Salt being necessary for preserving meat was important to the southern forces. Before refrigeration curing meat meant salt. Mobile troops required transportable preserved meat.
Before the war the southern states imported most salt from the Caribbean. It used vast amounts of salt- 450 million pounds annually according to one author.
During the war a Union naval blockade stopped that. The south had to scramble to keep the food supply viable.
Florida was a slave state that contributed 15,000 troops to the war effort. The state with several salt works produced much southern supply. The largest salt works were at St. Andrews and Apalachee Bay.
The working conditions at salt works was often very hard. The confederates employed slaves at some sites in harsh conditions. Many died on the job. Alabama had an especially cruel salt works.
Another important salt works was at Saltville VA. Union General George Stoneman twice attacked it. In the second battle he tore up the works and railroad tracks and took out the production a couple of months. The damage to the tracks lasted longer. It was the main eastern producer for the rebels.
I have wondered if one of the causes of General Lee’s starving troops was the damage to various salt works and the broken supply lines. Some confederate soldiers of the Army of Virginia went barefoot toward the end while thousands of pairs of boots were in warehouses in North Carolina that capitalists would not surrender to the war effort. Mass quantities of salt and food production sights, hog farms and so forth became scarce toward the end perhaps, comparable to Nazi production and supply attrition.