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By A Muhairini, M Eggers, J Smith, H Baxter

Detailed geochemical analysis of cored and non-cored drill hole data was used to characterise and model the Cenozoic detrital valleys of several deposits within the southern Pilbara region, Western Australia. The purpose of this modelling was to better characterise and understand the relationships between the various geotechnical units comprising mixtures of rock and soil for the purposes of slope stability and depressurisation studies.This paper presents data from several valleys where geological, geomorphological and climatic processes have resulted in the deposition of heterogeneous detrital rock and soil sequences. Seven primary detrital units are recognised as occurring within all the valleys studied, suggesting that the geological processes involved in the erosion and deposition of the units were widespread. Geochemical assessment of cored and non-cored data suggests correlatable geochemical signatures can be recognised for each of the units; however, local variability in the groundwater history of individual valleys is demonstrated by late-stage carbonate precipitation recognised both in the core and through the geochemical signatures, which has resulted in alteration of the parent rock/soil material. This paper discusses how the carbonate alteration may lead to improvements in rock/soil mass strength of a clay unit by comparing laboratory strength test samples of the same parent material with varying degrees of precipitate alteration to those with no discernible carbonate alteration. Following from this, correlations with geochemical assay results have been derived, whereby zones of more favourable strength conditions may be modelled through assessing areas of analogous geochemistry.The paper demonstrates how geochemical assessment can lead to improved geotechnical and hydrological modelling for a detrital valley system without the need for significant coring and laboratory testing. This in turn leads to improved confidence in the slope design and depressurisation recommendations for a slope.CITATION:Baxter, H, Eggers, M, Muhairini, A and Smith, J, 2015. The effect of carbonate alteration on detrital mass strength and implications for geotechnical slope design, in Proceedings Iron Ore 2015, pp 429–436 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Scott Ellenbecker

The formation in Newmont Mining?s Phoenix Mine near Battle Mountain, NV contains high levels of abrasive quartzite as well as gold, copper and silver. Newmont started mining operations at Phoenix (formerly Battle Mountain Gold) three years ago and the planners knew they were working with a challenging geological formation. But as it turned out, it was more challenging than anticipated. Mine manager Mark Evatz said, ?Anything that touches Phoenix rock wears fast. The rock fights back here.? To contend with the hard conditions, Newmont uses Atlas Copco?s Pit Viper 271 (PV-271) blasthole drill. Because of the hardness of the rock, drilling at Phoenix requires hammer drilling and the mine uses Atlas Copco TD65 hammers with 171 mm (6.75 in.) bits. The mine?s PV-271?s are outfitted with a single 41 m3/min (1450 cfm), 2.4 MPa (350 psi), oil-flooded air compressor. Phoenix has six Atlas Copco PV-271 drill rigs plus an Atlas Copco DML and a DM45 midrange blasthole rig. The mine?s goal is to keep 3.6 Mt (4 million st) of muck in inventory to stay ahead of the shovels and support needed operational flexibility (ore control related). Drilling efficiency has been a continuous point of improvement since operations began at the mine. The single-pass depth capability of 16.5 m (55 ft) on the PV-271 helped with that. Originally, the plans called for 6-m (20-ft) bench heights, supported by 7-m (23-ft) drill depths, and time spent moving from hole to hole was eating up productivity. Drilling on that plan resulted in drilling an average of 14 m/h (47 ft/hour). When depths were changed to 13-m (44-ft) drill depth, supporting blasting of 12-m (40-ft) benches, they were able to use the single pass capacity of the PV-271. Performance increased to more than 18 m/h (60-ft/hour) an hour. Although the drill depth change largely supported the improvement, other aspects of continuous improvement associated with improved knowledge of the Pit Viper drills helped as well.

Jan 1, 2009

By Thomas H. Hibner, Daniel Tempelis, John E. Shamma

Environmental protection of nearby resources is an issue that can not be ignored in tunnel construction. The Inland Feeder Arrowhead Tunnels Project is no exception. With keen interest from various stakeholders, Metropolitan developed a Groundwater Monitoring and Mitigation Plan. This plan provides for monitoring and management of selected water resource features within the San Bernardino National Forest along the proposed tunnel alignment. The plan specifically provides for monitoring of streams, springs, seeps, and piezometers for water temperature, pH, specific conductance, and chemical analyses, as well as flow or groundwater elevation. Metropolitan uses the data to evaluate for and manage potential impacts from groundwater ingress during construction of the Arrowhead Tunnels.

