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By W. H. Young

In response to increasing national energy requirements. highlighted by the continuing growth in demand for coal for the generation of electric power the output of bituminous coal and lignite in 1965 passed the 500-million-ton mark for the first time since 1956, thus emphasizing the steady up-ward trend from the recent low of 403 million tons in 1961. There were corresponding upward trends in consumption, exports mechanization, and productivity. Production.-The output of bituminous coal and lignite in the United States in 1965-512 million tons-was 5 percent greater than the 487 million tons produced in 1964. The gain was attributed largely to expanded consumption by the electric utilities, greater use at coke ovens, and an increase in exports.

Jan 1, 1967

By O. G. Lellep

IN every country economic circumstances prescribe the method used to produce a commodity at lowest cost. In Pennsylvania a man's wages for working 4 hr buys a ton of coal wholesale; in Germany a laborer must work 40 hr, or ten times as long. In western Europe, therefore, conservation of fuel is of primary importance, and recent practices of burning lime and cement differ from those employed in the United States. This paper presents data collected during a trip through western Europe in 1953. Considered uneconomical, shaft kilns for burning cement disappeared in the United States two generations ago. But because required capital investment is low and operation greatly improved, shaft kilns are still used to some extent in Europe, where fuel costs are high, and are even included in designs for plants under construction. During the last 50 years shaft kilns have been maintained at the same physical size, while their output has been increased at least four times.

Jan 7, 1954

By R. Gradnik

The continuous need for infrastructure expansion forces the mining industry to develop underground structures into more sensitive and violent environments. When underground excavation enters into deep and high stress rock conditions, geotechnical designers find themselves faced with the difficult task of selecting a rock support system that will meet today's stringent requirements. Whatever support system is chosen, it is mandatory that potential rock movement be controlled. All this has intensified the development of safety systems and new, unique solutions which can enable construction companies to go both, further and deeper, without reducing the level of safety. To address these needs, Atlas Copco developed the Roofex® bolt, specifically designed to withstand large static and dynamic deformations under prespecified load conditions. The Roofex Rock Bolt acts as stiff support up to a designable load level before the sliding effect of the mechanical frictional system is triggered and allows highly controlled rock mass movement without loosing the support function.

Jan 1, 2011

By Patrick Ph. D. Kennedy, Osvaldo A. Ph. D. Bascur

With the revolutionary progress in information and computer technologies, applying the latest information technologies in metallurgical complexes has become a serious challenge to both a major opportunity and a serious challenge to both management and technical teams. The emerging component and object technologies are changing the way everyone can beneficially use their computer and networks to add to their corporate bottom lines. Most mining and metallurgical plants use predictive maintenance policies based on statistical analysis and special techniques, like vibration analysis and oil and lube analysis for critical equipment. Process control strategies are installed in several metallurgical sites. All process equipment and control strategies require maintenance from local personnel at the mine. Integrated use of existing and emerging technologies is making it possible to implement an overall process effectiveness control index. This index is based on key indices such as losses due to plant availability, performance efficiency and rate of quality. The availability of real time and process history to identify the most critical part of the processing system from mechanical integrity is highlighted. An emerging plant integration paradigm is described to simplify the implementation of business enterprise resources management and distributed plant management systems.

