Dual Salt process is associated with which fertilizer

The dual salt process is associated with Ammonium Chloride.
Ammonium chloride is a nitrogenous fertilizer that usually contains 25% N and most of it is produced by the dual-salt process, in which NH₄Cl and (Na)₂CO₃ are formed simultaneously.
The double salt process is when two or more simple salts in stoichiometric proportions are attracted to each other, resulting in the formation of a molecular salt that exists only in a solid crystal state but dissociates into their constituent compound in water or any other solvents.