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By John B. Knaebel

This paper, describing the milling operations of the St. Joseph Lead Co. at Balmat, N. Y., is one of a series of similar papers being prepared by the United States Bureau of Mines on practice at various mills in the United States, Canada, and Mexico. The company also operates a mine end mill at Edwards, 12 miles northeast of Balmat. Mining practice in the district, as exemplified at the Edwards mine, is described in another information circular of the Bureau of Mines.3 The writer gratefully acknowledges the generous cooperation of the company officials which made this investigation possible, and wishes to thank R. J. Mechin, manager, P. W. Wolf, mill superintendent, and F. G. Kuehl, assistant mill superintendent, for their helpful assistance. Especial thanks are due J. S. Brown, geologist, for supplying information on the characteristics of the ore, and to C. F. Jackson, principal mining engineer, U. S. Bureau of Mines, for helpful suggestions.

Jan 1, 1932

By Chas Kemsley

NO. 6 shaft at Dome Mines, Limited, is an internal shaft going down vertically from the sixteenth, or 2,000-ft., level to the twenty-ninth, or 4,000-ft., level, with loading station and sump below this. It is located approximately 4,600 feet east of No. 3 shaft, the latter being Dome's main shaft through which ail ore, men, and material are handled. The decision to sink this shaft was made in May, 1935, and work was commenced almost immediately. To reach the site of the new shaft, 3,100 feet of cross-cutting, and 1,400 feet of slashing to widen existing cross-cuts, was necessary. On account of the long haul and the large amount of material to be handled, trolley haulage was decided upon and installed as soon as possible to facilitate the removal of waste rock from the crosscut and other necessary excavations. Figure 1 shows a cross-section of the cross cut and the manner in which the trolley wire is supported and guarded. For hanging each individual cross-piece, two holes are drilled into the roof and filled with snug-fitting wooden plugs. Into these, %-in. ragged hanger bolts arc driven by means of a stoper. The bolts are of various lengths to allow for irregularities in the face of the rock, and they have sufficient thread to permit several inches of adjustment for proper alignment of the cross-pieces. These hangers are spaced at 8-ft. intervals except at the curves, where 5-ft. spacing is used. A 2 in. by 6 in. cedar plank is fastened to the cross-pieces directly over the centre of the track. To this the trolley-wire supports are bolted, and 1 in. by 10 in. cedar boards are nailed on each side to act as guards. Two power-supply cables, one telephone cable, and one .Y2-in. conduit lighting circuit are also supported on the trolley-wire hangers, as shown in Figure 1. A 20-in. ventilating pipe and a 10-in. air line are placed as shown, thus acting as a guard to prevent workmen from walking on the track.

Jan 1, 1938

By J. W. Cunningham, M. J. Stultzman

THE demand for improved materials for high-temperature service has increased during the last few years. Iron,- nickel,- and cobalt-base alloys have been investigated extensively and many alloys with outs'tanding high-temperature strength have been developed. Considerable research has been directed toward improved methods of processing these alloys. The vacuum furnace as a tool for the purification and improved control of high-temperature alloys has been studied extensively and production units are in operation. The research covered by this paper studied the effects of casting in air, vacuum, or argon upon the elevated-temperature properties of two nickel- and two cobalt-base alloys. The alloys investigated were Stellite 31, He 1049, Udimet 500, and Guy Alloy. MELTING AND CASTING PROCEDURES Two heats of each of the four alloys under investigation were melted and investment cast under the following conditions: 1) Stellite 31 was melted and investment cast in air and in vacuum, with an argon atmosphere for pouring. 2) He 1049 was melted and investment cast in air and in vacuum, with an argon atmosphere for pouring. 3) Udimet 500 was melted and investment cast in vacuum with and without additions of zirconium and boron. 4) Guy Alloy was melted and investment cast in vacuum and in argon. The heats were all melted in induction furnaces equipped with preformed magnesia crucibles of 50-lb capacity. The air-melting furnace was powered by a spark-gap converter of 40 kw capacity. The vacuum-melting furnace was powered by a motor-generator set of 100 kw capacity. The argon heat of Guy alloy was melted in the vacuum melting furnace under an argon atmosphere. Virgin materials were used for preparing all heats except the air heats of Stellite 31 and He 1049. The charge for the air heat of Stellite 31 was a commercial blend of shot. The charge for the air heat of He 1049 was Stellite 6 shot plus those virgin materials necessary to give the desired composition. All of the materials used were of the same grade used com-