Jan 1, 2003

By M. S. Oudenhoven

This Bureau of Mines investigation was conducted to obtain an experimental solution of stress changes in the vicinity of a circular opening in an infinite plate. Plates were stressed biaxially in compression and subjected, by four different-length shoes, to a uniform pressure at opposing points on the opening periphery. The principal stresses along the vertical and horizontal axes, which result from peripheral pressure, were obtained from the photoelastic analysis of four frozen-stress epoxy models. These principal stresses were then super-imposed on the mathematically determined principal stresses (along the same axes) obtained from a theoretical biaxial stress field in which the magnitude of the lateral pressure was one-third that of the vertical pressure. The results indicate that an increase in shoe length increases the radial compressive stress and the tangential tensile stress (except tangential compression at r/a = 1, which exists for all shoe lengths). Also, a partial control of the stresses within one-half radius of the opening surface is accomplished by a change in the magnitude and placement of peripheral pressure.

Jan 1, 1966

By J. B. Knapp, J. W. G. Betts, Scott L. Burreill, J. H. Bassarear, E. A. Lowe, W. J. N. Davis, John L. Bolles, Gaylord P. Dopson, William H. Keener, N. S. L. Steenkamp

This chapter contains moderately detailed descriptions of some typical and well known mills that treat predominantly sulfide copper ores, some containing secondary values in gold, silver, and molybdenum. The descriptions are general in nature, because most of the specific data will be found in tabulations elsewhere in this section, covering a large number of mills in such matters as flotation reagents, crushing and grinding equipment and steel consumption, thickener and filter operating data, power consumption, and many others, in a manner that the reader will find convenient and comprehensive for reference and comparison. On the other hand, the plant descriptions selected for this chapter emphasize the kind of information that cannot be readily tabulated.

Jan 1, 1985

By Kevin Hegerle

The Henderson Mill has operated over a wide range of production rates, feed grades, manpower levels and recovery targets since start-up in 1976. Henderson Mill personnel, both management and hourly, have successfully responded to these changes by not only maintaining unit costs, but by actually decreasing unit costs. Methods of cost reduction have included conventional austerity programs, innovative technological improvements and creative work schedules. This paper addresses both maintenance and operating cost reductions and efficiency improvements.

Jan 1, 1986

By C. B. van den Berg

n this study, silver and palladium nanoparticulate inks with different metal-binder ratios were screen-printed onto a paper substrate. The printed layers comprised the metal nanoparticles and an ethylcellulose binder. The layers are not typical metal composites due to the low concentration of binder and high porosity. The electrical sheet resistivity of each particle concentration was measured, and the data fitted using the scaling law of percolation theory and the general effective media (GEM) equation. The percolation parameters, i.e. the percolation threshold and the critical exponent, for each system were determined from the fits and compared. The percolation threshold for the palladium layer (39.8 wt%) was lower than that found for the silver layer (44.9 wt%). The critical exponents determined for the palladium and silver layers were both lower than the universal value for three-dimensional percolation systems. Microscopy observations indicate that the difference in the percolation threshold for the two layers can be attributed to variations in their microstructure.

Jan 1, 2014

The New Technology of Enrichment of a Fine Low-Grade Tungsten from Complex Multi-Metallic Ore

Sep 13, 2010

By BruneJurgen F., Richard C. Gilmore, Matthew Schreiner, Ray Johnson

Explosive pockets of methane-air mixtures accumulate in underground coal mines and, when ignited, produce an air-blast wave that can disturb combustible coal dust on the floor, roof, and ribs. To prevent explosions, the coal dust must be continuously diluted through application of inert rock dust, usually powdered limestone. Application of powdered dust process creates a respiratory nuisance downwind, where miners cannot work until the dust settles. Rock dust suppliers have developed wet and foam applied products to reduce the nuisance and limit the interruption to mining during dust application. To test the effectiveness of these alternative dust products, researchers at the Colorado School of Mines (Mines) have constructed a full-scale explosion test drift located at the Mines Edgar Experimental Mine (Edgar) to study the dispersibility of different rock dust applications. This paper examines the use of Pentaerythritol tetranitrate (PETN) detonating cord to produce controlled air-blasts that simulate methane-air explosions. The air blasts are generated with curtains of detonating cord that produce shockwaves with wind speeds between 30 to 70 m/s (100 to 225 fps) depending on the length of 5.3 g/m (25 grain/ft) detonating cord used. These velocities represent the minimum air speeds required to trigger propagating coal dust explosions. Researchers have conducted 40 test blasts with various lengths of detonating cord. Results show the two primary waves and two reflected waves each decaying into airblast waves with overpressures of 14 to 27 kPa (2 to 4 psi). Pressures were recorded with commercial piezoelectric transducers and custom-built, bi-directional probes to record the total and dynamic pressures of the wind generated in the explosion. Researchers were able to generate consistent and repeatable wind speeds and air-blast durations sufficiently similar to a methane-air explosion to study the dispersibility of various rock dust products and application methods

