INDUSTRIAL ROCKSALT CHEMICAL FEEDSTOCK
The greatest single use for salt is as a feedstock for the production of chemicals. The chlor-alkali industry uses salt, primarily as salt in brine from captive brine wells, to produce chlorine and caustic soda. Demand for salt in to produce chemicals fell from 25 million metric tons in 1974 to a low of 16.7 million metric tons in 1992. However, chemical use rebounded in 1994 to 18.4 million metric tons. Much of the decreased demand for chlorine was attributed to environmental concerns about dioxins. Salt is also used to make sodium chlorate and metallic sodium by electrolysis and, sodium sulfate and hydrochloric acid by reacting with sulfuric acid.
All animals, humans included, require both sodium and chloride for life and health. Since the body cannot manufacture either, they are "essential" nutrients. While developed countries dedicate most of their salt to chemical production, developing countries often use most of their salt for human and animal nutrition.
A variety of materials, each of which is used in the production of many products, are produced by different treatments, or processing, of rock salt or salt brine. Following are a few of the most important:
· LIQUID SODIUM – in more recent years, used as the coolant, or heat exchanger, an essential element in the nuclear process.
· METALLIC SODIUM – used in making brass and bronze; sodium cyanide, in turn, used in making case-hardened steel and fumigating materials, in indigo and other synthetic dyes.
· CHLORINE – used primarily in producing polymers that are used in manufacture of plastics, synthetic fibers and synthetic rubber; also used in crude oil refining, for making pesticides; in household bleach, water treatment and sewage treatment.
· CAUSTIC SODA – an element used in making glass, rayon, polyester and other synthetic fibers, plastics, soaps and detergents.
· SODIUM SULFATE – used extensively in the manufacture of pulp and paper, dyes and ceramic glazes.
· SODIUM CARBONATE – used in manufacture of glass, pulp and paper, and rayon.
· HYDROCHLORIC ACID – used in making synthetic rubber and in cleaning gas and oil wells.
· SODIUM BICARBONATE – used in textile manufacturing, processing leather, making glass and neutralizing acids.
· SODIUM NITRATE – an ingredient in fertilizers and explosives.
PULP & PAPER
Salt is used to manufacture chlorine and caustic soda. In paper making, caustic soda is used to process wood fibers and chlorine is used to bleach the pulp. Sodium chlorate, also made from salt, is replacing chlorine as the primary chemical for bleaching pulp.
AND ALSO ROCK SALT IS
USED IN…
· It is used in metal processing and secondary aluminium making, to remove impurities
· Rubber manufacturers use salt to separate rubber from latex
· Salt is used as a filler and grinding agent in pigment and dry-detergent processes
· Ceramics manufacturers use salt for vitrifying the surface of heated clays
· Soap makers separate soap from water and glycerol with salt
· Oil and gas drillers use salt in well drilling muds to inhibit fermentation, increase density and to stabilize drilling in rock salt formations; hide processors
· Leather tanners use salt to cure, preserve and tan hides;
….
Cloud Seeding for
Rain: Though perhaps not an "industrial use," salt has been used
to "seed" clouds to produce rain in desert areas.