Search Documents

By D. Harrington

"Coal—mine explosions are accidents that can and should be prevented. In former years hundreds of lives were lost each year in the United States as a result of such explosions, but after 1932 the numerous precautionary measures adopted had reduced their frequency and severity 75 percent or more until in 1940 several very disastrous explosions marred the good record. Unfortunately, both the number and severity of explosions seem to be tending to increase compared with the relatively good achievement from 1933 to 1940. The requisites for an explosion are ever present in all soft-coal and many hard-coal mines. A certain combination of circumstances, such as a flame or an arc in a cloud of dust or in a body of gas or both may start an explosion at any time. The fact that the frequency and severity of explosions were lowered for 6 or 7 years is no guarantee that such freedom from explosions will continue, as the bad record of 1940 has shown, and underground workers should feel honor bound to exercise the utmost care so that they will not help to bring about the circumstances that will cause an explosion.Although mine operators bear the main responsibility for preventing explosions, miners can do many things to help. As about 9 out of 10 explosions begin at a working face, it is largely within the power of workers to prevent them. All miners should do their part willingly and should not defend a fellow workman from punishment, even from discharge, for disobeying necessary rules, whose disregard may cause the death not only of the safety-rule breaker but also of many of his coworkers.When a miner is careless and is injured some other way than by an explosion he may be the only one to suffer, but if his carelessness causes an explosion he not only endangers his own life but also that of every other man in the mine and possibly the lives of persons outside the mine.Experiments have shown that ignition of as small a quantity as 150 cubic feet of an explosive mixture of methane and air under certain circumstances can start an explosion that will traverse an entire mine. Thus, ignition of an explosive mixture of gas 1 foot down from the roof and 13 feet back from the face of a 12-foot entry might cause a widespread explosion if the right quantity and kind of dust were present. Many persons have ignited much larger quantities of gas without being killed, but they survived only because dust, confinement, and other conditions were not exactly ""right."""

Nov 1, 1940

By Larry Meinert

Most large skarn deposits are zoned in both space and time relative to associated intrusions, and this zonation can be used to guide exploration. Zonation occurs on scales from km to, and reflects infiltrative fluid flow, wallrock reaction, temperature variations, and fluid mixing. In most skarn systems, there is a general zonation pattern of proximal garnet, distal pyroxene, and vesuvianite (or a pyroxenoid such as wollastonite, bustamite, or rhodonite) at the marble front. In addition, individual skarn minerals may display systematic color or compositional variations within the larger zonation pattern. Such patterns are reviewed for several well-studied examples of Cu, W, Au, and Zn-Pb-Ag skarns. In addition, many deposits have endoskarn or other alteration of the associated intrusion and recrystallization or other subtle changes in the surrounding wallrocks.

Apr 24, 2001

By David Van Horsen

Operation and maintenance of California?s water tunnels is an important factor and vital link in California?s infrastructure. These tunnels are owned and operated by a variety of large and small private and public water and power utility companies, municipal agencies, and irrigation districts. Visionary pioneers such as Michael O?Shaughnessy (San Francisco Hetch Hetchy Water Supply System), William Mulholland (Los Angeles Department of Water and Power and Metropolitan Water District of Southern California?s Colorado River Aqueduct), and John Eastwood (Southern California Edison Big Creek Hydroelectric Project) built large and small water supply, irrigation and hydroelectric tunnels, which have supplied environmentally friendly-water supply, renewable electricity, and uninterrupted service to a burgeoning population and economy. This paper introduces these pioneers and describes several case histories and lessons learned during condition assessment and rehabilitation of tunnels providing enlightenment of California?s vital water projects.

Jan 1, 2008

By Steve Kral

The Prospectors and Developers Association of Canada (PDAC) was established in 1932 in response to proposed regulations that would have threatened prospectors in Ontario. From there, the association grew to represent the interests of Canada?s mineral exploration and development industry. The PDAC?s mission statement reads: ?The PDAC exists to protect and promote the interests of the Canadian mineral exploration sector and to ensure a robust mining industry in Canada. The PDAC will encourage the highest standards of technical, environment, safety and social practices in Canada and internationally. ?Today, the PDAC?s 6,000 individual members include prospectors, developers, geoscientists, consultants, mining executives and students. In addition, the association?s membership includes 950 corporate members, representing senior, mid-sized and junior mining companies in addition to organizations that provide services and equipment to the mining industry. In 2010, the PDAC adopted its e3 Plus principles, a framework to guide its membership in responsible exploration.

