kennecott copper corporation Five Deep Manmade Nevada Pits Yield Thousands of Tons of Copper Ore Each Day. By NEVADA HIGHWAYS AND PARKS | JANUARY-APRIL 1955 Kennecott Copper Corporation and Consolidated Coppermines Company, two famous names in Nevada’s mining register, have been identified with the Ely district for decades, mining ore from deep pits and producing blister copper in enormous volume. From the looks of things, they will be busy in that vicinity poking drill holes into the ground, shoveling rock and dirt into railroad cars or motor trucks, building up huge dump piles of waste material, hauling to and milling ore at McGill, shipping blister copper out by the ton, and handing out millions of dollars in payroll checks for a long, long time. The setup is enormous. It is recognized as Nevada’s greatest individual enterprise project involving hundreds of employees, hundreds of building units, thousands of pieces of mobile and stationary machinery, and investments running into millions of dollars. White Pine County, particularly in the Ely-Ruth-Kimberly-McGill sectors, was greatly favored by nature with tremendously large copper ore deposits, disseminated sparingly in large masses of rock, of such an extent that one colossal hole wasn’t enough to mine it all. Four other pits, already of great size but incomplete—like links in a monstrous chain—were necessary and came into being only a comparatively short time ago to adequately develop the ever-expanding potential of the area. Because both companies have learned, through years of wide experience and scientific application, how to successfully and efficiently handle these low-copper content rocks on a quantity production basis, the copper-mining business of eastern Nevada has grown from a puny beginning to one of stability and tremendous measurement even in this day and age when extraordinary things are commonplace. When Indian John (that’s the only name he was ever called), back in 1867, showed the then-desolate, almost forbidding, ground to a party of prospectors and displayed the mineralized pieces he found there, neither he nor the prospectors dreamed the site would develop into one of the world’s large copper-mining undertakings. Originally, the gold content of the area, which is now salvaged as a byproduct, was the more attractive feature, and mining was conducted for recovery of this precious metal itself. Since early 1900, the gold extraction assumed a secondary import, when, through constant churn and core drilling, it was disclosed that the rocks, over a large area having some alternating barren patches, were impregnated with copper ores of a low grade but could be profitably recovered provided efficient methods were adopted in the process. This, Kennecott and Consolidated Coppermines have done. The history begins with a site on the banks of Murry Creek, known as Murry Creek Station, the first settlement in the district and tied closely to the history of the Robinson mining district. The district was organized on March 16, 1868 and was named after Tom Robinson, who was a member of the party which Indian John befriended. Within a year after the discovery, over 1,000 mining claims had been recorded. During the march of time, some of the earlier camps all but disappeared. A few have maintained their status and importance, such as Ely, Ruth, and Kimberly. To these, a little later, was added another unit—McGill, where a huge concentrator and smelter were placed in service to beneficiate the ore. Ely seems to have been pinpointed as the center of activity when the county seat was transferred from the sensational, but diminishing, silver camp of Hamilton, about 30 miles to the west, in 1887. The name Ely supposedly came from John Ely, a native of Illinois, who was active in the area during the early days. In 1906, Mark Requa, another name frequently identified with the progressive upbuilding of the West, guided the construction of the Nevada Northern Railroad, which runs from Ely to Cobre in Elko County, to connect with the main line of the Southern Pacific. After this railroad was completed, it made large-scale mining in the Ely district economically feasible. Nevada Consolidated Copper Company started ore production in 1907 and began milling and smelting in 1908, using new methods originated by Daniel Cowan Jackling, one of the outstanding names connected with copper all over the world. Jackling evolved an efficient method for handling the low-grade copper ores, and then the Ely district started to unfold in earnest. Nevada Consolidated was later incorporated into the Kennecott Copper Corporation as the Nevada Mines Division. Aside from a joint operation with Consolidated Coppermines Corporation, on one or two units, at the Copper Flat Pit and the Veteran Pit, Kennecott digs the holes, turns the wheels of the mill, fires the smelter, highballs the trains, and dispatches the trucks from the bottom of the pits to the processing plant at McGill, 20 miles distant. Waste material is piled up on huge dumps while the ore is sent to the mill. To give one an idea of what has happened in the Ely district, evidence shows that the known ore reserves in 1954 were substantially greater than they were in 1906, even though the Ruth and nearby mines and pits have produced approximately $800 million in the form of 4 million tons of copper, 2 million ounces of gold, and 11 million ounces of silver. The copper deposits at Ruth, or rather the Copper Flat Pit adjacent to both the old and the new town of Ruth, are the center of all the mining activities in the district. They moved the town of Ruth—houses, garages, business and office buildings—to a new site around the corner from one of the biggest waste dumps in the state and called it “New Ruth.” This was done so that mining could be conducted, through the block cave method, under the site where old Ruth stood. The entire fertile area of copper impregnation is localized in a zone which runs roughly east and west for about seven miles and is about a mile wide. In this overall area, at the present time, five separate pits are in the process of excavation and development and each day each hole gets a little deeper and a little bigger. All of the work is integrated so that it is all just one big job. These huge cavities are the Veteran Pit, the Morris Pit, the Brooks Pit, the Copper Flat Pit (the granddaddy of them all), and the Kimberly Pit in their sequential occurrence from west to east. In addition, two other working units of major size, the Deep Ruth shaft and