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Two 6.17-m-diam (20.25-ft) shafts, said to be the largest ever opened with mechanical raise boring techniques, were completed in May and June 1978, at Monterey Coal Co.'s No. 1 mine near Carlinville, Ill. According to the shaft contractor for the project, Frontier-Kemper Constructors, the openings are 60% greater in cross section than the largest previous raise-bored shaft, which had a diameter of 4.85 m (16 ft). Both vertical shafts are 93 m (305 ft) in total depth, with the upper 28-30 m (90-100 ft) sunk and lined by conventional methods through unconsolidated overburden and the remainder mechanically bored through sedimentary rock. The two shafts will be used for service access as well as to augment ventilation.

Jan 12, 1978

By R. M. Schuster, F. M. Benavides

A plan is prepared to develop and operate a four mine complex over a 30-year period. The mining complex is in the vicinity of two existing processing plants and the most economical means of transporting the raw minerals to either or both of these processing plants is sought. The mines and processing plants are all within a radius of 5.6 km (3.5 miles). Existing transportation facilities consist of county and state roads and federal highways as well as haul roads in some areas. A navigable river meanders through the area under study and there are two railroad systems servicing the area. The analysis shows the economic and operational feasibility of using an overland conveyor in lieu of other means of transportation.

Jan 1, 1983

By Theodore H. Eyde

The Superior Oil Co. drilled two holes, 4720 and 5940 ft, respectively, using conventional oilfield rotary drilling equipment. The results indicated that large rotary drills can be adapted to mineral exploration purposes with few modifications. The principal advantages are: a large hole diameter, excellent samples of cuttings, a geolograph which is a constant drilling record, rapid penetration even in hard rocks, and the ability to use electric logs for measuring the properties of the rock being penetrated. The disadvantages are the high cost of mobilization, drilling, and oilfield service at remote locations. Though the oilfield sampling techniques are adequate for identifying lithology, improvements are necessary to obtain representative samples for analytical purposes. As deeper targets are explored, mineral exploration organizations will have to resort to rotary drilling.

Jan 1, 1975

By AIME AIME

PROBABLY no man has been of greater service to the Institute and has kept more in the background than Henry Krumb. A Vice-President continuously) for the last eleven years, apparently neither his picture nor a biographical sketch ever have adorned these pages and were he forewarned in the present instance he would order us to "forget it." He is a Columbia School of Mines man, Class of '98. He worked underground at Rossland, B. C. for a time, then for a year and a half a. chief engineer of the famous Camp Bird at Ouray, Colo. For three wars he was examining engineer for the Guggenheims and since 1901 has been an independent consulting engineer with experience throughout the Americas.

Jan 1, 1939

By H. W. Young

Development of high-tension outdoor substations during the past few years has been due primarily to economic reasons. The demand for power in small communities could not be met with the conventional and Fig. 1.—33,000-VOLT step-up outdoor air-break switch and substation installation outside of a powerhouse generating at 2300 volts stepping up to 33,000. Twenty-one coal mines are supplied from lines leading from this installation. comparatively expensive indoor types unless the rate for service was materially increased. To prove that the problems lncident to development have been solved successfully, it is only necessary to point to the wide adoption of outdoor substations by utility companies. Passing at once to the question as to whether outdoor substations are applicable to

Jan 1, 1920

By Whitman E. Brown

The installation in 1948 of a Humphrey spiral concentrator section at the Hill-Trumbull plant of The Cleveland-Cliffs Iron Co. is the latest commercial method on the Mesabi Range being used for the recovery of fine iron ore. In two stages of concentration 84 spirals treat approximately 120 long tons per hour of minus 1/8 in. ore. These spirals augment the production of the heavy-density plant which recovers the plus 44 in. iron from the plant crude ore. Structure of the ore is such that, when crushed, about 50 pct of the plant crude is minus 1/8 in. size. After desliming in a 66 in. Akins classifier, grinding the classifier product in a ball mill and again desliming in a 78 in. Akins classifier about 15 pct of the crude ore remains to be treated in the spiral plant.

