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Using mines in Canada, Boart Longyear, a leading provider of drilling services and products, has put its Stage 3 Coring Bit to the test and each time the bit has passed the test with great success. After more than a year in the field at a major mine operation in Sudbury, Canada, the Stage3 coring bit broke life records to become recognized as the most productive design in the industry. In addition to the proven advantage seen in regular bit life increases of as much as 300 percent in some cases, the design is quickly being recognized for its cost-saving operational impact. In Sudbury, the mine operation realized actual cash savings of more than C$45,000 within an eight-month period by making the switch to Stage3 bits. For years, the Sudbury Basin team has relied on the Alpha Extended Crown bit with the Express Waterway geometry option, ordering approximately 500 units per year. This 07 COM ECEX configuration performed well in medium-hard, non-abrasive to ultra-hard, non-abrasive formations with an average bit life of 150 m (490 ft). While satisfied with the performance of the Alpha Ex-tended Crown, the team agreed to put the new Alpha Stage3 to the test. Boart Longyear?s field engineers supplied five drill sites with Alpha Stage3 bits in a 07 COM configuration. After thoroughly testing the Stage3, the results were clear. Even with the well-known performance and versatility offered by the previously preferred configuration, the Stage3 set a new standard of bit performance. The new bit maintained its cutting edge for up to three times longer than the Alpha Extended Crown, a significant performance increase when compared to the 07 COM ECEX.

Jan 1, 2009

By Dan A. Brown

The New Mississippi River Bridge (MRB) employed conventional design-bid-build procurement, but the bidding process included the opportunity for pre-qualified bidders to develop and propose confidential Alternative Technical Concepts (ATC?s) for evaluation and approval in advance of bidding. The ATC process provides a mechanism for value-engineering prior to bid, with incentives and opportunities for both the owner and the bidding contractor. The contract described in this paper is for the river bridge composed of a cable-stayed crossing with two pylons and the anchor piers on each side of the river. The Massman-Traylor-Alberici (MTA) team developed a re-designed foundation system for the main pylon and anchor foundations which utilizes their equipment and experience along with field load test measurements to optimize the foundations. The paper describes the experience with the use of the pre-bid ATC process on the project from the perspective of the bidder, and outlines some of the benefits and limitations of this concept with respect to foundation design and construction. Some keys for success are identified and impediments to the effective implementation of the process are described.

Jan 1, 2011

By Georgene Renner, William R. Yernberg, Steve Kral

ABB offers complete electrical revamps of mining shovels with ac or dc drives, drive control, frequency converters with insular gate bi-polar transistor technology, intelligent control packages and visualization. Many of the world’s shovel excavators and draglines (walking excavators) were built in the1980s. After 15 to 20 years of round-the clock operation in openpit mines, these machines start to feel their age. Electrical parts are particularly vulnerable. Their performance deteriorates and availability and productivity fall. Even with regular ser-vice and maintenance, a machine of this age will accumulate 400 hours of unscheduled downtime a year. The need for a replacement becomes pressing, but the expense is often prohibitive.

Jan 1, 2005

By A J. Nick, I I. Townsend, J M. Schuler, J D. Smith, R P. Mueller, L Sibille, K Leucht, J J. Fox