Jan 1, 1960

"MASSACHUSE'M'S INSTITUTE OF TECHNOLOGYBOLSAITIS, PETERMassachusetts Institute of TechnologyDepartment of Mineral Engineering77 Massachusetts AvenueCambr1dge,MA 02130(614) 253-5069ELLIOIT, JOHN F.Massachusetts Institute of TechnologyDepartment of Mineral Engineering77 Massachusetts AvenueCambridge, MA 02130(617) 253-3305RING, TERRYDepartment of Materials Science and EngineeringMassachu5etts Institute of TechnologyCambridge, MA 02130(6117) 253-4299"

Jan 1, 1988

By André Kraszczuk

Esse trabalho avaliou a microestrutura e a microdureza do aço inoxidável martensítico AISI 440B nitretado a plasma em reator de fonte DC pulsada, a 480ºC, por 6 horas e pressão da câmara de 3,3 Torr. Foram utilizadas técnicas de difração de raios-X, microscopia ótica, microscopia eletrônica de varredura (MEV) e microdureza. A camada nitretada apresentou aproximadamente 24 µm de espessura, não tendo sido observada a formação de camada branca, constituída exclusivamente por nitretos de ferro ou de cromo. Entretanto, notou-se, na zona de difusão, a presença de nitretos nos contornos de grão, possivelmente, de cromo. O endurecimento superficial do aço AISI 440B, atingiu valores entre 1417 - 1677 HV0,025, ao passo que o a matriz metálica do aço temperado apresentou durezas de aproximadamente 54HRc.

Aug 17, 2017

By Juan Alfredo Espinoza Huamán

Las operaciones mineras subterráneas necesitan cada vez más indicadores de seguridad, calidad y productividad. En ese sentido, el presente texto señala la importancia del manejo de voladuras dentro de la minería subterránea a través del análisis de las vibraciones para determinar la influencia de daño como respuesta a los índices de caracterización geomecánica del macizo rocoso. De forma que se pueda aportar minerales contínuamente, desarrollar la mina y tener más sostenibilidad en el tiempo.

Jan 1, 2015

A great range of contacting equipment is used in solvent extraction. However, a tower filled with a regular packing offers many advantages in the direct extraction from slurries. A study was made of the flow of a dense slurry through a packed tower in which the continuous phase was kerosene. The grid type packing, which was preferentially wetted by the slurry, had slats inclined at an angle of 30¦, to the horizontal. On the sur- face of the slats there were uniformly spaced longitudinal indentat- ions. These were of a height slightly less than the film thickness and divided the slurry discharging from the bottom of the slats into a number of uniform streams. When slurry entered the tower it was distributed by means of a troughs and weirs type of distributor. Because of the relatively high slurry velocities that occur at the entry region, it was necess- ary to have the distributor and the first two grids above the solvent level. The interface at the bottom of the tower was located at the mid-point of the bottom grid, so that the slurry entered the interface as a continuous film across the full width of the slats. Using the above system, stable flow with low entrainment was achieved at slurry flow rates of 3.4 mis/cm/sec. This would be equivalent to a flow rate of 177 gallons per minute through a tower of cross-section 4 ft 4 in. by 4 ft 10 in., or 1200 tons per day of solids of specific gravity 2.6 when the pulp density was 65 per cent. Previous tests indicated that a total tower height of about 30 ft would be required for a recovery of better than 99 per cent.

Jan 1, 1969

By R. Reeves

Coal producers and utilities depend on automated coal blending systems to reduce costs and meet stringent environmental regulations. Over 30 systems installed in the United States since 1987 use on-line PGNAA (Prompt Gamma Neutron Activation Analysis) analyzers to accurately control the blending process. Experience and detailed engineering are required to integrate real-time data produced by the coal analyzer with a control system to meet demanding performance specifications. This article reviews successful installations and lists important features including interfacing analyzers with plant control systems, specifying feeders and weigh scales, and managing data.

