saltproduction

In 1957, Geologists developed a process called hydraulic fracturing. This is the basis for the modern technique of mining salt. Water under high pressure finds a weakness in the salt bed and is forced, like a wedge, into the bed until it reaches a target well. Hydraulic fracturing exposes larger faces of salt to the dissolving action of water. Brine of higher purity is produced. Cavity locations can be pinpointed and the brine fields developed efficiently. Brine, piped to the Watkins Glen plant on the surface, is refined into evaporated granulated salt.

nEvaporated salt is what is poured from the salt shaker. As its name implies, evaporated salt is made by evaporating water from brine to form salt crystals.

nAt Watkins Glen Refinery evaporated granulated salt is manufactured by the multiple-effect vacuum pan method. A vacuum reduces the amount of heat required by lowering the boiling temperature of the brine. Multiple-effect vacuum pans substantially increase the amount of water than can be evaporated by each pound of steam, hence improving the efficiency of the process.

n The brine enters four enclosed monel vacuum pans, each as tall as a six-story building and 15 feet in diameter.

The salt mix from the first vacuum pan is circulated at high speed through an external heat exchanger, where it is heated by low pressure exhaust steam from turbo-electric generators. A heat exchanger for each succeeding vacuum pan uses steam vapors from the evaporating brine in each preceding pan. All pans and exchangers operate concurrently.

nAs the water evaporates from the brine during the process, crystals of salt form and settle in long legs at the bottom of the vacuum pans. A slurry of salt crystals and brine is drawn from the legs and pumped to a settling tank. The brine is then returned to the evaporators, and the crystals are pumped to another tank, where they are washed with pure brine to remove impurities.

n Rotary vacuum filter-dryers remove the remaining brine and dry the salt. A rotary cooler lowers the temperature of the salt, which is 99.9% pure sodium chloride. Following screening, the evaporated salt is mixed with other ingredients, processed into several forms and then packaged, stored and shipped to customers across the country. The Watkins Glen Evaporated Salt Plant generates all of its electricity on site