Jan 1, 2011

By Víctor Cabrera

El objetivo de la ingeniería y construcción es preparar productos comerciales, tales como metales y concentrados, en base de la explotación minera para su posterior despacho y embarque al mercado comprador. Es decir, el proyecto minero es el puente entre la explotación minera y el mercado. En ese sentido, el presente texto señala las claves para la ejecución de un proyecto minero que va desde un inicio hasta su desarrollo. Así también debe cumplirse las metas del propuesto, calidad técnica y programación del proyecto.

Aug 25, 2002

By E. A. Metz

Ergonomics is the art and science that tries to understand the complex interrelationships among employees, their work environment, equipment, work methods and job demands. Coal and metal/nonmetal miners are exposed to a higher number of ergonomic risk factors than in non-mining occupations. In addition, studies have shown that these miners experience more degenerative disc disease and osteoarthritis than comparable industrial populations. A general discussion of the risk factors that cause overexertion injuries and disorders will be presented. In addition, the basic principles of ergonomics will be discussed with specific cases to show how successful programs have been developed. A successful ergonomics program should simultaneously improve health and enhance productivity.

Jan 1, 2002

By Iván Calmell del Solar Salas

Desde el año 2014, se ejecutaron pruebas piloto en zonas en condición de cierre progresivo dentro de la Unidad Minera Constancia, propiedad de Hudbay Perú S.A.C. El objetivo de estas pruebas fue lograr cierres sostenibles en base a metodologías no convencionales y al uso de conocimiento ancestral local. Para la revegetación de estas áreas hemos sustituido la práctica común de siembra de pastos exóticos de rápido crecimiento, por el uso de recursos fitogenéticos nativos con el fin de proveer a las áreas intervenidas de una cobertura vegetal idónea con el propósito de que sea la base para la rehabilitación y mejora de la Biodiversidad

Sep 1, 2017

Good morning ladies and gentlemen, and may I extend a particularly warm welcome to our shores to those of you who have travelled from overseas to attend this conference. I trust that you will find your visit to New Zealand both rewarding and enjoyable.   This is now my fourth appearance at a New Zealand minerals conference, the second of which has been jointly co-hosted by AusIMM and Crown Minerals. Since taking on the role of Associate Minister of Energy, I have had the opportunity to meet most of the industry players, and to visit a good number of the major mining operations. Through all of this I have become increasingly aware of not only how dynamic the minerals and coal industry is but also the array of factors that affect investment decisions in this business. Many of these factors, such as commodity prices and availability of investment funds, are determined primarily on the international stage. Others however, such as the allocation, regulatory and the fiscal regimes for minerals, are closer to home and are directly influenced by government policy decisions. I will talk more on what the government proposes in this area shortly.   But first, I would like to commend you all on your industryÆs continuing contribution to New Zealand Æs economy. 2004 has seen New Zealand Æs mineral and coal output top $1 billion for the second consecutive year. To put this achievement in perspective, it represents a staggering 47 per cent increase over the national output value recorded just five years ago. Notable contributions over the year came from gold which increased production to 10.2 tonnes (up nine per cent), ironsand production at 2.3 Mt (a 20 per cent increase), and industrial rocks and building stones (up six per cent) with rock for building, cement and roading showing significant rises on the back of strong regional growth and infrastructure development. Many regions, in particular Auckland, Bay of Plenty, Wellington and Southland, recorded significant increased regional activity with supply often struggling to meet demand. By contrast the coal sector had a relatively steady year with production remaining stable at just over five million tonnes for the second year running. Coal exports however are now consistently exceeding two million tonnes annually, generating export earnings of over $200 million, and could well be higher with rail capacity improvements. Many countries throughout the world are now importing our high quality bituminous coal for steel manufacturing and other industrial uses.

Jan 1, 2005

By Kurt RP Petersen, Hendriena van der Walt

With the decline in fine diamond production from the Argyle mine in Australia, there is a greater emphasis on efficiently treating the finer size fractions through a DMS circuit. Although it is generally well understood that smaller diameter cyclones are more appropriate for this application, practical results do not necessarily meet this expectation. In this paper the operational performance of particular sized cyclones throughout the group was compared. Based on the results there is evidence that under certain practical operating conditions, small cyclones are not necessarily best for fine size particle treatment, particularly given the production pressures faced by all mines. However, there seems to be considerable merit in using larger sized cyclones, which tend to exhibit less performance variability, irrespective of operation conditions.

