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By J. J. Fritts, J. L. Patrick, T. L. Wright, C. O. Ensign, W. S. White, J. W. Trammell, J. C. Wright, D. J. Hathaway, R. J. Leone

The copper deposit at White Pine, Michigan, from which a little more than 5 per cent of United States primary copper currently is produced, is a large stratiform orebody, 4 to 25 feet thick and several miles across. The present ore column, containing about 1.2 per cent copper as chalcocite and native copper, is confined to the basal beds of the Nonesuch Shale. This upper Keweenawan (Upper Precambrian) formation is a distinctive gray siltstone unit, about 600 feet thick, overlying and overlain by thick red-bed sequences. All these rocks contain abundant volcanic debris, but the latest known igneous activity within 50 miles antedated the Nonesuch Shale. The rocks are unmetamorphosed and only moderately deformed, mainly by tilting and faults. Pyrite, presumably syngenetic, is the only prominent sulfide throughout most of the Nonesuch Shale. The basal beds of the formation, however, contain disseminated copper minerals instead of pyrite and constitute the cupriferous zone. On a regional scale, the top of the cupriferous zone cuts across bedding, and ranges from an inch or so above the base of the formation in some areas to more than 50 feet in others. However, within the cupriferous zone the distribution of copper shows remarkable stratigraphic control. Certain beds are copper-rich compared to the beds that lie between them and the differences persist throughout the White Pine region. Several darkgray thinly laminated beds in the lower 10 to 25 feet of the Nonesuch Shale are rich enough and sufficiently close enough together to constitute a mineable thickness where they lie within the cupriferous zone. Pyrite is the characteristic sulfide of the Nonesuch Shale as a whole. The principal sulfide mineral of the cupriferous zone at the base of the formation is chalcocite. The succession of minerals outward and upward from the center of the cupriferous zone is native copper-chalcocite-bornite-chalcopyrite- pyrite. The bornite and chalcopyrite are confined to a narrow fringe at the margin of the cupriferous zone. This pattern of mineral zones is believed to represent reaction between syngenetic pyrite and introduced copper. The main copper mineralization is independent of structure and apparently antedates deformation. Details of the geometry of the cupriferous zone indicate the possibility that copper was introduced from the underlying sandstone prior to lithification. The source of the mineralizing solutions and their copper is not known.

Jan 1, 1968

Large scale mining of Mesabi taconites may have moved nearer to realization with the arrival of the latest model Linde Jet-Piercing machine at Reserve Mining Co.'s Babbitt, Minn. property. When the machine is placed in operation it is expected to pierce blast holes in the hard taconite beds up to 10 times faster than is possible with existing drilling equipment. The new primary blast hole drilling machine has been designated the JPM-3, and is the successor to the JPM-1, in operation at Erie Mining Co.'s taconite mines at Aurora, Minn. The size of primary blast holes which can now be pierced has increased from a nominal 61 in. diameter to 71 in. diameter and maximum hole depth has increased from 35 ft to 47 ft. Development has progressed to where 71/2 in. holes can be pierced with the same speed as 61/2 in. holes. Piercing progress is controlled by electronic blowpipe descent controls. Other features of the JPM-3 include: automatic burner ignition from the operating cab; heated and air conditioned operating cab designed for all-year operation; mechanical improvements for sub-zero operation common to the Mesabi, and redesign of wearing parts for longer service with minimum maintenance. The 40-ton machine is self-propelled. Power, oxygen, and cooling water lines trail from the machine. Jet piercing is based on combustion products of oxygen and a liquid fuel such as kerosene. The flame, jetting from a burner at speeds of about 6000 ft per sec, disintegrates layers of spallable rock. The burner is cooled by water which is then directed through orifices around the periphery of the burner. The water changes to steam and carries the spallings out of the hole. The equipment used in Jet-Piercing is essentially a tractor-mounted blowpipe containing a combustion chamber and nozzle, which is in effect a miniature rocket motor, from which the supersonic combustion gases emerge to do their work.

