Search Documents

By N. L. Richards

In manufacturing for the 21st century, the first company to market often leads the pack in product development and sales. In this respect, manufacturing processes play an important role in transforming “raw materials” into a product(s) for sale to a customer. Thus it can be seen that upfront modelling of a design concept, or modelling of manufacturing processes in a plant, can play an important role in effectively ensuring the overall design and manufacturing route is carried out in an expeditious manner. In the paper various scenarios are considered with respect to modelling the microstructure and/or process, in various manufacturing processes. Also considered are the effects of service condition on the manufactured product in terms of creep and fatigue.

Jan 1, 2010

By Robert W. Metcalf

The feldspars are a series of related aluminum silicates containing varying proportions of potash, soda, rind lime; smaller amounts of other minerals arc likely to be present as impurities. They comprise three principal types: Potash spars, microline and orthoclase (KA12Si208); soda feldspar or albite (NaA1Si308); and soda-lime e (plagioclase) fellspars. The last-named is an intermediate group ranging from albite through oligoclase, andesine, labradorite, and bytownite to anorthite or line feldspar (CnA12Si2O8), Minor varieties are barium feldspar or celsian and a potash-barium feldspar. Perthite is a mixture of orthoclase end albite in alternate layers. Graphic granite or "corduroy spar" is an intergrowth of feldspar and quartz characteristically in the ratio of 3:1. Cornwall stone is a natural mixture of feldspar, quartz, end kaolinite imported in former years in sizable quantity from Cornwall, England. (A similar synthetic mixture, including some fluorspar, has been blended and marketed in the United States as "Carolina stone".)

Jan 1, 1941

By T. K. Bose

According to the Intergovernmental Panel on Climate Change (IPCC), the average global temperature has risen over the last century. If this trend continues over the next century, the IPCC projects a significant increase in temperature and a rise in sea level. The changes in climate could adversely impact human health, agriculture, water resources and ecosystems. Most national and international agencies have concluded that our use of carbon-rich fuel is responsible for global warming through the greenhouse effect. In the future, the situation may get worse if the increased need for energy in countries like China, India and Brazil is fulfilled by burning fossil fuel. Advanced natural gas-fuelled vehicles have the potential to reduce carbon monoxide and reactive hydrocarbon emissions substantially compared to gasoline vehicles. Further environmental benefits can be realized by using a blend of natural gas and hydrogen. Such an approach will help create an infrastructure for an eventual transition to hydrogen.

Jan 1, 2005

By Timothy J. Rohrbacher

This report presents a U.S. Bureau of Mines study that incorporates coal mining factors, coal recovery factors, and economic factors into the definition of an economically recoverable coal resource. The relationship between these factors to the Energy Information Administration's estimate of U.S. coal resources-the "Demonstrated Reserve Base"-is discussed. The Boltsfork 7 1/2-minute quadrangle in eastern Kentucky was selected as the study area. Results indicate that of the original 280.2 M tons of resource in the quadrangle, only 99.8 M tons (35.6%) is recoverable at a mining cost of $25 per ton or less.

Jan 1, 1994

By J Samosir, L A. Snyman

Northparkes is located 27 km north of the township of Parkes in central New South Wales, Australia. The operations consist of underground block cave mines and an ore processing plant that produces high-grade copper and gold concentrate. Production is currently sourced from the E48 Lift 1 block cave mine and open cut stockpiles. Mining commenced at Northparkes in 1994 as an open cut operation. Underground block cave mining began in 1997. Northparkes was the first mine in Australia to use the highly efficient block cave mining method, which relies on gravity and natural rock stresses to fragment the ore.An issue affecting production in 2011 was the stability of the E48 mine. A small portion of the drives on the extraction level began to deteriorate as the ground support system failed. The problem was temporarily fixed by stopping production in three extraction drives and tight filling selected areas within these drives (and drawpoints) with low-strength concrete. This action provided immediate support and stability whilst allowing time to investigate potential ground support remedies. From these investigations it was decided to use resin injection technology and additional ground support to stabilise the rock in the aforementioned extraction drives as the concrete plug was excavated in a controlled advance and sequence. This made the area safe and ensured the ongoing safe operation of the E48 mine. The redevelopment of one of these drives began late in 2011, with the remainder being progressively redeveloped over the next two years in order to maintain the extraction level stability.This paper looks at the strategies employed to safely re-open previously converged drawpoints and associated extraction drives that were subject to high abutment loading that was possibly associated with premature cave breakthrough.CITATION:Samosir, J and Snyman, L A, 2014. Redevelopment at Northparkes following significant drive closure, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 87–92 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By Michael A. Trevits

