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By Craig Hartley

? A helper stands beside a continuous miner as the operator is at the controls. The operator means to push the stop button but hits the drum rotation start button by mistake. The drum begins to turn and the bits catch the helper's clothing. He is thrown violently to the ground and suffers multiple contusions. ? A farmer's wife helplessly watches her husband drawn into the claws of farm machinery while she frantically and unsucessfully searches for the control to stop the machine. ? A mechanic on the night shift replaces plugs in the lubrication systems of all three engines of an airliner following routine maintenance. In doing so', he fails to notice that "0" ring seals have not been mounted on the plugs. A few hours later, as the fully loaded airliner is cruising high over the ocean, oil pressure on one engine drops precipitously. The pilots quickly shut down the engine and turn for home. Almost immediately, the two remaining engines lose their oil and fail.

Jan 1, 1983

By S. C. Gouws

"SynopsisSustainable infrastructure development has long been identified as a key enabler for socio-economic growth and poverty reduction in societies globally. Twenty-one years into the young South African democracy, economic prospects are fragile and unemployment statistics are high. According to Trading Economics (2015) the GDP growth rate in South Africa averaged 3.07% from 1993 until 2015.Through the National Development Plan 2030, the government has responded by instituting the Presidential Infrastructure Coordinating Commission (PICC) to direct national growth and drive job creation by effecting a long-term infrastructure investment programme. The Commission is mandated by Cabinet to coordinate, integrate, and accelerate implementation of more than 150 individual social and economic infrastructure plans.In the civil infrastructure development sector, increased urbanization is compelling governments and the public sector to expand safe and reliable public amenities, but the availability of real estate for construction in congested cities is a challenge. Within the mining infrastructure construction industry safe, rapid, and efficient mine extraction strategies are imperative to realize increased production, business hurdle rates, and stakeholder expectations.Asset owners and stakeholders are obliged to consider advanced mechanized underground excavation and support technologies in order to present feasible solutions timeously. From an engineering design, procurement, and construction management (EPCM) perspective tunnelling technology and boring applications have a distinct advantage over conventional excavation techniques. These solutions may enhance commerce and transportation by expanding infrastructure in concentrations of national economic activity, providing crucial linkages with rural areas, between cities, and across international borders.This paper explores the contribution by mechanized tunnelling technology and boring applications applied in conjunction with digital and automation technologies compared with conventional methodologies. The technological expertise, combined with a paradigm shift in delivery of project objectives, will promote economic growth, aid recovery from the economic downturn, and improve social development."

Jan 1, 2015

By S. J. Boone, A. Poschmann, C. Pound, A. Pace

San Diego’s Stadium Conglomerate consists of poorly cemented cobbles, gravel, sand, silt and clay. Conventional laboratory and in-situ testing is not suitable for characterizing its engineering properties. Although the formation is often considered a “rock” its behavior is more readily modeled using soil mechanics. Static and seismic design of a tunnel for the Mission Valley East light rail extension required that the stress-strain characteristics of the ground be identified over a broad strain range. Geophysical methods and field plate load testing were used to develop a full non-linear stress-strain model of the expected ground behavior. Quantification of the coarse material distribution was also required for selection of tunneling methods and construction considerations.

Jan 1, 2001

By Alicia O'Reardon

DIFFIDENTLY, because don'ts are rarely greeted with cheers; humbly, because I, myself, have never lined up with the irreproachables, I venture on the subject of manners for the mining camp matron. Mining camps can be divided roughly into two types-the large, opulent settlement that blooms like the rose about a strong mine in full operation; and the puny group of adobe huts, or calamina shacks, or even canvas tents flung down in the wilderness to shelter the gay pioneers of a shining prospect or the shattered survivors of a lost hope. Of the first, I know nothing; but in the second, I have spent some of my best years, and from its curious code of morals and manners, its comic hates and its unreasoning loves, its high impatience and its engulfing kindness, I have charted the narrow .and pitted path which must be trod by the woman who would success¬fully live therein.

Jan 1, 1936

By Descour Jozef, Suguru Shirasagi, Takuji Yamamoto, Koji Murakami

For TBM tunneling no visual inspection of excavated ground is possible. This may hinder the high-speed excavation, particularly in complex ground conditions. The TBM Excavation Control System was developed for better prediction of geological conditions ahead of the tunnel face during excavation. The seismic reflector tracing produces volumetric images of anomalies in the ground in “near-real time.” These images are verified using logging data from pilot boring and TBM driving data, to improve reliability and precision of ground mapping. Also good correlation was obtained between the rock strength index computed from TBM data, and one derived from volumetric seismic images.