Jan 1, 1998

By Robert L. Akre

When Marco Polo visited China in the 13th century, no one knew what black powder was except the Chinese; they knew enough to make dazzling fireworks with it. But the realization that black powder could also do useful work came much later and, like all important discoveries, it altered the course of history. It was in the 14th century that black powder was first used to break rock in a very crude way; there were no drills and the powder was simply poured into cracks and exploded by setting it afire. Because its energy value was pretty low, the need for something more powerful was felt when the industrial revolution began. In the 1850s, miners began experimenting with liquid nitroglycerine on a limited scale. This was a very sensitive and dangerous explosive. Fortunately in the 1860s, Alfred Nobel succeeded in stabilizing nitroglycerine by absorbing it in kieselguhr-and a new product, dynamite, was born. With it, miners were able to unleash the great energy of nitroglycerine for blasting purposes. But dynamite was still a very sensitive explosive. In subsequent years, other explosives of various strengths and characteristics were developed, such as blasting gelatin, gelatin dynamite, ammonia dynamites, (all containing some nitroglycerine or nitrostarch), and liquid oxygen explosives. These products and their variations supplied the blasting trade for many years. A grained ammonium nitrate product containing some carbonaceous material entered the market in the 1930s. This explosive had below-zero sensitivity-meaning: a No. 6 blasting cap imbedded in it would not detonate it. A more sensitive initiator, called a primer, was needed to detonate this mixture. From Rags to Primacord to Solid-State The first initiator for an explosive charge was probably a rag slowly burning its way to the charge; this method was quite unreliable. Then came the burning fuse, which was an improvement. Next was the nonelectric blasting cap initiated by a fuse. With these initiators, a miner needed quick reflexes and good legs; upon lighting the fuse, he had to run immediately for cover. Development of the electric blasting cap that allowed for accurate timing eliminated this hazard; the electric cap, however, introduced other safety problems because of its susceptibility to extraneous electricity, e.g., ground currents, lightning, and static electricity. These caps also became available in millisecond delays. Development in the mid-1930s of Primacord, a detonating fuse insensitive to electrical currents or impact, further reduced blasting hazards, and is generally acknowledged as the safest known means of initiation. Eventually, Primacord millisecond connectors also became available for delay patterns in blasting. In the mid-1960s, the Primadet delay was introduced; it is a practical nonelectric detonator system that offers the precise timing of electric blasting caps-and is immune to the hazards or effects of extraneous electricity. Recently, Research Energy of Ohio, Inc. introduced a new type of solid-state blasting machine that combines a sequential timer and delay caps. It enables the efficient breakage of rock with a minimum amount of shock, ground vibration, and noise. Improvements in Blast-Hole Drilling World War II created an enormous demand for coal and other minerals in the U.S. and elsewhere. Great efforts and large amounts of capital were spent to find new mineral deposits and develop better mining methods. But while mechanization in mining proceeded at a rapid pace particularly in open-cut work, there was a definite lag in developing new or improved machines for drilling blast holes. The industry continued to depend largely on horizontal, churn, and pneumatic drills. No better machine was available for large scale production. The need for improvement in this phase of mining became more acute in the post-war years. Despite efforts toward further mechanization, mining costs rose rapidly because of mounting inflation and increasingly high wages. In most operations, drilling and blasting the overburden became the principal item of cost. Therefore, whatever size holes were being drilled, the holes had to be spaced so that any foot of the bore hole could be loaded with the maximum load required for the number of cubic yards of material that each foot of the hole was carrying. With the smaller holes that were being drilled, the proportion of drilling cost to the total drilling and shooting cost was much higher than it would have been with larger holes (because of the closer spacing required by smal-

Jan 1, 1977

By John Ross Middleton

Based upon 30 years+ experience in the Development, Implementation and Ongoing Support of Computer based Melt Shop Management Systems in about 40 plants in the UK, Europe and the USA, consideration of the overall facilities of a state of the art, comprehensive, Integrated Melt Shop System covering Melting and Secondary processes for all grades of steels and superalloys; the scope of functionality of these systems, covering Raw Materials and Consumables Procurement and Inventory Management, Laboratory Management, Melt Shop Scheduling, Furnace Charge and Additions Optimisation, Level 1.5 to Level 2.5 Materials Optimisation and Process Control Calculations, Process Data Recording, Management of Ladles, Furnace Bodies, Vessels and Moulds, Comprehensive Management Reporting and Integration with Corporate ERP Systems. The second section of the paper reviews the key ‘Success Factors’ to achieve rapid, successful implementation, comprehensive, fast response user support, continuing system improvement and maintaining ‘perfect fit’ of system to operations in an ever changing future technical, operations and business environment.

