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By P Wapner, C Lo Edwards, S CO Schmidt, J N. Johnson, R Oliver

Shale oil recovery rates that can be achieved in underground in situ retorts can be strongly influenced by the shale breakage and fragment-size distribution achieved during rubblization. Since the fragmentation pattern in the retort is a direct result of the blast design used for rubblization, the characterizing blast parameters should be carefully selected. Explosives should be matched to the host material and blast geometries properly chosen so that the required fragmentation results are achieved at optimum costs. Special attention must be directed to selecting blast parameters that produce uniform bed permeability, suppression of fines, proper fragment size distribution, and minimal damage to the retort walls and ceiling. The influence of joints and natural fractures should also be known. In instances where the requisite blasting parameters are unknown, they should be determined from test blasts.

Jan 1, 1979

Falling asleep at the wheel of a moving vehicle is not only dangerous but avoidable. It is implicated in up to 30% of all road fatalities in general and up to 65% of mining incidents involving haulage trucks. These types of crashes normally result in serious injury and/or fatality due to the lack of breaking that occurs. However, when a 300 tonne haul truck has a sleep related crash it is not only the safety of the driver that has a high price but also the commercial impact on the mines? productivity and efficiency. We have been developing our ASTiD technology which stands for the Advisory System for Tired Drivers to seamlessly integrate in to Modular Mining?s Dispatch system to provide real-time early warning fatigue risk management. The benefits being driver shift optimisation, sustained productivity and of course less accidents. By monitoring the drivers alertness levels in real-time using ASTID, the Dispatcher becomes empowered to make critical, management decisions that will ultimately prevent serious injury or loss of life and the driver gets to stop when he needs to and not just when he is supposed to. This paper shows how this integrated solutions works.

May 1, 2011

By Lewis L. Oriard

The purpose of this paper is to provide an overview of close-in blasting effects on various types of structures and building materials, as encountered in this writer's professional practice. Structures range from old, deteriorated historical monuments to new, heavily reinforced buildings. Materials range from clay adobe to concrete and steel. Site locations range from tropical to arctic. Blasting ranges from sculpture blasting inside buildings to "coyote" blasting and large surface blasting operations. Space limitations permit a brief discussion of only 25-30 specific cases, but they have been selected to be typical of conditions found on hundreds of similar cases. The writer was asked to present a discussion of representative cases where relatively high vibration intensities were experienced. Virtually all of these cases were free of damage, but the few damage cases provide valuable insight to the mechanisms involved. Observations of such damage and non-damage cases have served as the basis of this writer's criteria for various structures and materials, as well as the technology to conduct blasting operations within those criteria. A sampling of these experiences is gladly shared with the reader.

Jan 1, 1991

By Vincent J. Murphy

INTRODUCTION Geophysical applications to engineering projects are usually considered for reconnaissance exploration, and for some preliminary design phases. Recent experience indicates a growing need and a greater number of requests for measurements during construction. This is particularly true where seismic velocity values are related to strength properties of rock. Typical project objectives during construction are: dike and tunnel realignments required by surprise conditions encountered during foundation preparation; checks on grouting effectiveness which require velocity measurements before and after grouting; and dynamic moduli measurements along the walls of tunnels and deep excavations. This paper considers one of the on-site seismic applications that is rather simple and straightforward, and yet has few references in the literature. The specific objective is the measurement of seismic velocities (both "P" waves and "S" waves) for determining the thicknesses and dynamic moduli values of loosened zones of tunnel wall rock. PRE-EXCAVATION SEISMIC METHODS The seismic methods suitable for engineering project studies are well known and especially suited for routine site reconnaissance; these are illustrated in Fig. 1. The seismic refraction profile with a

Jan 1, 1997

By Irsan Chandra

It is generally recognized that the gold thiosulfate leaching system requires the presence of copper and ammonia in order for acceptable leaching kinetics to be observed. However, the presence of copper and ammonia complicate the chemistry of the system as thiosulfate is rapidly oxidized by oxygen under these conditions. In addition, the environmental impact of ammonia would need to be considered before the adoption of this system. This paper describes fundamental studies into the thiosulfate oxygen system. The two reagents for this system are thiosulfate and oxygen, and leaching is carried out at pH < 7. It will be shown using electrochemical techniques that both the reduction of oxygen and the oxidation of gold-to-gold thiosulfate are hindered. Thus, if leaching is to work under these conditions, then both half reactions need to be improved. The use of additives, such as thiourea and lead have been shown to dramatically improve the oxidation of gold and the reduction of oxygen respectively. The leaching of gold in the presence of such additives is discussed.

