To Move A Mountain
Railroads and Mining in Utah's Bingham Canyon
This page last updated on December 8, 2018.
Copper Era, From 1981 to 1989 (Sohio)
June 4, 1981
Standard Oil Company of Ohio (Sohio) bought Kennecott Minerals Company (KMC); British Petroleum (BP) owned 53 percent of Sohio; British government owned 25 percent of BP, Bank of England owned 20 percent. (Salt Lake Tribune, September 24, 1981) (Read more about Sohio ownership of Kennecott)
The sale to Sohio would give Kennecott access to financial reserves needed to modernize all of its copper properties in Utah, Nevada, New Mexico and Arizona, including developing a recently discovered high-grade body in Utah known as the North Ore Shoot Extension. Kennecott had been seeking to develop this new ore body through a joint venture with Fluor Corporation. (New York Times, March 14, 1981)
Modernization of ore haulage and pit crusher planned, along with a new concentrator site. New smelter began operations in spring 1978. (Salt Lake Tribune, October 30, 1981)
Visitor Center at Bingham Mine closed, to be replaced by a new one, to be built later. Bingham Mine has been listed as a National Historic Site since 1972. (Salt Lake Tribune, May 27, 1981)
Production for the Bingham Mine, at 223,123 tons of copper, is 60 percent of all Kennecott Copper's 1981 production of 372,213 tons of copper. (Salt Lake Tribune, April 6, 1982)
March 3, 1982
Kennecott Corporation announced a lay off of 530 employees, about 10 percent of the workforce in Utah, beginning on Sunday March 7, 1982. Copper prices had hit a new low of 70 cents per pound, compared to an average price of 80 to 90 cents per pound. (New York Times, March 3, 1982)
July 1, 1982
910 employees laid off. Lay-offs began on February 12, 1982, with a total so far of 2,000 employees laid off. (Deseret News, July 1, 1982)
Truck haulage replaced rail haulage between the 5440 level and the 5190 level. (source not recorded)
Four 1500 hp locomotives arrive (numbers 714-717), for service as switchers, to replace retired electrics. (source not recorded)
Due to a glut in the copper market, Kennecott has had a $48 million loss during this first quarter. Kennecott began 1982 with 7,300 workers. Ray Mines Division was shut down on May 2, 1982, and mine activity was cut back to care and maintenance on August 15, 1982. (Salt Lake Tribune, July 1, 1982)
Copper selling in range of 55 cents per pound in recent months, compared to $1.80 per pound in February 1980. (Deseret News, September 1982)
Kennecott Minerals Company became Kennecott, (an operating company of Sohio) (source not recorded)
In 1983, the entire mine was converted to shovel and truck mining. Rail haulage was used for reload only, at the 6040, 5840, and 5490-Tunnel levels. The last rail and shovel mining took place between the 5540 and 5990 levels. Prior to the end of 1983 there were 42 truck haulage levels, 36 above the 5990-Level and six below the 5490-Level. The 11 rail haulage levels were between the 5490-Level and the 6040-Level. By this time there was very little ore left above the 6040-Level and all operations were concerned with removal of waste to allow ore mining in the lower levels.
The last electrics were removed from ore haulage service in the Bingham pit with the arrival of the third order of seven high-cab GP39-2s in October 1980. After that, the last 13 electric locomotives (85-ton electrics 700 and 703, 90-ton electrics 761 and 762, and 125-ton electrics 766-773, and 778) were only used occasionally as standby units, and for maintenance trains until late 1982 or early 1983. All were either retired and scrapped by late 1983, or donated to museums for presevation.
