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By John C. Machisak

THIS CHAPTER of the Minerals Yearbook (volume III) contains overall injury experience and employment data at bituminous-coal, lignite, and anthracite mines, coking plants, metal and nonmetal mines, metallurgical plants, and stone quarries in the United States for the calendar year 1956. Volume I of the Yearbook includes injury experiences and related employment data in the metal, nonmetal, and quarrying industries, and in the milling operations connected with the mining of those commodities. Volume II contains the injury and related employment experience of the coal mining, coking, and oil and gas industries. Reporting is voluntary on the surveys conducted by the Bureau of Mines to collect injury and employment data in the mineral industries, except in the coal-mining industry, where operators are required by Federal law to furnish the information requested.

Jan 1, 1958

By V M. Silva, P A. A Martins, V O. Matthew, A L. S Fonseca, E B. Cunha, A J. D Ferrari, E M. S Silva, A C. Silva, D R. T Vilela

The Anglo American phosphate mine is located in the Brazilian state of Goiás and possesses one of Brazil’s most important phosphate rock deposits, with the site being the country’s second largest producer of phosphate rock concentrate. Despite the site having been in operation since 1979, the mining team only started using explosives in 2004 when rocks with greater hardness started to appear in the mine’s geological profile. Rock excavation was previously performed mechanically. Until 2013, only rocks with high hardness were blasted, this following the standard drilling grid that was defined in 2004 without any changes in the blast parameters. The aim of this paper is to show how fragmentation optimisation has yielded positive results at all stages of the production chain, from the mine to the mill passing through an impact hammer crusher, a rod mill and ball mill, operating in close circuit with hydrocyclones.While incorporating the mine to mill holistic approach during the operational integration, the focus was on defining the blasting domains and respective optimal fragmentation and measuring the benefits of blasting in terms of reduction in energy and grinding media consumed in the comminution processes. In the first stage, the blasting team made changes to the blasting parameters and assessed the effects of these changes on fragmentation using computer software and on-site measurements. This generated a database that made it possible to divide the mine into blasting domains. For the second stage, teams from the plant, geology, mine planning and operation departments jointly made comparisons between the performance when processing stockpiles, which only included high hardness blasted ore (20–30 per cent of blasted ore). Changing the drilling grid’s size from 3.0 m × 3.8 m to 2.0 m × 2.6 m for high hardness rock with the presence of silicates resulted in a 40 per cent reduction in the P80 for the blasted material (from 459 to 278 mm), while changing the grid from 3.0 m × 3.8 m to 2.6 m × 3.2 m for high hardness rock without the presence of silicates generated a reduction of 25 per cent (from 270 to 204 mm). There were gains observed from the measurements at the mineral processing plant in terms of specific energy spent on comminution and on the consumption of grinding bodies in the rod mill. There was a measured reduction of circulating load during secondary grinding and a reduction in slime generation.CITATION:Silva, A C, Martins, P A A, Silva, E M S, Fonseca, A L S, Ferrari, A J D, Cunha, E B, Silva, V M, Matthew, V O and Vilela, D R T, 2015. Fragmentation optimisation – adopting mine to mill for reducing costs and increasing productivity, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 363–368 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Michael B. Cortie

Mesoporous gold sponge has the unique property of being both metallic and highly resistant to oxidation. It has potential application in catalysis, in bio-sensors, in optical coatings, in analytical chemistry and, as we show here, as the basis for a new kind of ultra-capacitor. Due to the cost of gold, the most probable niche for a gold-based ultra-capacitor would be in the high-power/high-energy regime, a region where gold would compete with devices based on RuO2. A high internal resistance limits the power that can be usefully drawn from existing carbon-based ultra-capacitors, and that this problem can potentially be overcome by gold-based devices. A simple proof-of-concept ultra-capacitor based on mesoporous gold is described and its behaviour during charge and discharge cycles examined. In this work a step change in the input or output voltage of the device was used as the controlling parameter. There was also a residual faradaic current resulting from traces of undissolved aluminium left over from the AuAl2 precursor used to make the sponge, and some charge storage due to polarization of the solution. Deconvolution of these three effects was not entirely accomplished, but an ostensible capacitance of about 7 to 14 mF/g Au was demonstrated. Further improvement from these early results seems likely.

