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By H. C. Fowler, G. B. Shea

MODERN industry's incessant demands for increased operating efficiency and lower costs require that hazards attending all occupations be reduced to a minimum. Reduction of the inevitable losses that result from accidents and injury to the worker is one of the important economic problems confronting industry today and is the basis for the widespread safety movement. Dr. Charles E. Munroe, chief explosive chemist of the U. S. Bureau of Mines, is father of the statement, "The existence of a nuisance is evidence of an economic waste." This pointed expression of the internationally recognized scholar and explosives engineer has a direct relation to the prevention of accidents. Every injury and death in industry is a waste in human endeavor and a lessening of productive gain. Dr. Munroe has aptly paraphrased his previous summation with reference to wastes as follows: "A lost-time accident is evidence of an economic waste." That the economic waste entailed by occupational accidents is chargeable to industry is well substantiated by the fact that all but four states (Mississippi, South Carolina, Florida and Arkansas) now have workingmen's liability and compensation laws.

Jan 1, 1933

By Ken Cross

This paper aims to demonstrate that explosives organizations and workers have a legal, moral and financial duty to be able to demonstrate their competence when required, and how that may be achieved at any level from explosives storekeeper to senior explosives engineer on a major project. The concept of competence is outlined, as are the benefits to members of staff, management and the organization, particularly in a regulatory regime that includes competence management as a key performance indicator.

Jan 1, 2013

By D. S. F. Silva

A survey of 120 recent NI 43-101 technical reports was conducted to evaluate the current state of practice regarding resource classification techniques. The most common classification techniques are based on search neighbourhoods (50% of recent reports), drill-hole spacing (30% of recent reports), and/or kriging variance (6% of recent reports). Two new techniques are proposed. The first is based on kriging variance and involves removing one or more drill-holes with the highest weights while performing kriging and using the resultant kriging variance for classification. This technique has the advantages of variance-based techniques and reduces artifacts. The second technique is based on conditional simulation and uses a moving window approach for classification at the desired selective mining unit resolution based on larger production volume criteria. This technique has the advantage of accounting for heteroscedasticity, which is a common characteristic in mineral deposits, and also reduces artifacts since a production volume scale is considered for the actual classification. The drill-hole spacing, search neighborhood, kriging variance, and simulation-based techniques are described and compared for 2D and 3D examples with regular and irregular drilling patterns to highlight the advantages and disadvantages of each method.

Jan 1, 2014

The need for legislative reform of health and safety legislation has been recognised in New Zealand for about a decade. Previous legislation did not cover all work places, many areas were excluded from coverage, and there were at least 14 different acts and dozens of sets of regulations dealing with various aspects of health and safety.

Jan 1, 1993

The Waimumu area, 12 km southwest of Gore, is underlain by the Gore Lignite Measures, an early Tertiary fluvial sequence approximately 500 m thick resting on Triassic-Jurassic argillitic basement. The Waimumu Quartz Gravels (Pliocene) have been deposited locally and are in part due to the localised reworking of the Gore Lignite Measures. Structurally the area is dominated by the Dunsdale Fault System, a steeply dipping series of NE trending reverse faults (Isaac and Lindqvist, 1990). The Belle-Brook, Hedgehope and Parker Road sites sampled are adjacent to the downthrown (east) side of the Hedgehope Fault.The authigenic gold-sulphide association at Belle-Brook was discovered in 1987 (Falconer, 1987: Clough and Craw, 1989). Despite a very limited amount of alluvial mining a significant quantity of authigenic marcasite has developed. Authigenic sulphide trace element analysis has shown anomalous amounts of As, Ni, Cr and to a lesser extent Zn, Pb and eu (Table 1). It has been established that the nickel occurs as a colloform banded Ni sulphide, possibly bravoite, within the marcasite (Figures 1 & 2). Arsenic and nickel (re)mobilisation are well documented in the literature. Generally As and heavy metals are mobilised in the groundwater as a result of the oxidation of sulphides (ie as a result of mining). At Belle-Brook it is reasonable to assume the authigenic sulphide trace element composition reflects either localised groundwater contamination or hydrothermal mineralisation. This poster presents some preliminary findings.