Jan 1, 1952

By Richard A. Kesler, W. Michael Reed

Grindability or resistance to fine comminution is the fundamental issue involved in the application and sizing of grinding mills. Over the years, many theories for determining the amount of energy required for size reduction to a specified fineness have been proposed. The first published theory, introduced by P. R. von Rittinger in 1867, stated that the energy required for crushing or grinding is proportional to the increase in surface area produced. The surface area of a ton of particles of diameter (d) is proportional to (1/d), therefore the work input per ton for particles of diameter (d) would be proportional to (1/d). The second significant theory is that of F. Kick published in 1885. Kick said that the work required is proportional to the reduction in volume of the particles concerned. If (f) is the diameter of the feed particles and (p) is the diameter of the product particles, the work input relationship would be: [W =Ioq(f/p) 9] The "Third Theory" of F.C. Bond, introduced in 1951, states that the work required is proportional to the length of the new crack tips produced in particle breakage during crushing or grinding and equals work represented by the product minus that represented by the feed. This takes the form: [W=]

Jan 1, 1982

By C. David Mann

Metal prices continued to improve in 1964, resulting in the opening of new mines and re- activation of old ones. Larger and deeper shafts are being bored. At the AEC's Nevada Test Site, a 72-in. diam shaft is being bored to 3200 ft. In New Mexico a 1650-ft shaft was bored with a 48-in. bit, then reamed to 124 in. to 935 ft, and 102 in. to 1650 ft. Deviation was only 26 in. In California a shaft sinking machine has been developed which combines drilling and mucking equipment into one mobile, integral unit.

Jan 2, 1965

Jan 1, 1967

Organization Place Date 1919 American Society of Mechanical Engineers... New York, N. Y. Dec. 2-5 American Institute of Chemical Engineers.... Savannah, Ga. Dec. 3-6 Geological Society of America..: Boston, Mass. Dec. 29-31 American Society of Heating and Ventilating 1920 Engineers New York, N. Y. Jan. Mining and Metallurgical Society of America.. New York, N. Y. Jan. 13 American Institute of Min. and Met. Engineers New York, N. Y. Feb. 16-19 American Ceramic Society Philadelphia, Pa. Feb. 23-26 American Electrochemical Society Boston, Mass. Apr. 8-10* *On Apr. 9, a joint meeting will he held with the A. I. E. E.

Jan 12, 1919

By Linn M. Farish

SOVIET RUSSIA reserves must be stupendous. In 1937 I. M. Goubkin placed the reserves of all categories it approximately 48 billion barren which was about twenty billion horn Is in excel:, of all the oil produced in the world since 1857. It is not unlikely in fact it is probable, that these huge stores of petroleum may ultimately be proven to exist within the present boundaries of the U.S.S.R. The size of the country is almost beyond imagination it is 2.7 times as big as the United States. Great sedimentary basins exist in all its different geological provinces, much of which are entirely untested and barely prospected. Oil in commercial quantities is actually produced from formations in every period from the Devonian to the Pleistocene. In the Emba region alone, 300 salt domes are known with an estimate of 700 still to be found. Only 22 of the 300 have been drilled and all showed oil. Of the 22 domes drilled six are now producing. There are 400 mapped structures reported in Azerbaijan

Jan 1, 1940

By L. O. Howard

THERE are three active mines in the Chewelah-Colville district, the United Silver Copper near Chewelah, and the Old Dominion and the Chloride Queen near Colville. The Admiral near Valley is also doing development work. The Chewelah district is in the south central part of Stevens County in the Colville Valley. Chewelah, a thriving town of 1600 people, and the scene of operations of the Northwest Magnesite Co., is about the center of the district. It is situated in a farming community on the Spokane-Nelson branch of the Great Northern railway, about 65 miles north of Spokane. Only two or three of the mines in the district have been extensively developed, although many have been prospected. The general elevation of the valley, is about 1600 or 1700 ft., that of the mountain ranges on each side about 3000 to 4000 ft., with gentle slopes and rounded glaciated tops. Prospecting is often difficult because of much glacial debris.

