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By B Chi, A Mahanta, R A. M Maddever, O Dominguez

BHP Billiton, in collaboration with Sodern and CSIRO, has developed a downhole logging tool for measuring geochemistry in situ. The FastGradeTM 100 (alternatively, FG100), exploits pulsed fast and thermal neutron analysis (PFTNA) to analyse the rock. This method is based on the detection and measurement of characteristic gamma rays emitted from isotopes in the material that become briefly radioactive when they are bombarded with neutrons. The tool outputs raw spectra arising from three types of neutron interaction, namely, inelastic scattering, neutron capture and neutron activation, which occur in successive time-windows (Smith et al, 2015). The spectra contain peaks at specific energies that are characteristic of the different elements interacting with the neutrons, the gamma count of which is related to elemental concentration. BHP Billiton uses in-house data processing software to convert the measured spectra to elemental concentrations.Much work has been done to understand the tool response under a wide variety of environmental and operating conditions, including logging speed, borehole rugosity, the presence of cavities, water etc. Effort has also been directed at understanding and quantifying the current sources of error in our conventional assays due to sample collection, preparation, and laboratory instrumentation in order to use this information as a baseline to compare against the FastGradeTM 100 results.To date, the FastGradeTM 100 primary use has been as a verification tool (JORC, 2012). However, beyond this, it has considerable potential to improve productivity in both exploration and production environments due to its ability to provide geologists with assay results soon after a hole is drilled.This paper presents initial test work and tool performance, including accuracy and precision under various conditions. Results are illustrated by comparing tool measurements to assays from laboratory samples collected from both reverse circulation and diamond-drilled holes.CITATION:Chi, B, Maddever, R A M, Mahanta, A and Dominguez, O, 2017. Near real-time assay with downhole assay tool (FastGrade™ 100), in Proceedings Eighth World Conference on Sampling and Blending , pp 137–144 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By S. Sarac

Solving ventilation networks of natural splitting is a basic problem in mine ventilation. Several mathematical techniques are used to solve this problem. This paper proposes a new method which combines the advantages of both classical Hardy Cross method and unconstrained optimization techniques. The trials carried out on model networks have shown that the method offers some facilities in the analysis of mine ventilation networks. Keywords: Ventilation network analysis, Hardy Cross method, Steepest Descent method.

Jan 1, 2000

By Larry G. Stolarczyk

[STATES REPORT Mining Research Mine Health and Safety Research for Period Ending 30 September 1980 PROGRAM Wireless MF Communication System DATE STARTED January 1980 TPO (USBM) Robert I. Chufo (PSRC) CO ( USBM) Alan G Bolton, Jr, (Mr. Patrick Neary RESEARCH AREA Industrial Type Hazards SCHEDULED COMPLETED Phase I 29 September 1980 Phase II 29 June 1981 Phase III 29 April 1982 Subject OBJECTIVE Development of demonstration Hardware. for medium frequency mine tireless communication system.]

By C. Thiart

Kriging is an interpolation technique for predicting unobserved responses at target locations from observed responses at specified locations. Kriging predictors are best linear unbiased predictors (BLUPs) and the precision of the BLUP is assessed by the mean square prediction error (MSPE), commonly known as the kriging variance. Both the BLUP and the MSPE depend on the covariance function describing the spatial correlation between locations and on specific parameters. The parameters are usually treated as known, whereas in practice they invariably have to be estimated and the empirical BLUP (that is, the EBLUP) so obtained. The empirical or estimated mean square prediction error (EMSPE), or the so called ?plug-in? kriging variance estimator, underestimates the true kriging variance of the EBLUP, at least in general. In this paper five estimators for the kriging variance of the EBLUP are considered and compared by means of a simulation study in which a Gaussian distribution for the responses, an exponential structure for the covariance function, and three levels of spatial correlation ? weak, moderate, and strong ? are adopted. The Prasad-Rao estimator obtained using restricted or residual maximum likelihood (REML) is recommended for moderate and strong spatial correlation and the Kacker-Harville estimator for weak correlation in the random fields.

Jan 1, 2014

By James W. Reil, Douglas A. Anderson, Steven L. Burchell

A total of 26 full-scale production blasts at three sites were extensively monitored with sophisticated instrumentation systems to determine the benefits of more accurate detonators. The new and more accurate MS electric Masterdet detonator was tested against conventional detonators to determine any increase in productivity outputs. All blast design parameters between paired blasts were kept as constant as possible with the only difference being the inherent accuracy of both detonator systems.

