Utah's Phosphate Rock Industry and Utah Railroads

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This page was last updated on May 13, 2022.

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Vernal Mine

In 1915, Harry Ratliffe staked nearly 15,000 acres of low to medium grade phosphate rock along the southern flank of the Uintah Mountains. This deposit became the largest privately owned phosphate deposit containing approximately 700 million tons of reserves. Initial development of the deposit began in 1958 by San Francisco Chemical, a joint venture between Stauffer Chemical Company and Mountain Copper Limited. In 1968, Stauffer Chemical Company bought out Mountain Copper Limited and became sole owner and operator. In 1981, Chevron Resources Company bought the property from Stauffer and operated the mining and milling operations after that date.

October 1957
Vernal was seen as the source for "huge deposits of phosphate rock." The deposits were reported as being the largest in the West, and were held by San Francisco Chemical Company. The limitations for development were lack of electrical power, and transportation facilities. A market developed for the deposits near vernal with the construction of Western Phosphates, Inc. at Garfield, which was jointly owned by Stauffer Chemical (50%) and Asarco and Kennecott Copper (50% jointly). The planned dam and generating station at nearby Flaming Gorge dam would provide the cheap electrical power. A reduction mil was concentrate the phosphate to make transportation by trucks more economical. (Deseret News, October 16, 1957)

(Construction of Flaming Gorge dam was started in June 1958. The dam was completed in December 1962, and filling the reservoir started. The power generators were turned on on September 27, 1963 by President John F. Kennedy. The completed dam was dedicated on August 17, 1964.)

April 1960
San Francisco Chemical was to start construction of a phosphate concentration plant on April 15, 1960. (Deseret News, March 18, 1960) (Actual construction was delayed until 1962)

February 1965
The State of Utah passed a law that would allow Stauffer Chemical to haul phophate concentrate from its mine near Vernal to the railroad at Keetley, using trucks with 60-tons capacity. By October 1966, the trucks were limited to hauling 43 tons to allow federal dollars to be used in the maintenance of U. S. 40, over which the overweight trucks had been traveling. (Deseret News, February 24, 1965; October 2 1966; October 26, 1966)

(Read more about the railroad at Keetley; Union Pacific's Park City Branch)

The phosphate rock was loaded into rail cars on Union Pacific's Ontario Branch, which connected to its Park City Branch at Keetley Junction. The loadout was at a new station called Phoston, which included a balloon track that minimized train handling for a return trip.

(View an aerial photo of the loadout at Phoston)

The following comes from a suit filed in U. S. Court of Appeals, Tenth Circuit, decided in January 2003:

In the 1980's, Chevron built an integrated phosphate fertilizer project. The purpose of the project was to utilize sulfur by-product from Chevron's natural gas operations in Carter Creek, Wyoming. Rather than attempt to sell the sulfur to existing phosphate fertilizer producers, Chevron chose to produce phosphate fertilizer itself. Entry into the phosphate fertilizer business was consistent with Chevron's preexisting nitrogen fertilizer business and fertilizer distribution system. In furtherance of this plan, Chevron purchased an operating phosphate mine located near Vernal, Utah. Because it was roughly equidistant between Carter Creek and Vernal, and because it was a railhead, Chevron chose to construct its fertilizer plant in Rock Springs, Wyoming. Chevron built a pipeline to transport phosphate concentrate slurry from the Vernal mine to the fertilizer plant in Rock Springs. This pipeline runs over lands owned by the United States, including environmentally sensitive lands, pursuant to a right-of-way issued by the Bureau of Land Management. The project became operational with the first shipments of phosphate concentrate through the pipeline sometime after May of 1986.

When Chevron purchased the Vernal phosphate mine it assumed an existing phosphate sales contract with Cominco, Ltd., a phosphate fertilizer producer in western Canada. Prior to the time the pipeline became operational, Chevron supplied Cominco by trucking phosphate to a railhead near Park City, Utah. In 1988, Cominco cancelled its phosphate contract with Chevron, concluding that it could obtain all the phosphate it needed at a lower cost from its own mining operations. Neither Chevron nor its successor-in-interest, SF, ever sold phosphate concentrate to a third-party after 1988, despite repeatedly trying to find outsider purchasers. During the entire time Chevron owned and operated the pipeline, no additional phosphate mines were developed in the United States and, after 1988, there were no third-party phosphate sales from a western United States phosphate mine.