Jan 1, 2003

By S. Maluadzi, D. Rocchi, S. Luyckx, S. S. Potgieter-Vermaak, C. Machio, J. H. Potgieter

The aim of this work was to compare the corrosion behaviour of thermal spray WC ? based coatings before and after annealing. X-ray diffraction (XRD) was used to determine the phases present in the coatings at various stages. The corrosion resistance of the coatings was measured using electrochemical and immersion corrosion tests. The results obtained from electrochemical corrosion (quantified by corrosion current density) and immersion corrosion tests showed that annealing appears to decrease the corrosion resistance of the coatings. From the XRD results it was determined that the phases that corroded preferentially were cobalt (Co), eta (Co6W6C) and W2C. Keywords: Corrosion, thermal spray, coatings, hardmetals.

Jan 1, 2006

By S Zaffron, O Loffredi

A critical concern of any mining company today is its relationship with the different stakeholder groups impacted by the operational activity û communities, unions, vendors, local partners and competitors, local and federal governments, interest groups and non-government organisations. What ten years ago would have gone unnoticed, now, and even more so in the future, can drastically impact the profitability and even existence of a mining operation. This paper describes the development and delivery of a new paradigm for creating effective external stakeholder relationships. We report on the actual measurable results of an integrated and highly complex initiative led by Lonmin Plc (Lonmin) and Landmark Education Business Development (LEBD) that significantly altered the nature of the relationship with the stakeholders. Given the nature of the long-term investment required in a mining operation, any breakdowns or surprises in its relationship with external stakeholders brings with it the potential for major loss. The transformation of executive and senior management and community leadership was required to enable them to be effective in managing this complex set of circumstances.

Jan 1, 2006

By Dante Rodríguez Alvarado

El presente trabajo describe los logros del proyecto Ally Micuy “Buen Alimento” desarrollado por el Fondo Minero Antamina (FMA), donde se busca optimizar y reducir los índices de desnutrición crónica en la región Ancash y Huánuco. El proyecto se inició hace tres años con el apoyo de Caritas del Perú y ADRA Perú, donde participan el Ministerio de Salud (MINSA), Ministerio de la Mujer y Desarrollo Social y Ministerio de Educación, el gobierno regional de Ancash y los gobiernos locales.

Sep 12, 2011

By Joseph E. Chilton, Robert J. Timko, Charles D. Taylor

No regular monitoring of methane is required in areas of gassy coal mines outby the mining face. Methane ignitions that have occurred in mine outby areas indicate the need to provide better protection to workers. Handheld methane monitors are now used by some miners to make periodic measurements of methane at the working face. The IYONI II gas detector which is incorporated into a miner’s cap lamp and worn on a miner’s helmet can continuously provide an alarm signal whenever methane levels exceed a set level. Tests were conducted to evaluate the performance characteristics of this methane detector by measuring response times with methane gas supplied through a calibration fixture or adaptor. Other response time tests were performed with the detector in an environmental test box. Performance was also evaluated in a full scale test gallery where face methane emission and underground ventilation were simulated. Procedures for calibration by response time measurement of the IYONI II detector have been developed. In limited testing, the IYONI II detector was found to reliably detect the presence of 1 percent by volume methane.

The income of the Institute is derived from dues, subscriptions to MINING AND METALLURGY sale of publications. These sources are fortunately supplemented by the interest from invested funds now amounting to over $500,000, a considerable portion constituting endowments for especial purposes. Aside from the medal funds the principal endowments are the James Douglas Fund for support of the Library, the Rocky Mountain Fund and the Seeley W. Mudd Memorial Fund. The income from the two last named is available for the support of research and a variety of other purposes. It is allocated by the Board of Directors upon recommendation of standing. committees in each case. An active effort is being made to increase the endowments of the Institute, it being felt that unusual opportunities exist for research and public and professional service through the organization and at a minimum of expense. J. V. W. Reynders is chairman of the Endowment Committee.

