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By J. Boitano

This paper discusses the study, design and implementation of the new gas handling system for the Caletones Smelter of Cbdelco..Chile. A discussion on design conditions for a Mure Sulphuric Acid Plant using Teniente Converter.gases.is also included. The old system which started to be modified in 1985 and relied on natural draft and used balloon flues, resulted in a limited .gas handling capacity for operation under Mure process conditions. This system also caused excessive fugitive gases in the smelter working areas. The new system permits handling of process gases from the higher capacity Teniente converters installed in 1987-1989 Improving the gas handling of the reverberatory furnaces and Peirce-Smith converters as well as the environmental conditions of the smelter. This system utilises improved converter gas hoods, evaporative cooling and electrostatic precipitators gas cleaning, and is based on natural draft.

Jan 1, 1992

Table A. Conversion of English to SI Units Table B. Strength Properties of Rocks Table C. Engineering Properties of Rock Table D. Properties of Common Minerals Table E. Material Properties and Characteristics Table F. Heat Value of Various Fuels Table G. Geometrical Relationships and Mensuration Formulas Table H. Standard Sizing and Meshes Table I. Ship Measures Table J. International Atomic Weights Table K. Time Value of Money Factorsfor Discrete Compounding

Jan 1, 2008

By Charles T. Ford

In 1971, Bituminous Coal Research, Inc~ established a program to provide the coal industry with the necessary information and technical capability to investigate and evaluate potential problems concerning trace elements in coal and coal-related materials. The initial efforts at BCR in developing or adapting analytical procedures for the precise determination of trace elements in the parts per million to parts per billion range were detailed in a report titled "The Development of Analytical Methods for Determining Trace Elements in Coal and Coal-related Products." A subsequent reports contained descriptions of reliable analytical methods refined by BCR for determining mercury in coal and coal ash and also in coal mine water. his paper reports initial progress in applying recently-acquired trace-element analytical capabilities to solving potential coal industry problems. In this case, the effect of a coal-cleaning process on the distribution and removal of potentially harmful trace elements in coal was evaluated. Coal cleaning offers the possibility of controlling potentially harmful emissions resulting from combustion of large tonnages of coal by removing the pollutants prior to combustion.

Jan 1, 1977

By S. Sinha, S. Ganguly

"In an opencast mine explosives are used for fragmentation of rock. Inefficient use of explosive energy in an opencast operation produces excessive ground vibration, which is measured by peak particle velocity (PPV). To mitigate ground vibration, it is essential to develop a model to predict PPV. At present empirical models are used. These models are based on only a few input variables, hence they fail to take into account the effects of the myriad factors that cause ground vibration. Due to lack of explicit knowledge about the complex mine blasting system the scope of application of mathematical and statistical modeling techniques is limited. The artificial neural network (ANN) technique is a learning algorithm that can remove some of these limitations and can be applied to predict PPV. In this paper an ANN model is developed for prediction of blast vibration using 248 data records collected from three coal mines with diverse geomining conditions. The correlation coefficient between measured PPV and model output was found to be 0.96 and the average error percentage 11.85. The ANN model output was compared with the output of three empirical models that are widely used for prediction of PPV. The correlation coefficient between the PPV predicted by an empirical model and measured PPV data was 0.63 and the relative error percentage 38.47. This result demonstrates the superiority of the ANN model compared to empirical blast models. By using site-specific structural discontinuities as input the model performance can be further improved. Sensitivity analysis and 3D plotting were used to gain further knowledge about blast-induced ground vibration. IntroductionIn an opencast coal mine explosives are used for fragmentation of coal and overburden. If the explosive energy is not fully utilized it causes blast-induced ground vibration, which may damage nearby structures. Ground vibration is expressed as peak particle velocity (PPV). During different stages of mine planning and operation, it is necessary to use a ground vibration prediction model for blasthole design. Selection of the modelling technique is crucial. Mathematical and statistical modelling techniques have limited application because of the lack of explicit knowledge about the complex mine blasting system. Vogiatzi (2002) highlighted the problem of multicollinearity in case of statistical modeling techniques. Mutalib et al. (2013) stated that mathematical models are unable to capture the nonlinear relationship between several blasting-related parameters due to the complexity of the model input data. However, the difficulty involved in modelling complex blast vibration problems can be removed by adopting an alternative soft computing modelling approach. One of the soft computing techniques is the artificial neural network (ANN). Ragam and Nimaje (2018) developed an ANN model for predicting PPV using six input variables. Kosti et al. (2013) stated that the conventional predictors fail to provide acceptable prediction accuracy. They showed that a neural network model with four mine blast parameters as input could make significantly more accurate on-site predictions. Sayadi et al., (2013), using a database from Teheran Cement Company limestone mines, found that a neural network resulted in maximum accuracy and minimum error. Khandelwal and Singh (2009) developed an ANN model using 150 data records from an Indian coal mine with site-specific rock characteristics and geomining setting. Khandewal and Singh (2007) built a ground vibration prediction model for a magnesite mine using four prediction variables with 20 data records. Kamali and Ataei (2010) predicted PPV in the structure of the Karoun III power plant and dam using an ANN. El Hafiz et al. (2010) evaluated ground vibration predictors using data from a single-station seismograph at a limestone quarry in Egypt."

