The Solvay process is also called ammonia recovery.

The calcium hydroxide is reacted with the ammonium chloride separated out of the carbonating tower by filtration.

$\mathrm{Ca}{{\left(\mathrm{OH}\right)}_2}_{\left(\mathrm{aq}\right)}+2{\mathrm{NH}}_4{\mathrm{Cl}}_{\left(\mathrm{aq}\right)}\stackrel{}{\to }{{\mathrm{CaCl}}_2}_{\left(\mathrm{aq}\right)}+2{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)}+2{{\mathrm{NH}}_3}_{\left(\mathrm{g}\right)}$

The ammonia is recycled back into the process to form ammoniated brine.

Calcium chloride is formed as a by-product of the Solvay process.