In April of 1992, Chevron sold its entire integrated phosphate fertilizer project to SF (a joint venture between J. R. Simplot Company and Farmland Industries, Inc.). In 1992, Chevron completely exited the business by selling its interest in the entire integrated fertilizer project to SF for $64 million, only half of what it paid for the Vernal mine alone.

In 1985, Chevron Resources Company owned and operated an open pit phosphate mine and mill 11 miles north of Vernal, Utah. At that time, the plant produced 500,000 tons per year of concentrate and had the capacity to produce 750,000 tons per year. The operation was about to be expanded to 1,300,000 tons per year of concentrate in order to supply a new fertilizer plant being constructed by Chevron Chemical Company in Rock Springs, Wyoming. A 10-inch, 96-mile pipeline was being built to transport the concentrate from Vernal to Rock Springs.

In 1993, the Vernal phosphate rock concentrator was located in the Uinta Mountains near Vernal, Utah. Ore was sedimentary rock from the Phosphoria Formation. Truck and shovel mining was done at a rate of 11,500 tons per day. Run of mine ore was crushed and then milled through a SAG mill and ball mill to minus 16 mesh. Milled ore was deslimed using cyclones and hydrosizers. Sands were conditioned with fatty acid, petroleum sulfonate, diesel fuel and frother prior to primary rougher and cleaner flotation. Primary flotation tailing was milled to 95 per cent minus 48 mesh, deslimed in cyclones, conditioned using reagents previously described, and then processed through rougher and cleaner scavenger flotation. Product of scavenger cleaner concentrate was upgraded by reverse flotation of dolomite. Flotation concentrates were combined and dewatered, pulp being milled to 99.5 per cent minus 65 mesh and then thickened to 65 per cent solids. Product was pumped from storage through a 10 inch, 94 mile pipeline to a conversion plant at Rock Springs, Wyoming. Mill tailing was stored behind an earthen dam, water from the settled tailing being reclaimed for mill use.

As of 1997, the mine near Vernal was being operated by S. F. Phosphates Limited Company.

"The original SF Phosphates mine–near Vernal, Utah–was developed by the San Francisco Chemical Company in 1960. Chevron Resources Company purchased the mine in 1981, and in 1984 began construction of the slurry pipeline and the fertilizer manufacturing plant near Rock Springs, Wyoming. Chevron's plant and pipeline operations were underway by 1986. Spring of 1992 saw the formation of SF Phosphates Limited Company with the purchase of the mine, pipeline, and fertilizer plant in a joint venture between the J.R. Simplot Company and Farmland Industries, Inc. In 2003 the J.R. Simplot Company purchased Farmland Industries' interest in the operation, renaming it Simplot Phosphates, LLC." (Simplot Phosphates, LLC, brochure, which includes a well-done illustration of the fertilizer making process)

Western Phosphates at Garfield

September 30, 1952
Firm Name Chosen -- Western Phosphates, Inc., has been chosen as the name for the new multi-million dollar treble superphosphate fertilizer plant which will be erected near Garfield, Utah. Participating in the company are Stauffer Chemical Co., and Garfield Chemical and Manufacturing Co. (jointly owned by American Smelting and Refining Co. and Kennecott Copper Corp.). Building permits for the plant -- to be completed in 1953 -- have been issued by Salt Lake County. Five in number, they total $9,850,000." (Salt Lake Tribune, September 30, 1952)

December 1953
Western Phosphates, Inc. opened its new fertilizer plant at Garfield, as the first plant of its kind in Utah. (Deseret News, December 16, 1953)

The following information about the destination of phophates loaded on UP's Park City Branch, comes from a 2005 EPA report about environmental issues at Kennecott, both at and near Garfield, and the Bingham canyon mine. The report was obtained by a FOIA request.