Oct 1, 2003

By C McGuire, W Harris, S Arsenault, D Witow, B Rogers

Mining deep orebodies is increasingly becoming the norm as the ‘easy’ orebodies are depleted. Deep ore mining requires significant ventilation and cooling infrastructure to not only meet regulatory requirements for air quality but also to achieve acceptable workplace temperatures with the higher strata rock temperatures and increased auto-compression. At the same time, advances in battery equipment technology are turning the possibility of a battery powered fleet into reality. The switch from a diesel fleet to a battery powered fleet offers several positive opportunities for the design and operation of a deep mine.The potential to reduce ventilation and cooling requirements due to battery powered equipment results in significant cost savings for mine development and infrastructure. Battery powered fleets are not subject to the same dilution requirements associated with diesel fleets thus allowing lower ventilation rates. At the low ventilation volumes possible with a battery powered fleet, surface refrigeration plants are limited with respect to the amount of cooling that can be delivered to the workface. Considerations for calculating the optimum air flow and cooling requirements are presented. Considerations for locating the refrigeration plant are also discussed. This paper presents these opportunities and considerations; including a case study comparing the ventilation and cooling system design with a diesel fleet versus battery fleet for a planned mine in Northern Ontario, Canada.CITATION:Harris, W, Arsenault, S, McGuire, C, Rogers, B and Witow, D, 2017. Diesel to electric – creating a positive paradigm in underground ventilation and cooling, in Proceedings Australian Mine Vent Conference 2017, pp 169–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By M. Sunkpal, K. C. Kocsis

"An underground environment with high air temperature and humidity conditions generated from various heat and moisture sources can significantly affect the thermoregulation processes of the human body. This can lead to a series of heat-related illnesses such as heat exhaustion, heat cramps and heat stroke. The majority of the metabolic energy of a mine worker results in the production of heat. If the human body is to maintain thermal equilibrium, then this metabolic heat must be transferred to the ambient surroundings at the same rate. The heat loss from the human body occurs through a combination of heat transfer processes, such as respiratory heat exchange, convection, radiation and evaporation. If the heat loss from the human body to the ambient surroundings is less than the metabolic heat produced, the excess will be accumulated within the human body, which will result in a rise in the core and skin temperatures. This can ultimately lead to a heat-related illness or a combination of heat-related illnesses. This paper aims to discuss major heat-related issues and provide an overview of various mine ventilation and cooling systems, which can be employed to overcome high levels of heat and humidity in underground mines. In this paper, the effects of heat exposure on the health, safety and productivity of the mine workers are also highlighted. IntroductionMining in the United States remains one of the most hazardous industries, despite significant reductions in fatal injuries over the last century (Coleman and Kerkering, 2007; Saleh and Cummings 2011; Jacklitsch, Musolin and Kim, 2016). Occupational health hazards within the mining industry include hazards that are physical, such as traumatic injury or hearing loss; chemical, such as silica or diesel particulate matter; biological; ergonomic; and psychological (Donoghue, 2004; Saleh and Cummings, 2011). The effects of some of these hazards can be diagnosed immediately, while many, like black-lung and silicosis, will have long-term effects on the health, safety and life quality of mine workers (Donoghue, 2004; National Institute for Occupational Safety and Health, NIOSH, 2000). Among these hazards, exposure to heat and humidity can significantly affect the safety, health and productivity of mine workers, particularly in deep and hot underground mines (Roghanchi, Sunkpal and Kocsis, 2015). Short-term acute heat exposures can cause a rise in the core temperature of the human body, which can result in a heat-related illness or combination of heat-related illnesses. Adverse long-term chronic heat exposure can generate serious occupational heat-related illnesses, such as cardiovascular diseases, mental health problems and chronic kidney diseases. High core body temperatures coupled with dehydration can generate negative behavioral effects such as physical fatigue, irritability, lethargy, impaired judgment, loss of dexterity and loss of concentration (Xiang et al., 2014)"