During the time period from 1990-2007, there were 1601 reportable fires that occurred in the U.S. mining industry (an average of 89 fires per year). The leading causes of U.S. mine fires include flame cutting and welding operations, frictional heating and ignitions, electrical shorts, mobile equipment malfunctions, and spontaneous combustion. The National Institute for Occupational Safety and Health (NIOSH) is conducting a program of research addressing metal/nonmetal and coal mine fire prevention, detection, management and suppression. In the metal/nonmetal area, work was focused on technology transfer and training, and research to reduce the number of mobile equipment fires and their hazards. In the coal arena, research is underway to determine the root cause of cutting and welding-related fires and to evaluate the effects of ventilation schemes relative to the spontaneous combustion risk in longwall mines. Relative to fire management, research is ongoing on remote mine seal installation and remote mine fire suppression technologies. Finally, research is continuing to develop comprehensive and usable smoke management techniques and to develop mine fire growth models, propagation, and suppression. This paper presents a summary of some of the mine fire research and provides an overview of the next phase of the NIOSH mine fire research program.

Jan 1, 2010

By Michael J. Klishis

It was the goal of this project to develop training materials specific to two areas of the mining industry: (1) safe use and care of the self-contained self-rescuers, and (2) awareness and avoidance of electrical hazards. This report describes the development of the following training material: Instructor's modules for the OCENCO EBA 6.5, CSE AU-9A1, and PASS 700E self-contained self-rescuers; and a textbook, slide tapes, and accident case study scenarios for mine electricity, and a computer based instructional package on mine electricity and electrical hazards. The report concludes that additional efforts are needed in mine training and four recommendations are made: (a) tailor existing materials to fit specific mine sites, (b) develop and evaluate computer based instructional material, (c) develop parallel training materials for metal and non-metal mines and, (d) develop additional training materials for preparation plants and surface areas of underground mines.

Jan 1, 1985

By Marcel0 Mondring

Transportation and the logistic requirements are set very high for the German coal mining industry. Short transportation resources, crowded quarters, and long transportation distances to destinations are some basic conditions that logistic employees of the mines have to deal with. Therefore, in the context of these processes, human effort and technology are faced with great challenges. There can be a total of 300 transport units, depending on the size of the mine. Every day, they are moved through a nearby 150-km-long transportation network of floor and monorail tracks. Of these transport units, 150 are new, and the other 150 units are split into cross traffic units that are moved only in the underground and return travel units. Beside track-bounded transports, all material transports take place in the shaft. As a result, many involuntary transports and changes in the means of transportation make the daily work more difficult. Typical transports in the shaft include the supply of new materials from above to below, as well as returnable goods from below to above. Cross traffics throughout several levels, which are rather rare, would have to be handled above the shaft. Due to limited shaft capacity, these cross traffics should be avoided when possible. Based on the gas resources in coalmine slopes, track-bounded transports using monorails (powered by diesel or rechargeable means) are preferred. This depends on the road degree, the depth, and track cross section of the shaft/slope. The variety of the material spectrum includes more than 100,000 different types of material.

Jan 1, 2014

By Dave J. Porter

Si bien, los proyectos son el camino para que una organización minera cumpla con su estrategia, la gran mayoría de su historial de cumplimientos son un fracaso puesto que el impacto del proyecto no es tan rico en sus etapas y las organizaciones mineras no pueden cumplir con su visión y estrategía. En ese sentido, el presente texto señala la importancia de una adecuada gestión de proyectos para que la organización minera cumpla con su estrategia. Así, la madurez de la gestión de proyectos es un indicador de éxito continuo y requiere de visión, compromiso en las etapas iniciales, ya que sus ganancias son difíciles de cuantificar.