Feb 1, 2019

By E. R. Leeman

INTRODUCTION The first references in the literature to the so-called C.S.I.R. 'doorstopper' strain cell were made in 1964 1,2,3,4. These were the climax of nearly two years of experimental and developmental work with the instruments and the operating techniques involved. Since that time numerous field measurements have been made with 'doorstoppers' and they have been developed to a stage where they are in commercial production and are being supplied to users throughout the world. No detailed description of the latest 'doorstopper' equipment has, however, appeared in print and this paper is written to bring the literature up to date in this respect. The triaxial strain cell was developed three years ago 5, 6, 7 and was first described at the First Congress of the International Society for Rock Mechanics in Lisbon in 1966 8. Since that date laboratory tests and-particularly important-field tests 7' 9 have demonstrated the validity and practicality of the instruments and techniques. These instruments have also been developed to a stage where they have been released for commercial production. In this form they are very different from those described two years ago and a full description of them at this stage seems to be justified. THE INFORMATION SUPPLIED BY 'DOORSTOPPER' AND TRIAXIAL STRAIN CELLS Both the 'doorstopper' and triaxial strain cells were designed specifically to determine the absolute stress in rock using an overcoring stress relieving technique. They were not designed to measure changes in stress. They may, however, be used for the latter purpose provided the glue which is used to stick the strain gauges to the rock is known to possess sufficiently stable strain-time characteristics as not to affect the accuracy of the results during the time the measurements are made. The 'doorstopper' was designed primarily to measure the major principal stress in situations where its direction and those of the two other principal stresses were either known or could be assumed. For example, at great depth in undisturbed virgin ground, it is reasonable to assume that the maximum principal stress is vertical and that the other two lie in a horizontal plane. The borehole in which the 'doorstopper' is installed would thus be drilled in the horizontal plane parallel to one of the minor principal stresses, the direction of which would either have to be assumed or determined as described later. The stresses measured would be the vertical major principal stress and the principal stress acting in a horizontal plane normal to the borehole axis. It is possible, as will be shown later, to obtained the complete state of stress using 'doorstoppers'. In this event, it is necessary to make measurements in three boreholes drilled in any three known directions to each other and relative to a system of three orthogonal axes. The triaxial strain cell was designed to determine the complete state of stress in a single borehole drilled in any direction in any stress field. At first glance it would appear to supersede the 'doorstopper'. This is not necessarily true since there are

By G. P. Gu, B. Fang, R. W. Revie, M. Elboujdaini

Stress-corrosion cracking (SCC) tests were conducted in the near-neutral pH standard solution, NS4, and in an actual soil solution, using four-point bending at high a stress ratio and low frequency conditions very similar to those of operational pipelines. Pitting incubation appeared first and then pitting initiated and grew in both solutions although there were many more pits on the specimen tested in soil purged with 5% CO2 + 95% N2 than in the specimen tested in NS4 solution purged with the same gas. These observations show that samples in soil solution are more susceptible to pitting than those in NS4 solution. When the pit reached a critical size, the increased stress concentration around the pits, resulted in the transition to a crack.