Kennecott closed its 175 megawatt coal-fired generating station because of financial losses. In the meantime, Kennecott could purchase power from Utah Power and Light at a reduced rate. The generating station's 100 employees remained working for maintenance purposes. (Coal Age, Volume 88, Number 6, June 1983, page 33, "Coal in Brief, Plant Closed")
During 1983 Kennecott was reported as being the nation's largest producer of copper, including production from all four mines: Bingham (Utah), Ray (Arizona), Chino (New Mexico), and Ely (Nevada). (part from New York Times, November 14, 1987, "four years ago")
Kennecott's $400 million modernization program depended on proposed property tax breaks by Utah State Legislature. (Deseret News, August 30, 1983)
The last waste train was operated on September 19, 1983. (Strack, 1983 research notes)
September 19, 1983
Switcher number 704 was transferred to Ore Haulage. Renumbered to 123 on 13 January 1984. (from Kennecott records at Dry Fork shops and at Magna engine house)
Two pit high cab diesel locomotives (number 784 and 786) were transferred to Ore Haulage (as number 910 and 911) (Strack, 1983 research notes)
In 1981, Kennecott had 7,400 employees in Utah, with an annual payroll of $250 million. By June 1984, after a series of layoffs that started in February 1982, the company had 4,400 employees, a reduction of 3,000 jobs. A further reduction of 2,000 jobs was announced on June 15, 1984, reducing Kennecott's payroll down to 2,400 jobs in stages through July and August 1984. Production was to be scaled back from 200,000 tons of copper per year, down to 60,000 tons of copper per year. The cutback of production was forced due to the plunging prices of metals, due mostly to cheap foreign imports. (Deseret News, June 16, 1984)
June 30, 1984
Ed Shurtliff was the Magna shop foreman in the late 1970s and early 1980s. During a visit on the last day in June 30, 1984, he gave the author the last shop log book, which is still in the UtahRails collection. It covers the period from March 19th to the last day. Ed very soon got a job working for Utah Railway in their Martin shop, and stayed on with MK when they took over at Martin.
With all the changes at Magna, the Ore Delivery Department (later Ore Haulage Division) locomotive shop building is still there in 2018. Today it is where Omaha Track does some minor maintenance on the KCCX acid cars, under contract to Kennecott/Rio Tinto. Many former employees told of the B&G shop crews and their ability to do any needed repairs in the Magna shop. And they did, too, including total rebuild of #105 after its boiler explosion, along with rebuilding the two ex N&W engines that came in 1943. They rebuilt wreck-damaged Ore Haulage electrics, the wreck-damaged Baldwin road switcher after its encounter with a D&RGW GP in 1952, and chopped the noses of three diesels in 1972. The Ore Haulage shop was closed in 1984, at the same time that the entire Ore Haulage Division was shut down. All later locomotive repairs were done at Dry Fork shops in Bingham canyon.
July 1, 1984
Kennecott laid off 1,795 workers on July 1, 1984. (Deseret News, July 13, 1984); 2,000 workers (two-thirds of workforce) were laid off. (Deseret News, March 26, 1985)
July 1, 1984
Ore Haulage Division was shut down and the organization was dissolved. Ore trains were to be operated by the mine crews. (Ore Haulage logbook)
September 4, 1984
Former Ore Haulage crews transferred to the mine began the operation of ore trains to Bonneville crusher, using mine locomotives. Trains were moving 35,000 tons per day, using 400 ore cars. (Strack, 1984 research notes)
Copper production at Bingham took about 1,200 to 1,400 cars of copper ore to produce about 20 cars of concentrate for the smelter. Kennecott's Chino operation was sending about 10 cars of concentrate per day to the Utah smelter. (Strack, 1984 research notes)
Utah legislature exempted Kennecott from paying sales tax on purchases of machinery to replace old equipment and equipment needed to expand operations. (Deseret News, March 26, 1985)
January 6, 1985
Kennecott laid off 100 more workers, leaving just 2,200 workers remaining of a peak in 1980 of 7,300. (Salt Lake Tribune, January 1, 1985)
Kennecott announced that it would close down and lay off 2,200 employees in Utah, beginning on March 31. Another 1,100 employees were to be laid off on April 30. (Deseret News, March 26, 1985)
March 26, 1985
Kennecott announced that it would spend $400 million to modernize its Utah operations. In December 1984, the company had received approval for the zoning changes needed to build the Copperton mill. Contracts with 14 unions were set to expire on June 30, 1986. It was reported that in 1981, Kennecott had 7,400 employees, with an annual payroll of $250 million. "Some 2,500 kennecott workers lost their jobs by the time the shutdown was complete in September ." To fund the Utah modernization program, Kennecott's parent company Standard Oil Company of Ohio, reported that it would take $1.15 billion charge against fourth quarter 1984 earnings, while still reporting a $290 million profit on $3.2 billion in revenues. The $400 million cost of the program was to be spread over a period of three years. (Deseret News, December 3, 1985, citing information in three separate articles)
Features of the modernization program included:
- A 60-inch by 109-inch gyratory ore crusher installed in the pit of the Bingham Canyon mine. The crusher was designed to be movable and could be relocated within the mine as needed. The crushed ore would be 8-10 inches in diameter.