Jan 1, 1925

Organization Place Date 1918 Institute of Metals Division, A. I. M. E Milwaukee, Wis. Oct. 8-11 Iron and Steel Members, A. I. M. E Milwaukee, Wis. Oct. 8-10 American Foundrymen's Association Milwaukee, Wis. Oct. 7-12 American Museum of Safety and Sanitation, Exposi- tion St. Louis, Mo. Oct. -7-12 National Safety Council St. Louis, Mo. Oct. 14-17 Business Show : New York, N. Y. Oct. 21-26 National Society of Naval Architects New. York, N. Y. Nov. 14-15 American Society of Mechanical Engineers New York, N. Y. Dec. 3-6 Geological Society of America Boston, Mass. Dec. 25-31 American Association for the Advancement of Science Boston, Mass. Dec. 27-Jan. 2. 1919

Jan 10, 1918

Coal production during 1963 amounted to 446 mil- lion tons, an anticipated increase of about 6% over the 1962 production of 422 million tons. Electric consumption was 207 million tons, a continuation of its upward trend with an increase of about 7%. The metallurgical market consumed 77 million tons: the industrial market, 96 million tons; and the retail market, 26 million tons. Exports were 46 million tons. Modernization continues in the coal industry as it approaches the mid-1960's. The industry has shown a keen desire to explore and pursue new developments, new concepts and new managerial methods and techniques that have become so vital and important for industrial well-being.

Jan 2, 1964

Jan 1, 1903

ANNUAL meeting of the Woman's Auxiliary of the American Institute of Mining and Metal-lurgical Engineers convened on Tuesday morn-ing, Feb. 20, the president, Mrs. H. W. Hardinge, presiding. President Hardinge, in opening the meet-ing, said: "I have the honor and great pleasure to welcome you to our seventh annual meeting. It has been a happy year, though I started in fear and trembling. My fear is partly gone and my trembling becomes less as time goes on. Never has a chairman had such splendid cooperation and harmony in her work; no. matter how much was asked nor what the task, I have always received the same answer, `We are with you, of course we can do it.' Often the road has been untried and the way full of snares, but we have all pulled together. Is it any wonder we have had a prosperous year? I cannot thank the governing -board and officers enough for their help." Mrs. Hardinge described her trip through the West last summer, during which she visited many of the local sections of the Auxiliary. She also spoke of the work of the Rossiter Raymond memorial library which has been started as an activity of the Woman's Auxiliary. Mrs. Reynders read the minutes of the last annual meeting, and Mrs. Kemp read the treasurer's report. The latter showed that on Feb. 1, 1922, there was a bank balance of $683.61 and on Feb. 10, 1923, the bal-ance was $947.93. Mrs. Westervelt expressed the sorrow of the Auxiliary for the death -of Mrs. Florence Howe Hall and of Mrs. Levi P. Holbrook.

Jan 4, 1923

Born, March 28, 1853 Died July 23, 1916 On July 25, 1916, the Board of Directors adopted the following minute and directed that it be entered upon the records of the Board & published in the Bulletin of the Institute, and thereof be sent to the family of Mr. Kirchhoff: Charles Kirchhoff was one of the oldest, most widely known and most highly esteerned members of the American Institute of Mining Engineers. On his return in 1875 from a European course of study, to begin a highly successful professional career, he joined the Institute, then just commencing to acquire both national and international recognition. He became at once, and-for more than 40 years continued to be, its earnest , and active supporter, serving it as Manager, Councilor or Director for terms aggregating 9 years,-as Vice-President for 2 years, and twice as President for a year. During the critical period of the erection of the United Engineering Society's building, and the transfer of the Institute to permanent head-quarters therein, Mr. Kirchhoff was its efficient representative in the United Engineering Society, and on the Building Committee. In 1910, amid the congratulations of colleagues, employees, and innumerable friends, Mr. Kirchhoff retired from active business as Vice- President and General Manager of a great technical publishing company. Yet he sacrificed of his well-earned leisure yet one more year, to serve the Institute as President through 1911.

Jan 9, 1916

By H. O. Hofman

Jan 1, 1896