Jan 1, 2005

By William E. Roscoe

"Non-producing mineral properties include those at various stages of exploration, properties at the pre-feasibility or feasibility stage, properties with currently uneconomic mineral resources, and past-producers. The market approach is applicable to all these types of non-producing mineral properties. Income approach methods such as discounted cash flow and option pricing are generally not applicable to properties at the exploration stage, but may be applicable to non-producing mineral properties with defined mineral reserves or mineral resources.The value of a non-producing mineral property depends on its perceived potential for the existence and discovery of an economic mineral deposit. The potential, in turn, depends on a number of factors which must be considered when choosing market comparables. These comparability factors include such items as geology, mineralization, stage of exploration and results, mineral resources, location and geography, and political jurisdiction. The date of the market comparables must be within a reasonable time period of the valuation date of the subject property. Although it is difficult to find good market comparables because of the unique nature of mineral properties and the small number of transactions, these difficulties are compensated for by analyzing a number of transactions on similar properties to develop a range of values for the subject property.For valuation purposes, market comparables can be expressed in terms of total property value, value per unit area (e.g., $ per hectare), or value per unit of metal contained in mineral resources (e.g., $ per ounce of gold, or $ per pound of copper). The market comparable value can be used to estimate the value of the subject property by using the total property value, unit area value or contained metal value."

Jan 1, 2003

By R. Krentz, P. D. Cordingley

The nickel-cobalt sulphides produced from limonitic laterite ores by Moa Nickel S.A. in Cuba are refined at the Corefco nickel-cobalt refinery in Canada. Major changes to the refining process were required when the Moa sulphide feed, with its unusually high cobalt content, was introduced in the early 1990's. In the period 1994 to 2005 the production capacity of the refinery has increased dramatically to match increases at Moa, and significant process improvements incorporated. The process flowsheet consists of the original ammonia leach process, optimized for cobalt chemistry and overall leaching capacity. Extraction of metal values is followed by the unique nickel-cobalt separation technology, in which most of the cobalt is separated from the ammoniacal nickel sulphate leach solution by precipitation as a nickel-cobalt hexammine salt. This salt is refined from a Co:Ni ratio of 1:1 to over 10,000:1 by selectively leaching nickel, redissolution and recrystallization in ammonium sulphate solution. Nickel and cobalt are recovered using the well-known Sherritt hydrogen reduction technology. This paper reviews the chemistry described above, examines some of the changes in operating conditions made over the years and highlights some of the recent physical changes made to the refinery.

Jan 1, 2005

Getting it right is a very profitable outcome. Shareholders would ideally like to see their directors get it right all the time on the major economic decisions. But it is very difficult for mining directors to get it right all the time in such an uncertain environment. Primary decision-makers of companies with significant stakes in the mining industry should get it right much more frequently. The legal measures of evidence (beyond reasonable doubt and on the balance of probabilities) can be used to determine whether grade estimates (a key revenue variable) are realistic. The application of this approach can be far reaching. More frequently correct decision-making would result in more effective allocation of limited resources (capital and labour). In turn, this would result in higher financial returns and a more extensive mining industry.