Jan 1, 1949

By Bobby P. Faulkner

The Tennessee Copper Co.'s flotation plant, refer- T red to as London Mill, processes approximately 4800 tons of a massive complex sulfide ore per day. The ore is predominantly pyrrhotite and pyrite, the other sulfides being chalcopyrite, sphalerite, and a small amount of galena. Magnetite of economic value is also present. There are four concentrates produced. In decreasing tonnage, these are iron, copper, zinc and lead. The ore feeding the mill is a composite of ores from five mines which vary in grade. Therefore, in order to provide a fairly constant feed to the mill, the ore is blended several times before reaching the flotation machines. The flotation plant is divided into three main sections: bulk, copper and zinc. Fig. 1 shows a simplified flowsheet. The first two sections, the bulk and copper, were the two sections studied most closely in utilizing the computer.

Jan 11, 1966

By AIME

After an adventurous past-four changes of government in thirty years -the whole of Silesia and attached coal territories have become part of the Polish State. The coal resources of this area are the biggest among the European countries. Under a surface area of 5700 sq km are about 100 coal seams, with a total thickness of 150 meters. According to German estimates, there are some 150 billion metric tons of coal ranging in thickness up to 14 m within a depth of 1500 m. The seams are mostly level, free from faults, with good top and bottom; the coal is of excellent quality, hard and clean; and mining conditions are favorable. The mines are worked at considerable depth by means of vertical shafts and operate with cage and skip hoisting. Before the war, the mines were up to date, equipped with modern machines. Among the European countries, output per man shift was the highest ? 1.9 to 2.1 metric tons ? and cost of production was the lowest.

Jan 1, 1949

Edward A. UehlinG, New York City (communication to the Secretary*):—Mr. Baker's paper is one that brings up a subject of great importance, and if full statistics could be collectecl of the number of furnace-linings ruined by reason of bad distribution by skip-hoists, it would be found an astonishing array. Unfortunately a universal remedy has not yet been found. The fact that Mr. Baker has apparently succeeded in overcoming the trouble at Sydney, is no guarantee that the same remedy applied at another plant, where very different or even slightly different conditions prevail, mould cure the trouble. That it requires but a slight continuous difference of penetrability in the column of the descending stock of one section, over another, to produce channeling, is clearly demonstrated by Mr. Baker's experiments, by which he reversed the channeling from front to rear instead of remedying the trouble. Every change in the physical make-up of the charge necessarily requires a specific adjustment; even supposing this feasible, the regular working of the furnace is by no means assured, because with the high pressures now customary, the tendency of the ascending gases to plow their way through in a direct course, prevails, and having once opened up a passage, they will persist and cause trouble. Homogeneous filling-, hard driving and regularity of working are incompatible. The higher the furnace, the greater the

Jan 1, 1905

By Donald F. Hammer, Donald W. Peterson

The Magma mine at Superior, Arizona, has produced over 13 million tons of ore yielding 1.5 billion pounds of copper. It is a mesathermal deposit, and, although the bulk of the ore has come from the Magma vein, most of the recent production has come from replacement deposits in limestone. The mine lies in a Precambrian and Paleozoic sequence of rocks that includes schist, diabase, quartzite, shale, and limestone; nearby, these rocks are intruded by igneous bodies of Mesozoic age that were probably the source of the ore-bearing fluids. Locally, these rocks are overlain by Cenozoic volcanic rocks and conglomerate. Layered rocks at the mine dip eastward about 30°. The area is extensively faulted, and surface faults are grouped into an earlier east-trending set and a later northtrending set. An additional set of diagonal faults that trends northwest and northeast is recognized underground. The east-trending Magma vein-fault, with its splits and branches, is the principal mineralized structure of the district. The bulk of the ore occurs in large ore shoots that plunge steeply westward and are sporadically connected by irregular ore shoots dipping gently eastward. The main ore controls apparently are selective zones of permeability related to the transverse faults. A bed of crystalline limestone near the base of the Martin Limestone (Devonian) is the host for the replacement ore bodies-discontinuous tabular pods dipping eastward parallel to the bedding. Selective permeability is again the apparent ore control, caused both by local hydrothermal solution of limestone and by deformation along faults. The principal copper minerals in the vein are chalcopyrite, bornite, enargite, tennantite, chalcocite, and digenite; these minerals vary in abundance according to a distinct zoning pattern. The upper part of the mine yielded considerable zinc as sphalerite, and the oxidized zone was rich in silver. The chief gangue minerals are pyrite, quartz, and hematite. In the limestone replacement bodies, chalcopyrite and bornite are the chief ore minerals.