the Kellinski shaft, about a mile apart, will be connected underground to facilitate block cave mining beneath the site of old Ruth of 25 million tons of copper ore in the subsurface ground. Production from this area is expected some time early in 1956. The Veteran Pit, farthest west of the five, was started in October 1953, and then the dirt flew. Between that date and December 31, 1953, a three-month time lapse, 4 million tons of waste material had been moved. The pit, when fully developed, will be 2,500 feet long, 1,500 feet wide, and about 600 feet deep, and will yield approximately 20 million tons of copper ore with 40 million tons of waste material removed. That in itself is a major undertaking and reflects the progress which has been made since the pick-and-shovel days because, now, 30-ton carry-alls, high-powered diesel bulldozers, and 5-cubic-yard power shovels get rid of the dirt in a hurry. The Morris Pit and the Brooks Pit, next-door neighbors across the road, farther east from the Veteran Pit, already have reached large-scale size with the removal of additional millions of tons of waste material. Eventually, these two pits will reach the size of the Veteran Pit and contribute their share of the colossal tonnage of recoverable copper ore. The Morris Pit already looks like a big hole headed for China. The king-size cavity nearest the city of Ely is the Kimberly Pit, and, like the other three, so much waste material is moved at the same time that 70 cars of ore are made available for shipment to the mill daily. This Kimberly Pit eventually will reach dimensions like this: 1,000 feet long, 1,500 feet wide, and 300 feet deep. This pit is considered the smallest of the group. To do the big job of excavating and hauling, one of the largest contracting firms in Nevada, the Isbell Construction Company of Reno, was called in to help. But these four pit operations, at present, are really “small potatoes,” as big as they are, when compared with the colossal hole at Copper Flat, sometimes called the Liberty Pit. That cavity has been in the making for 46 years, and, naturally, you’d expect to see a very big hole in the ground. You won’t be disappointed; we can assure you. When miners first began to work at the site in 1908, it wasn’t a hole—it was actually two small hillocks about 50 feet high. Those hills had to be leveled down before the status as a hole could be started. After all those years with 5-yard shovels chewing away at five different places on the walls and bottom, thousands of pounds of powder blasting down hillsides, whistling locomotives pulling their hearts out to reach the rim over 14 miles of rails, with eight cars filled with 65 tons of ore, miles and miles of automobile roads switchbacking from the rim to the bottom, 500 feet down, millions of man hours of labor, hundreds of employees, and millions of dollars in working payrolls, you get the idea as to the staggering magnitude of the material removed and the size of the hole. Currently, Copper Flat Pit is one-mile long and five-eighths of a mile wide and has an average depth of 500 feet. To keep you busy on the adding machine for a few minutes, listen to this: To date, Kennecott Copper Corporation has removed nearly 125 million tons of ore and more than 200 million tons of waste from this pit alone. This has produced the staggering total of more than 3 trillion pounds of copper valued at nearly $475 million, as well as more than 1.3 million ounces of gold and more than 4.8 million ounces of silver with a total valuation of more than $40 million. Have you ever thought that much copper came from one hole in Nevada? This enormous pit reflects spectacular color effects. Many different tones and hues are characteristic of the wall rocks and the bottom of this oval-shaped hole, with so many benches climbing its sides and ends they are hard to count. The pinkish-colored rock is described as rhyolite porphyry; the grayish-green rock is limestone, and the light white-to-gray rock is the ore-bearing material. When one stands at the east end of the pit, at the top rim, when the sunlight strikes the project just right, the colors of this colossal hole are gorgeous to see. It’s almost breathtaking. After the ore is brought to the surface, from the bottom of the pits, it is hauled 20 miles to the mill at McGill. There the ore is dumped into bins, and, under complete control, fed into a series of huge crushers which grind it into a powder. Next it gets into flotation cells with chemical solutions where it is processed, then concentrated. Concentrates are subsequently moved to the smelter for further treatment in furnaces—the end result of which is blister copper. The huge mill, grinding and groaning all day long, processes about 21,000 tons of ore daily, which is further processed down to about 750 tons of concentrates. The first step in the smelting operation is to melt the concentrates and produce a product called matte. This is done in reverberatory furnaces, of which there are two at McGill, one operating and the other ready as a standby. The matte coming from the reverberarories is further treated in a converter, where the iron and sulfur are oxidized by blowing air through the molten matte. The end product comes out as blister copper. It takes about 20 hours to convert a charge of 18 pots of matte to blister copper in the converter. Blister copper eventually goes to an electrolytic refinery where the gold and silver are recovered and the copper is made ready for fabrication. That, briefly, is the cycle of copper production in the Ely district. We have skipped over a thousand details, accessory to the process, and many stages through which the ore, concentrates, and matte must be checked before the final result is achieved. Administration offices, employee recreational features, health and welfare, safety alertness throughout the entire set-up, libraries, swimming pools, playgrounds for children, and many other supplemental activities have been inaugurated by Kennecott to maintain a harmonious spirit between workers and management. Through Kennecott and Consolidated Coppermines, the Nevada people in the eastern section of the state approach the future with faith and hope in its industrial potentialities. With the present outlook for ore reserves, it is likely the two companies—Kennecott and Consolidated—will be handing out payroll checks for many years. Posted by permission of Nevada Magazine.
Posted on: Sat, 29 Mar 2014 00:25:58 +0000
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