MINING AND LAND SPEED RECORDS COME TOGETHER AT BONNEVILLE SALT FLATS
Domestic mine article by Harold Hough
Mention the Bonneville Salt Flats and most people think of racing and land speed records. But this remnant of Lake Bonneville is a critical provider of potash for agriculture and magnesium chloride for dust control.
The Bonneville Salt Flats is a densely-packed salt pan in northwestern Utah that is a remnant of the Pleistocene Era, Lake Bonneville. It is the largest of many salt flats located west of the Great Salt Lake. The area was named after Benjamin Bonneville, a U.S. Army officer who explored the West in the 1830s. In 1907 Bill Rishel and two local businessmen tested the suitability of the salt for driving on by taking a Pierce Arrow onto the surface of the flats. The first Bonneville land speed record was set in 1914 by Teddy Tetzlaff. Since then, it has become home to many land speed records, including the Blue Flame rocket-powered vehicle that achieved the world land speed record on October 23, 1970. The Blue Flame's kilometer record of 630.388 mph lasted until 1997 - for 27 years.
The Bonneville Salt Flats continue to attract speed freaks every year at SpeedWeek, which allows racers to establish speed records in several categories.
But, the area is also home to a major potash mining operation. Intrepid Potash’s Wendover Potash Mine takes advantage of the same minerals that make the area ideal for high speed racing. The salt bed is rich in minerals containing potassium, sodium and magnesium. Intrepid Potash is based in Denver and has operations in Utah and New Mexico.
The Wendover potash mine is located about 120 miles west of Salt Lake City and has been actively used for potash production for over 65 years. Potash production from the local brines at the Wendover facility dates back to World War I. During the period from 1920 to 1936, several attempts were made to commercially produce potash. However, it wasn’t until 1939 that a successful commercial potash operation was established – the same one that continues today.
Potash is the common name for several potassium salts, the most common being potassium chloride (KCl). Potash is an important fertilizer because it improves water retention, yield, nutrient value, taste, color, texture and disease resistance of food crops. Demand for potash in food and animal feed has been on the rise since 2000 thanks to rising incomes in developing countries. With more money in the household budget, consumers add more meat and dairy products to their diets, which mean more demand for potash in agriculture.
The potash at the Wendover operation comes from the brine in the aquifer. Brine from the very shallow aquifer is collected in open ditches. In addition there is a deep aquifer 1,000 feet below ground that provides additional brine. The brine that is collected in the ditch system is pumped into an 8,000 acre solar evaporation pond to evaporate water and precipitate several mineral salts.
As the brine becomes saturated with potash, it is transferred through a series of smaller evaporation ponds into harvest ponds. When the ripened brine finally reaches the harvest ponds, the ore (a combination of salt and potash) is precipitated out of solution on the pond floor. The remaining brine in the harvest ponds is removed and the ore is harvested and transported by self-loading scrapers to the mill for processing. In the mill, the potash is separated from the salt by flotation. The material is then dried, compacted and screened into premium grades of white potash. The ore from the harvest ponds can be sent directly to the dryer to be dried and screened into a metal recovery salt (MRS) which is a combination of potash and salt. The final products are conveyed and stored in bulk storage warehouses. From the warehouses, potash and MRS can be loaded directly into railcars or trucks for shipment.
The potash-free brine moves on the next stage. That brine is rich in magnesium chloride and is transferred into additional evaporation ponds to concentrate further. After reaching 28-30% magnesium chloride in the brine, it is transferred into storage ditches and lined ponds. It will eventually be processed into several products, including dust control agents popular at mining operations.
The mine also pumps brine onto the surface of the Bonneville Salt Flats in order to protect it from erosion caused by weather, traffic, and racing. The project consists of a series of canals and old salt ponds through which water is pumped to dissolve the old salt. The resulting salt brine is then pumped onto the Salt Flats throughout the winter months to ensure the Flats are ready for the summer and fall racing events. Since the project began in 1997, over 7 million tons of salt have been pumped onto the Salt Flats – ensuring that Bonneville will remain a source for land speed records as well as potash.