1) Chemical process 
The Solvays process or ammonia-soda process is the major industrial process for the production of sodium carbonate (AKA: soda ash). The ammonia-soda process was developed into its modern form by Ernest Solvay during the 1860s. The ingredients for this process are readily available and inexpensive: salt brine (from inland sources or from the sea) a...
An industrial process, also known as the ammonia-soda process, for the manufacture of sodium carbonate (see sodium). Sodium chloride (common salt), ammonia, carbon dioxide, and water react to give precipitated sodium bicarbonate, which on heating gives sodium carbonate and carbon dioxide for recycli...
[n] - a process for producing sodium carbonate from sodium chloride and ammonia and carbon dioxide
noun an industrial process for producing sodium carbonate from sodium chloride and ammonia and carbon dioxide