Jan 1, 2019

By Robert C. Speck

The U.S. coal industry has long utilized the pillar-extraction mining technique as a method for maximizing coal recovery. Like longwall mining, it causes large-scale movements that progressively propagate from mine-level to the ground surface and may affect the groundwater regime, surface drainage and surface structures. The U.S. Department of Energy, in an effort to foster in- creased use of total extraction mining techniques, has recognized the need for a better understanding of these movements that will lead to a greater compatibility between coal mining and present and future land use. As part of that goal, GAI Consultants, Inc. is currently in- stalling instrumentation to monitor the ground movements associated with pillar extraction mining at Kitt Energy Corporation's No. 1 mine in northern West Virginia.

Jan 1, 1982

By O. B. Hopkins

The reports for the years 1942 and 1943 were written in 1943 and 1944, respectively, and were summarized at the meetings of the Institute in February 1941 and February 1944, but were held in manuscript form until released for publication in 1945. 1942 During the year 1942, developments in the Peruvian oil industry continued to be subject to repercussions from the swelling war effort, which steadily diverted more of the normal supply of men and materials into war channels, and necessitated the rerouting of supply lines. The result in Peru was an increasing demand for crude oil and products. The production of petroleum in Peru in 1942 was 13,626,259 bbl., as compared with 11,935,584 bbl. in 1941—an increase of 1,690,675 bbl., or approximately 14 per cent. The largest increase, amounting to over 61 per cent, was from the Lobitos fields, but this increase was caused largely by the subnormal production in 1941. International Petroleum Company's production in the La Brea y Parinas field increased 727,111 bbl., or 7 per cent, whereas the Peruvian Government's production in the small Zorritos field declined 10,380 bbl., or approximately 20 per cent. The final production figures for the Ganso Azul field at Agua Caliente were not available for 1942 at the end of the year, but the production was believed to have increased approximately 80 per cent from 1941, or from 13,750 to approximately 25,000 barrels. Development and Exploration Exploration in Peru in 1942 was very limited and confined to areas adjacent to the older producing fields, and the efforts there were largely expended in the extension and development of the producing areas. This situation resulted partly from the shortage of transportation and drilling equipment, and also from the strong demand for increased production of oil. . International Petroleum Co. completed 69 wells during the year, including seven exploratory wells, three of which added moderate extensions to the proven areas. Sixty of the completions were oil wells and nine were dry holes. Lobitos Oilfields, at Lobitos and Restin, is understood to have concentrated its drilling effort on development rather than on exploration. The Peruvian Government operating at Zorritos confined its drilling to the development of the small producing areas previously found. During the year it announced plans to drill three exploratory wells in the Pirin area of southern Peru (see map on p. 638). It was reported that the Government had made a survey of the Sechura area (representing the southern part of the Northern National Reserve as shown on the map), but no work under this arrangement was announced. The Cia. Ganso Azul, at Agua Caliente, completed its No. 6 well as a producer on March 27, and during the year it completed the installation of a 400-bbl. topping plant.

Jan 1, 1945

By Christian Divis

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Jan 1, 2002

By M. J. Beus

This paper will describe the research approach being initiated by the Spokane Research Center to assess hazards and design criteria to prevent ground and muck falls in and around ore passes in hard-rock mines. The major goal of this research is to compile detailed information about ore pass processes and hazards, identification and testing of prevention strategies, and development of computer-based measurement and design methods. Recent ore pass failures have underlined the lack of OE pass design capabilities and standards available to both mine engineers and MSHA personnel. Design criteria and ore pass hang-up prevention and remediation strategies will include the effects of internal ore pass loads, blasting to relieve hang-ups, and rock mass stress redistribution and structural interaction from nearby mining. New visualization and three- dimensional analysis methods will be presented as an extension of existing ore pass design and analysis techniques. A sophisticated particle-flow analysis program will be used to simulate the response of various ore pass designs to a wide range of loading conditions driven by rock mass deformation, muck flow, ore pass blockage, and blasting in both nearby stopes and the ore pass. Analysis techniques will be calibrated and design criteria validated at the Spokane ore pass test facility. These tools will serve to reduce research costs by limiting the number of experimental field tests required.