The first steps for in situ resource utilisation (ISRU) on target bodies such as the Moon, Mars and near-Earth asteroids (NEA), and even comets, involve the same sequence of steps as in the terrestrial mining of resources. First exploration including prospecting must occur, and then the resource must be acquired through excavation methods if it is of value. Subsequently a load-haul-dump sequence of events occurs, followed by processing of the resource in an ISRU plant, to produce useful commodities.While these technologies and related supporting operations are mature in terrestrial applications, they will be different in space since the environment and indigenous materials are different than on Earth. In addition, the equipment must be highly automated, since for the majority of the production cycle time, there will be no humans present to assist or intervene. This space mining equipment must withstand a harsh environment which includes vacuum, radical temperature swing cycles, highly abrasive lofted dust, electrostatic effects, van der Waals forces effects, galactic cosmic radiation, solar particle events, high thermal gradients when spanning sunlight terminators, steep slopes into craters / lava tubes and cryogenic temperatures as low as 40 K in permanently shadowed regions. In addition the equipment must be tele-operated from Earth or a local base where the crew is sheltered. If the tele-operation occurs from Earth then significant communications latency effects mandate the use of autonomous control systems in the mining equipment. While this is an extremely challenging engineering design scenario, it is also an opportunity, since the technologies developed in this endeavour could be used in the next generations of terrestrial mining equipment, in order to mine deeper, safer, more economical and with a higher degree of flexibility. New space technologies could precipitate new mining solutions here on Earth.The NASA Kennedy Space Center (KSC) Swamp Works is an innovation environment and methodology, with associated laboratories that use lean development methods and creativity-enhancing processes to invent and develop new solutions for space exploration. This paper will discuss the Swamp Works approach to developing space mining and resource extraction systems and the vision of space development it serves. The ultimate goal of the Swamp Works is to expand human civilisation into the solar system via the use of local resources utilisation. By mining and using the local resources in situ, it is conceivable that one day the logistics supply train from Earth can be eliminated and Earth independence of a space-based community will be enabled.CITATION:Mueller, R P, Sibille, L, Leucht, K, Smith, J D, Townsend, I I, Nick, A J, Schuler, J M and Fox, J J, 2015. Swamp works – a new approach to develop space mining and resource extraction technologies at NASA’s Kennedy Space Center: prospecting, excavation, load, haul and dump for in situ resource utilisation, in Proceedings Third International Future Mining Conference, pp 297–304 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By J. Shawn Peterson, David S. Yantek, Adam K. Smith

Occupational noise-induced hearing loss continues to be one of the most pervasive health problems in the mining industry, despite over 25 years of regulation. One of the loudest pieces of equipment used in underground mining is the continuous mining machine. Noise sample data collected by the Mine Safety and Health Administration indicate that 42% of noise overexposures between 2000 and 2005 involved continuous mining machine operators. Previously conducted field and laboratory tests have determined that the continuous mining machine conveyor system is a dominant noise source. Loud impacts occur as the conveyor chain flight bars, used to move the mined aggregate, traverse their path from the top to the underside of the conveyor deck. Various noise control treatments have been applied to abate noise caused by the conveyor system. A durable polyurethane coating has been developed for the conveyor flight bars, resulting in a time-weighted average reduction of 3 dB(A) for an eight-hour work shift. In an attempt to further reduce continuous mining machine operator overexposures, a similar urethane coating has been applied to the tail roller component of the conveyor system. Laboratory results showed a 2 dB(A) reduction in sound power levels, but the component failed during underground durability testing. An outer steel sleeve has been added to the urethane coating of the tail roller to enhance wear resistance during mining. The urethane jacketed tail roller is the latest effort, combined with previous noise treatments, to bring the continuous mining machine into compliance with federal noise regulations.

By Donald A. Bruce

Various types of contemporary Deep Mixing Method (DMM) techniques have been used in the United States since 1986. Such techniques owe their origins to Japanese and Scandinavian developments, which began almost three decades ago. The growing demands of urban infrastructure development and rehabilitation have created a very active and rapidly expanding market demand in the United States especially since the early 1990s, and there is a clear need for a new and fundamental review of the surprisingly large number of DMM techniques that are being used domestically, or are available in other parts of the world. Following a summary tracing the historical development of DMM, and a generic classification of applications, the paper provides a review of each of the many different proprietary methods, which the authors have identified during preparation of an international survey funded by the Federal Highway Administration (FHWA). Data are also provided on commercial aspects of the various DMM techniques worldwide.

Jan 1, 1998

A short account is given of the theory and practice of determining the true U3O8 content of ore samples by the determination of the beta and gamma activities separately, using the method of Eichholz and his associates.It is shown that, despite the variation of sample activity without change in U3O8 content, the true U3O8 value can still be found.Thorium can be determined simultaneously if this element is also present.