Apr 1, 2012

By S. H. Ash

THIS REPORT covers the third in a series of five projects into which the Conowingo tunnel system has been divided for geographical and practical reasons. It outlines the work constituting Project No.3 that consists principally of the following: (a) To sink the No. 15 shaft and extend the Alden, Sugar Notch, Baltimore No.2, and Laflin shafts from their present depths to tunnel level; (b) to drive a tunnel off these shafts to connect with the western end of the tunnel in Project No.1 (Lackawanna) and to a point 1 mile south of the No. 15 shaft; (c) to construct an emergency pumping plant at the No. 15 shaft, complete with 3 centrifugal pumps of 200-cubic-foot-per-second (c. f. s.) capacity each, and a discharge-water shaft and a discharge tunnel for conducting the water from the pumping plant into the Susquehanna River; and (d) to construct a lateral tunnel 1 mile long off the main tunnel in the vicinity of the No. 15 shaft, to be known as the Wyoming lateral. The project, as outlined, is a self-contained drainage unit that will permit unwatering inundated mines and safeguarding active mines in the Wyoming Basin of the Northern field and also will handle the water in the Lackawanna Basin, thus permitting the temporary pumping plant provided in Project No.1 to be discontinued. The pumps installed in the temporary pumping plant provided in Project No.1 can then be moved to the emergency pumping plants recommended in Projects Nos. 2 and 3, to be installed as the third or standby unit.

Jan 1, 1955

By Arthur Notman

THE raw material men in all industries, and copper is no exception, are accustomed to think of them- selves as the whole show, and not without justice, for if there were no copper mines the world would have no copper. Nevertheless, many different things costing money and resulting in profits must be done to their product before it is ready for the world's use. In other words, they are making the frequent mistake of Chinking in terms of partial costs. Nobody really uses electrolytic copper. Possibly that is why nobody seems willing to pay anything for it. The manufacturers, being canny, do not buy any more electrolytic than they feel that they can work up and sell profitably, although they like to make the raw material men Chink that they will take all that can be produced. This is a state of affairs that has aroused my sympathy and curiosity, and has induced me to study the financial history of the copper wire and brass industry of the country or such portion of it as publishes any records readily available to the curious minded. About 60 per cent of the electrolytic copper used in this country is drawn into wire and consumed by the electrical industries. The remaining 40 per cent is

Jan 1, 1926

By Stephen van Duin

As productivity in coal extraction demands increase in underground coal mines, the industry is faced with finding new ways to support production without jeopardising safety. In modern mines the capacity and scale of longwall coal extraction has steadily increased to a point that support processes are failing to keep pace. In particular, roadway development is continually placed on the critical path of activities which maintain mine production, so any inefficiency in this area is quickly exposed. Original equipment manufacturers are under immense pressure to modify their machines to be more interconnected with each other, with machine communication and logistical sharing of space becoming a known requirement. This paper looks at the changing trends in mining practice, analysing available technology as well as currently emerging research into hard automation and discusses the need to integrate machinery and processes in order to see increases in productivity and safety.

