Mineral Deposit Intrepid’s Wendover operation produces potash by transporting subsurface potassium-rich brines to the surface where they areexposed to western Utah’s arid climate. The aqueous portion of the brine is removed through evaporation, allowing the evaporiteminerals to precipitate and be collected for further processing. Because the potash is derived from subsurface brines, the mineral depositis best represented by characteristics of the aquifer(s) containing the brine. The shallow-brine aquifer, as it is called, exists within the near-surface carbonate mud layer. The carbonate mud transitions to theless-permeable lacustrine deposits at 20–30 ft depth. Brine extraction involves excavating a network of ditches, which allow the natural inflow of aquifer fluids, thereby exposing the brine to dry atmospheric conditions. Significant Mineralized Zones The zones of mineralization at Wendover are defined by the presence of potash-rich brines. These brines are known to occur in two out of three local aquifers: the shallow-brine aquifer and the deep-brine aquifer. The third aquifer, which is not potash-bearing and occurs stratigraphically between the other two, is the alluvial-fan aquifer. The shallow-brine aquifer is a near-surface aquifer and serves as the primary source of potash-rich brine. It is contained in the highly permeable salt and gypsum crust and underlying fractured carbonate muds. The alluvial-fan aquifer, the middle of the three, resides in the sand and grav ........

Potash at Intrepid-Wendover is produced through solar evaporation of naturally occurring brines collected from the sedimentary basin adjacent to the processing facility via brine collection ditches and extraction wells. The potash content of the collected brine is concentrated by solar evaporation to the point that solids are precipitated and can be collected. Harvested solid salts are hauled to the processing facility, where they are dried, sized, and stored for shipment. Potash, MRS, NaCl, and MgCl are shipped by both truck and railvia I-80 and the UPRR.

Brines from the shallow-brine aquifer, drained by gravity, are gathered by a system of collection ditches, which are approximately 20 to 30 ft deep by 9 to 40 ft wide. The total collection ditch system covers a length of 117 miles and annually collects 3.4 billion gallons of brine from the shallow-brine aquifer. Brines pumped from the deep-brine aquifer are used to augment the shallow brine to the collection system.

Collected brines are pumped into a primary pond, and solar energy is utilized to heat the ponded brine so that evaporation may proceed. As the brine is concentrated to a point just short of potash precipitation in the primary pond, the brine is then transferred into a harvest pond for selective precipitation of the potash crude salt.

As water evaporation continues in the harvest pond, sylvinite, a physical mixture of NaCl and KCl, is precipitated to the pond floor until the brine ........

The potash content of the collected brine is concentrated by solar evaporation to the point that solids are precipitated and can be collected. Harvested solid salts are hauled to the potash processing facility, where they are dried, sized, and stored for shipment as potash, MRS, and NaCl. MgCl rich brines are transferred to the MgCl ponds and processed in the Carnallite Plant.

The Intrepid-Wendover potash plant processes a nominal 5 billion gallons per year of deep-well and near-surface brines. The combined brines are estimated to contain 0.8–0.9 wt% KCl, 18 wt% NaCl, 4.2 wt% MgCl and all brines are near-saturated with gypsum (CaSO) at 0.5–0.6wt%.

The first step in processing is the solar evaporation in the pond system. The Intrepid-Wendover operation production is weather-dependent, most specifically rainfall. Anecdotally a wet winter increases potash production but produces diluted MgCl, which limits production of Road Saver brine. The annual rainfall ranges fr ........