Jan 1, 1957

By Alonso Marchena, William Martínez, Joel Otero

En Arequipa, Moquegua y Tacna se han definido diversos arcos magmáticos. En los arcos jurásico, paleoceno y oligo-mioceno ocurren pórfidos de distintas características, los cuales presentan diferencias litogeoquímicas (LaN/YbN>20, Sr/Y>40, Eu/Eu*>1, U/Th>0.27, NbN/TaN>0.7). Estos parámetros pueden ser utilizados como guías de exploración, ya que son anomalías desde el punto de vista litogeoquímico. En caso no haya mineralización visible (depósitos ocultos), el empleo de estos trazadores en unidades ígneas (diques, cuerpos subvolcánicos e intrusivos) puede señalar la probabilidad de encontrar depósitos en profundidad.

May 22, 2019

By Catherine T. Aimone-Martin, Meyers Joseph A.

A new strain-based criteria is being adopted for rock blasting in New York City (NYC). This criteria is based on several years of research involving vibration measurements of tall structures during blasting within several feet from buildings designated historic and Landmarked. This research has demonstrated that tall, heavy structures show little upper-structure vibratory response during hard-rock, urban blasting carried out in NYC. The Fire Department of New York City (FDNY) permits rock blasting and regulated limits for ground vibrations using the U.S. Bureau of Mines (USBM) safe blasting criteria. However, these regulations are often superseded by a 0.5 in/s (12.7 mm/s) limit imposed by the New York City Department of Buildings for historic and Landmarked buildings that are adjacent to the majority of blasting projects in the City. This onerous limit is often exceeded resulting in frequent stop work orders that increase the cost and time of rock excavation projects. The

Jan 1, 2019

By Tom A. Armour

Different variations of soil nailing techniques have been used in the United States since the late 1970's. Such techniques owe their origins to French developments, which began in the early 1970's as a spin-off from European tunneling excavation support practice. The growing demands of urban infrastructure development and rehabilitation and environmental protection have created an active and expanding soil nailing market demand for earth retention and slope stabilization in the United States since its early developmental years. There is a clear need for a fundamental review of the large number of soil nailing techniques that are currently being used in the United States. Following a brief summary tracing the historical development of soil nailing and a generic classification of applications, this paper provides a review of the different recent advances in the design and construction of soil nailed systems. Discussion topics include nail design advances, permanent "top-down", structure support/underpinning, alternative face stability measures, composite systems, hollow bar and fiberglass nails and architectural reinforced concrete/shotcrete facings. Case histories will be presented to illustrate each of these advances.

Jan 1, 2003

By E. H. Wells, A. Andreas

Greater progress than in any previous year was accomplished by the oil industry in New Mexico in 1936. The total number of completions in the state was 631, of which 549 were oil wells, 21 were hydrocarbon gas wells, three were carbon dioxide gas wells, and 58 were dry holes. The total oil production for the year was 26,804,446 bbl. Compared with the production for 1935 of 20,228,947 bbl., this represented a gain of 32.5 per cent. Of the total production, 25,337,382 bbl. came from Lea County. The average daily nonmarginal well allowable for that county was 115 bbl. the first of the year and 86 bbl. at the close. Production was regulated by the New Mexico Oil Conservation Commission,

Jan 1, 1937

By R Tom Watts

The blasting industry has changed more in the last five years than in any period to date. The equipment utilized to load boreholes has changed in response to more precise blasting products and programs, and the need to maintain tighter control over product formulations produced by bulk loading equipment. Tread Corporation has built over 1,300 heavy ANFO type bulk loading units currently operating in over 40 countries worldwide. These units have been designed to meet almost every possible loading scenario but there are always new situations that require special designs and configurations to meet the challenge. The focus of this presentation is to make you aware of the process that should be used to determine the equipment best suited for your application. We will discuss loading cycle times, delivery rates, multiple product mixing capability, capacities, manpower utilization, regulatory compliance, and where and when to use automation in the loading process. We will also discuss the suitability of chassis with regard to ground pressure, turning radius, terrain, weather conditions as well as highway suitability. The US Bridge Law as well as laws that cover the concept of axle loading and spacing will be covered. Through new computer aided design and modular design capabilities, you can now have almost any configuration required to meet your bulk loading objectives. We will also review the range of equipment currently available in the market place and discuss tradeoffs between price, capacity, and complexity.