Jan 1, 1994

By L. A. Cisternas, R. I. Jeldres, D. Calisaya

"Flotation of copper-molybdenum sulphide ores in seawater entails critical challenges such as selective recovery of molybdenite, effective pyrite depression, and reducing the lime addition required to reach highly alkaline conditions. It is essential that laboratory flotation tests aimed at solving these problems give reliable, reproducible results and indicate the correct approach for industrial operations. Rougher flotation of coppermolybdenum sulphide ores in seawater was investigated using two different cells: a modified Denver cell and a standard commercial cell. The effect of an organic reagent on the flotation performance was tested, and the fast/slow-floating model was used to describe the results. The modified Denver cell significantly improved the reproducibility of the flotation test results, due to technological enhancements such as the impeller being driven from below without a stator, which enables the whole froth surface to be scraped with a paddle at a constant depth and rate. Organic reagents are a promising alternative to inorganic reagents for depressing pyrite in seawater. However, further studies should be conducted to investigate their impact on molybdenite recovery, as well as to evaluate the possibility of depressing pyrite after molybdenite separation. The fast/slow-floating model was found to be appropriate for describing the flotation kinetics of the copper-molybdenum ores. The parameters are useful for comparing the performance at different conditions. IntroductionOwing to the increasing scarcity of fresh water, the use of seawater mining and mineral processing is becoming increasingly important (Cisternas and Moreno, 2014). Seawater can be desalinated by reverse osmosis, but this involves considerable costs, limiting it to the big mining companies (Akgul et al., 2008; Leidner et al., 2012; Ghaffour, Missimer, and Amy, 2013). Furthermore, desalination has environmental consequences (Lee, Arnot, and Mattia, 2011); for example, a desalination plant designed to process 2.5 m3/s requires an electrical energy supply of around 30 MJ/s. To supply this power demand, a thermoelectric plant burning bituminous/sub-bituminous coal mixtures at a thermal power generation efficiency of 35% might release around 1200– 1500 t of CO2 per day. Furthermore, the effluents from desalination plants are typically discharged into the sea, and their high temperature and ionic content inevitably modifies the marine environment, with unknown consequences. The direct use of seawater is, therefore, more attractive, but it also poses major challenges since seawater contains ions that adversely affect mineral recoveries. In particular, in the flotation of sulphide ores in seawater, the floatability of molybdenite is depressed (Castro, 2012; Laskowski, Castro, and Ramos, 2014)."

Jan 1, 2017

By Thomas Brunsing

The program was carried out to develop deep kerfing and core breaking techniques to be incorporated into the design of a field prototype hard rock mining machine. The field machine is designed to mine non-abrasive bedded deposits up to 20,000 psi in uniaxial compressive strength. The mining technique involves cutting approximately 2 ft deep parallel kerfs spaced 2 ft apart in either a horizontal or vertical direction and subsequently breaking out the cores so defined. The prototype machine is intended for demonstration of the technique in a quarry or equivalent field environment. The program was aimed at minimizing the required kerf width, obtaining reliable breaking within that kerf width and determining cutter blade requirements necessary to achieve a mining rate of 20 ft3/min. Full scale breaking experiments and 1/2 scale kerfing experiments were employed to evaluate the system. High strength concrete test specimens were used to simulate the rock being cut and broken. The test results indicate the kerf/break technique can achieve the desired mining rate by utilizing two 7 ft diam blades to cut 2 in. wide by 24 in. deep kerfs. A lateral load applied at the base of the kerf (base shear) was selected at the core breaking technique to be employed by the full-scale prototype machine.

Jan 1, 1983

By J. Perlacia, J. M. Eguiluz

"INTRODUCTION The Bulk Handling Technology has suffered an important development in the recent years, allowing the use of conveyor belts in the most important and critical applications. As a consequence of this, the reliability and lasting performance of the conveyor belt components is becoming more and more significant, thus the implementation of preventive maintenance programs is a must. The rollers are one of the consumables in the conveyor belts, which have to be changed once arrived to the end of life. The actual ways of detecting this moment always require intensive use of labour and they are not very accurate. Indeed, if the rollers get broken before replacement, the consequences could be very important, generating additional costs and operational losses. The R&D Department of ULMA Conveyor Components, has been working since early 2012 on the development of Monitored Rollers along with a Management Software to provide users the capacity to Manage and Monitor the rollers from its desk, getting continuous online information on the internal temperature of the bearings, on the working status of the rollers as well as the identification of the rollers close to their end of life so that they could be changed during the next maintenance stop of the conveyor belt. In short, a system of Preventive Maintenance for Conveyor Belt Rollers BACKGROUND AND CURRENT STATE The malfunction of a single roller in certain conveyor belts can suppose the standstill of the whole installation until its replacement, due to the risk of greater and more expensive failures like the rip of the belt. In the case of a bulk handling installation where a continuous supply of material is necessary, a bare stop of one hour could entail huge economical losses. What’s more, many conveyor belts are several kilometers length or the access to some parts of them is very complicated. Due to these difficulties the inspection and maintenance operations can become expensive and hard going, with staff going over the whole area checking the correct condition of the conveyor and rollers, which means a dangerous activity. In addition, it’s quite common to find rollers working in very harsh conditions, completely exposed to the elements or working in corrosive closed environments like underground mines. These tough working conditions together with the very demanding features of Bulk Handling sector (high loads, speed, dangerous materials etc.) can bring the unexpected failure of a roller, even being designed to support them. Thus, to have the working conditions of the rollers real time is clearly required, in order to achieve an actual predictive maintenance of the system and avoid fatal failures. Nowadays the most common procedures to identify a broken roller is to hear how it sounds or use thermo-graphic cameras to measure their internal temperature, both of them implying workers inspecting the whole length of the conveyor while the conveyor is running. This means intense use of workmanship and operational safety level reduction."