Jan 1, 2007

By Richard Manrique, Alberto Paz

Este articulo muestra cómo la implementación de un Sistema de Control de accesos y asignación automática del personal a sus equipos—basado en el intercambio electrónico de datos automatizados— hizo posible lograr, en mina Toquepala, un incremento en la producción de 4,824 t durante el turno día y de 3,990 t durante el turno noche, lo que significó un positivo impacto económico anual promedio por mineral procesado superior a los US$ 11 millones. Se evidenció asimismo una optimización en los tiempos de transporte y supervisión, además de haberse descongestionado el uso de la radio al inicio de turno.

Jan 30, 2020

By M. K. Larson

Proper employment of numerical stress analysis design tools is based on the demonstrated ability of a model to capture key elements of the geologic site model and accurately simulate how these elements interact with a mine design. While these tools have progressed markedly, they are, at heart, a gross simplification of the abundant complexity of a natural setting and its response to mining. A generic deep longwall site model was developed that includes aspects of the geology of deep coal mines in the Wasatch Plateau and Book Cliffs coal fields of Utah. The site model contains a set of common features and observations of how these features typically respond to mining. This site model was the basis for evaluating use of empirical, boundary element and volume element stress analysis tools to analyze the distribution of stress around a deep longwall panel. More specifically, this evaluation examined shifting of stress to panel abutments and gob, distribution of stress in the abutment, and deformation and failure of bridging strata. Measurements of abutment stress changes at two sites in the Wasatch Plateau region were used to illustrate model calibration. Overall, these comparisons highlight the considerable differences between methods. Volume element tools can incorporate considerable detail and have fewer underlying assumptions, but this detail carries a considerable computational cost. Boundary element tools are much more efficient. But this efficiency also comes at a cost of added assumptions. These assumptions were challenged by the presence of a strong sandstone unit in the overburden, leading to boundary element results that depart significantly from volume element results. Empirical rules are the simplest, but are even more burdened by assumptions, many of which are implicit in underlying cases. Insight into the nature and impacts of underlying assumptions in each method is essential to proper use of results in mine design. Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health

Jan 1, 2009

At last year's. annual meeting of The Institute, Sir George Fisher, as President, compared it somewhat nostalgically with a meeting of its kind in the 1920s when comment was expressed on the decline of Australianmining and on the lack of new mineral discoveries.I feel that tonight's annual meeting is even more an occasion for nostalgia, for it represents the seventy-fifth anniversary of the founding of The Australasian Institute of Mining and Metallurgy. I hope, therefore, that I may be allowed to retrace some of the circumstances of this Institute's origin and at the same time to look at some of the broader happenings of those 75 years.From this distance in time it is, of course, much easier to get things in perspective and one of the things that compels enormous admiration in looking back over the history of our Institute is to note the qualities of foresight and keen concern for professional standards which moved the pioneers in this Institute. They had no benefit of hindsight to aid them.Just over 75 years ago, a small group of men met in Broken Hill to discus.s the possibilities of forming an association of mining engineers. The moving spirit was Uriah Dudley, our first secretary, manager of the Umberumberka mine at Silverton. The first formal move to form an association of mining engineers came from the Amalgamated Mining Managers Association of Australasia. At the time, this association was a fairly new group, being 5 years old.It had been formed to try to raise the standard of management throughout the industry. Uriah Dudley and our first provisional president, John Howell, held their first talks in 1891 and further meetings at Broken Hill followed. The inaugural meeting, attended by 200 members, was held in Adelaide in April, 1893.

Jan 1, 1968

By M. Andrews, B. J. Göhre, G. Strong, C. Terblanche

Mechanized mining can be experienced as a symphony by substituting the instruments for the different machines that each perform their own function and thus have different sounds. The drill-rig is the soloist around which all the other machines must play their part in harmony. Each machine can function on its own, but productivity is achieved only when all of the machines function in a holistic manner, as the different sounds of instruments form a symphony when playing together. To produce a symphony is to have the ability to put together all the pieces. It is the capacity to synthesize rather than to analyse. Today?s managers have to apply this harmonic way of thinking to make the system of mechanized mining work. In other words each of these people must have the ability of a conductor, whose job involves corralling a diverse group of notes, instruments and performers, and producing a unified and pleasing sound. At Modikwa Mine the introduction of the MAPS (Mine Activity Performance System) has allowed management to obtain a clear view of all the activities associated with the equipment. Through synthesis the issues that hampered productivity were identified and addressed to improve production and reduce costs.