Jan 1, 1929

By G. Blackwell, E. Bozorgebrahimi

The trend in open pit mining has been to maintain cost competitiveness through economies of scale, particularly by implementing larger trucks and shovels. This paper considers the potential adverse impact of such scale adjustment, however, on dilution, maintenance, flexibility, and other aspects of operations. It examines the mine production characteristics affected by increased equipment size and attempts to quantify the impact on the overall operation. Reference is made to data from operations that have experienced a variety of equipment size ranges changes over the last decade.

Jan 1, 2003

By A. J. Phillips, C. H. Mathewson

BERYLLIUM, magnesium, zinc and cadmium, together with mercury, constitute a coherent sub-group of the periodic system and these metals, excepting mercury, have been studied in sufficient detail by the new X-ray diffraction methods to prove their common adherence to the hexagonal close-packed type of crystal structure with a progressive increase in axial ratio as we pass through the group from beryllium to cadmium. The first four columns of Table 1 summarize the data on crystal structure of these metals reported in the International Critical Tables.1 The last two columns are based on results obtained in the present investigation. [ ] Twinning has often been observed in zinc and cadmium. The general aspects of this twinning are abundantly illustrated by photomicrographs, diagrams, etc., in the papers by Romig, and Mathewson and Phillips reported to this Institute in 1927.2 A determination of the composition

Jan 1, 1928

By T. C. Craig

During the year 1936, there were 654 oil wells drilled in the Texas Panhandle, with a total daily initial production of 256,049 bbl. Although 74 more wells were drilled than in the previous year, the total initial production lacked 109,303 bbl. to equal that of 1935. The explanation is that during 1935 most of the drilling was in the granite-wash area, which is much more prolific than the dolomite, in which the major development was done during 1936. Twenty-one oil wells were drilled deeper, increasing their potential 3683 bbl. The total daily oil potentid of the field Dec. 31, 1936, as determined by the Texas Railroad Commission, was 834,888 bbl., with a daily allowable production of 71,335 bbl. No overall field decline in production is recognized by the Texas Railroad Commission. A well is tested upon completion to determine its potential production. If the well is then shot with nitroglycerin or is treated with

Jan 1, 1937

The following resolution was passed by the Military Engineering Committee of New York on April 12, 1917. Copies are being sent to each member of Congress and to each of the five members in every State forming the committee representing, the five National engineering societies which carried on the industrial census under the direction of Howard Coffin. The Committee is urging every man to wire his Congressman and his Senator, asking him to do everything in his power to obtain favorable action by Congress on this resolution: Whereas in any large army to be created for the war, engineer troops will be needed in large numbers, and Whereas they should be officered by skilled engineers only, and Whereas the composition and training of such troops differ so much from the composition and training of non-technical troops that they should be organized under one central authority rather than under many scattered authorities. Now, therefore, be it resolved: That the members of the Senate and House of Representatives be requested to insist that all new units of engineer troops be organized and maintained by the War Department and not by the individual States.

Jan 6, 1917

By Hopkins G. M F

Intensive exploration of the Archaean ultra mafic sequence bordering the Kambalda dome has resulted in the discovery of at least ten dis- tinct areas of nickel sulphide mineralisation subsequent to the initial drill intersection in January, 1966. Sulphide ore reserves to June 30, 1972 were 19.36 million tonnes at 3.3% nickel after mining of 3.0 million tonnes at 3:7%,nickel since production commenced in March, 1967. About 75% of contained nickel metal reserves occur in sulphide concentrations located at the base of the-ultramafic sequence, in contact with underlying meta-tholeiitic basalt. The remaining reserve occurs in concentrations of sulphides within the ultramafic sequence, usually within 100 metres of the underlying contact and typically in proximity to contact mineralisation. These hanging wall orebodies are smaller, contain significantly lower con- centrations of sulphide, and generally exhibit higher Ni:S ratios than underlying contact ore- bodies. The majority of contact sulphides concentr- ations form narrow, elongate, north north-west trending bodies, closely coincident with fault bounded depressions in the contact. Detailed study of the Lunnon Shoot ore environment in- dicates that it was a locus of crustal failure during, and subsequent to, emplacement of ultra- mafic rocks. Resultant structures parallel and