Jan 1, 1968

By Bernard MacDonald

Introduction. OF the treatment of the slime-pulp of gold- and silver-ores by cyanidation, agitation is an essential part. When prepared for treatment, this pulp, consisting of ore reduced to such fineness that approximately 80 per cent. of it will pass through a 200-mesh screen, is mixed with a certain proportion of water, carrying in solution the quantity of cyanide (KCN) and other chemicals required. The water-constituent of the pulp thus prepared usually ranges from 1 to 2 parts by weight to 1 of the dry ore. Thus constituted', the pulp is charged into treatment-tanks, the shape and capacity of which vary, according to the quantity of pulp to be treated daily and the method of agitation to be employed. Tanks have no other function in a cyanide-plant than that of being economical and convenient containers or receptacles for holding the pulp, solution, or water used in the operations. It is by agitation that the solids in the pulp charged into the tanks are kept in suspension in, and mixed with, the solution in the proper proportions required for the treatment. If the proper mixture of solution to solids be determined to be 2 to 1 by weight (which is, approximately, 5 to 1 by volume), this proportion should be maintained in every part of the charge ; -that is, each solid particle of the pulp, whether it be of 180- or 400-mesh size, should, be surrounded by five times its own volume of solution throughout the whole period of treatment. The reason is, that the amount of chemicals ascertained to be necessary for dissolving the gold and silver contained in the solids, is held in uniform solution in the water-constituent of the pulp, and, therefore, the determined proportions of solution and solids must be maintained at all times during treat-

Apr 1, 1912

By H. T. Hildage

ALTHOUGH Greater New York does not bear any resemblance to a great mining district, the mining operations that are being conducted in and about the city are both extensive and interesting in character. With regard to the extent, it may be mentioned that, at. present, there is more dynamite used in New York than in any mining district in the United States; that there are under construction about 38 miles of tunnel, and that 66 miles more are projected, most of which must be constructed in the near future ; that since 1902 at least 2,000,000 tons of earth has been removed in underground work, in addition to about 3,500,000 tons that has been removed in, open-cut in connection with tunnel-work, and many times this quantity that has been removed in excavating foundations for buildings not connected with tunnel-work; and that there are to-day probably more than 5,000 men engaged in mining-work in and about New York City. These undertakings include almost every operation connected with underground work, from exploration by means of trench and boring, to the sinking of large shafts and the driving of large tunnels through every kind of ground from hard rock to soft, semi-fluid silt and quicksand. It is proposed in this paper to give a general description of some of the methods and appliances used in the opening-up ,of a "mine" in a large city, and a brief description of some of the "mines" now being developed in New York, connecting as far as possible the methods described with the particular work for which they were designed, in order to give a general idea of the

