimed by a front-end loader or other bulk-handling machine.

Soda Ash Production

The Leblanc process, the first successful commercial process for making soda, is no longer used in the United States but played a major role in the Industrial Revolution. 

Soda ash can be made synthetically using limestone, salt and ammonia. This is known as the Solvay process and was the main source of soda ash until the Wyoming trona deposits were discovered. However, it is more expensive than mining natural sodium carbonate deposits.

A series of refining steps are required to produce soda ash from trona ore. First, the raw ore from the mine is crushed and screened. The material is then fed to rotary calciners and heated. In this process, the trona decomposes to form crude soda ash, which is dissolved in water.

The insoluble shales are separated from the solution by a combination of settling and filtration steps and the resulting insoluble tailings are taken back into the mine as backfill. The soda ash solution is treated to remove organic materials yielding a high-purity saturated solution of sodium carbonate.

Next, the solution is fed to crystallizers where water is evaporated and sodium carbonate monohydrate crystals are formed. The industry-familiar term "mono-process" originates from this process step. The crystals are dewatered and washed using cyclones and centrifuges, and the solution is recycled to the evaporator units for further recovery of soda ash. The monohydrate crystals are fed to rotary kilns where they are dried to finished soda ash. Finally, product is screened and sent to storage silos awaiting rail and truck load out.

Soda ash also is used to clean the air and soften water. As environmental concerns grow, demand increases for soda ash used in the removal of sulfur dioxide and hydrochloric acid from stack gases.

Chemical manufacturers use soda ash as an intermediate to manufacture products that sweeten soft drinks (corn sweeteners), relieve physical discomfort (sodium bicarbonate) and improve foods and toiletries (phosphates). Household detergents and paper products are a few other common examples of readily identifiable products using soda ash.

Light soda ash is one of the most important basic industrial chemicals. Light soda ash is used to regulate pH in many chemical process streams. The superior buffering capacity of soda ash versus caustic soda offers advantages in adjusting plant wastewater pH ranges.

Applications of Soda Ash

Soda ash is used as the sodium source for sodium sulfite/bi-sulfite pulping liquors used in the sulfite, CMP, and CTMP processes, and in NSSC pulping.

It is also possible to replace a portion of the caustic soda with sodium carbonate in many pulp bleaching applications such as caustic extraction or hydrogen peroxide bleaching of mechanical or chemical pulps.

It is also possible to replace a portion of the caustic soda in many pulp bleaching applications such as caustic extraction or hydrogen peroxide bleaching of mechanical or chemical pulps.

In addition, washing soda is the most widely used fixed alkali for the manufacture of other alkali products, sodium salts, glass, soap, sodium silicates, detergent, bicarbonates, bichromates, cellulose and rayon, iron and steel, aluminum, cleaning compounds, textiles and dyestuffs, drugs and many other materials. It is also used as an alkali for household purposes and as washing powder by laundries.

One of the most common products that can be made with soda ash is glass. More than 50 per cent of all sodium carbonate produced around the world is used for this purpose. When mixed in proportion with sand and calcium carbonate, heated to the right temperature, and then cooled quickly, the end result is soda-lime-silica glass with excellent durability and clarity.

Soda ash is a very common industrial chemical as well. In addition to food and cosmetic products, it also finds major applications in agricultural sector chemicals such as fertilizers. When it comes to exhaust towers and chemical stacks, this ash can play a very important role in air purification because when sodium carbonate reacts with sulfur dioxide and hydrochloric acid, for example, less harmful compounds are produced.

In laboratories, this sodium salt serves as an excellent electrolyte in the electrolysis process. It helps to reduce the water content in the clay and makes the task of molding the clay in the shape of a brick easier. In the dyeing industry, it is used to improve the chemical bonding between the dye and the fibre.

Washing soda is a key component of laundry soaps and other household cleaning products as it can easily remove dirt and tough greasy stains from clothes, utensils, floors, and various other surfaces. It is also used as a cleansing agent for removing dirt stuck on silver and glass items. Water in the swimming pools turns acidic due to the repeated addition of chlorine as a disinfectant. Washing soda is added to this water to make it chemically neutral.

Sodium carbonate is important in taxidermy for preparing hunting trophies. When added to boiling water, it helps in the removal of flesh from the skulls and bones of dead animals. Washing soda acts as a strong base and can neutralize acidic effects.


[1] © From, http://www.cefic.org/Documents/About-Us/Industry%20sectors/ESAPA_Soda_Ash_Process_BREF3.pdf

[2] © From, http://www.nlm.nih.gov/medlineplus/ency/article/002486.htm

[3] © From, http://www.genchem.com/pdf/SodaAshTech.pdf                     

[4] © From, http://www.mineralseducationcoalition.org/minerals/sodium-carbonate-soda-ash-or-trona


To contact the author mail: articles@worldofchemicals.com

© WOC Article

www.worldofchemicals.com uses cookies to ensure that we give you the best experience on our website. By using this site, you agree to our Privacy Policy and our Terms of Use. X