Jan 1, 1986

By Kouichi Tomisawa

Two bridges were constructed for extension work of Central Hokkaido Connection Road in 2005 at two different sites. Pile group foundations were employed for the foundations of abutments of the two bridges. In order to assess the performance of the constructed piles in the sites and to obtain design parameters for design in future, static alternating cyclic horizontal load test was carried out on one of the open-ended steel pipe piles constructed at each site. The ground at one site was characterised as a thick deposit of volcanic soils, and the ground at the other site was characterised as a very soft peat layer near the surface. In this paper the results of static alternating cyclic horizontal load tests on the piles at the two sites are presented and discussed in detail.

Jan 1, 2006

By C. H. Kats, E. G. Meiter, J. J. Bloomfield

"INTRODUCTION.Street manholes for underground power and signal circuits, and for sewers vary in size from small openings that a workman can enter, to large central vaults. As the gas hazards in manholes are similar to those in mines, the mine safety committee of the Bureau of Mines was asked whether the miners' flame safety lamp is a practicable device for indicating inflammable gases in manholes.The coal miner detects firedamp (methane or CH4) with his flame safety lamp by observing the luminous can or the increased length of flame that appears when 1.5 per cent or more of the combustible gas is present. The lamp flame also warns him of lack of oxygen by going out when the oxygen becomes less than 16 to L7 per cent. A tentative rule regarding the proposed use of safety lamps at manholes has been suggested previously as follows: ""Testing for gas: Do not enter manholes until you have .assured yourself that the manholes are free from dangerous gases, by testing with an approved safety lamp, by ventilation, or by other adequate methods."" The Bureau's committee recommended that miners' flame safety lamps are not suitable,testing in manholes because hydrogen gas may be formed therein. The flame safety lamps approved by the Bureau of Mines for use in aseous mines are safe in presence of methane and while not tested against the members of the paraffin hydrocarbon series (CnH2n+2) higher than methane they been have been used therein; the lamps should not be used in hydrogen or acetylene they can initiate explosions in presence of these gases."

Oct 1, 1925

By Fábio Rogério do Carmo

O ar soprado é uma das principais utilidades responsáveis pelo processo de transformação do minério de ferro em gusa no Auto Forno. Para que ocorra o processo de redução o ar soprado é superaquecido nos regeneradores dos autos fornos a uma temperatura de 1.300°C. Este energético é fornecido na CSN-UPV pelos turbos sopradores da Central Termoelétrica nº 2 (CTE#2), área dos Motos Sopradores 1 e 2 e os turbos sopradores n°1 e 3 da CTE#1 que operam com a velocidade reduzida 24 horas soprando para atmosfera e consumindo vapor de 30Bar. Devido à obsolescência do sistema de ar soprado da CTE#1, alto custo de operação e risco para a segurança operacional, este trabalho apresenta o estudo do problema em questão, a metodologia utilizada para desativação do ar soprado da CTE-1 e a redução de custo.

Sep 25, 2017

By F. De Lucio

Para la aplicación de la instalación de un sistema de relleno hidráulico es necesario evaluar las funciones que el relleno debe contener y determinar si el material a usar cumpla con las funciones especificadas. En ese sentido, el objetivo del texto presenta una interpretación científica sobre tal método para especificar las funciones que el relleno deba cumplir y la metodología experimental adecuada que evalúe cuantitativamente a un relleno hidráulico.. Asimismo, se describen sus propiedades estructurales como la densidad relativa, reducción de volumen y estabilidad de tajeos contínuos, así como los métodos indirectos para inferir dichas propiedades y las posibles consecuencias secundarias que pueda generar el empleo de relleno hidráulico.

Nov 20, 1972

By J Belke

Murrin Murrin Operations have not had a successful beginning. Numerous reliability and operability issues, many of which are the result of design decisions, have been addressed through mechanical and operational changes and the CCD circuit is no exception. Four design aspects of the CCD circuit that have caused and continue to cause operational problems are: the inclusion of solution neutralisation gypsum in the CCD circuit feed which was designed solely for HPAL residue without proper investigation of its impact on the achievable underflow density and resulting wash efficiency; the decision to construct the thickener base from thickened solids; the lack of redundancy in the overflow, underflow and tailings pipe work; and the lack of thickener operational flexibility in the central rake-lift and feedwell dilution system. In November 2002, the lack of operational flexibility in the rake-lift and the feedwell dilution system was improved through mechanical modification as follows:CCD1 rake mechanism was modified to allow central vertical lift of 600 mm; and CCD1 changed to forced dilution using the Outokumpu TurbodilRântechnology by replacing the E-DucânRtechnology of Eimco. The installation and the results of the CCD1 rake-lift mechanism and feedwell dilution system changes are discussed in this paper.