Jul 29, 2018

By Marshall K. I

THE problem of satisfactorily eliminating the fumes and dust which are unavoidably produced in various metallurgical and manufacturing industries is one which has received considerable attention in the past, and has been the subject of much investigation and research. The solution of this problem was urgently desired for two reasons, the principal one being the fact that a considerable percentage of the total process losses in many industries was represented by the commercial values of the fumes and dust that escaped from the stack.The other reason is that, in some instances, the emission of the matter is regarded as objectionable. Various methods have been designed with a view to solving the problem thus presented, and the latest development that has beendesigned is the process of electrostatic precipitation. Continued investigational and developmental work with this process has already demonstrated its applicability to many industries, and new uses to which the process can be put are being opened up. Its use is already widespread, and the economic success that has attended its application in most instances would indicate that its use will become more general in the future.It has proved its ability to treat gases over wide ranges of temperature, and has successfully handled various types of fumes whose chemical characteristics differ very considerably. In many processes it has now come to be regarded as standard equipment.HISTORY OF ELECTRICAL PRECIPITATIONThe first recorded observations on the influence of an electrified insulated wire on gases containing solid particles in suspension was made as early as 1824 by Hohlfeld, in Leipzig. He found that, if he electrified a wire hung in a bottle filled with smoke, the smoke cleared rapidly, and a deposit formed on the sides and bottom of the bottle.

Jan 1, 1923

By Tatiana Bendo

Amostras de ferro puro sinterizadas foram enriquecidas superficialmente com molibdênio e em seguida foram cementadas. Todos os tratamentos térmicos foram realizados utilizando descarga luminescente anormal. Durante o processo de sinterização e de enriquecimento superficial as amostras são colocadas sobre o ânodo da descarga, na configuração cátodo-ânodo confinado. O bombardeamento da superfície do cátodo por espécies energéticas produz a pulverização de átomos do cátodo que se depositam na superfície da amostra e se difundem até certa profundidade. Foi observado que a espessura da camada superficial enriquecida está relacionada à energia de bombardeamento das espécies. Durante o processo de cementação, a presença de Mo na região superficial favorece a estabilização da fase a- Fe alterando a cinética de precipitação da cementita nessa região. A cementação das amostras enriquecidas com molibdênio elevou os valores de dureza obtidos para a região superficial.

Aug 16, 2017

By C R. Ferrari

Residual subsidence is generally accepted as being about 5% of the total subsidence occurring within 12 months of all mining finishing. This paper looks at five case studies from different parts of the country, in various mining settings within a depth range of 430m to 760m. From a single seam single panel working to working the eleventh seam, all are within the concealed coalfield, similar to today's mining. The monitoring of subsidence continued for many years once the mining had finished and the results obtained are at considerable variance from the accepted norm. Subsidence has been found to carry on for up to eleven years after mining has ended, within a range of 8% to 45% of total subsidence. A highly significant factor was that subsidence, as a whole, was generally much more than predicted. The residual subsidence aspect has to he viewed in this context and in order to debate the subject at length, the causes of residual subsidence have to be balanced against the apparent inability to accurately predict subsidence. The results from the case studies were similar, even though the mining settings differed considerably. Subsidence of around 10% to 20% continued for several years after mining had ceased.

Jan 7, 1997

By J. A. Haggman

In a country richly endowed in mineral wealth, Climax Arimco Mining Corporation's (CAMC) Dinkidi porphyry Au?Cu deposit in Nueva Vizcaya province, Philippines, represents the most significant mineral discovery in the country in recent times. The deposit is located within a belt of young intrusive and volcanic rocks in the Sierra Madre mountain chain of north Luzon a region previously unassociated with porphyry-style mineralization. Since 1989, drilling of the Dinkidi deposit has outlined a resource of 124 million tonnes of 1.0 g/t gold and 0.41 % copper. Regional exploration throughout CAMC's 37,000 hectare FTAA has identified a further sixteen potential porphyry-related deposits. A new mining law was passed in March 1995 but prior to that CAMC had the first Financial and Technical Assistance Agreement (FTAA) granted by the Philippine government allowing 100% foreign ownership of mining projects.