Jan 1, 1995

After more than 20 years dependence on bituminous coal as a primary fuel for generating electricity, the Pennsylvania Power and Light Company initiated a one-year study on the economics of building an electric generating station using anthracite as a fuel. The study will be completed in December 1976. If the feasibility study so indicates, PP&L will consider installing four 400,000 kilowatt generating units for scheduled commercial operation in 1985. Each unit would consume up to one million tons of anthracite annually. Anthracite generally is more difficult and expensive to extract than bituminous coal, but it has a significantly lower sulfur content than the bituminous coal currently being used by PP&L, thereby eliminating the costs of installing sulfur emission controls at generating stations. Moreover, significant reductions in transportation costs may be realized because the utility's operating territory is situated in the center of the anthracite region in northeastern Pennsylvania. These advantages may indicate that the use of anthracite is more economical than bituminous coal to PP&L. ASBESTOS -Asbestos production in the U.S. dropped again in 1975 until it was just two-thirds of that in 1973. This was in spite of the very strong demand caused by the Quebec strike. The 7-month strike of the asbestos miners in Thetford Mines, Quebec cut off 55 percent of the normal supply of U.S. consumers. Apparent domestic consumption was less than 75 percent of that in 1974. The wage settlement will probably result in a 20 percent increase in asbestos prices.

Jan 1, 1975

By W. H. Hough, P. B. Leavenworth

Development in the Upper Texas Gulf Coast during 1943 resulted in the discovery of 11 new fields as compared with 12 discovered in the same area during I942. Of the 11 new fields, eight are classed as oil and/or condensate and three as gas fields. In addition to the new discoveries, several more or less important new horizons and extensions were encountered in some of the older fields, as noted in the text under the heading "New Pays and Extensions.'' Drilling During the year, 418 wells were drilled, as compared with 356 drilled during 1942. Of these, 323 were field wells, of which 188 produced oil, 21 were gas wells and 114 were dry holes. The remaining 95 viere wildcats, 12 of which produced oil, 4 produced gas and 79 dry holes. Distribution of themwildcats with respect to the various trends may be summarized as follows: over the 91,340,492 bbl. produced in the same area during 1942. The production statistics in the text and the accompanying tables include condensate or distillate as oil production, because many Gulf Coast fields produce oils with a wide variation of specific gravities, all of which are commingled in pipe lines. Table 3 shows by counties all of the drilling and production" data applicable to this particular area. Outstanding Fields of 1943 The Upper Texas Gulf Coast covered in this report has 178 more or less active oil and gas fields, including the 1943 discoveries. Of these Table 4 lists those that were most important from the standpoint of production. Each of these fields pro duced in excess of one million barrels of oil during 1943. Some of the interesting facts to be noted from this list of some 26 oil fields are: (I) four of the fields— namely, Conroe, Hastings, Friendswood and Thompson—each produced more than 10 million barrels during 1943, whcrcas Conroe and Hastings were the only fields that produced 10 million barrels during 1942; (2) some of the older fields (discovered prior to 1920), such as Barbers Hill, West Columbia, and Hull, are still producing in excess of one million barrels annually; (3) some of the fields more than doubled their 1942 production—e.g., Anahuac and Friendswood. The large increase in production in practically all instances is the result of increased allowables from wells drilled prior to 1943 and

Jan 1, 1944

By W. H. Hough, P. B. Leavenworth

Development in the Upper Texas Gulf Coast during 1943 resulted in the discovery of 11 new fields as compared with 12 discovered in the same area during I942. Of the 11 new fields, eight are classed as oil and/or condensate and three as gas fields. In addition to the new discoveries, several more or less important new horizons and extensions were encountered in some of the older fields, as noted in the text under the heading "New Pays and Extensions.'' Drilling During the year, 418 wells were drilled, as compared with 356 drilled during 1942. Of these, 323 were field wells, of which 188 produced oil, 21 were gas wells and 114 were dry holes. The remaining 95 viere wildcats, 12 of which produced oil, 4 produced gas and 79 dry holes. Distribution of themwildcats with respect to the various trends may be summarized as follows: over the 91,340,492 bbl. produced in the same area during 1942. The production statistics in the text and the accompanying tables include condensate or distillate as oil production, because many Gulf Coast fields produce oils with a wide variation of specific gravities, all of which are commingled in pipe lines. Table 3 shows by counties all of the drilling and production" data applicable to this particular area. Outstanding Fields of 1943 The Upper Texas Gulf Coast covered in this report has 178 more or less active oil and gas fields, including the 1943 discoveries. Of these Table 4 lists those that were most important from the standpoint of production. Each of these fields pro duced in excess of one million barrels of oil during 1943. Some of the interesting facts to be noted from this list of some 26 oil fields are: (I) four of the fields— namely, Conroe, Hastings, Friendswood and Thompson—each produced more than 10 million barrels during 1943, whcrcas Conroe and Hastings were the only fields that produced 10 million barrels during 1942; (2) some of the older fields (discovered prior to 1920), such as Barbers Hill, West Columbia, and Hull, are still producing in excess of one million barrels annually; (3) some of the fields more than doubled their 1942 production—e.g., Anahuac and Friendswood. The large increase in production in practically all instances is the result of increased allowables from wells drilled prior to 1943 and

