The Solvay process is an industrial method which was used to produce sodium carbonate and sodium hydrogen carbonate. This process uses salt (sodium chloride) to provide the sodium ions and limestone (calcium carbonate) for the carbonate ions in the sodium carbonate. The overall reaction is shown below:
CaCO3 (s) + 2 NaCl (aq) à Na2CO3 (s) + CaCl2 (aq)
However, salt and limestone do not react together, so this reaction requires burning of coke. Also, ammonia is needed in the process. Thus, the raw materials in the Solvay process are the following:
Sodium chloride (NaCl) or commonly known as purified brine
Calcium carbonate (CaCO3) or commonly known as limestone
Coke
Ammonia
Moreover, this process manufactures different products:
Light sodium carbonate (light ash)
Granular sodium carbonate (heavy ash)
Refined sodium hydrogencarbonate
Calcium chloride – major by-product