Jan 1, 1997

By W. R. Hargrave

"Mining OperationsOre will be mined by open pit techniques. Because of the high grade of the deposit and the low strip ratio, mining rates are small relative to most other open pit operations.The ore deposit is located in the valley of the main fork of Red Dog Creek. The bulk of the deposit is located on the southwestern flank of the creek, but mineralization does traverse the creek in both the north and east directions.Erosion has exposed the orebody in a number of locations, and has resulted in oxidation of the mineralization closer to the surface. Although much of this oxide material is very high grade, it leaches readily and, at least in the initial phases of the operation, will be stockpiled and not treated in the concentrator.During construction, 2.3 million mt. (2.5 million st.) of overburden and waste will be stripped from the orebody to expose ore for initial operations. Competent non-mineralized waste will be used to build roads and waste dumps, but the bulk of material removed consists of oxide or ice-rich soils and weathered rock which is not suitable for construction.The annual ore mining rate will be 1.9 million mt. (21. million st.). The strip ratio will start off at 1.2 to 1, falling to 1.0 to 1 by year 5 and ultimately to 0.8 to 1.Bench heights are set at 7.6 m (25 ft). Pit slopes will vary depending on the material present in the wall. The slope, through competent waste and the sulphide package, was set at 45 degrees. This is flattened to 26 degrees (i.e. 2: 1) through overburden and Upper Kivalina shales. The Kivalina Shales are an ice-rich shale whose carbonate matrix has been leached out and which exhibits little or no strength as it thaws. In addition, a 100 ft containment berm will be left in the wall below overburden and Kivalina."

Jan 1, 1989

By A. Faber du Faur

At the request of some of the members to whom I have shown a collection of specimens of sulphur from southern Utah, I herewith present some notes relating to the mines and the method of extracting the sulphur from the ore. In preparing these notes I have borrowed from a paper by Prof. G. vom Rath, published in the Neue Jahrbuch fur Mineralogie, vol. i., 1884, dated Salt Lake City, December, 1883. The Cove Creek sulphur-bed, now worked by the Dickert & Myers Sulphur Co., is in Beaver county, near the line of Millard county. It was first discovered by Mr. Ferdinand Dickert in 1869 ; other beds in the same neighborhood mere found by him from 1872 to 1875, making altogether 22 mining claims. The want of railroad communication prevented the early development of these claims; but in 1883 Mr. F. Dickert put up a plant for extracting sulphur from the ore, which proved a perfect success; and in 1885 the property was transferred to a stock company organized under the laws of Utah. The railroad station nearest to the Cove Creek mines is Black Rock, on the Utah Central Railroad, 204 miles south from Salt Lake City, and about 26 miles west of the mines. The road from Black Rock to the mines passes through desert and lava-bed, to the road leading from Kanosh to Beaver, which latter road it joins near Cove Creek fort, a square stone enclosure, erected by the Mormons for protection against the Indians. Cove Creek fort is situated near the eastern limit of a plain bounded on the west at a distance of about 12 miles by the Mineral range, and on the east by the Sulphur mountains, forming part of the Tushar mountains. To the northwest the plain runs into the Sandy desert. About 3 miles from the fort rises a solitary hill about 1000 feet above the

Jan 1, 1888

Filter Presses are used in a wide range of process industries where high quality filtration at elevated pressure is required. This is mainly due to the fact that modern presses are fitted with polypropylene filter plates which combine excellent corrosion resistance with high mechanical strength. Filtration pressures of 15 Bar at ambient temperatures are common ensuring low residual moisture content and easily manageable filter cakes. Recessed polypropylene chamber plates have been in use for the last 15-20 years and have replaced plates and frames almost entirely. The latest development in plate technology is the polypropylene membrane plate. These provide lower moisture content cakes at significantly higher capacity than recessed chamber plates. Because of their stayboss-free construction, membrane plates provide excellent cake washing facilities which make them suitable for a wide range of process applications. Membrane plates are available both as fixed and exchangeable membrane types. Overhung membranes can be fitted to existing plates manufactured in cast iron or plastic to enhance the performance of existing presses.