Jan 1, 1944

By William Gleason

The numbers tell the story of this one. More than 50,000 people and 1,890 exhibitors took over the Las Vegas Convention Center Sept. 24-26 for the largest mining trade show in the world ? MINExpo. Inside the convention center, some of the largest machines used in mining were on display. Caterpillar, Liebherr, Komatsu and Hitachi displayed ultraclass offroad mining trucks and shovels. Atlas Copco and Schramm were among companies that rolled in mining drills and Bridgestone, Goodyear and Michelin were among the companies showing off the massive tires used by the trucks. Throughout the three halls and an outdoor display area, just about every kind of product, gadget or service used in the mining industry could be found on display somewhere.

Jan 1, 2012

By Manuel Gomez

This, report presents correlative data on ash and sulfur forms for Pittsburgh seam coal from Greene County, Pa. Prediction equations were developed for sulfur form distributions and washability characteristics. The equations developed were evaluated with an independent set of exploration core samples. It was demonstrated-that both sulfur distributions and washability characteristic's can be predicted from exploration core data ahead of mining. This information can improve the efficiency of selective mining techniques for the production of a uniform metallurgical coal product.

Jan 1, 1967

By Robert H. Ridgway

Scrap iron and steel attracted attention during 1937 because of the unprecedented exports and the concomitant agitation in some quarters to prohibit the exportation of this essential raw material except on license by the President. This report does not attempt to analyze the statistics given in the light of the controversy over the limitation of scrap exports, but it is believed that students of this problem will find many essential basic data in the various tables presented herein. This paper presents the results of the third in the series of annual canvasses on the consumption of ferrous scrap and pig iron in the United States. The study was inaugurated in 1935 by the Bureau of Mines in response to requests from trade organizations and others for detailed

Jan 1, 1938

By S. M. Marshall, B. M. Bird

For a number of years European investigators have used laboratory methods of predicting the probable strength of coke made from coal, and recently several investigators in the United States have reported the use of various tests for this purpose. There is at present no method accepted as standard, however, nor is there even agreement as to the general type of test that should be used. Furthermore, because the details of most of the tests have not been worked out carefully, one investigator can not hope to duplicate the work of another. The extension of coke manufacture to new localities in the United States, and the increasing need for cokes of exceptional qualities made from the most economical mixtures, made it desirable to have some simple laboratory test which will determine whether given coals, alone or blended with other coals, are more satisfactory from the standpoint of coke strenpth- than others of different cost. The work described herein has resulted in the development of a simple laboratory test which, it is believed, can be generally adopted in coal laborat,ories, and which will give concordant results even though performed by different investigators in different laboratories. The general method of predicting whether a coal or a mixture of coals will produce a strong coke, resistant to crushing and shattering, has been to correlate the known strengths of the cokes produced in commercial ovens with some measurable constituent or with some property of the coals, and then to use the relationship so found for forming an estimate of the coking strengths of coals unknown. Several such correlations have utilized the percentages of the various ultimate constituents of coal, such as the oxygen content and the hydrogen-oxygen ratio;(39)§ other correlations have involved the proportion of a, B and r com-pounds, (17,21,30c) or of "oil and solid bitumens."(16,30) Also a relationship has been traced between the coking properties of coal and the rate of change of the resistance offered to the flow of an inert gas by fine particles of the coal while being slowly heated. (11,176) But the most general corre-

Jan 1, 1930

By Pedro Henrique Barbosa Souza

A Aperam é uma grande consumidora de gases do ar, principalmente Argônio. A produção de Argônio é feita através de coluna de destilação, onde são também extraídos Oxigênio e Nitrogênio. A modalidade de contrato adotada pela Aperam é do tipo take-or-pay para todos os gases, porém nem todo Oxigênio produzido era consumido. A Aperam então desenvolveu um projeto visando aproveitar esta “sobra” de Oxigênio no seu forno Walking Beam, para enriquecimento do ar de combustão. A utilização de Oxigênio permite reduzir, de maneira indireta, o consumo de Gás Natural neste forno. Após a implantação do projeto a Aperam está apta a consumir acima da capacidade de Oxigênio produzida, sendo necessário implementar uma estratégia de controle que permita limitar a máxima velocidade deste gás na tubulação (risco de explosões) e reduzir a interferência entre os diversos consumidores, o que poderia provocar desarmes ou oscilações na estequiometria dos gases. Para isto foi aplicado técnicas de controle antecipatório. Este trabalho irá abordar as estratégias de controle utilizadas, sua sintonia e os resultados obtidos.