Jan 1, 2018

By Osvaldo A. Bascur

One of the most vigorous of the continuous improvement methodologies is Six Sigma. While usually associated with improving manufacturing and product quality, leading manufacturers are using it to improve their extended supply chain and logistics capabilities. At the same time they are improving reliability, some companies have cut hundreds of millions of dollars of fat out of their supply chain. Mine to Mill optimization is a transformation of culture from processing tons to processing a quality feed size distribution which reduces the overall operational costs and add the highest value to the mine. This is not a constant endeavor. As such, a dynamic performance monitoring and diagnosis is necessary. We will review a systemic way to performance improvements and avoiding metal losses from the blast to the metals. We show the requirements of using raw data to analysis the data to define operational maps which provide assistance to run the mine and mill. A case study is provided with the mine and mill data was integrated combining process control and quality information resulting in reduction of water and energy consumption while improving the overall value of the mine. The results of reengineering the current system with this SIX SIGMA Strategy had the following results: an increase of ore milling: 4.6% decrease of mil power: 3.9%, decrease of fresh water consumption: 6.8%, with a total of net profits: US$ 31.8 million, the PI System infrastructure contribution: US$ 7.95 million. These estimates were for the period 2009/04/04 to 2009/12/31.

Sep 1, 2012

By Siavash Mahvelati, Alireza Kordjazi, Joseph Thomas Coe

Deep foundations are often constructed as end bearing members with a significant amount of their capacity derived from bedrock. Sites with highly variable bedrock conditions therefore present a unique challenge when attempting to estimate the design elevation of deep foundations. Typical subsurface characterization techniques such as drilling, standard penetration testing (SPT), and cone-penetration testing (CPT) may fail to adequately establish top-of-rock elevation in geologic settings prone to karst and/or significant amounts of residuum, saprolite, and deformed bedrock. Seismic surface wave geophysical methods have been increasingly used to map bedrock topography in such settings. However, the current standard of practice for these methods introduces resolution limitations in spatially variable subsurface conditions due to averaging effects from the analytical framework used to process the acquired data. This study explores the use of a tomographic approach with full waveform inversion (FWI) to map top-of-rock elevations at a numerically simulated site representative of highly variable bedrock topography. Comparisons are made with seismic refraction (SR) and a dispersion-based multichannel analysis of surface waves (MASW) approach as more commonly used in geophysical subsurface investigations. The results highlight that FWI provides a superior estimate of top-of-rock topography than SR and MASW at a cost of a significant increase in the required computational resources and time.

Sep 8, 2021

By Siavash Mahvelati, Alireza Kordjazi, Joseph Thomas Coe

Deep foundations are often constructed as end bearing members with a significant amount of their capacity derived from bedrock. Sites with highly variable bedrock conditions therefore present a unique challenge when attempting to estimate the design elevation of deep foundations. Typical subsurface characterization techniques such as drilling, standard penetration testing (SPT), and cone-penetration testing (CPT) may fail to adequately establish top-of-rock elevation in geologic settings prone to karst and/or significant amounts of residuum, saprolite, and deformed bedrock. Seismic surface wave geophysical methods have been increasingly used to map bedrock topography in such settings. However, the current standard of practice for these methods introduces resolution limitations in spatially variable subsurface conditions due to averaging effects from the analytical framework used to process the acquired data. This study explores the use of a tomographic approach with full waveform inversion (FWI) to map top-of-rock elevations at a numerically simulated site representative of highly variable bedrock topography. Comparisons are made with seismic refraction (SR) and a dispersion-based multichannel analysis of surface waves (MASW) approach as more commonly used in geophysical subsurface investigations. The results highlight that FWI provides a superior estimate of top-of-rock topography than SR and MASW at a cost of a significant increase in the required computational resources and time.

