A method of acid manufacturing using acid cation resins for recycling salt and/or salt products from wastes and/or waste waters utilizes a brine solution, an acid cation resin, an acid solution, and an ion exchanger. The acid cation resin is into hydrogen form with the acid solution within the ion exchanger. The acid cation resin is then washed using water with salinity to remove any excess acid from the exterior of the acid cation resin. A selected brine of salts is then prepared of the desired acid(s) to be produced. The desired acid is produced by contacting the acid cation resin containing cations in concentration with the selected brine. A second ion exchange reaction is executed to substitute hydrogen for cations in the selected brine.