Arizona Mining Association

Back to the Salt Mines

Solar Salt is produced at Glendale using the solution mining method.

It still remains a little known fact that there is a working salt mine here in Arizona. The Morton Salt, Glendale Facility is located outside of Phoenix and beneath the ground in every direction of the facility lies a vast salt deposit known as the Luke Salt Body. The salt deposit is estimated to contain at least 15 cubic miles of salt.

Salt production at the Glendale facility began in 1969 by the Southwest Salt Company. Morton Salt purchased the facility from Southwest Salt in 1985. When visiting the Glendale facility, don't expect to see a mine shaft protruding upwards from the ground. Solar Salt is produced at Glendale using the solution mining method. Two active brine wells were drilled 3,600 feet below ground level. Each well has a steel casing cemented from ground level into the salt. A second pipe or tube is inserted inside the first to a depth of 1,000 to 2,000 feet below the first. Water is pumped or injected from five water wells down the inner tubing of each well, where it dissolves the salt and returns it up the outer casing and back to the surface as saturated brine. The brine that is discharged from these brine wells is pumped into solar ponds which are 4-5 feet deep. Arizona's sun, wind and low humidity remove the water from the brine causing salt crystals to form and settle to the bottom of the pond. The Glendale facility differs from most solar salt facilities because it discharges, on the average, 98% saturated brine into the ponds, thus making every pond a crystallizer.

Salt production at the Glendale facility began in 1969 by the Southwest Salt Company. Morton Salt purchased the facility from Southwest Salt in 1985.

The salt is harvested from the solar ponds by a "one-of-a-kind" harvester that removes the salt from the pond's bottom while it is still covered with brine. Most other solar salt facilities drain the brine from the pond and harvest the salt from the dried pond. Glendale's harvester pumps a slurry of salt crystals and brine to a wash-plant where the salt crystals are separated from the brine and washed to remove any contaminants. The salt is then stockpiled to cure before processing. After curing several days the salt is taken from the stockpile by a front end loader and fed into a natural gas fired kiln for drying. After drying the salt is screened into various grades for end use. The sized salt is then shipped to end users, either as bulk or packaged salt.

Approximately two-thirds of the salt produced at Glendale is used for water softening products, with the remaining third going to agricultural or industrial use. No food grade products are produced at Glendale. All of the equipment used in the production of the solar salt is maintained in-house. Mill/packaging operations are adjusted by product line based on demand. The facility employs a total of 35 employees.

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