Oct 1, 2021

By E. Heikkinen, J. Suikkanen, T. Siren, J. Valli, M. Hakala

Diametrically faced borehole breakout observations are a fairly good indication of magnitude of the secondary stresses acting perpendicular to the borehole. In cases of low in situ stresses, where borehole breakouts are not observed naturally, it is possible to increase the prevailing stress state around the borehole by increasing the rock temperature. When the temperature is increased sufficiently, thermally induced borehole breakouts will occur. By implementing the temperature increase in boreholes located at excavated tunnels, it is also possible to study the effect of the near-field stresses caused by the excavation. The near-field stress state changes as a function of borehole depth, thus increasing the information available from experiment. To study the feasibility of this proposed low cost method, a Borehole Thermal Spalling (BTS) experiment was executed in ONKALO Underground Rock Characterization Facility, in Western Finland in 2014. The first borehole pilot test with the method was conducted in ONKALO at the POSE niche in already at May 2010, with the second pilot test following in August 2010 at Äspö HRL. The major objective of the experiments was to define the trend of the maximum in situ stress component, while also providing knowledge of the in situ spalling strength of the ONKALO rock mass. The stress state in ONKALO is nearly isotropic in horizontal layer, causing problems for the use of more traditional stress measurement methods. With boreholes heated over long interval, the weakest rock parts are observed to fail, thus providing statistical confidence. For these reasons, continuous test sections have an advantage in ONKALO, compared to spatially limited stress measurement methods such as overcoring and hydraulic fracturing. The BTS experiment is conducted in 9 meter deep vertical boreholes located at the POSE niche, situated -345 m depth below the ground surface. The boreholes used within the BTS experiment are located in migmatitic granite, in an experiment area where the surrounding stress state and the rock strength are fairly well known. The prior knowledge of the stresses is favourable for the experiment, as it requires careful planning and iterations to determine the appropriate heating power domain. Too low heating power will not be sufficient to cause borehole breakout, while too high heating power causes breakout in all directions thus making determination of stress direction hard or impossible. The initial state of the borehole and induced borehole breakouts will be monitored using acoustic televiewer logging (ABI) and optical borehole logging (OBI) imaging techniques. Fracture mechanics modelling is used in planning of the experiment, also in back-analysis to link the observed breakout angle to stress state. Both the pilot test in 2010 and BTS test in 2014 resulted in similar borehole breakout direction. The results are in line with so called EDZ & VT1 stress interpretation, revealed the maximum horizontal component bearing the magnitude of 21.5 MPa, with the trend of 166°.

Jan 1, 2015

By Madan M. Singh

Hydraulic mining has been practiced in the United States since 1852 and many mineral commodities, such as gilsonite, phosphates, lead-zinc, silver ores and St. Peter Sandstone can be mined in this manner. In 1958, the U. S. Bureau of Mines initiated research into the mining of coal using these techniques.1-4 These early investigations were conducted in the 5000 psi pressure range. The large nozzle diameters used in this pressure range produced extremely high flow rates which created visibility problems at the coal face, and required removal of large amounts of water from the mining area. Besides, the production rates were not much better than with mechanical methods. This indicated that with higher pressures the water quantities might be reduced using the same or higher horsepowers but enhanced breakage. For this reason intensive investigation in material removal using fine water jets at extremely high pressures (50,000 psi to 100,000 psi) has been undertaken. This was not the entire reason for this contract from the Bureau of Mines, however. The contract objective is outlined later. IIT Research Institute has done pioneering work in high pressure jet development in the United States.5-8 Similar schemes have been investigated abroad. 9-13 Hydraulic mining of coal at relatively low pressures is successfully being done in the Soviet Union, Japan, Canada, and most recently, in Germany.