- A five-mile conveyor belt system t move the crushed ore to the site of a new grinding and floatation plant one mile north of Copperton. The 72-inch main ore conveyor exited the mine through an existing railroad tunnel at the 5,490-foot level. The conveyor belt would have a capacity of moving 10,000 tons every hour. Along the 5.1 miles of total length, there were five transfer stations, large steel structures several stories high that were needed each time the conveyor belt changed direction. After exiting the former railroad tunnel, the conveyor continued for two miles to the new grinding and floatation complex.
- At the grinding and floatation complex, the ore was dumped into a stockpile that could contain 350,000 to 400,000 tons of copper ore beneath an A-framed structure.
- The grinding plant included a grinding building, with three separate grinding lines, each consisting of a semi-autogenous grinding (SAG) mill (34 feet in diameter by 15 feet in length) and two ball mills (18 feet in diameter by 28 feet in length).
- The floatation portion of the Copperton complex included 33 3,000-cubic-foot cells as well as a number of smaller cells for the copper concentrating circuit. The complex included a molybdenum recovery plant.
- Three pipelines were to be constructed between Copperton and existing Utah Copper Division facilities. A five-inch buried steel line was to be utilized to move concentrates to the smelter, 17 miles away. A 48-inch concrete overland pipeline would transport tailings to the existing tailings pond. Reclaimed water from the pond was to be pumped back to the grinding and floatation facilities in a buried 48-inch steel pipeline.
- The modernized Utah Copper Division would be capable of processing 77,000 tons of copper ore per day.
- (Magnaian newspaper, January 29, 1987; Deseret News, November 1, 1987)
April 30, 1985
Bingham Canyon Mine operations were shut down.
"Most of the workers were laid off when Kennecott shut down operations completely in August 1985." (Deseret News, December 14, 1986)
Magna, Arthur, and Bonneville Mill operations were shut down.
The Magna Mill was one of the two original mills built in the area by the two Bingham Canyon copper companies. After experimentation with a prototype mill in Copperton, Utah Copper Company built their Magna Mill on a hillside above the Great Salt Lake. The mill opened in 1907 and had reached a capacity of 6000 tons per day by 1908, expanding again in 1911 to 10,000 tons per day. The grinding at the mill was done with 7 foot Chilean mills. After a brief closure between 1919 and 1922, the Magna mill reopened and a froth flotation circuit was added. (Froth flotation experiments were begun in the 1914 and by 1926, the gravity technology had been completely replaced by the flotation method.) At the Magna Mill, sodium xanthate was used as the flotation agent and a plant was added to manufacture the xanthate. But the neutralized reco cresylic acid reagent in use at the adjacent Arthur Mill proved more cost effective and the Magna Mill began using the same reagent in 1933. The Magna Mill remained open during most of the Depression but operated at only a fifth of its capacity. The portions of the plant not in operation were reconditioned at this time. Full scale operations resumed and the normal capacity of the mill was about 40,000 tons/day. When the Bonneville Crusher was opened in 1966, the grinding portion of the Magna mill was no longer needed and it was eventually demolished in 1991-1992. However, the Bonneville Crusher continued to feed the flotation circuits of the Magna Mill and this portion was upgraded in 1975 and again in 1982. The concentrates were loaded into rail cars and were shipped to the smelter. The tailings were sent via a flume to the Magna Tailings Pond. The Magna Mill, known also as the North Concentrator, was shut down in 2001. (source not recorded)
Demolition started of the Magna concentrator complex in April 2007, shut down since November 2001. The work, expected to be completed by June 2007, included the removal in May 2007 of the overhead pipeline from the mill to the tailings pond that crossed over State Route 201. (Salt Lake Tribune, May 10, 2007)
In 1906, the Boston Consolidated Company began construction of a large ore milling facility adjacent to the site of the ASARCO smelter. Located on a 810 acre site, the mill was put into operation in 1909 with a capacity of 3000 tons per day. Utah Copper, which was operating its own plant next door, bought out the Boston Consolidated Company and all its facilities in 1910, and Utah Copper ended up with two mills side by side. The former Boston Consolidated Mill, renamed the Arthur Mill, expanded in capacity to 8000 tons per day. Based on the results of flotation experiments which began in 1914, the Arthur mill was equipped with a flotation circuit by 1918 and flotation completely replaced the gravity separation technology by 1926. Flotation reagents tested at the mill included coal tar creosote, petroleum, petroleum residuum, petroleum