May 1, 1907

By J. E. Graham, A. H. Glenn

Oil operators engaged in drilling on the Continental Shelf of Louisiana and Texas are in agreement that adverse weather and wave action are two of the greatest hazards to the safety and efficiency of their work. It was ami-pated when the offshore operations commenced that such would be the case, and experience to date has verified this assumption. Because atmospheric conditions and wave action involve tremendous amounts of energy it is highly unlikely that it will be possible to control any but the most localized weather and wave phenomena within the foreseeable future. Thus. as long as the offshore operations involve the movement of small craft and barges over exposed waters, and the transfer of personnel and heavy equipment from these craft to either fixed structures or larger craft at close quarters, the weather and wave problem will remain. Taking into consideration the persistence of the wave and weather problem and the improbability of achieving a direct solution, the Humble Oil & Refining Company, in planning its offshore campaign investigated the possibility of forecasting wave and weather conditions in order to provide warnings of dangerous conditions and increase efficiency in day-to-day planning of work. It was recognized that predictions of wave and weather conditions based on meteorology and oceanography, both geophysical sciences, are not 100 per cent accurate and application of forecasts in the offshore work was dependent on whether they provided information which was sufficiently greater in accuracy than the layman's guess to be worth the expenditure involved. During World War 11. meteorology and oceanography were used with success in reducing danger resulting from environmental conditions and increasing efficiency of operations exposed to the elements. This success was partially the result. of improvement in the scientific techniques involved and the procurement and distribution of observational data, and partially due to the large scope of the military operations which meant that a reduction of losses of a relatively small percentage of the total cost amounted to a large figure expressed in terms of dollars. Since the offshore drilling involves an extremely large financial investment, it was considered that the experience of the Armed Services in successfully employing meteorology and oceanography might be duplicated in the oil industry. In addition. the oil industry's successful experience in utilizing seismology, geology, and terrestrial magnetism; all geophysical sciences, indicated that meteorology and oceanography, also of the family of geophysical sciences and sharing their scientific assets and liabilities, might be profitably put to use. Since the immediate problem involving the sciences of meteorology and oceanography in the offshore campaign is wave action, a program was inaugurated within the Humble Oil & Refining Company during June 1947. the purpose of which was to ascertain the applicability and limitations of wave forecasting in the offshore campaign. A summary of the effective wave forecasting techniques developed during the war was prepared in the form of a forecasting manual for the Continental Shelf off Grand Isle, Louisiana, by Bates and Glenn. After completion of this manual, experimental forecasts were prepared daily over a two-month period by Graham and Thompson to determine the accuracy of the forecasts. It was considered that the accuracy of the experimental forecasts justified a more extensive test under actual operating conditions in the offshore work and the firm of A. H. Glenn and Associates was set up under the sponsorship of the Humble Oil & Refining Company to work with the Humble Grand Isle District in providing forecasts of wave and weather conditions over a one-year period. This paper discusses the service now provided to the Grand Isle District, its applicability and limitations. TYPE OF FORECASTS REQUIRED It was apparent before the commence-mence of the forecasting service that a specialized type of forecast was required. Many of the weather elements of interest to the general public, such as rain and temperature, are of minor concern to offshore operators. On the other hand, such elements as wave height and wind speed and direction are of great concern in the offshore operations since variations in wave height of a few feet in the critical range divide safe from hazardous working conditions. To be of utility. a forecasting service for the offshore work must provide detailed forecasts of the elements which affect the operation. With this in mind, it was decided that forecasts would include the following information: average wave heights to the nearest foot, wind speeds within a range of approximately 5 miles per hour, and wind directions within 221 degrees. Since the procedure for forecasting these elements involves thorough analysis of weather data, it was decided to include a generalized forecast of weather conditions such as rain and cloud cover, although these are of secondary importance.