Jan 1, 1973

By K. Zipf, Z. T. Bieniawski

"An extensive mixed-mode fracture toughness testing programme was conducted on coal from three coal fields. A special mixed-mode testing fixture for coal and other geologic materials was developed together with reliable specimen preparation procedures. Dynamic modulus measurements made on each of the 116 fracture toughness specimens showed that these coals exhibit certain degrees of anisotropy. The fracture toughness testing programme systematically varied the loading rate, specimen orientation and fracture loading mode. Loading rate did not significantly effect the fracture toughness over the quasi-static range tested. Orientation did have a significant effect on measured fracture toughness. In the coals tested, the divider orientation and arrester orientation had higher fracture toughness than the short transverse orientation. Data showed that one orientation could have almost twice the fracture toughness as another. The fracture toughness testing enabled certain evaluations of three mixed-mode fracture theories: maximum tangential stress, maximum energy release rate and strain energy density theory. Due to the extreme heterogeneity of the coals tested, definitive conclusions regarding the best mixed-mode fracture theory are not possible; however, data do tend to support the strain energy density theory. INTRODUCTIONThe major aim of this research is to ·develop a fundamental understanding of how fine· fragments of coal (respirable dust) are generated during a fracture process. In a related paper [l], a hypothesis was presented for the mechanism of fine fragment formation during a generic coal material/cutting tool interaction. In this hypothesis, fine fragments are created during coal material/cutting tool interactions that are best described as general mixed-mode fracture processes. Data are required on the mixed-mode fracture behaviour of coal, the physical character of the newly-created fracture surfaces and the character of the inherent flaw structure of the coal material. Accordingly, a test programme was designed that provided some information in each of these areas. The testing effort seeks to measure critical fracture toughness under mixed-mode loadings as a material parameter characterizing in part the tendency of various coals to generate undesirable quantities of fines and respirable dust."

Jan 1, 1990

By Michel Carreau

Presentation topic Introduction to Renewable Power in Remote Mining Industry Trend What are the Challenges and How to address them Acceptability (Management Buy-in) ? RP not core business to mining company Significant upfront costs Project Risks - Technological and Delivery Wind and solar power variability Operating hybrid power (Operator Buy-in) Conclusion Introduction ? RP at Remote Mining Sites Mining Project Cost Energy represents 25% of mining project CAPEX Energy represents 25% of OPEX Diesel, HFO, ? cost : 30+ cents/kWh RP - Proven technology - Excellent track record ?Wind (20 years), Solar PV (10+ years)? Hundreds of GW installed ?Reliable, High availability, very small OPEX. ?Wind/Solar cost : 15 to 22 cents/kWh (with good resource) ?Potential 10% to 20% Reduction in net cost of energy ?Price certainty for 20 to 25 years

May 1, 2013

By D Kent, J Bullock, M Wilkinson

Over the last few years at Glencore’s Mount Isa Copper Operations (MICO) mining conditions have become increasingly challenging through lower head grades and higher work indices. MICO has had great success improving operating efficiencies and increasing productivity through focusing on technology, innovation and operational discipline. The recent implementation of the Mine Site Technologies (MST) ImPact System has supported the continued transformation of the MICO operations through improved personnel safety and direct measurement of productivity. The ImPact System has implemented new safety systems such as the heavy vehicle proximity detection system, underground personnel tracking system and emergency evacuation dashboards improving the overall safety of the workforce. The ImPact System has facilitated productivity improvements via real-time equipment and personnel monitoring, and the implementation of exception reporting (personnel productivity), KPI reports and production dashboards, and transparent reports highlighting developing maintenance issues.This paper discusses the components of the ImPact System, the current installation at MICO, and critically analyses the implementation processes and right sizing of the system to meet the needs of the business today and into the future.CITATION:Bullock, J, Kent, D and Wilkinson, M, 2017. Productivity and safety improvements supported by MST’s ImPact System at Glencore’s Mount Isa Copper Operations, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 279–286 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017