Jan 9, 2017

By L. J. Cabri

Although no complete mineralogical balances have been published, the background knowledge and proven, highly sensitive analytical techniques to produce them already exist. For PGE-Cu-Ni sulphide ores a combination of ore microscopy, image analysis and electron microprobe analysis with proton microprobe analysis of sulphides for Pd, Rh and Ru and ion microprobe analysis for Pt, Ir and Rh (in some minerals) should provide the necessary data when combined with reliable assays. Other sulphide ores, such as the Cu-Ni-(PGE) ores of Sudbury, Ontario, require a similar approach except that the ion microprobe would be more suitable for the analysis of Pd, Pt and Rh because of its greater sensitivity. Oxide-silicate ores may be harder to deal with quantitatively, although the potential to confirm the presence of trace PGE within silicates and oxides may be greater than in PGE sulphide and Cu-Ni-(PGE) sulphide ores. However, solid solution of PGE in oxides and silicates still requires thorough documentation and evaluation in terms of their significance for the overall metallurgical balance

Apr 1, 1994

By D. W. Nel

Nanofiltration (NF) has attracted much attention over the past few years due to the reduced energy consumption compared to reverse osmosis (RO) and better separation performance compared to ultrafiltration (UF). Although research has been done in the area of NF of nickel ions, sodium ions, and acid separation, not much attention has been given to the separation of high nickel concen¬trations from sulphuric acid streams. The use of NF for the separation of nickel and acid from a spent nickel electrolyte is an innovative process alternative for future industrial application within a base metal refinery. In this study, the separation performance of a composite polyamide NF membrane on a spent nickel electrolyte was investigated by varying the sodium sulphate concentration in the feed (50-150 g/l), the trans-membrane pressure (35-55 bar), and cross-flow velocity (1.5-3.5 m/s), and measuring quantities such as total permeate flux, acid rejection, nickel rejection, and sodium rejection. The nickel and acid concentration in the feed were kept constant with variations between 40-60 g/l and 25-40 g/l respectively, while the temperature of the experiments was kept constant at 50°C. The membrane was found to be very selective for nickel ions, with the rejection of nickel ions varying between 54.4% and 98.2%. The rejection of acid ions varied between -5.9% and 21.8%. The rejection of sodium ions varied between 16.6% and 72.4% at a cross-flow velocity of 2.5 m/s and sodium sulphate concentration of 50 g/l in the feed solution. An increase in trans-membrane pressure increased the rejection of nickel, sodium, and acid ions, while an increase in sodium sulphate concentration decreased the rejection of nickel and acid ions. The total permeate flux was found to increase with an increase in trans-membrane pressure and decrease with an increase in sodium sulphate concentration. The cross-flow velocity had an insignificant effect on the total permeate flux and the rejection of nickel, sodium and acid ions.

Jan 1, 2013

By G. G. Lambert

The paper traces the pattern of spontaneous combustion in the workings of what was originally Hemsworth Colliery, but since July 1967 is now part of South Kirby Colliery. Examination is made of the Barnsley Seam sections and the part played by the top section of the seam as it comes in close proximity to the main seam. In this area of the colliery nine mechanised faces were set away between the years 1953 and 1968, every one "fired" at the pillar edge and six "fired" at the face line when production had ceased. The paper deals with the different preventative measures used, from sandbag walls, cement injections, spraying with polyurethane, until finally using Mandoseal as a sealant. Since the latter method was first used, the last three faces worked in this particular area were all salvaged completely, without any sign of a heating developing.

May 23, 1905

By D. Hopkins, D. Türler, R. D. Giauque, W. B. Davis, M. Karaca

In a highly collaborative research and development project with mining and university partners, sensors and data-analysis tools are being developed for rock-mass characterization and real-time measurement of mineral content. Determining mineralogy prior to mucking in an open-pit mine is important for routing the material to the appropriate processing stream. A possible alternative to lab assay of dust and cuttings obtained from drill holes is continuous on-line sampling and real-time x-ray fluorescence (XRF) spectroscopy. Results presented demonstrate that statistical analyses combined with XRF data can be employed to identify minerals and, possibly, different rock types. The objective is to create a detailed three-dimensional mineralogical map in real time that would improve downstream process efficiency.