Jan 1, 2004

By Norman] [Seldle

This report describes the development of a mine machinery training system from initial conception through a task and skill analysis, a training system analysis, implementation of a prototype system, and initial validation of the prototype system. The objectives of the training are to improve safety and productivity simultaneously via complete, thorough training. A task and skill analysts was executed for shuttle cars, continuous miners, cutters, loaders, face drills, tractors, and scoops. The prototype training system is for shuttle car operator training.

Jan 1, 1976

By Goutam H. Shahani

Today, the mining and mineral sectors are being impacted by highly fluctuating supply ? demand, extreme price volatility and tremendous market uncertainty on a world-wide basis. This pattern is expected to continue for the foreseeable future. In particular, large consumers of tonnage quantities of industrial gases (oxygen, nitrogen) all have to make informed investment decisions in this uncertain economic environment. Plant owners ? operators need to carefully examine their current and future industrial gas needs in order to develop the most cost-effective industrial gas plant configuration. This can be done by partnering with an experienced engineering company that offers a complete technology portfolio for producing industrial gases. Ideally, the mineral and engineering companies have to work together as a single team to identify the most efficient and economic plant design. This includes an in-depth assessment of capital and operating costs, in order to deliver an optimal solution, taking plant reliability and process safety into account. It is important to consider all the industrial gas needs at a given manufacturing complex, in conjunction with available utilities and infrastructure to develop the best possible long term solution. Oxygen (O2) requirements include: oxygen enriched and oxy-fuel combustion, smelting and hydrometallurgical operations. Nitrogen (N2) is used for annealing. All of these industrial gas requirements have to be examined at a given site over a long term horizon in a holistic manner. Cryogenic air separation was first practiced at a commercial scale in 1902. Since then, the technology has been constantly refined to reduce cost; and improve reliability and flexibility. Today, using advanced engineering techniques, including proprietary process simulation, and modern fabrication techniques, it is possible to build air separation plants that are both low cost and high quality at the same time. It is important to work with an engineering company that owns a complete portfolio of industrial gas technologies, functional engineering capabilities and a variety of plant solutions. Such a partnership can quickly identify a ?sweet spot? for a given situation. By drawing on experience gained from hundreds of projects, it is possible to quickly optimize a given requirement. In situations where a customer wants a complete solution it may be appropriate to provide an air separation plant on a turn-key basis. This will enable the mining and mineral processor to focus on their core business. By using global procurement and construction capabilities it is possible reduce cost and improve project execution, thereby making industrial gas plant procurement simpler and cheaper for the mining and mineral sector.

Nov 1, 2011

By William D. Monaghan, Michael A. Trevits

Over the period 2000 to 2003, roof falls have accounted for 4 to 14% of the fatalities in underground mining operations. The National Institute for Occupational Safety and Health (NIOSH) is conducting research to reduce the frequency, exposure, and risk of these events through an ongoing program of field and laboratory studies. One area of research involves the evaluation of polyurethane grouting technology that is commonly used to stabilize fractured mine roof strata. Concurrently, NIOSH is conducting work to evaluate the application of ground penetrating radar for advanced delineation of problematic mining areas. In this study, NIOSH partnered with Sub-Technical, Inc. who injected a polyurethane grout (also known as glue) into a roof area of NIOSH’s Safety Research Coal Mine. The mine roof area was scanned using ground penetrating radar technology before and after grout injection in an attempt to determine the extent of grout infiltration. A comparison of the pre-and post-grouting radar records showed a significant change at a mine roof depth of about four to five feet. The interpreted radar records were then compared with drill core information, borescope evaluation of roof-bolt holes in the study area, and underground observations. At this site, the interpretations of the radar records correlated with data obtained from the core holes, borescope evaluations and underground observations. This study showed that ground penetrating radar technology can be a useful tool for detecting changes in mine roof due to the injection of the grout.

Gold was determined directly in eight different mill cyanide solutions, by atomic absorption spectroscopy in an acetylene-air flame. Some of the mill solutions were diluted with water to bring them into the most sensitive absorption region (5-50 p.p.m. Au) whereas those solutions with very low gold content «2 p.p.m.) were concentrated by evaporation.Calcium was complexed with ethylene diamine tetra-acetic acid (EDTA) to avoid the undesirable effect of a precipitate on atomization.When added to standard gold solutions, EDTA had no effect on absorption, nor did any of the impurities common in mill cyanide solutions.Known amounts of gold, ranging from 2 to 30 p.p.m., were added to mill solution'aliquots and recovered to within 100 ± 2·5 per cent. For duplicate determinations under normal worKing conditions, standard deviation was 1·32 p.p.m.Excellent agreement was found between atomic absorption gold values and accurate fire assay values.INTRODUCTIONAtomic absorption spectroscopy has been shown to offer a rapid and accurate method for the determination of trace amounts of a number of metal ions. In the field of primary metallurgy atomic adsorption has been used for routine determinations of lead, copper, silver, zinc, cadmium and iron in a variety of raw materials and intermediate products.The scope of atomic absorption spectroscopy was reviewed recently by Willis (1963).The noble metals silver, gold, platinum, rhodium and palladium were determined by atomic absorption from chloride solutions by Lockyer ·and Hames (1959). In their determination of gold down to 1 p.p.m., they found no interference from the noble metals, nor from considerable excess...

