 Ion exchangers and demineralized water are used in all chemical industries, drinking water production, and many food industries.Hydrochloric acid is used for a large number of small-scale applications, such as leather processing, purification of common salt, household cleaning, and building construction.Oil production may be stimulated by injecting hydrochloric acid into the rock formation of an oil well, dissolving a portion of the rock, and creating a large-pore structure.