Jan 1, 1989

McCulloch, Leon.-Experiments with Sherardizing. Discussed by Fred. L. Wolf, Willis M. Peirce, Jesse L. Jones, O. W. Storey, David R. Kellogg, William H. Finkeldey, L. H. Marshall 2 Bassett, W. H. and Davis, C. H.-Spectrum Analysis in an Industrial Laboratory. Discussed by C. S. Brainin, C. H. Davis, W. H. Bassett, George K. Burgess, George K. Elliott, Leonard Waldo, Keivin Burns 8 Roast, Harold J. and Pascoe, Charles F.-Arsenical Bearing Metals. Discussed by Jesse L. Jones, William A. Cowan,. William K. Frank, William M. Corse, Harold J. Roast 10 Bain, Edgar C.-Crystal Structure of Solid Solutions. Discussed by Ancel St. John, Edgar C. Bain, Paul D. Merica 14 Peirce, Willis M.-Studies on the Constitution of Binary Zinc-base Alloys. Discussed by George K. Burgess, Willis M. Peirce, D. H. Ingall, J. L. Haughton, K. E. Bingham 16 Webster, William R.-Application in Rolling of Effects of Carbon, Phosphorus and Manganese on Mechanical Properties of Steel. Discussed by George B. Waterhouse, J. O. Liebig, Ralph H. Sweetser, H. T. Morris, F. D. Carney, W. P. Barba, John H. Nelson, George K. Burgess 19 Barba, W. P. and Howe, Henry M.-Acid Open-hearth Process for Manufacture of Gun Steels and Fine Steels. Discussed by W. J. Priestley, Haakon Styri, C. T. Patterson, Harry Brearley, W. P. Barba, George F. Comstock, Alexander L. Feild 24 Kellogg, David R.-Electrolytic Deposition of Iron for Building up Worn or Undersized Parts. Discussed by Jesse L. Jones, William Blum, C. R. Hayward, George K. Burgess, C. P. Perin, David R. Kellogg 33 McQuaid, H. W. and Elm, E. W.-Effect of Quality of Steel on Case-carburizing Results. Discussed by H. J. French and L. Jordan, W. J. Priestley, M. H. Schmid, A. E. White, H. J. Stagg and S. C. Spalding, Henry S. Rawdon, J. S. Vanick 35 Phillips, Arthur and Davenport, E. S.-Malleableizing of White Cast Iron. Discussed by Samuel Epstein, H. A. Schwartz, A. E. White, R. S. Archer.... 58 Priestley, William J.-Effect of Sulfur and Oxides in Ordnance Steel. Discussed by Harry T. Morris, William J. Priestley, C. P. Perin, James H. Gray, W. P. Barba, Haakon Styri, Frank D. Carney, W. L. Harbrecht, George F. Comstock, E. J. Janitzky 67

Jan 5, 1922

By Hall G

The Mount Isa silver-lead-,zinc deposit possesses a number of features which sets it apart from usual occurrences of ores containing those metals. The deposit has been described in vario:us papers, but development upon deeper levels during the past two years has, yielded much information not hitherto published. Purpose of the present paper is to furnish a unified and coherent perspective by tracing briefly the full rock deformational and mineralization processes responsible for the ore deposition. The paper represents the outcome of ten years' organized geological effort at Mount Isa. Information contained in it supersedes that previously published.A bibliography of published articles relating to Mount Isa ore deposition is appended. In preparing the present paper previously published data have been drawn upon freely wherever applicable. The authors are especially indebted to the papers by Grondijs and Schouten, and by O'Malley and McGhie, which present results of systematic microscope studies of thin and polished sections from comprehensive suites of Mount Isa ore.

Jan 1, 1942

By D. Brunner

System simulation is an increasingly popular technique for analyzing and improving existing as well as newly designed underground mining operations. An engineering firm that specializes in simulation helped a major metals producer build a long-range planning model of an existing underground mine. Subsequently the team adapted this model to assess technology alternatives in the design of a new mine. The two models differ in the level of detail used for modeling the development process. This paper discusses the differences in approach between the models along with the experiences gained and challenges faced during the construction and use of the models.

Jan 1, 1999

Sherwood?s Minto Project ? High grade copper copper-gold deposit ? Yukon Territory, Canada ? Development underway ? Permitted ? Production by mid mid-2007 ? 40 40-50m lbs Cu plus Au/Ag by by-products ? Parallel exploration program underway ?Discover more high grade resources ?But what kind of deposit is it?