Jan 1, 2001

By Richard L. Gordon

At almost no time since the end of World War I has the coal industry been free from serious threats to its competitive position. At present, the critical question is whether the industry can maintain its position in the electric power market and this paper reviews the prospects in this area. Our report is part of a study, supported by Resources for the Future Inc., dealing with coal demand in general. Like most elements of coal economics, it has received much less analysis than problems in other energy sectors--a defect we felt worth correcting. We have concentrated on electric power elements of the market. The nature of the coal market makes this the natural choice. Three markets absorb over 80 per cent of coal production and are considered in our overall work. The completely excluded sectors are largely catchall categories in which coal use is declining anyway. Comparing the three markets included in the overall study, we see: modest growth is the most optimistic forecast for metallurgical coke; export growth depends to a large extent on policies of foreign governments. Electric power use, however, has rapidly grown to absorb over half of coal output and coal's prospects depend almost entirely on continued expansion of this market. Throughout the 1960's the demand for coal used to generate electrical power in the United States grew at an average rate of 6.5 per cent annually. This growth rate will be sustained until at least 1976.

Jan 1, 1971

By Frederick Laist

I. INTRODUCTION The new slime-concentrating plant at the Washoe Reduction Works, Anaconda, was put into operation during March, 1914. This plant, which has a capacity of 26,000,000 gal. of slime pulp carrying 2,500 tons. of solid matter per day, consists of Dorr thickeners and Anaconda multiple-deck slime concentrators.' This plant is the culmination of a great deal of experimental work extending over a considerable period of time, which work will be described briefly in the following pages.

Jan 8, 1914

By Whiten W. J

A simulation model was used to study the performance of various types of screen cloth on industrial vibrating screens. The model takes into account the effect of loading upon screen performance and predicts both themass flow rate and size distribution of the screen products.It was found that the use of the simulation model allowed the reconstruction of data for identical conditions and hence has simplified the analysis of the comparative performance of the screens. The dependence of performance upon operating conditions was found to vary markedly with screen cloth type.

Jan 1, 1977

By J. M. Garcia

This paper highlights several management practices from the oil and gas industry to support the proposition that financial performance in the finite, non-renewable resource business relates more to upstream rather than downstream activities. Based on the analysis of nine oil and gas companies, this study supports a previous study involving fourteen mining companies that showed reserves growth is one of the main levers of value creation in mining. Interestingly, this study also finds that the oil and gas industry has been historically more profitable than mining. The reason, it is argued, is that oil and gas companies count on management practices that focus primarily on the upstream segments of the business, compared to the traditional downstream focus of mining. This paper delves into these ideas to conclude that what mining may need to improve its competitive advantage is a new organizational framework. Another conclusion is that the upstream management focus is vital not only for strategy formulation in the resource business, but also for policy formulation in economies based on the export of finite, non-renewable resources.

Jan 1, 2011

By D. R. Wardrop, G. Walton

Paper presented at the UK minerals industry conference held in Leeds, UK, 3-5 April 1995. A description is given of the approach that has been taken to the design of the 550 000 000 t superquarry with a planned life of 60 years that is proposed for development. The quarry has been designed to replicate a corrie and a sea loch and will include excavated slopes more than 570 m high. The main geological and physical controls on the layout and the choice of development method are outlined. The operation phasing is presented and the geotechnical constraints on slope design and the feasibility of alternative quarry limits are discussed. Environmental considerations have been dominant in planning and the quarry has been specifically designed for closure

Jul 1, 1996

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

Based on the examination of thirty sets of contiguous matte and slag samples taken from industrial nickel smelters a relationship is predicted between oxidic nickel in slag, oxygen in matte and the Ni/Fe ratio in the matte. Oxidic nickel in the slag is found to increase with an increase in oxygen content of a matte of constant Ni/Fe ratio, and it is proposed that the relationship may be used to predict nickel solubility in slag from a knowledge of matte composition alone.