Jan 1, 2000

By S Telford, J Weir

Heathgate Resources Pty Ltd (Heathgate) operates the Beverley Uranium Mine in South Australia, located on the plains between the northern Flinders Ranges and Lake Frome some 600 km north of the state capital Adelaide. The uranium orebody exists in permeable sands within the confined, highly saline Beverley aquifer, approximately 125 m below the ground surface and the uranium is mined using in situ recovery (ISR) technology. The Beverley mine is a highly technologically advanced ISR mine and is operated in accordance with stringent safety and environmental standards. The mine is currently licensed to export 1500 t of uranium oxide (U3O8) per annum. This paper outlines the fundamental differences between ISR operations and the more traditional uranium production methods, such as agitation leaching and heap leaching, where the ore is removed from the deposit, stockpiled, crushed, milled and leached on the surface. Solids tailings from either the mill or the heap are finally deposited in a tailing storage facility. ISR mining differs from conventional mining because the ore remains in place underground (in situ) and the groundwater contained in the ore-bearing aquifer is utilised as the mining fluid. This is achieved by drilling into the deposit and installing wells for extracting and re-injecting the groundwater which is fortified with chemicals. The fortified groundwater (ie mining fluid) flows through the permeable sands containing the orebody, dissolving the uranium. The pregnant mining fluid is then collected and transferred to the recovery plant where the uranium is captured (on ion exchange (IX) resin in the case of Beverley). The barren mining fluid is then re-fortified and recycled to the wellfields. Once mining is completed in a wellfield, the surface infrastructure is relocated to a new wellfield, and the mined-out wellfield is rehabilitated to its original surface condition. A comparison of 'standard' hydrometallurgical plants, heap leach and ISR shows a number of key differences, such as the rate of leaching, the level of control available to the operators, and the type of contact/reaction that occurs. While limited in its applications, ISR mining has proven successful at Beverley and provides another mining and processing method for the production of uranium.

Jan 1, 2008

By Ruilin Yang

"Blast vibrations are essentially a strain/stress wave propagating in rock or structures inthe vicinity of a blast. However, blast vibration has always been quantified in terms ofpeak particle velocity (PPV) or acceleration (PPA), and a meaningful relationshipbetween blast vibration and strain/stress has not been established. The determination ofthe dynamic strain from blast vibration may improve quantification of blast damage andselection of a blast vibration limit for critical structures or high walls. Dynamic strainrelates to rock mechanics or material strength more directly than peak particle velocity(PPV). This paper documents a method to calculate the three-dimensional dynamic straintensor from recorded blast vibration signals. The method is based on determination of thedisplacement gradient at a point of interest for each time instance during the vibrationduration. The method to calculate dynamic strain is applicable to generic seismicwaveforms including near and far field blast vibration from a production blast withmultiple blast holes. In order to minimize measurement errors the specifications of thespacing between monitors and the sampling frequency of the vibration recording aredescribed."

Jan 1, 2012

By Stephen C. Tadolini, Dennis R. Dolinar

The risk of injury caused by minor roof falls continues to increase in underground mining. Most ground control injuries result from small rock falls that occur in a supported area, but do not involve the failure of the support system. In the roof, these are the "skin failures" that occur between previously installed primary or secondary bolting systems. To minimize skin failures and the associated accidents, several devices were designed and tested in the laboratory to maximize stiffness, minimize material thickness and weight, and ease material storage and handling on roof bolting machines. The goal of this project was to design and evaluate devices that can be installed with traditional primary or secondary roof supports, and that are easy to handle/install under temporary or previously supported roof.