Jan 1, 1973

By G. T. Lineberry, R. Q. Honaker

Coal extraction typically results in the recovery of pure rock that ranges from small to very large quantities depending on seam thickness and other characteristics. The removal of pure rock may allow the recovery of three times the amount in middling coal particles, which has significant economical benefits. In an industrial example, a 150% increase in revenue was realized from deshaling a low-ash, run-of-mine coal and blending with a processed clean coal product. Deshaling is the process of removing pure rock from coal, which normally involves a high-density separation in a gravity-based process. The removal of the relatively pure rock near the point of extraction has the potential to further enhance the economics of an operation due to reduced materials handling and refuse storage costs.

Jan 1, 2004

By John Birkinbine

Mr. Neilson was born Aug. 12, 1842, at Philadelphia, Pa., where he died Dec. 30, 1906. His business career began with his graduation, in the class of 1862, from the Polytechnic College of the State of Pennsylvania. For a short time after graduation he was instructor in mathematics at the college, and then became associated with Messrs. Booth & Garrett, chemists, of his native city. In 1867 he was sent to the Adirondack mountains to care for mining interests of the late Jay Cooke, and spent about three years there, operating the forges at Elizabethtown, Essex county, N. Y. He also prepared an interesting monograph on Catalan forges and their operations. In 1868 he published a chart showing the material progress of the United States, and the cost of certain staple products during a series of years, which is believed to be the first of its kind issued in this country. In 1870 he made a trip to the Pacific Coast, prior to entering the service of the Pennsylvania Steel Company.

Jan 1, 1908

By William B. Thayer, James H. Meinholz

The Milwaukee Metropolitan Sewerage District (MMSD) has been working since mid-1977 on a fast track to meet a court-imposed schedule to rehabilitate a large wastewater collection and treatment system at an estimated cost of $1.7 billion. Because of glaciation, the Milwaukee area has an extremely complex geologic environment. The rock surface ranges from outcroppings in the northern and western parts of the area to 76 m (250 ft) below the surface at the mouth of the Milwaukee and Menomonee Rivers. Bedrock beneath the glacial mantle is a thick sequence of early to middle Paleozoic sedimentary rock. To cope with the many complexities of this large public works project, a Program Management Office (PMO) concept has been employed. A Geotechnical Engineering Group was established within the PMO to provide a continuous , unified approach to geotechnical engineering and full disclosure of all geotechnical information in the construction contract documents. It provides qeotechnical engineering to design and construction, develops and maintains a qeotechnical data base, and participates on the claims resource team.

Jan 1, 1983

By W. C. Kerr

WHEN Agassiz and his party of geologists commenced their exploration of the interior of Brazil and the Amazon region, one of the first and, to the last, one of the most novel and striking phenomena which met them everywhere was the great depth of decomposed or partially decayed rock in situ, which mantles, and for the most part conceals, the underlying strata. The same facts strike all geological observers from the North who happen to penetrate the middle and southern latitudes of the Atlantic States. In North Carolina, e. g., the entire middle and western regions, outside of the Quaternary clays, sands, and gravels of the East,-that is, all that portion of the State occupied by the Arch can and Mesozoic rocks,-show everywhere this peculiarity, so new to those accustomed to glaciated surfaces. Not only do the hills and slopes, the mountain chains and

Jan 1, 1880

By G. Rebel

Owing to the helical construction of the wires and strands in a triangular-strand rope, a torque is generated when the rope is restrained and tensioned. When a rope is suspended vertically, there is a load differential along its length due to the self weight of the rope. This load differential gives rise to an initial torque differential m the rope. Since the rope is constrained only at the conveyance and sheave wheel, the torque along its length must be constant ID order to maintain equilibrium, a variation in lay length occurs so that the lay length at the conveyance end decreases, and the lay length at the sheave end increases, from the manufactured state. The tension-torsion testing of steel-wire ropes is discussed, and it is shown how the results of the tests can be used to predict static in-shaft torsional behaviour. The expected changes in strand lay length in very deep shafts (deeper than 2500 m) are calculated, and the associated problems and of severe changes m lay length on rope endurance and safety are discussed. Examples of current in-service rope distortions such as kinks and corkscrews are shown.

Jan 1, 1996