Jan 1, 1980

By F. T. Da Silva

Concentrates of titaniferous minerals containing around 30 wt% Ta2O5 are processed hydrometallurgically by hydrofluoric acid leaching and solvent extraction, followed by the precipitation of hydrated potassium heptafluorotantalate. A fundamental study of the thermodynamics of this precipitation and recrystallisation was undertaken to increase understanding of the conditions most conducive to the production of pure, well-crystallised K2TaF7. Activity-pH diagrams for the Ta-K-F-H2O system explained the dissolution of Ta2O5 in fluoride solutions quite well and also the precipitation-recrystallisation of K2TaF7.H2O. X-ray diffraction and scanning electron microscopy confirmed the thermodynamic observations. It was concluded that the best precipitating agent for K2TaF7 from fluoride solutions is KF but a recrystallisation step in a HF environment produces purer, well-crystallised K2TaF7.H2O, eliminating oxy-salts and other impurities

Jun 21, 1905

By R. K. Agarwal

In this paper, a new technique developed to analyze two-dimensional nonhomogeneous models is described. A simple three-layered medium with a circular hole centrally located in the intermediate layer is considered. The layered sheet is loaded uniaxially perpendicular to the stratification. The Young's modulus of the intermediate layer is lower than that of the outer layers. The stress distribution around the circular hole in a stratified medium is significantly different when compared to the case of a continuous homogeneous medium. The distribution depends upon the ratio of the height of the intermediate layer and the hole diameter. A comparison of stress distribution and procedures for preparation and testing of the model are given. The potential of the technique is outlined. In the process of applying the techniques of stress analysis to problems of rock mechanics, the recent discernible trend has been to postulate highly idealized models of physical situations. As new techniques have been developed, more complicated models have been conceived to simulate mote accurately the physical environment to which the analysis results are eventually applied. In this investigation, a new technique is developed to analyze two-dimensional nonhomogeneous models. The technique is used to determine the stress concentration around a circular hole in a soft material overlain and underlain by a hard material. In mining practice, such situations arise commonly in coal deposits and frequently in bedded or vein-type metallic mineral deposits. DEFINITION OF THE PROBLEM A plate, consisting of three layers with a circular hole in the intermediate layer, is loaded uniaxially, Fig. 1. The variable in the experimental investigation is the height of the intermediate layer, H. The diameter of the hole, D, is kept constant. The stress concentration factors around the periphery of the hole, for various values of H/D, are evaluated using the technique of photoelasticity, Table I. TECHNIQUE OF EXPLORATION Photoelastic analyses of composite models have hitherto been limited to the study of lap and butt joints between glued metals and dissimilar materials.1-3 In mining, Haber and Oudenhoven used composite models to study the stress distribution around a circular hole in two-layered media and the behavior of elastic liners in shallow underground openings.4-5 They used the stress freezing technique devised by Dally et a1.6 The procedure used in this investigation is outlined below: Casting of Layer A: Flat sheets of plastic were cast in a silicon-coated mold using Araldite 502 with hardener 951 in the ratio of 100:8 by weight. After

Jan 1, 1969

By E. Roman, M. Brissette

"For its end of life, Kemess Mine processed its difficult-to-treat hypogene ore from the east pit, which is a lower grade copper and higher pyrite content gold ore. Metallurgical testwork showed that improvement was possible with finer grinding. In July 2010, small grinding media were introduced into the regrind mill resulting to a nearly 50% decrease of the power draw with a finer grind, an increase of 1.1% in the final copper grade, an increase of 1.2% in copper and 2.9% in gold recoveries at the cleaners. The overall recoveries of copper and gold increased by 0.6% and 1.3% respectively.INTRODUCTION Kemess Mine was located at 430 km North West of Prince George in North Central British Colombia. Its production started in May 1998 by Royal Oak Mines and was acquired by Northgate Exploration in 2000. Kemess reached its end of life production with its last of production on March 9th, 2011. The concentrator nominal capacity was 56,000 TPD consisting of a primary gyratory crusher feeding two identical conventional SAB circuits totalizing 35,840 kW available for grinding. Rougher flotation consists of four parallel rows of eight 130 m³ tank cells to produce a concentrate of 2% Cu and 6 gr/t Au which was pumped to a 5 m x 10.8 m regrind ball mill. The regrind installed power was 4,480 kW to generate a final grind of 80% passing 40 microns. This product fed the two stage cleaner flotation circuit, first stage being two parallel rows conventional 17 m³ Denver cells and second stage, two 3.3 m x 11.0 m flotation columns in series, designed and constructed by Kemess, to produce a 22% copper concentrate grade. The cleaner flotation middlings were returned back to the regrind mill (Froehling, Mohns, Roman & Grady, 2005; Froehling, Mohns, Rajwani & Fullam, 2007). The large copper-gold porphyry deposit was composed of 15% of oxidized supergene and leach cap ore and 85% of hypogene ore having three major alteration zones, mainly characterized by their sulphur/sulphide content. Chalcopyrite is the main copper mineral species with minor bornite. Gold was mainly present as free gold or electrum. The first alteration zone consisted of a phyllic alteration characterized by moderate and intense sericite alteration which had the highest mill throughput and twice the mine grade when in contact with the supergene horizon. The second zone consisted of a potassic alteration characterized by more competent groundmass and moderate to intense quartz stockwork which had a slightly lower mill throughput. Finally, a third alteration found beneath and on the east side of the deposit having almost no quartz stockwork and hardened groundmass, sulphide content is two to four times more. This zone had the lower mill throughput with significant drop in the mine average gold and copper grade. Through its mine life, the average life of mine copper head grade was 0.21% Cu and 0.64 gr/t Au. Head grades began to decrease from 2008 to be substantially lower in 2011 as shown in Table 1."