stove oil, pine oil, reco pine oil, reco turpentine, calura (lime, sulfur and sodium hydroxide), rosin, lime, soap solution, sodium sulphide, sodium hydroxide, light oil, coal tar, phenols, sulphuric acid, alpha naphthylamine, xylidine, thiocarbanilid, ortho toluidine, and potassium ethyl xanthate. In 1924, a typical charge consisted of creosote oil, steam distilled pine oil, sodium hydroxide and sulphur. New reagents for flotation were introduced in 1925 including reco cresylic acid (a reaction product of cresylic acid and phosphorus pentasulfide) and reco alcohol (a reaction product of alcohol and phosphorus pentasulfide). The tailings and whatever reagents were used in the process were discharged to the Magna Tailings Pond. (source not recorded)
During the Depression, the Arthur Mill was closed between 1930 and 1936 and the mill was reconditioned at that time. The Arthur Mill then operated until 1966 when the Bonneville Crusher opened. Some ancillary activities continued until 1985. The buildings were demolished in 1988-1989. Only the Arthur Mill Administration Building and a few storage sheds remain of the original mill and its support buildings. (source not recorded)
The Arthur mill was shut down in 1984, and was demolished in 1991. The adjacent Magna mill was shut down in 2001 and was demolished in 2007. (Salt Lake Tribune, May 10, 2007)
In 1966, Kennecott opened the Bonneville Crusher, constructed to provide a finer grind for the ore than could be accomplished at the Arthur or Magna mills. When it was first opened, the crusher fed the flotation circuits for both the Arthur and Magna mills. Processing capacity was markedly increased from 90,000 tons per day before the opening of the crusher to 108,000 tons per day shortly after the Bonneville Crusher came on line. Since 1985, the Bonneville Crusher fed only the Magna Concentrator. The Bonneville Crusher was a rod mill which is more effective with harder ores than the facility in Copperton. These harder ores were shipped to the Bonneville Crusher from the pit via rail. After crushing, the ore slurry was sent to the Magna Concentrator for flotation. The Bonneville Crusher and the Magna Concentrator (known as the North Concentrator Complex) were closed in 2001. (source not recorded)
Actual construction and site preparation started on new $400 million modernization program. (Deseret News, August 2, 1988)
February 27, 1986
Standard Oil of Ohio changed its name to Standard Oil Company on Thursday, February 27, 1986. At the same time, British Petroleum, which owned 55.5 per cent of Standard Oil, doubled it representation of the 14-member Sohio board of directors, from three positions to six positions, and removed both the chairman and the president of Sohio, who had both held those same positions when Sohio took control of Kennecott in June 1981. The acquisition of Kennecott by Sohio had been the subject of shareholder criticism since the time of the sale. It was reported that Sohio earnings for 1985 were 79 per cent less than 1984, $308 million compared to $1.49 billion. (Deseret News, February 28, 1986)
September 11, 1986
Chino and Ray Sold -- The Standard Oil Company announced that "it had agreed to sell two major units of its copper mining subsidiary, the Kennecott Corporation, for about $220 million. The Cleveland-based energy company said it had agreed to sell its two-thirds interest in the Chino Mines Company in New Mexico to the Phelps Dodge Corporation. It also said that it would sell its Ray Mines division in Arizona to Asarco Inc., the New York mining company. The remaining third of the Chino Mines is owned by the Mitsubishi Corporation. The two units represent about half of Kennecott's annual production capability. The sale of the two operations leaves the mining unit with its copper division in Bingham Canyon, Utah. The Utah mines have been closed since March 1985 and are undergoing a $400 million, three-year modernization program. Standard Oil said the sale was part of a reorganization in which it planned to divest itself of certain operations that it considered inconsistent with its long-term strategy. 'After completing a study of all our operations, we decided to focus on our strengths, and that is primarily in petroleum,' John F. Andes, a Standard Oil spokesman, said." (New York Times, September 12, 1986, "yesterday") (Read more about Ray Mines Division) (Read more about Chino Mines Division)
Operations at Sohio's Utah Copper mine were shut down in March 1985, but were restarted in 1986 after obtaining concessions from labor unions. (Deseret News, September 23, 1988)
Bingham Canyon Mine resumed operations.
Kennecott reopened the Bonneville crusher and Magna concentrator mill. (Deseret News, January 3, 1989)
January 29, 1987
Utah Copper Division Modernization Project:
A $400 million modernization project currently is underway at the Utah Copper Division of Kennecott. The project will provide in-pit crushing and the construction of new grinding and flotation facilities located near the mine.