Jul 30, 2018

By W. H. Young

The thickness of the coal seam is one of the more important items influencing the productivity and general overall efficiency of operation 1 of a coal mine. The average thickness of coal seams mined in the United States decreased 2 inches between 1950 and 1955 to an average of 62 inches, which also is 3 inches less than the 65 inches in 1945. The decrease in thickness is due partly to the increased production from strip mines with thinner seams and partly to the increased percentage of total production at underground mines in certain States having thinner seams. The thickness of seams at auger mines was measured for the first time in 1955 and was 53 inches. Though bituminous coal and lignite is mined today from seams of exceedingly variable thickness -less than 2 feet to ore than 50 feet -a large majority of the production, 65 percent in 1955, came from seams 3 to 6 feet thick. This is not surprising since the coal seam of moderate thickness presents the least mining difficulties.

Jan 1, 1957

By M D. Goodz

MacPhersons Reward gold deposit is in a post-kinematic tonalite intrusion which is a setting different from many other deposits of the Coolgardie goldfield that are hosted in early Archaean tholeiitic sills or meta-sedimentary rocks. Gold mineralisation at MacPhersons Reward consists of auriferous quartz veins that are best developed in the tonalite but extend to the adjacent komatiitic rocks and along the lithological contact zones. The gold-related alteration halo is dominated by biotite-chlorite and pyrrhotite. Unlike many other Coolgardie deposits, the As concentrations are low.

Aug 22, 2011

By David Ramírez

"Dentro del proceso de optimizar la fragmentación del mineral por voladura, el principal objetivo es determinar el impacto que tendría la incrementación de las partículas medias y finas sobre la extracción de cobre en elmineral ROM, (Run of Mine), que actualmente constituye una de las fuentes de producción por lixiviación en la Sociedad Minera Cerro Verde. En ese sentido, el presente trabajo describe la cantidad de cobre que aporta el mineral ROM a través de su optimización en el proceso, así como el impacto económico que tendría a futuro. Para ello, se utilizan los resultados de las pruebas para los módulos experimentales 12 y 13 desarrolladas entre 1998 y 2000, y la validación preliminar del sistema de análisis granulométrico por fotos (Split Desktop) desarrollado en julio del 2002 para así otorgar validez a los resultados fotográficos de granulometría reportados para las diferentes pruebas de voladura. "

Jul 31, 2003

By T. Sakaguehi

Some attempts were made to recover and remove of uranium that may be present in refining effluents, mine waste Water, and other waste sources by using microbial biomass. To establish which microorganisms accumulate the most uranium, 135 species of microorganisms (42 bacteria, 26 yeasts, 34 fungi and 33 actinomycetes) were screened. Of these 135 species of microorganisms tested, extremely high uranium absorbing ability was found in Pseudomonas stuzeri, Neurospora sitophila, Streptomyces albus and Streptomvces viridochromogenes. In addition to the research on uranium uptake, thorium recovery by using microorganisms was investigated. High abilities were found in Streptomyces levoris and Bacillus subtilis. The selective accumulation of heavy metal ions by various microorganisms has also been examined. Uranyl, mercury and lead ions were readily accumulated by almost all of the species of microorganisms tested. Actinomycetes and fungi differ from many bacteria and most yeasts in their selective accumulation of uranium, and mercury. The basic features of uranium uptake by Streptomyces viridochromogenes, a microorganisms with high uranium-uptake ability, were investigated systematically. Synthesizing these results, we suggested that the accumulation of uranium into these microbial cells is not directly mediated by any metabolic process:, but almost completely dependent upon physicochemical adsorption on the cell components. In addition to this fundamental research, uranium recovery was investigated in immobilized Streptomyces viridochromogenes. These immobilized cells adsorbed, uranium readily and selectively. The immobilized cells recovered uranium almost quantitatively and almost all uranium adsorbed was desorbed with 0.1 N Na2CO3, These results showed that microbial cells are more stable after Immobilization and can be used repeatedly for the process of uranium adsorption-desorption. These results suggested that these microbial cells can be used for the recovery and removal of nuclear fuel elements, such as uranium and thorium, from refining effluents and mine waste water.

Jan 1, 1991