Jan 1, 2012

By M. J. Farrell

Mining is a significant emitter of greenhouse gases and is the focus of increasing attention from green groups and regulators. Miners need to know their own carbon emissions and how they compare with the rest of the industry. Miners and mining companies need to know where they fit in the emissions curve. Who is in the bottom quartile? This article is based on research report data from minecost.com and Metalytics Pty Ltd which detail the specific carbon dioxide emissions for 208mines producing 90% or more of western world copper, zinc, lead and nickel in 2007. The copper and nickel mines also include Norilsk in Russia, KGHM in Poland and Kazakhmys in Kazakhstan. This is the first time that such information has become available.

Jan 1, 2009

By C. L. Kosmoski

The mining industry faces many workplace hazards that are a threat to human health and safety. The Bureau of Labor Statistics has found that employees in coal mining are more likely to be killed or sustain an injury or illness than workers in private industry. These injuries are also likely to be more severe (Bureau of Labor Statistics, 2007). In recent years, coal mining injuries have attained national attention due to highly publicized disasters. Despite these threats to worker safety and health, the U.S. relies on the mining of coal to meet its need for electrical power, with42% of electricity in the U.S. generated through the burning of coal (U.S. Energy Information Administration, 2012b; United Mine Workers of America, n.d.). Furthermore, the production of coal continues to increase and reach record levels every year(National Mining Association, 2012; U.S. Energy Information Administration, 2012a). For this reason, the coal mining industry must continue to find ways to protect its workers while maintaining productivity. One potential approach to protecting workers while maintaining productivity is through improving the safety culture at coal mines. In order to achieve this culture, operators, employees, the inspectorate, etc. must share a fundamental commitment to safety as a value. This type of culture is known in other industries as a ?safety culture? and can be defined as the characteristics of the work environment, such as the norms, rules, and common understandings that influence facility personnel?s perceptions of the importance that the organization places on safety. Fundamental to improving safety culture within an organization is understanding the existing safety culture; improvements cannot be made without first elucidating areas that require improvement. This manuscript details the process undertaken by researchers at the National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) to assess the safety culture at five underground coal mines across the United States. The purpose of this manuscript is to introduce the mining industry to a multi-methodological approach to safety culture assessments. Further, it is the goal of this manuscript to highlight the value of including both quantitative and qualitative methods into safety culture assessments in order to obtain the most comprehensive view of an organization?s safety culture. Because this manuscript focuses solely on the methodology implemented, data and results obtained during the five safety culture assessments will not be presented in this manuscript, but will appear in a future publication.

Feb 27, 2013

Mine waste and mine reclamation are topics of major interest to the mining industry, the government and the general public. This publication and its companion volume are the proceedings of a conference held in Pittsburgh, April 19-21, 1988. There were nine sessions (50 papers) that dealt with the geochemistry, hydrology and problems of mine waste and mine water, especially acid mine drainage. These comprise Volume 1. The nine sessions (43 papers) that dealt with reclamation and restoration of disturbed lands, as well as related policy issues, are included in volume 2. Volume 2 also contains the ten papers that pertained to control of subsidence and mine fires at abandoned mines. Poster session presentations are, in general, represented by abstracts; these have been placed in the back of both volumes.