Transportation improvements include an ore conveying system and the installation of three pipelines. The project will utilize some of the largest state-of-the-art crushing, conveying, grinding and flotation equipment available in the industry today. The modernized Utah Copper Division will be capable of processing 77,000 tons of ore per day.
Major Change Components:
-- A 60-inch by 109-inch gyratory ore crusher installed within the pit of the Bingham Canyon mine. The crusher is designed to be movable and will be relocated in the mine as a function of the mining plan.
-- A five-mile belt conveyor system will move the ore from the mine to the site of new grinding and flotation facilities one mile north of Copperton. The 72-inch main ore conveyor will exit the mine through an existing railroad tunnel at the 5,490-foot level (elevation).
-- The grinding plant will consist of a coarse ore stockpile and a grinding building, which will house three grinding lines, each consisting of one semiautogcnous grinding (SAG) mill (34 feet in diameter by 15 feet in length) and two balls mills (18 feet in diameter by 28 feet in length).
-- The flotation portion of the Copperton complex will include 33 3,000-cu. ft. cells as well as a number of smaller cells for the copper concentrating circuit. The complex includes a molybdenum recovery plant.
-- Three pipelines will be constructed between Copperton and existing UCD facilities. A five-inch buried steel line will be utilized to move concentrates to the smelter, 17 miles away. A 48-inch concrete overland pipeline will transport tailings to the existing tailings pond. Reclaimed water from the pond will be pumped back to the grinding and flotation facilities in a buried 48-inch steel pipeline.
March 26, 1987
British Petroleum made its planned offer to buy the remaining 45 percent of Sohio it did not already own. (Toronto Star, March 26, 1987, "today") British Petroleum bought 45 per cent of Sohio, at a reported price of $7.8 billion. (New York Times, September 8, 1989)
By mid May 1987, BP owned 95 percent of Standard Oil Company, the new name of the Standard Oil Company of Ohio (Sohio). (New York Times, May 14, 1987)
June 30, 1987
British Petroleum completed its purchase of Standard Oil Company, formerly Standard Oil Company of Ohio. The acquisition was made through BP's wholly owned subsidiary, BP America Inc. (New York Times, June 30, 1987, citing a Reuters story)
The Garfield smelter was scheduled to reopen in August 1987, and the Garfield refinery was scheduled to reopen in September 1987. (Deseret News, December 14, 1986)
Smelter produced its first cathode of Utah copper, after reopening of mine.
September 24, 1987
BP America announced the formation of BP Minerals America. The new unit combined the assets of Kennecott Corporation, headquartered in Salt Lake City, and Denver-based Amselco Minerals. BP Minerals America was to be headquartered in Salt Lake City. (BP America news release, dated September 24, 1987, "today")
The price of copper reached $1.05 a pound, its highest level in seven years, up from about 60 cents a pound a year ago. The increased price came from reduced inventories in the past two years, and increased demand from South Korea, Japan and Taiwan. Worldwide inventories were down to a 30-day supply, their lowest point since the early 1970s, and inventories continued to drop as demand continued to increase. Phelps Dodge was the nation's largest producer, earning $140 million on $1 billion in revenues in 1987, up from $64 million in 1986 and a loss of $405 million in 1982-1984. Magma Copper Company, a subsidiary of Newmont Mining Corporation, was the nation's number two copper producer. In the 1980s, United States copper producers' costs were at an all-time high, exceeding $500 million in 1982 alone, when the price of copper fell sharply due to increased production and lower costs in countries like Zaire, Chile and Zambia, whose higher grade ores and lower wages made American producers uncompetitive. United States producers addressed their high costs by cutting back their inefficient operations and the industry became "much smaller, leaner and profitable." The national average for cost-of-production fell from 90 cents per pound in 1982, to 65 cents per pound in 1987. Phelps Dodge expected its costs to sink to 50 cents per pound by the end of 1988, down from 57 cents in 1987, and 80 cents in 1984. The industry as a whole was set to produce 1.3 million tons of copper in 1987, up from 1.1 million tons in 1980, but with a third less workers (21,000 workers compared to 28,000 in 1980). (New York Times, November 14, 1987)
"The nation's largest copper producer four years ago, Kennecott, a unit of the British Petroleum Company, now ranks fourth. It has sold most of one of its three mines to Phelps Dodge and all of another to Asarco Inc and now owns a single mine - the Bingham Canyon mine in Utah, which recently reopened for production." (New York Times, November 14, 1987)