Jan 1, 2006

By C. C. Anderson

"While conducting investigations in connection with the helium program of the Bureau of Mines, the Cryogenic Laboratory has improved an apparatus for the rapid and accurate determination of the helium content of natural gas and gaseous mixtures derived from that source. The separation of helium is effected by the use of activated coconut charcoal which, when cooled to liquid-air temperatures, absorbs the nitrogen and other constituents of the gas, leaving the helium in a. spectroscopically pure state. This absorptive property of activated charcoal was discovered- by Dewar3/ in 1875. Several years later, while conducting their original researches on helium in natural gas, Cady and McFarland employed the charcoal method for the absorption and removal of the common constituents of natural gas and constructed an efficient apparatus in which this operation could be effected.4/ Shortly after initiating the government's helium activities during the World War period, the Bureau of Mines adopted, with Minor modifications, the Cady and McFarland apparatus and method of analysis. Seibel.5./ described this modified apparatus and method of procedure as part of a publication on helium-bearing natural gas. Subsequently, the Bureau's apparatus for helium analysis has been simplified and improved to facilitate more rapid and positive operation. The apparatus and method of procedure now being used by the Bureau of Mines Cryogenic Laboratory arc described in this paper.The personnel of the Bureau of Mines Cryogenic Laboratory has improved and brought the helium apparatus described herein to its present state of perfection. The writer's contributions have been-of minor importance, and he wishes to give the various members and former members of the laboratory staff full credit for the improvements they have made. He also desires to express his appreciation for suggestions and criticisms offered during the preparation of this paper to the following members of the Petroleum and Natural Gas Division, Bureau of Mines, which now includes the Amarillo Helium Plant and Cryogenic Laboratory: H. A. Cattell, chief engineer; C. W. Seibel, supervising engineer of the Amarillo Helium Plant; W. M. Deaton, chemist-in-charge of the Cryogenic Laboratory; and H. S. Kennedy.The quantitative determination of helium in a gaseous mixture is accomplished by the removal of the other constituents from the sample, either by chemical or physical Means, leaving only the helium which can be measured directly. Chemical methods, when applied to natural gas, require the burning of the hydrocarbons in oxygen, the, absorption of the resulting carbon dioxide in a caustic solution, the removal of the excess oxygen in a suitable solution such as an alkaline pyrogallate, and the elimination of nitrogen by sparking or by combination with hot calcium or magnesium.. Such procedures are very slow and tedious compared with the physical method which employs the absorptive property of activated charcoal to effect the separation of the other constituents from the helium."

Jun 1, 1934

By Wilbert J. Huff

The work of the Explosives Division, Bureau of Mines, United States Department of the Interior, for the fiscal year ended June 30, 1939, is described in the following pages. This paper is the fourth of a series of annual reports covering the activities of the division since July 1, 1936. The studies outlined in this and preceding reports of the series have been conducted under the direction of the author and the respective unit leaders to whom specific credit is indicated.

Jan 1, 1940

By J. L. Konchesky

The technical feasibility of gasifying powdered, noncoking, low-rank coal with steam in an externally heated tube has been demonstrated. The tube, 112 ft. of alloy-steel tubing shaped into a helix, served as an electrical conductor of electricity used for heating. The effects of the following variables were studied: Residence time of coal in reactor, average reaction temperature, steam concentration, and rank or geologic age of coal. Reaction pressure was maintained in the range 19-26 p.s.i.a. High carbon conversions and large yields of synthesis gas were obtained with low-rank coal. In one test, for example, about 88 pct. of the carbon in a subbituminous C coal was gasified at 1,910* F. with a residence time of 1 sec. The gas contained 58 pct. H2, 19 COD 15 CO, and 3 CH4; the yield was 30 cu. ft. (at 32' F. and 14.7 p.s.i.) of synthesis gas (CO + H2) per pound of dry coal.