Jan 1, 1964

Jan 1, 1997

By G. L. Smith

Central to the success of any mining company is the ability to manage capital investment effectively so as to ensure acceptable stakeholder returns within an overall strategic context. Critical to this process is the effective selection and implementation of a strategically aligned project portfolio that enables optimal resource exploitation while operating within mandated bounds and identified constraints. Consideration is given to the strategic long-term planning process, an investment prioritization methodology and specific tools and techniques based on the discounted cash flow philosophy.

Jan 1, 2007

By Svend [Bue] Rondum

The final report contains a summary of the work performed under this contract, In addition to the report itself, other products were derived from this effort. Several hardware items were prototyped for use with underground belt conveyors, and a manual for installation and maintenance procedures was developed and published under separate cover. Recommendations have been included for implementation of the tools and the manual or, an industry-wide basis.

Jan 1, 1982

By M. Fan

Froth flotation is the most widely-used method of separating fine coal, especially coal with coking properties. However, froth flotation is not efficient for treating ultrafine coal and coarse coal particles. Our previous fundamental test results demonstrated that cavitation-generated nanobubbles can significantly improve coal and phosphate flotation performance over a wide particle size range. In this study, the effect of nanobubble on the flotation performances of different particle size fractions of coal was investigated using a bank of 10-liter flotation cells, a specially designed 50 mm inside diameter column and a 152 mm inside diameter column. It was found that nanobubbles that were either directly formed on or subsequently attached to the surface of coal particles during coal froth flotation process improved flotation efficiency. The use of nanobubble in a bank of mechanical cells flotation and column flotation significantly increased the flotation recovery at a given product grade. Nanobubbles increased the flotation rate constants of different coal particle sizes. The presence of nanobubbles in flotation slurry could extend the lower and the upper particle size limits for effective coal flotation.

Jan 1, 2012

By Jack Wasserman, Don Wasserman, Logan Mullinix, Shekhar Khanal, Kelly Neal

This paper presents current finding on truck driver average exposure to acceleration for several different manufacturer’s cab-over trucks on a variety of roads in different countries. The predominant time, for this aspect of the study has been spent in the area around London, England and Warsaw, Poland. The ECE directive 2002/44/EC has provided specific guidelines for vehicle operators 8 hour average acceleration exposure. The primary considerations have been on truck design including the air-ride driver’s seat. The truck manufacturers have produced truck cabs that have some separate suspension from the truck frame. The truck seat manufacturers have been producing air-ride suspension seats for the cab. Both of these designs have had the objective of meeting the ECE directive and providing the vehicle drivers with some degrees of comfort. This paper will provide some information on the ability of the vehicles to operate on a variety of roads and meet the objectives. Method The primary method for evaluation of the driver’s exposure has been the use of a seat pad attached to the driver’s seat. Although this sensor system provides the critical information for the driver, an understanding of the reasons for the values requires additional measurements. The initial study in England used both driver and passenger seat pads, as shown in Figure 1, as well as triaxial accelerometers mounted on the base of the seat. The latest studies used significantly more transducers to better understand the relative rotations and translations on the truck frame, the cab, and the driver. [ ]

Jan 6, 2006

By Paul Headland

The Washington Suburban Sanitary Commission (WSSC) has recently completed design for the Bi-County Water Tunnel Project. The project will include a 10-foot diameter, 5.3-mile long hard rock tunnel located within the Piedmont Physiographic Province in Montgomery County, Maryland. The rock formations present along the alignment are comprised of igneous and metamorphic lithologies. This paper presents the steps taken to characterize the complex geology along the tunnel alignment into a single ?Engineering Unit? based upon the intact rock and rock mass properties. The Rock Mass Rating (RMR) system is planned to be used as the basis for dividing the ground into three ?Excavation and Support? classes. This RMR approach was selected to establish contractual baselines as presented in the Geotechnical Baseline Report (GBR) and is intended to facilitate management of the ground support characterization during construction.

Jan 1, 2008