Aug 1, 2013

By Shenghua Yin, Xun Chen, Rongfu Yan, Zepeng Yan, Wei Chen

The application of cemented paste backfill (CPB) with alkali-activated slag and phosphogypsum (ASP) can contribute to the sustainable development of the mining industry. The effects of PG content, NaOH content, solid content, and waste rock-rod milling sand (W/R) ratio on workability, unconfined compressive strength (UCS), and setting time of ASP-CPB were investigated in this paper. The results showed that the workability of ASP-CPB decreased with PG content and NaOH content. Compared to OPC-CPB, ASP-CPB exhibited better workability and higher long-term (7 days and 28 days) strength at predetermined backfill formulations and curing times. The mid-term strength of ASP-CPB first increased and then decreased with PG content, while the short-term strength (3 days) decreased gradually due to the influence of soluble acidic impurities. Excessive NaOH will harm the strength of ASP-CPB, possibly due to the swelling effect of the reaction products (ettringite and sulfate). Strength and setting time increased and decreased with solid contents, respectively. Moreover, the compactness of the mixture has an important effect on strength and workability. The workability and strength of ASP-CPB reached the minimum and maximum values at a W/R ratio of 5:5, respectively. Pollutant index detection indicated that most of the pollutants in ASP-CPB leachate met the discharge standard, which proved that ASP-CPB is an effective method to recover PG. The results of the research will provide theoretical guidance for the efficient recovery of PG resources and support the achievement of safe, clean, and efficient mining.

Nov 17, 2023

By D. W. Euler, D. G. Brophey

"In an attempt to address the issue of rising labour costs, and to improve productivity, a laser-based system to guide underground LHDs and trucks has been developed. This comprehensive system is known as the Opti-Trak system.Essentially, the vehicle is equipped with front and rear-mounted lasers which scan a reference strip mounted on the drift back. The vehicle follows this reference strip and in addition, based on reflective bar codes mounted beside the reference strip, initiates certain functions (i.e. dump cycle, speed change, brake check, etc.). Any programming that is drift-specific is handled by the positioning of the reference strips and bar codes. Consequently, the vehicle can easily travel to many different haulageways or branches, providing the reference strip and bar codes are in place.The advantages of this system are an immediate elimination of haulage operator costs and an increase in available hauling time to 7 hours out of an 8-hour shift as compared to the typical 5Y2 out of 8 hours that a manned haulage system offers.This paper describes the Opti-Trak system and the benefits to be realized from automation of mine haulage requirements."

Jan 1, 1994

By George S. Koch

We evaluate the exploration effort by diamond drilling for zinc in central Tennessee and southern Kentucky through a statistical analysis comparing the Middle Tennessee district with the older Tri-State and Upper Mississippi Valley districts. All of the ore deposits are of the Mississippi Valley type and are similar geologically. Through statistical analyses we attempt to answer these questions: Had the drilling density in the Middle Tennessee district been applied to the Tri-State district, how much of the ore in the Tri-State would have been discovered? Had this drilling been done in the Upper Mississippi Valley district, how much of the ore in that district would have been found? Which of these two older districts does Middle Tennessee more closely resemble in intensity of zinc mineralization? Is more drilling warranted in the Middle Tennessee district? Our data base includes tonnage and area distributions of ore deposits in the Tri-State dis¬trict, sizes of ore bodies and probabilities of their recognition in the three districts, and data for the Elmwood mine in the Middle Tennessee district. Our statistical analysis considers the consequences of drilling holes in the three districts on square grids at coarse, intermediate, and fine spacings. We conclude that the drilling pattern assumed for Middle Tennessee would have found some but not all of the ore in the two older districts. We believe that in intensity of mineralization Middle Tennessee more closely resembles the Tri-State than the Upper Mississippi Valley district, and that more drilling is warranted in the Middle Tennessee district.

Jan 1, 1979

By J. Hunter

The Highland Uranium Project in Wyoming is an in-situ leach (ISL) facility owned and operated by Power Resources Inc. It is the largest uranium producer in the U.S. and the largest uranium producer by ISL in the western world. With its limited capital investment and low operating costs, the ISL technique has been demonstrated to be an effective and environmentally sensitive method for recovering minerals from these low grade and otherwise uneconomic orebodies.