Jan 1, 1960

By Robinson Reis Miranda

Este trabalho discute o desenvolvimento de massas de tamponamento de furos de corrida de fornos de redução: altos-fornos, fornos de ferros-ligas, cubilôs, entre outros, a partir de resíduos de chamote, materiais refratários, alumina e piche de alcatrão, subproduto da coqueria, utilizado como aglomerante. Foram investigadas as condições de plasticidade, resistência, usinabilidade, moldabilidade e poder de adesão. Os resultados obtidos mostram a possibilidade de emprego industrial destas massas de tamponamento.

Aug 7, 2018

By Jose R. Hernandez-Aguilar, Chris J. Martin, Rob Thorpe

"This study presents an approach to establishing relationships between metallurgical performance and the characteristics of the bubble population (gas dispersion) inside flotation cells. Bubble size Db, superficial gas velocity Jg, and bubble surface area flux Sb (Sb = 6Jg/Db) measurements were obtained along with metallurgical samples in full-size equipment processing different ore types. The gas dispersion was manipulated by changing the operating conditions of the cells (gas flowrate and frother type) and the metallurgical performance (grade-recovery) was determined. In two cases, the Sb had a strong relationship with grade and recovery, hence, Sb could be used as practical operating parameter. In another case, Sb did not correlate with recovery. The reasons were attributed to creating small bubbles using frothers with desired anti-coalescence properties. This illustrated that bubble size was the key parameter for metallurgy rather than Sb.INTRODUCTIONUnravelling the mechanisms that govern the relationships between metallurgical performance and the characteristics of the bubble population (gas dispersion) inside a flotation cell remains a major challenge. Information on this subject is scarce in the literature, particularly, plant-scale data. The report of Jameson and Allum (1984) appears to be the first gas dispersion study conducted in industrial (mechanical) cells. To introduce concepts, some aspects of their work are reviewed here.The prime motivation of that study was to establish whether any particular cell design (among 44 cells surveyed) could produce very small bubbles (< 0.1 mm), which laboratory research suggested would increase the recovery of fine particles. Although one of the outcomes was that the (examined) cells did not seem to produce such small bubbles (Sauter mean1 D32 ˜ 0.9 mm), the analysis highlighted the importance of including other factors. Jameson and Allum indicated that, besides bubble size (Db), other characteristics of the bubble dispersion should be considered, namely: gas holdup ?g – the fraction of cell volume occupied by bubbles, superficial gas velocity Jg – is the gas flowrate divided by the cross-sectional area of the cell and, bubble surface area flux Sb – the rate of production of (new) bubble surface area (m2/s) per m2 of cell cross-sectional area. It should be noted that, whereas Jg, ?g and Db can be measured directly, the Sb is derived: Sb = 6Jg/Db, where Db is usually substituted by the Sauter mean diameter (D32)."

Jan 1, 2006

? CONSTRUCTION AND MINING COSTS ARE HIGH IN THE ARCTIC ? VERTICAL KIMBERLITE PIPES WITH HIGH STRIP RATIOS ? SITE SPECIFIC GEOMETRIC CONSTRAINTS ? OPEN PIT FOLLOWED BY UNDERGROUND MINING ? HIGH KIMBERLITE UNIT COSTS TRACK INSTALLED ON PIT WALL ? INTENDED TO REPLACE MAIN HAUL RAMP ? 5 MIN HOIST CYCLE TIME ? KEY ADVANTAGES - REDUCED CYCLE AND STRIPPING RATIO ? TECHNOLOGY EXISTS IN OTHER APPLICATIONS

May 1, 2003

By R. E. Wilmot

This paper is based on the experiences, over many years, of numerous authors in the South African mining industry and of the hot dip galvanizing process and its application as a corrosion protection system. The paper sets out the extensive development, financial resources and stringent operating requirements of the South African mining industry. After many years of research and operational experiences, hot dip galvanizing and, when necessary, duplex systems, have been found to meet the demanding requirements of this particular industry. The paper sets out the requirements from the standpoint of corrosion criteria and is followed with a case where the corrosion protection properties of hot dip galvanizing are demonstrated. This case history traces the early investigation of the expected corrosive conditions in a new mining operation and concludes with two follow-up visits to the mine in order to examine actual performance of the corrosion protection system after ten years in service.