By Randall M. Wheeler

It is important to be able to quantify the effects of blast delay designs on vibration characteristics. White was the first company to develop commercially available software, called Alpha-Blast, for this purpose. The program can indicate relative amplitude and frequency results to be expected from the use of particular delay intervals. If enhanced vibration effects from delays are a problem, a technique to evaluate this situation will be invaluable.

Jan 1, 1994

By F. Parada Torres

Xstrata Tintaya S.A. opera el yacimiento a tajo abierto y procesa el mineral en dos plantas: Planta Concentradora de Sulfuros y Planta de Lixiviación de Óxidos, donde anteriormente consideraba al mineral mixto complejo como intratable en la planta concentradora, por lo que se le destinó a ser tratado como óxido marginal en la planta de lixiviación. En este sentido, el presente texto describe el nuevo tratamiento al mineral complejo en la planta concentradora. De forma que se busca definir las variables geometalúrgicas del mineral de Chabuca Norte, optimizar los procesos metalúrgicos del mineral mixto mediante la investigación geometalúrgica, así como correlacionar el entendimiento de la geología y alteraciones del yacimiento con los procesos metalúrgicos y crear valor mediante la optimización de la tasa de tonelaje de tratamiento y el incremento del porcentaje de recuperación de cobre en el proceso.

Sep 12, 2011

By D. F. Malan

This paper presents an overview of work conducted over several years to investigate the continuous stope closure profiles recorded in tabular excavations and the use of this data as a hazard indicator. In spite of the brittle nature of the rock, measurements in gold mines and intermediate depth platinum mines revealed a significant time-dependent closure component. Various approaches to simulate the time-dependent closure have been investigated. Viscoelastic theory is able to simulate the time-dependent closure behaviour, but there are subtle problems with the use of this theory as it cannot simulate the failure processes in the rock. To overcome these problems, continuum and discontinuum elasto-viscoplastic models were developed by the authors. Discontinuum models have the advantage of being able to simulate the creep behaviour of prominent discontinuities. Development of these models has led to useful insights into rock mass deformation and has made the numerical simulation of parameters, such as rate of mining, possible for the first time. A number of practical applications for the mining industry have been developed from this study. Among these are the delineation of geotechnical areas using closure data, use of the data as a hazard indicator and to give warning of large collapses in the platinum mines, identification of areas to be preconditioned in the gold mines, measurement of the effectiveness of preconditioning and improved da

Jan 1, 2007

By I. W. Farmer

Weightings and water inflows into longwall workings often occur together, giving rise to discussions on their relative genesis. Case histories are introduced which indicate that most water inflows are associated with heavy weightings. Resultant large releases of energy can lead to extensive vertical fractures, which can drain water from aquifers or other sources, such as separation accumulations, onto the face. Effectively control of water inflows in these cases depends on face support and weighting control.

Jan 1, 1996

By R. D. Lindsay

"Pamour Porcupine Mines, Limited is involved in the mining, milling and primary refining of various gold, gold - copper and refractory gold ores. Pamour operates five mines in the Porcupine Mining District of Ontario, and two 2,550 t/d milling facilities.Both metallurgical facilities use conventional cyanidation technology including zinc cementation for precipitation of gold and silver from solution. The precipitation process, as applied to clarified leach solutions (less than 1 ppm suspended solids) at Pamour is called the Merrill - Crowe process. Precipitates from both milling operations are treated at Pamour's Area Refinery. Schumacher precipitates, unlike Pamour No. 1, require an ''Acid Treatment Stage"" prior to refining to remove the high contained copper. This is accomplished by leaching the precipitates initiallv with sulphuric acid to remove zinc and then with sulphuric acid and manganese dioxide to dissolve copper. Refining procedures after ''Acid Treatment"" are essentially the same for both precipitates.The following considerations highlight the basic principals applied to refining cyanidation precipitates at Pamour, including:"

Jan 1, 1986