Jan 1, 2006

By R. Patterson

Tracer gases have been utilized successfully in a variety of industries, each with specific releasing and sampling methods. The various attributes of tracer gases are dependent on the industry the tracers are utilized in. Tracers must be chemically and thermally stable, safe, odorless, detectable at low concentrations, have a low background concentration, and should not be naturally occurring in the environment if they are utilized in underground mining applications (Thimons et al., 1974). In addition, the tracer gas should be inexpensive, non-corrosive, non-toxic, easily transportable, readily attainable, and non-radioactive (Kennedy et al., 1987). Sulfur hexafluoride (SF6) met many of these above requirements and therefore was introduced as an ideal tracer gas to use in mining industry in the early 1970?s (Thimons et al., 1974). Due to the nature of underground mining including complicated geometry, irregular flows, turbulent flows, obstructed airways, and leakages it is difficult to use conventional anemometer and smoke tube techniques to accurately measure the effectiveness of ventilation controls (Thimons et al., 1974; Klinowski and Kennedy, 1991). There have been several applications of SF6 as a tracer gas in underground metal/non-metal and coal mines. Thimons et al. conducted early testing of SF6 in an underground limestone mine and determined that it is an effective technique for evaluating auxiliary fans, estimating volumetric flow rates in large areas, and measuring low flow velocities. A rapid face ventilation measurement method (FVM) utilizing SF6 was developed by the Bureau of Mines to make face measurements in underground coal mines (Timko and Thimons, 1982). When measuring the effectiveness of jet fans in dead headings SF6 was proven more effective than smoke tubes (Timko and Thimons, 1982). Experiments related to determining methane liberation in the gob were also conducted by injecting SF6 into a borehole (Timko and Thimons, 1982). Also, in an emergency situation where the gob had to be sealed due to a fire, SF6 was released to determine the effectiveness of the seals (Timko and Thimons, 1982).

Jan 1, 2011

By Massimo Concilia, Remo Grandori, Paolo Nardone

Paul Y. – SELI Joint Venture had been contracted to build the longest section of the Strategic Sewage Disposal Scheme (SSDS) – Stage I. This involved two tunnels under urban and marine areas excavated by high performance hard rock open type TBMs operated from deep shafts. A specific ground treatment program was developed using advance probing and grouting to control water inflow into the excavations. The article describes: the technologies adopted, the experienced problems, the encountered productions and their interrelation with the water inflow amounts, the possible improvement in the technologies for the excavation of the future stages of the same project as well of any other project under similar conditions.

Jan 1, 2001

By Jack Eloranta

To improve control of blasting, tests were performed to assess non-electric cap accuracy. Simultaneous testing using a Velocity of Detonation Recorder (VODR), Red Lake Lo-Cam and an Instantel DS-677 blast monitor was done. Favorable comparisons were found in the three records . This testing confirmed the accuracy of an inexpensive and expedient cap testing procedure.

Jan 1, 1992

By F. Navarro, F. Soto, G. Díaz, E. Jélvez, G. Morales, N. Morales

The increasing availability of tools on the web provides a great opportunity for the research community to boost investigation by accessing computational resources from all over the world. For example, data analytics libraries implemented in languages like Python can be accessed through many open and commercial platforms, therefore providing researchers with a common set of tools or shared datasets. Unfortunately, that is not the case with research in resource assessment and mine planning, where the most standardised tools are commercial applications designed to work on the desktop, but there are not many standard platforms for research. As a result, researchers from different groups often need to start from scratch in order to develop their work, and rarely share implementations details. Similarly, apart from a few publicly available examples, there is a lack of common datasets that are validated and can be used to compare results between different approaches. In this paper, we introduce a platform that provides tools for resource assessment and mine planning, which can be accessed remotely utilising Jupyter Notebooks. In its current version, the platform provides (i) definition and implementation of basic structures for managing samples and models (loading, saving, adding or removing columns, etc.), (ii) definition of experimental and modelled variograms for spatial continuity analysis, (iii) definition of standard interpolation methods in resource evaluation (inverse distance and kriging), (iv) definition of standard problems in mine planning (ultimate pit and precedence constrained production scheduling), (v) generation of 2D standard graphs like grade distribution, conditional means, tonnage-grade, and production plans (vi) a set of datasets, which can be used for case studies, and (vii) a set of notebooks with examples and documentation. In this paper, we introduce the platform and show some examples that illustrate some of the possibilities that it has for research and education in the area of resource assessment and mine planning.

Sep 1, 2021

By Albert L. Toenges

This report is the second of a series describing methods and systems of mechanical mining; where operations are conducted on more than one shift. The first report, Information Circular 7014,4/ describes mining operations at 14 mines and the present paper describes operations at 11 additional mines. The purpose of this study is to analyze the advantages and disadvantages of the various types of equipment and mining systems now used where more than one shift is worked per day. Physical conditions vary in different and in the same mining districts and determine, together with economical considerations, the systems of mining and the types of mechanical loading equipment to be used. The information presented in this paper may be helpful to operators or others who may contemplate installing a mechanical mining system. The equipment used in the mines described comprises conveyors, scrapers, mobile loaders, mobile conveyors, and combination of these types. The description of the mining systems and practices at the mines investigated is detailed only as they relate to and affect mechanization. In computing the operating data in mines that are not totally mechanized, employees not working directly on production have been charged to output from mechanized sections in proportion to the percentage of mechanization. The operating data for comparing various systems are for an average working dry, as the number of men working on idle days varies greatly in different mines.