Jan 1, 2007

Hot briquetting is a reliable, fully developed industrial concept for the passivation of direct reduced iron produced with the various processes of direct reduction. During hot briquetting, the large specific surface area of direct reduced iron is drastically reduced, and therefore the well-known problems caused by reoxidation and overheating are avoided. Even the shipping instructions published by the International Maritime Organisation (IMO) confirm that Hot Briquetted Iron (HBI) can be handled and shipped without special precautions. From the mid-1970s until today, after extensive pilot testing of the technology, a number of industrial plants for the hot briquetting of direct reduced iron have gone into operation. Additional hot briquetting plants for already established but also for new direct reduction processes are tinder construction or in different stages of planning. This paper describes the characteristics of HBI and its current industrial application for various Direct Reduction Processes.

Jan 1, 1999

By Hongfei Li, JianLong Wang

This paper introduces the technical characteristics, transformation scheme and production practice of the project in which Copper P-S Converter was replaced by Bottom Blowing Continuous converting for the first time, and introduces the technical achievements obtained by the project. The application practice proves that bottom blowing copper continuous converting technology can completely solve the problems of fugitive off-gas pollution in the ladle transportation, large amount of flue gas and fluctuation of flue gas caused by P-S converting. Comprehensive energy consumption and operating costs of producing blister copper, safety and environmental risks are greatly reduced, and economic, environmental and social benefits are significant. It is one of the preferred technologies for upgrade and to replace P-S converting technology. INTRODUCTION At present, more than 80% of copper production capacity is still using the P-S converting technology with a history of more than 100 years. During P-S converting process, melted copper matte needs to be transported by ladle, and it needs to rotate the furnace body several times, causing a lot of serious environmental and safety risks such as SO2 flue gas emission and low-altitude SO2 pollution. In addition, the high operating cost caused by low rate of air blowing, the short life of the refractory materials and high energy consumption during P-S converting become big problems. Other problems such as large amount of flue gas, low SO2 concentration, large fluctuation of flue gas volume and SO2 concentration, and discontinuous flue gas cause high cost of subsequent flue gas treatment are also needing to be solved. In order to solve these problems during the P-S converting, metallurgical engineer in various countries has spared a lot of efforts to develop continuous blowing process for decades. The continuous converting that have been industrially applied are flash continuous converting, Mitsubishi continuous converting, Noranda continuous converting, Bottom Blowing Continuous converting and multi-lance top blowing continuous converting

Jan 1, 2019

The Federal Coal Mine Health and Safety Act of 1969 requires that each operator of a coal mine shall take accurate samples of the amount of respirable dust in the mine atmosphere to which each miner is exposed, a measure designed to prevent the development of coal workers&apos; pneumoconiosis. This textbook manual is used in the training of personnel to operate respirable dust sampling devices and to conduct sampling programs. It contains the portions of the act applicable to respirable dust standards, the procedures to be followed to insure compliance with Federal regulations, and descriptions of sampling devices.

Jan 1, 1971

By G. R. Hopkins

For several years prior to about the middle of 1928 both the number and capacity of natural-gasoline plants showed a steady increase; this resulted from a material gain in the supply of casinghead has due to the discovery of a number of flush fields with relatively high gas-oil ratios. From 1928 to date some form of proration has been continually in force, with a consequent curtailment in the supply of wet gas. This decline in available gas and a severe decrease in prices, due largely to the increasing competition of light refinery products, has eliminated virtually all of the weaker units during the last 5 years, with the result that the number of plants declined from 1,155 on January 1, 1928 to 19035 on January 1, 1930, to 909 on January 1, 1932, and then to 859 on January 1, 1934, The struggle of the small high-cost producers to exist is illustrated further by the trend in the number of shut-down plants, which has increased from 36 on January 1, 1930 to 100 on January 1, 1932 and to 128 on January 1, 1934. The increase in the number of plants prior to 1929 resulted in a material gain in the total capacity, but the decline in number between 1929 and 1932 was not followed by a corresponding decrease in capacity, as gains resulting from the construction of a few very large plants overbalanced the loss due to the dismantling of a large number of small ones. However, the low prices of 1932 and 1933 supplied little incentive for new construction, and the total capacity declined in approximately the same ratio as the number. Thus the total capacity declined from 11,387,000 gallons daily on January 1, 1932 to 13,060,000 gallons daily on January 1, 1934, Of the latter 9,181,000 gallons (91 percent) represented the capacity of the operating plants and 679,000 gallons (9 percent) the capacity of the idle plants.

Jan 1, 1934