Jan 1, 1996

By Millard M. Gilkey

This Bureau of Mines report presents results of a detailed study of water usage in the Wyoming mineral industry along with projections for the future In 1964, the mineral industries of Wyoming used 20 billion gallons of new water, nearly all self-supplied, and reused 72 billion gallons, a total usage of 92 billion gallons. Consumption amounted to 2.8 billion gallons. About one-half of the 20 billion gallons of new water was obtained from [srface] sources and the rest from ground water. Reported costs, covering power and maintenance, for the self-supplied new water at mineral industry operations ranged from less than 1 cent to 20 cents per thousand gallons and aver-aged 8 cents. At one mineral-related operation, water was hauled by truck to supplement a well supply. The cost was $2.00 per thousand gallons delivered. However, the supplemental requirement was only 10 gpm. Cost figures for the recirculation of water, covering power and maintenance, averaged 2 cents. In terms of water usage, the value of product for the entire industry was $25 per thousand gallons of new water intake and about $180 per thousand gallons consumed. The study revealed that Wyoming has a water deficiency but that the shortage is less severe than in the arid Southwest. Projection of the water needs of the Wyoming mineral industries indicates that the demand for new water will increase from the 20 billion gallons used in 1964 to 25 billion gallons in 1980, a 25-percent increase. The projected new-water requirement for the year 2000 is 40 billion gallons, a 100-percent increase compared with the 1964 figure.

Jan 1, 1967

By C. H. Lieb

ONE astounding fact in the production of petroleum is the comparatively recent realization by producers that flowing production is the cheapest crude produced. About 1910 or even later, operators actually endeavored to get a producing well to pumping as quickly as possible after completion. A well was not really considered to be completed until it was operating on the pump. Remarkable progress has been made since then. It was not until about 1920 that producers began to take a serious interest in pressures and to think a little about proper methods of handling oil wells. Pressure gauges were installed, and records of pressures maintained, which was quite an innovation. Desultory experiments were made with tubing of different sizes, as well as experiments with placing the bottom of the tubing string at different levels in the well. Probably the first important departure from customary procedure was about 1926, during the Seminole development, when gas lift

Jan 1, 1936

By J. Dubinski

Underground mining of copper ore in the Legnicko-Glogowski Copper District basin generates a number of seismic events, whose energy often exceeds 108 J (Butra, 2010). The number of tremors and their location shows that the area of rock mass involved in the deformation and failure processes significantly exceeds the area of mining operations. Locations of seismic foci of high energy tremors, as well as the aftershocks that accompany them, extend hundreds of metres, confirming that processes to restore the energy balance of rock mass occur in a short amount of time and over a wide area. Thus, an area of similar size should be considered in predictive analyses of the tremor?s position. It should be emphasized that a large portion of the rock mass still has a level of freedom resulting from the way the rock mass is held together and its geometric continuity. This level of freedom is dependent on the scale and duration of mining, the number and size of natural structures, and rock mass pressure, including gravitational pressure constricting individual fragments of rock mass in the area (Burtan, 2012). It can therefore be assumed that in real conditions, areas where mechanical strength of the layers has been exceeded may be located a considerable distance from each other and do not necessarily need to coincide with the working area location. In this sense, a rock mass influenced by mining exploitation is essentially a rock mass in which numerous fragments with concentrated energy exist simultaneously. Energy will be released within these rock mass areas each time rock mass strengths are exceeded by the induced stress changes related to mining operations. This paper presents a discussion on how to predict the location of seismic activity areas based on a change of position of seismic energy equivalents. This parameter is calculated for a given set of seismic tremors with defined foci coordinates. For a given set of seismic tremors, the location of seismic energy equivalents may be used for predicting the location of high-energy seismic events.

Aug 1, 2013

By R. V. Ramani

This report is volume 1 of an eleven-volume final report for a Grant completed by The Pennsylvania State University for the Bureau of Mines to develop a dynamic general purpose computer simulation model for underground coal mining. The simulator developed under the Grant has a wide range of possible applications in the design and evaluation of underground coal mining systems from the standpoints of health and safety, productivity, and mine environment. The Master Design Simulator consists of nine free-standing function-oriented subsystem models linked together into an integrated, comprehensive model of an entire mining system. The subsystems comprising the Master Design Simulator include geology and reserves, methane generation, roof support, subsidence, production, rail haulage, cost, water generation, and ventilation. This volume of the final report contains a statement of the purpose and scope of work of the Grant, and provides an overview of the Master Design Simulator with a brief description of each subsystem. Also included is a discussion of several areas of application for the simulator.

Jan 1, 1975