Jan 1, 1949

By A. H. Glenn, J. E. Graham

Oil operators engaged in drilling on the Continental Shelf of Louisiana and Texas are in agreement that adverse weather and wave action are two of the greatest hazards to the safety and efficiency of their work. It was ami-pated when the offshore operations commenced that such would be the case, and experience to date has verified this assumption. Because atmospheric conditions and wave action involve tremendous amounts of energy it is highly unlikely that it will be possible to control any but the most localized weather and wave phenomena within the foreseeable future. Thus. as long as the offshore operations involve the movement of small craft and barges over exposed waters, and the transfer of personnel and heavy equipment from these craft to either fixed structures or larger craft at close quarters, the weather and wave problem will remain. Taking into consideration the persistence of the wave and weather problem and the improbability of achieving a direct solution, the Humble Oil & Refining Company, in planning its offshore campaign investigated the possibility of forecasting wave and weather conditions in order to provide warnings of dangerous conditions and increase efficiency in day-to-day planning of work. It was recognized that predictions of wave and weather conditions based on meteorology and oceanography, both geophysical sciences, are not 100 per cent accurate and application of forecasts in the offshore work was dependent on whether they provided information which was sufficiently greater in accuracy than the layman's guess to be worth the expenditure involved. During World War 11. meteorology and oceanography were used with success in reducing danger resulting from environmental conditions and increasing efficiency of operations exposed to the elements. This success was partially the result. of improvement in the scientific techniques involved and the procurement and distribution of observational data, and partially due to the large scope of the military operations which meant that a reduction of losses of a relatively small percentage of the total cost amounted to a large figure expressed in terms of dollars. Since the offshore drilling involves an extremely large financial investment, it was considered that the experience of the Armed Services in successfully employing meteorology and oceanography might be duplicated in the oil industry. In addition. the oil industry's successful experience in utilizing seismology, geology, and terrestrial magnetism; all geophysical sciences, indicated that meteorology and oceanography, also of the family of geophysical sciences and sharing their scientific assets and liabilities, might be profitably put to use. Since the immediate problem involving the sciences of meteorology and oceanography in the offshore campaign is wave action, a program was inaugurated within the Humble Oil & Refining Company during June 1947. the purpose of which was to ascertain the applicability and limitations of wave forecasting in the offshore campaign. A summary of the effective wave forecasting techniques developed during the war was prepared in the form of a forecasting manual for the Continental Shelf off Grand Isle, Louisiana, by Bates and Glenn. After completion of this manual, experimental forecasts were prepared daily over a two-month period by Graham and Thompson to determine the accuracy of the forecasts. It was considered that the accuracy of the experimental forecasts justified a more extensive test under actual operating conditions in the offshore work and the firm of A. H. Glenn and Associates was set up under the sponsorship of the Humble Oil & Refining Company to work with the Humble Grand Isle District in providing forecasts of wave and weather conditions over a one-year period. This paper discusses the service now provided to the Grand Isle District, its applicability and limitations. TYPE OF FORECASTS REQUIRED It was apparent before the commence-mence of the forecasting service that a specialized type of forecast was required. Many of the weather elements of interest to the general public, such as rain and temperature, are of minor concern to offshore operators. On the other hand, such elements as wave height and wind speed and direction are of great concern in the offshore operations since variations in wave height of a few feet in the critical range divide safe from hazardous working conditions. To be of utility. a forecasting service for the offshore work must provide detailed forecasts of the elements which affect the operation. With this in mind, it was decided that forecasts would include the following information: average wave heights to the nearest foot, wind speeds within a range of approximately 5 miles per hour, and wind directions within 221 degrees. Since the procedure for forecasting these elements involves thorough analysis of weather data, it was decided to include a generalized forecast of weather conditions such as rain and cloud cover, although these are of secondary importance.

Jan 1, 1949

By Scott Tzcrner

WITHIN recent years people have begun to realize the importance and significance of the mining and allied industries. The leading part the engineer plays in civilization is becoming recognized. However accurate quantitative knowledge of the industrial importance of mining is still seldom possessed except by those close to this business. It is true that there are a few who go to the extreme and represent the whole progress of civilization as a reflection of man's gradual mastery of mineral utilization, but on the whole, the magnitude of the-industry is underestimated. In this paper I shall call attention briefly to the importance of mining in the United States, in Canada, and in the world. Ordinarily, the annual primary mineral production of the United States is about $5,500,000,000. The average for the last 5 years has been a little over that, but last year, sadly enough, it was less than 31/4 billion. Just now, we are on the decline, and have been for the last two years. In Canada, the 5-year average was about $268,000,000, and last year it was 227 million. Due in part to gold mines (in 1930, for the first time, Canada's gold production exceeded that of the United States), the Canadian average is holding up better than ours. Average world mineral production over the last -5 years has been estimated at about $12,000,000;000 whereas in 1931 it was less than than 8 billion.

Jan 1, 1932

By H. W. Gillett

BATTELLE Memorial Institute is an endowed in stitution for scientific research in metallurgy, fuels, and allied fields, established by the will of Gordon Battelle, 2nd, as a memorial to his father, Colonel John Gordon Battelle. Before I tell you more of what Battelle Memorial Institute is, I want to go back a bit and tell you why it is. Colonel Battelle began his services in the iron and steel industry in Wheeling in 1866 and in 1883 came to Ohio, where he successively engaged in the iron and steel industry in Cincinnati, Piqua and Columbus. The family had been prominent in Ohio affairs since 1788, when Gordon Battelle's great-great-grandfather came from New England to settle in Marietta. He was one of the pioneers and a member of the famous "Ohio Company."