The price of copper rose to $1.40 per pound during the third week of December 1987, but was expected to drop to about 85 cents by mid-1988. At Kennecott's Utah mine, testing of the modernized plant was scheduled to begin in February 1988, and continue for several months. "High production costs and low copper prices caused the closing of the mine in spring 1985. Copper mining resumed in September 1986, but it wasn't until July 1987 the first copper cathodes were turned out." This new production was coming from the old equipment, with the modernized plant not yet operational. Employment had dropped from 7,000 in 1980, to 4,300 in 1984. (Deseret News, December 31, 1987)
British Petroleum, parent company of BP Minerals America (owner of Bingham Mine), is 21.68 percent owned by the government of Kuwait. They bought the interest after the October 1987 world wide stock market crash, at the urging of the British government. The British had just offered the stock of BP to the open market and the crash was causing it to lose value. (Wall Street Journal, August 10, 1988)
The new conveyor belt installed in the 5490 rail tunnel was put into operation in January 1988. The conveyor system consisted of six separate conveyor belts, with the longest, known as C-6, being 17,300 feet in length. By the time it was replaced due to normal wear and tear, in August 2002, the conveyors had carried 700 million tons of 10-inch minus material, from the in-pit crusher, out to the material storage pile adjacent to the Copperton mill. The conveyor belts were 72-inches wide. The C-6 belt was replaced during a normal 10-day downtime to move the in-pit crusher. "After almost 14 years of service, the most critical belt was removed after exceeding all warranty expectations. In particular, it exceeded warranty life by 40 percent and warranty tonnage by 245 percent. The belt was finally replaced [in August 2002] due to the convenience of system downtime created by a crusher move and because of the awareness of the increasing incidence of cord damage/breaks." (Dr. Robin B. Steven, The Goodyear Tire & Rubber Company, "Replacing C-6 Conveyor Belt at Kennecott Copper, Bingham Canyon Copper Mine")
"In February , ore was fed to the crusher. By the end of March, the three grinding lines were operating and the flotation circuit was producing copper concentrate. In July, the design through-put rate of 77,000 tons per day was reached. October saw the achievement of targeted metal recoveries that corresponded to the fully modernized operation." (Society of Mining Engineers, "BP Minerals Completes $400 Million Modernization At Bingham Canyon," 1988)
BP Minerals America had applied for the necessary permits to begin mining gold at its Barneys Canyon and Melco mines, four miles north of the Bingham Canyon copper mine. Raw ore was to be sprayed with cyanide solution to leach out the minerals, and the leached material would be processed at a proposed new facility. When in full operation, the new gold mine was expected to produce 70,000 ounces of gold per year. The company currently produced 300,000 ounces of gold each year from its Bingham Canyon mine. (Deseret News, July 13, 1988)
Kennecott completed the modernization of its ore processing operations, from mine to mill, to smelter. BP Minerals officials announced the $400 million modernization project in December 1985 as a means of remaining competitive in the world copper market. Actual construction and site preparation began in February 1986. (Deseret News, August 2, 1988)
September 23, 1988
At a ribbon cutting ceremony marking the completion of the $400 million moderization project, officials of BP Minerals America and Utah Governor Norm Bangerter worked together as a team to cut a special six-inch ribbon made of copper. The ceremony was held in the parking lot of the new Copperton concentrator.
September 23, 1988
An open house of the newly completed modernization was held for the media on September 23, 1988, in which a six-inch ribbon of copper was cut in a formal ceremony. Before the modernization, rail cars were used to move ore from the mine to the Magna and Arthur mills, a trip of 16 miles over Kennecott's own, private railroad. At the mills, the ore (at about 0.6 to 0.75 percent copper) was crushed and ground, then processed to become copper concentrate (at about 26 percent copper). The concentrate was then shipped from the mills to the smelter, also by rail car. Both mills were closed in 1985, at the same time that mining operations were suspended at the Bingham mine. The modernization program included a new concentrator adjacent to the new Copperton crushing and grinding mill, along with a new primary crusher in the mine, which was then connected to the new secondary crushing and grinding mill built at Copperton. From there, water was added to the finely ground concentrate, and the slurry mix sent by way of a pipeline directly to the smelter. Ore is dumped into a primary crusher in bottom of pit, passed out of the pit by way of an new conveyor belt running through the old 5490 railroad tunnel, to the new Copperton crusher, crushed to a fine powder, added to water and sent via a new six-inch, 17-mile pipeline to the Garfield smelter. (Deseret News, September 23, 1988)