Jan 1, 1939

By J. Kretschmann, A. Müterthies, T. Rudolph, C. Yang, P. Goerke-Mallet

Catastrophic failures of dams and tailing storage facilities (TSF) have triggered the development of integrated ground monitoring concepts for hazard assessment, risk management and public safety. These concepts are based on knowledge and expertise of persons technically responsible for TSF. The aim is to combine this implicit and explicit knowledge with the data of in-situ- and remote sensors. Risk management for TSF must include a comprehensive monitoring program that integrates data from ground based-, air-borneand satellite-based sensors. Researchers at Technical University Georg Agricola (THGA) in Bochum, and EFTAS, Muenster, Germany, are fusing a variety of sensor data to enhance the capability and performance of TSF monitoring to ensure public safety downstream of TSFs. This paper describes the variety of sensors implemented in numerous research projects. It gives an outlook in terms of planned satellite missions with innovative equipment like hyperspectral sensors. The implementation of the data of these sensors in the analysis will increase the understanding of spatio-temporal impacts of mining activities. Future opportunities are explained by a datacube approach.

Mar 2, 2022

By Daniel H. Isreal

Because the federal government owns and controls nearly 80% of the most valuable oil shale reserves in the West, it is inevitable that federal leasing and siting will play a prominent role in development of an oil shale industry during the 1980s. Also, because of recent enactment of the Synthetic Fuels Corp. authorizing up to $88 billion in loan and price guarantees-federal financing will provide the critical incentive to permit private investment in a still infant industry.

Jan 1, 1981

By Lloyd A. Morley

The performance of electrical grounding systems in open-pit metal mines is evaluated, using techniques which are described thoroughly. The normal electrical distribution and grounding practices used in metallic open-pit mines are reviewed and compared with coal mine usage. The results are used to generate the included recommendations for Federal Regulations concerning open-pit metal mine grounding systems.

Jan 1, 1976

By David A. Monaghan

On January 14, 1974 a fire occurred in the 3 East mains of the Joanne Mine of Eastern Associated Coal Corp. in Rachel, West Virginia. The mine was evacuated without injury and sealed completely at the surface within 24 hours. It was decided by the coal company along with the U, S, Bureau of Mines, the West Virginia Bureau of Mints and MESA that remote sealing of the fire zone would be attempted. This report summarizes the remote sealing effort and those activities directly related to the remote sealing effort. This chapter provides a brief history of previous remote sealing attempts, a description of the recently developed remote sealing system and a description of the Joanne Mine operation as it related to and affected the remote sealing effort.

Jan 1, 1975

By I M. Howard

With the bell-less top (BLT) charging system replacing the centuries old double bell charging method, the furnace efficiency has been greatly improved together with considerable reduction in the furnace down time and operational problems. But still there are many draw-backs which need further attention to achieve better efficiency and operational effectiveness. The performance and operational problems of the BLTs have been highlighted and possible solutions to overcome some of the major problems are discussed.

Jan 1, 1999

By Albert L. Toenges

[The i~ ortance o~ S3~e, fdequnt, nQ economical tr~n~po~t~t on 8ys~em Th~a bee~ e~~~~siz8d by the introduction of mechanical loading in co 1 mines, pa.rticula:c y \'r~ e::-e ~o?oile loaciine; ~ac~ine!;j rrre u .... ed. This papar i tr_e . eco:1d or' ?. ~eries deGcribi 1{) t:;'~~11>ort:ltion G stems et1-p oyed in mech3JlizeG. f!lincs. Progre,-s ?. epo~ t J...2.t deal t ~~tirel.: ,'Ii th the l:se of rail .laulagr £or c;atl:erine tran~ortc;tion, ailc, in t-!is paper 'Ii 11 be i acuss d c .icilY rub"col'-t? ro ~ t:tto::"ing as Ie _ as ani:naJ., con-",reyor, an ot.he~ systems of rnil gatheri?1.g. ~ho l)urpo~e of this invosti-gation is, as outlined in Progress ,~ort 1, to studT . Q analyz0 v rious systems nov.: in. u"'e El.I1d to derivQ cor..cl :cicn .... tllcrcfrom.]

Jan 1, 1941