Jan 1, 1996

By Frank Parrish

History and performance data of 17 water-injection projects in Cooke and Grayson Counties in north Texas are presented for the purpose of studying and comparing operating practices and oil-recovery techniques. Water is injected into Strawn and Canyon sands of Pennsylvanian age. The principal formation flooded is the Strawn, which ranges in depth from 725 to 6,900 ft in the projects covered. Estimated ultimate recoveries range as follows: Primary, 22 to 494 bbl per acre ft; and secondary; 63 to 296 bbl per acre ft. These figures represent the following percentages of original oil in place: Primary, 10 to 46 pct; and secondary, 8 to 23 pct. Shallower projects; 725 to 1,500 ft in depth, had higher average primary and secondary recoveries than did deeper projects. Crude-oil gravity, which ranges from 20° to 45° API, was not relatable to yield of secondary recovery oil. Analysis of the data indicates that five-spot injection patterns will yield the highest percentage of oil remaining at start of flooding; that is, 28.8 pct for five-spot injection patterns, compared with 20.8 pct for line-drive patterns and 11.6 pct for random patterns. Waterflooding in this area appears to be very successful. Secondary recoveries of most projects are expected to nearly equal primary recoveries.

Jan 1, 1963

By A. B. Cecala

Video technology coupled with data logging exposure monitors have been used to evaluate worker exposure to different types of contaminants. However, previous application of this technology used a stationary video camera to record the worker?s activity while the worker wore some type of contaminant monitor. These techniques are not applicable to mobile workers in the mining industry because of their need to move around the operation while performing their duties and tasks. The Helmet-CAM is a recently developed exposure assessment tool that integrates a person-wearable video recorder with a data logging dust monitor that are worn by a miner in a backpack, safety belt, or safety vest to identify areas or job tasks of elevated exposure. After a miner performs his or her job while wearing the unit, the video and dust exposure data files are downloaded to a computer and then merged together through a NIOSH-developed computer software program called EVADE (Enhanced Video Analysis of Dust Exposure). By providing synchronized playback of the merged video footage and dust exposure data, the EVADE software allows for the assessment and identification of key work areas and processes, as well as work tasks that significantly impact a worker?s personal respirable dust exposure. The Helmet-CAM technology has been tested at a number of metal/nonmetal mining operations and has proven to be a very valuable assessment tool. Mining companies wishing to use this technique can purchase a commercially available video camera and an instantaneous dust monitor to obtain the necessary data, and the NIOSH-developed EVADE software will be available for download at no cost on the NIOSH website.

Feb 27, 2013

By Robert A. Farnfield

This paper outlines the theory behind transfer functions and illustrates their application in the prediction of structural response to blast induced ground vibration. The ability to predict the response of a structure to a recorded ground vibration is desirable for a number of reasons.

Jan 1, 1994

New Products Equipment

Jan 3, 1951

By Christopher Haycocks, J. Richard Lucas

The growth of computer and ground control technology in recent years, combined with an urgent demand for low-cost fossil fuels and mineral resources, has set the stage for full-scale utilization of computers in mine planning. Steeply rising production costs and the need to preserve the environment are placing great demands on engineers to improve their mining efficiencies, which can best be accomplished by applying the full capabilities of the computer. Pressure to develop and perfect programs with an immediate potential for improving mine design, reducing mining costs and extending the viable coal reserves of the country has already come to bear in the form of exploding energy requirements, environmental considerations and the visible limitations of other energy sources.

Jan 4, 1973

By Y. Wang

In this paper, the tribological and electrochemical corrosion properties of Al2O3/polymer nanocomposite coatings were studied using a micro-hardness test, a single-pass scratch test, an abrasive-wear test, and finally an electrochemical technique such as potentiodynamic polarization measurement, The coatings containing Al2O3 nanoparticles showed improvement in scratch and abrasive resistance compared with polymer coatings; this improvement is attributed to the dispersion hardening of Al2O3 nanoparticles in polymer coatings, Corrosion test results showed that the embedded Al2O3 nanoparticles in the polymer matrix do not sacrifice the corrosion resistance of the polymer itself.

Jan 1, 2005

By T. Mills, M. Evatz

Newmont’s Lone Tree Mine, located in northern Nevada, is an open pit gold operation supported by a standard truck and shovel mine production fleet (Caterpillar 785Bs and Hitachi EXs). Newmont continues to search for ways to decrease capital expenditure and lower operating cost, hence the implementation of the Ultra Light Body (ULW) concept. The fundamental idea associated with the ULWs is the increased payload potential. Economic justification comes from successful achievement of additional payload, within the truck’s rated GVW, without changing its loading and hauling characteristics. The increase in payload capacity allows equivalent tonnage movement using fewer trucks.

Jan 1, 2001