May 1, 2006

By Kenneth F. Wyman

The following report details the successful construction of Contract 2A of the Three Rivers Water Quality Management Program, Intrenchment Creek Combined Sewer Overflow Conveyance System, in DeKalb County for the City of Atlanta, Georgia. The contract required construction of approximately 2878 m (9443 ft) of tunnel bored to an initial diameter of 7.95 m (26 ft 1 in), with provisions to concrete line those portions designated by the engineer to a finished internal diameter of 6.91 m (22 ft 8 in). Flanking the tunnel are two shafts. The upstream shaft was excavated to a nominal diameter of 4.87 m (16 ft) to accommodate a finished internal diameter of 3.66 m (12 ft). This shaft required a transition boot fully concrete lined to final dimensions of 6.91 m (22 ft 8 in) wide, 13.72 m (45 ft) long, and varying in height from 6.91 m (22 ft 8 in) to 12.80 m (42 ft). Associated work necessary to complete the contractual obligations included installation of 22.86 m (75 ft) of cut-and-cover box culvert, 484 m (1589 ft) of open-cut sewer installation in sizes ranging from 0.30 m (12 in) to 1.68 m (5 ft 6 in), one river crossing, 137.46 m (451 ft) of monolithic concrete trapezoidal channel, and installation of 19125 cu m (25000 cu yd) of select fill material compacted and graded to finished contours. The downstream shaft was excavated to a minimum diameter of 12.04 m (39 ft 6 in) and concrete lined to a finished internal diameter of 10.67 m (35 ft). Requirements here included installation of a complete pumping station with all mechanical, electrical, and structural elements necessary for dewatering the tunnel through the controlled use of four 250 hp submersible pumps discharging into the facilities of the Intrenchment Creek Water Pollution Plant. The objective of this project was to collect combined storm runoff and sanitary flows currently coursing through Intrenchment Creek

Jan 1, 1985

By Luciana Vilarinho Ramos de Carvalho

Este trabalho tem como objetivo avaliar o efeito do nióbio e do vanádio no aço estrutural, conforme norma brasileira NBR 7007 AR 415, quando laminado a quente a diferentes temperaturas de reaquecimento, nos resultados de limite de escoamento, limite de resistência e alongamento. Os demais parâmetros de processo que influenciam as propriedades mecânicas dos aços como temperatura e taxa de deformação de cada passe, temperatura de acabamento e taxa de resfriamento foram controlados e considerados constantes. Os resultados do ensaio de tração mostraram que os limites de escoamento e resistência da corrida com vanádio foram bem superiores aos obtidos da corrida com nióbio. O alongamento, em contrapartida, foi reduzido na corrida com vanádio, mas acima do valor mínimo especificado pela norma. Além disso, na corrida com nióbio, foi observado aumento das tensões de escoamento e resistência com o aumento da temperatura de reaquecimento de tarugos. Esses resultados propiciam uma maior flexibilidade da usina em trabalhar com os dois tipos de liga dependendo das condições de mercado e operacionais.

Jul 30, 2018

By Karl J. C. Harries

"14.1. INTRODUCTION1The boilerplate of an agreement is not a single provision, but a series of provisions that are expected in “every agreement”. They are sometimes also referred to as the “lawyer’s provisions”. Many businessmen consider the boilerplate to be superfluous and, to some extent, window-dressing by the lawyers – even legalese. They will often offer advice to the effect that it can “pretty well be ignored”. Such advice could not be more wrong.Most boilerplate provisions are essential parts of every agreement. Some may be part of a “standard package” and may have little relevance to the agreement at hand, but these are the exception rather than the rule. The exceptions should not be treated as justification for giving all these provisions short shrift. The boilerplate should receive the same review, consideration, and negotiation as the provisions that set forth the business deal. It is often these provisions that make the deal work or that are turned to at the time of disputes. If they are inadequate, as they sometimes are (unfortunately, some draftsmen are also loath to review or update their standard boilerplate provisions or to tailor them to the deal at hand), they can create problems, rather than offer solutions. Such problems can be costly and time-consuming for the parties to address. Inadequate or incomplete provisions may ultimately be one of the reasons for the parties to turn to the courts to settle their differences. On the other hand, good boilerplate provisions can help keep them out of the courts.One of the principal objectives of an agreement should be to provide procedures, or mechanics, for implementing agreed principles and for the parties to follow to settle their differences, real or perceived, without going to the expense and disruption of a lawsuit. An agreement should aim to keep the parties away from the courts, not serve as a springboard to the courts. It must nevertheless be acknowledged that, if there is a major falling-out among the parties to an agreement, the chances are that, however carefully the provisions of that agreement have been negotiated and drafted, the parties will end up before the courts or some other adjudicating body."

Jan 1, 2003