Jan 1, 1929

By Harry E. Krumlauf

The year 1957 was one of declining metal price and production. Many lead-zinc-copper mines were forced to close, and the remaining mines limited production to stay more in line with demand. High cost of labor, supplies, and equipment and high taxes aggravated the situation. Some operators postponed or abandoned expansion programs because of uncertain economic conditions. Output was curtailed by elimination of over- time employment and reduction of the working force. The number of employes laid off was small- reduction in the labor force was accomplished by not replacing those who left a company's employ.

Jan 2, 1958

By AIME AIME

WITH the example of the steel open-hearth men and their round table conference before the copper men, the query naturally arose "Why cannot we do likewise?" The advantage of pooling and comparing knowledge on smelting in the copper reverberatory furnace seems particularly pertinent at this time when all metallurgical economies possible must be rigorously enforced. A great deal of data had also been obtained and filed during the period of litigation over the Carson patent, and it would naturally be available with the cessation of further suits. With these ideas in mind, H. Foster Bain took up the advisability of holding such a conference directly with the heads of all the companies in the United States operating copper reverberatories, and found a nearly unanimous response. The mining companies appointed representatives directly, or indicated to the heads of various metallurgical operations what members of their staffs should be sent to such a conference.

Jan 1, 1930

By Henry F. Herley

The New Orient mine, owned and operated by the Chicago, Wilmington & Franklin Coal Co., has caused a great deal of comment and interest because of its unusual features and huge daily production. It is in Franklin County, Illinois, adjacent to the town of West Frankfort. The seam being mined is the Illinois No. 6 which in this locality is 9 to 12 ft. thick and lies approximately 500 ft. below the surface. Without fear of contradiction, it can be said that this is one of the largest coal mines in the world from a daily production standpoint. During 1928, New Orient produced 2,400,000 tons, which amounts to over 10,000 tons each day the mine operated that year. The mine is built for a capacity of 12,000 tons but has actually hoisted over 15,000 tons in one 8-hr, shift. This enormous production can perhaps be better visualized if it is realized that each day's operation depletes over two acres of coal. The general features of this mine have already been fully covered in a paper by George B. Harrington,' President of the Chicago, Wilmington & Franklin Coal Co. In a paper of the nature of Mr. Harrington's, it was unnecessary to stress any particular phase of mining conditions, consequently the ventilation problems were touched upon but lightly. In this paper an attempt has been made to describe some of the problems which have been encountered in providing adequate ventilation for the mine. Ventilating Conditions The acreage allotted to New Orient mine has a length, north and south, of approximately 6 miles, and a width, east and west, of 2 to 4 miles. A number of important considerations caused the hoist shaft, air shaft and surface plant to be located near the southeast corner of the property, instead of near the center, as is usual. During the initial phase of the mine development, the mine was ventilated through these shafts, although there was a full realization that at some future date other shafts would be required.

Jan 1, 1930

By Roy P. Full, Robert M. Grantham

Regional structural adjustments in early Tertiary time resulted in the development of the Republic graben, a major down-dropped block that is from 6 to 10 miles in width and more than fifty miles in length. The graben became the center of extensive volcanic activity during Eocene and Oligocene time, resulting in a thick sequence of water-laid tuffaceous sediments, volcanic flows, and associated intrusives. A younger series of sediments, pyroclastics, and flows were deposited in structural depressions within the graben following the period of widespread volcanic activity. The Republic mining district is located along one of the major intragraben structural zones, where continuing subsidence during the period of volcanic activity resulted in an increased thickness of flows and associated flow breccias and pyroclastics. Intrusive masses in part healed early graben-forming faults, but later subsidence reopened old faults and created new fracture zones which later became the control for the gold-quartz veins. Considerable block adjustment along the subsidence area is evidenced by the structural pattern in the mines, and telescoped vein structures indicate north-south compressional stresses and east-west graben-forming tensional stresses prior to and during the emplacement of the veins. The veins, varying from a few feet to more than 50 feet in width, are filled primarily by fine-grained quartz, commonly chalcedonic or porcelain-like in appearance. Finely laminated dark-gray to black concentric banding within the veins generally distinguishes the better-grade ore zones, which contain finely disseminated sulfides and ore minerals that include principally electrum, stephanite, naumannite, and native silver.

Jan 1, 1968