The Chevron phosphate fertilizer plant was created as a joint venture between Stauffer Chemical Company, American Smelting and Refining Company, and Kennecott Copper Corporation. The project began in 1952 with partners incorporating under the name of Western Phosphates, Inc. Kennecott supplied the land (749 acres), which was deeded to Western Phosphates; ASARCO supplied the sulfuric acid; and Stauffer was designated as plant operator.

The property was located immediately northwest of the former Magna Tailings Pond. Ownership of the property was transferred to Stauffer in 1966 when Stauffer purchased the holdings from Kennecott. Chevron Chemical company acquired the facility from Stauffer in February 1981. Chevron operated the facility from 1981 to 1986 at which time the phosphate fertilizer production operations were terminated. Prior to acquisition of the property by Kennecott in August, 1994, Chevron leased the property to FCI Agri-chem, formerly called Four Court, Inc. The firm intermittently mined and sold the phosphogypsum stack tailing raw material as a soil additive. Kennecott bought out FCI's lease at the time Kennecoutt bought the land from Chevron. Only a small portion of the 385 acre gypsum tailings stack was mined by FCI.

Beginning in 1952, raw materials consisting of phosphate rock concentrate, sulfuric acid and anhydrous ammonia were imported to the site to produce phosphoric acid and dry phosphate fertilizers. Phosphate rock containing calcium phosphate was dissolved in sulfuric acid to form phosphoric acid and gypsum (calcium sulfate). The gypsum was filtered from the phosphoric acid and slurried to the gypsum tailings impoundment (phosphogypsum stack) and the phosphoric acid was concentrated and sold. Original plans included recovery of uranium and vanadium concentrates as a by-product.

Original production rates of phosphates were projected at 90,000 tons per year [DN 2-15-53]. The original cost of the plant was about $5M. A later article indicated that actual production varied between 10,000 tons to 70,000 tons [SLT, 7-8-56] Byproducts included about 300,000 tons/year of gypsum.

Because of the "unfirm surface of the ground" construction of the plant required workers to build a haul road from the ASARCO slag pile so that thousands of yards of slag could be used for fill. The slag was then covered with sand "to stabilize it" [SLT, 5-17-53].

At the time production ceased in 1986, phosphoric acid and dry phosphate were being produced at rates of 150 tons per day and 200 tons per day, respectively. Since 1986, a portion of the gypsum from the gypsum stack was mined, processed for sale, and sold as a soil additive for off-site applications. From 1987 - 1994, Four Court Inc pelletized the phosphogypsum tailings material with potassium chloride, potassium sulfate and molasses and sold the material as a soil additive. The footprint of the phosphogypsum stack covers about 385 acres. It is believed to contain approximately 6 million cubic yards of material. The plant was dismantled in June - Oct 1995. The non recycleable materials were disposed of on the phosphogypsum stack. In 2005, only the Administration building remained.

The following comes from "Utah's Cinderella Minerals" published in Utah Historical Quarterly, Summer 1963, Volume 31, Number 3, page 233:

Although phosphate rock had been mined intermittently since 1941, Utah's output of that mineral attained national significance in 1954. That year the San Francisco Chemical Company began phosphate-rock mining operations in the Crawford Mountains area of Rich County. The ore was shipped to Leefe, Wyoming, for beneficiation, and a large portion was sold to the Western Phosphates Company plant at Garfield, Utah. This plant was built at Garfield in 1953, principally because of availability of the sulphuric acid recovered by the Garfield Chemical Company by processing the gaseous effluents from the smelting of copper concentrates. Operations beginning in 1954 produced a wide variety of phosphate and phosphate-based fertilizers, as well as phosphoric acid, principally for out-of-state markets. The San Francisco Chemical Company acquired phosphate-rock reserves north of Vernal, Utah, in 1959, and began full scale production in 1961. A concentrating mill on the mining site produces concentrates which are hauled by truck (and rail) about 200 miles to the Western Phosphates Company plant.

September 1958
The fertilizer plant at Garfield used an yearly average of 12,000 tons of phosphate rock mined near Vernal. (Salt Lake Tribune, September 11, 1958)