Jan 1, 1988

By R. H. Seraphim

"Western Mines Limited produces gold, silver, copper, lead and zinc from a number of Paleozoic volcanogenic deposits near Buttle Lake on Vancouver Island. The deposits were emplaced along a series of submarine linear volcanic ridges that extended for at least 6,000 metres in a northwesterly direction.Rock types mapped include: andesitic, dacitic and rhyolitic flow s and volcanic breccias; detrital breccias, tuffs and hematitic silts; black and green cherts; and a variety of dykes and sills, including quartz porphyry and diorite. Orebodies are associated invariably, and in places intimately, with quartzsericite schist and rhyolitic rocks. The ore is complex, varying in mineralogy and tenor both within each deposit and from one deposit to another.Recent studies have increased our knowledge of the structure and left no doubt that the orebodies were deposited both within the throats of the linear vents and on paleoslopes adjacent to these vents.IntroductionWestern Mines Limited operates an 850-tonne-per-day mine, located 85 km south of Campbell River, B.C. The mine is at approximately 400 metres elevation, near the south end of Buttle Lake on Vancouver Island (Fig . I). It has operated since early 1967 and produced 3,650,000 tonnes with an average grade of 1.9 g (0.06 oz) gold, 93 g (3.0 oz) silver, 1.6 per cent copper, 1.0 per cent lead and 7.5 per cent zinc per tonne by the end of 1978. Current reserves are 1,157,000 tonnes of 2.7 g (0.09 oz) gold, 117 g (3 .8 oz) silver , 1.2 per cent copper, 1.2 per cent lead and 8.0 percent zinc per tonne (December 31, 1978).Ore from one zone, known as Myra High-Grade, is mined and milled separately because of its grade. Ore milled prior to December 31,1978, plus reserves, 180,715 tonnes of6.6 g (0.21 oz) gold, 554.5 g (17 .7 oz) silver, 0 .8 per cent copper, 3.2 per cent lead and 10.6 per cent zinc are included in the figures listed in the preceding paragraphs."

Jan 1, 1980

By B Mobilio, G B. Sharrock, J L. Lett, I Brunton, T Thornhill

Full-scale marker experiments at Cadia Valley underground operations have been ongoing for over 14 years. Initial marker experiments were undertaken in the Ridgeway sublevel cave (RW) (2002), and subsequently at Ridgeway Deeps (RWD) (2008) and Cadia East PC1 (CEPC1) (2012) block caves. Over 25 000 markers have been installed at the three caving operations to date (approximately 20 000, 3000 and 2500 for RW, RWD and CEPC1 respectively). These experiments aimed to quantify and assess the geometry of the extraction zone, development of the extraction zone over time, variability of flow behaviour and factors affecting flow behaviour in both the near and far field cave column. This paper discusses marker recovery results from the RWD and CEPC1 caves.With respect to the two cave operations, marker recovery in both the near field (markers recovered vertically within 70 m of the extraction level) and far field (markers recovered vertically above 70 m of the extraction level) indicates disturbed flow behaviour where marker recovery is not spatially uniform during material extraction. Two distinct patterns or transient behaviours in the extraction zone are indicated. For RWD (advanced undercut), early material recovery was close to the major apex, and expanded towards the centre of the drawbell as more material was extracted. The inverse was observed for CEPC1 (post undercut), where recovery occurred in the centre of the drawbell initially, and expanded outwards towards the major apex. This trend of recovery for the two operations continued in the far field. In the region above the major apex, recovery was observed for all heights, with no clear height of interaction zone (HIZ) indicated. All of these behaviours significantly deviate from both conventional ellipsoidal flow theory and Laubscher’s (2000) design guidelines. For this reason these new mechanisms are termed the Disturbed Extraction Zone (DEZ).For the CEPC1 marker experiment, electronic markers were utilised to investigate the vector movement of material in the near field. Marker recovery movement vectors in the near field indicate extraction zone widths in the order 30 m, with localised marker recovery outside this region (significant horizontal movement of material potentially due to cave muck pile rilling and blast burden movement). Analysis is ongoing for far field marker vector movement, and will be reported once additional marker recovery has been obtained.CITATION:Brunton, I, Lett, J L, Sharrock, G B, Thornhill, T and Mobilio, B, 2016. Full-scale flow marker experiments at the Ridgeway Deeps and Cadia East cave operations, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 141–150 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016