Jan 1, 2002

By Ed D. Thimons, Douglas E. Pollock, Andrew B. Cecala, Gregory J. Chekan, Jay F. Colinet, John A. Organiscak

Researchers at the Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) work to reduce respirable dust exposures in mining operations. One focus of this research is silica dust control for surface and underground operations in the metal/nonmetal mining industry. PRL researchers analyze dust sampling results from the Mine Safety and Health Administration (MSHA) to identify high-risk occupations to guide research efforts. Research is then conducted in an effort to improve existing technologies and/or develop new controls for reducing worker exposure to airborne silica dust. During the last few years, PRL researchers have conducted research related to the following goals: improving protection provided by enclosed cabs on mobile surface mining equipment, reducing dust generation from surface drills, reducing dust levels in iron ore operations, and developing a new method to clean dust from workers’ soiled clothes. A description of each of these controls and subsequent dust reductions quantified through site surveys will be provided.

By J Harris, P Kirsch, D Cliff, M Spinks, S Goater, D Sprott

Fires are a common and recurrent unwanted event in the operation of open pit mines. In most cases, the causes of events such as fires are already æknownÆ but are either overlooked or not fully addressed in planning. Ongoing rapid growth of the global mining industry is creating a scarcity of skilled personnel, and high turnover within operations. This contributes to loss of corporate memory in risk management activities. RISKGATE« is an online risk management system designed to support and assist in the analysis of priority unwanted events in Australian coal mining operations. Funded by the Australian Coal Association Research Program (ACARP), RISKGATE« is a knowledge management program that delivers best-practice controls for unwanted events and assists operations in staying abreast of emergent risks and threats. RISKGATE« content has been primarily developed from an association of industry experts, and enriched with input from additional academic and technological resources. In mining operations, RISKGATE« provides a continuum of knowledge and best practice for risk identification, assessment and management. RISKGATE« will assist companies in improving safety performance, operational efficiency, operating practice and training. Here we present the RISKGATE« prototype as developed in 2011 for Fires, with a case study presented for the initiating event Fires on Mobile Plant.CITATION:Harris, J, Sprott, D, Spinks, M, Cliff, D, Goater, S and Kirsch, P, 2012. RISKGATE« - A case study in application to fires on mobile plant, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 49-54 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

By W. L. Heidenreich

This report describes the methods and results of field investigations conducted by the Bureau of Mines between December 1956 and December 1957 on seven deposits of nickel-cobalt-iron-bearing laterite and weathered serpentine near the west coast of Puerto Rico east and south of Mayaguez. These deposits were named, for purposes of identification, Guanajibo, Punta Guanajibo, Las Mesas, north and south deposits of the Rosario Southeast group, and the west and east deposits of the Maricao Southwest group. In addition, the lower 17 miles of the Guanajibo River Valley was tested at widely spaced intervals for possible concentrations of magnetite and chromite in the alluvial sands. The objective of the investigations was to appraise, by drilling and sampling, the two largest deposits--the Guanajibo and Las Mesas. Testing of the smaller deposits was much more restricted. Field investigations consisted of mapping, drilling with power auger, sampling drill-hole sections, and pre-paring samples for chemical analyses, mineralogical studies, and metallurgical tests. The work was financed jointly under a cooperative agreement by the Bureau of Mines and the Economic Development Administration, an agency of the Puerto Rican Commonwealth.

Jan 1, 1959

Since the 1950's drilling has been rapidly mechanised. First from hand held drills with air legs to pneumatic jumbos, then to more effective hydraulic jumbos. Development of underground drilling equipment naturally could not have stopped here. Hydraulic drilling saw an improvement in drilling capacity and efficiency after the introduction of second generation drifters in the early 1980's. Also in the early 1980's a few equipment suppliers started to study how to improve the efficiency in operating the rigs. The first computerised rigs for tunnelling were delivered to work sites in mid 1980's. At the same time a few computerised longhole drills started drilling in mines.

Jan 1, 1988

Geological Parameters Controlling the Improvement of Manufactured Sand Using Vertical Shaft Impact Crushers Instead of Cone Crushers Natural sand is a limited resource. In Sweden the total use of natural sand and gravel is around 20 million tonnes per year and the goal is to halve the use of this resource in the near future. Most of this natural sand is used for concrete production, so the consequence of this goal is that more and more concrete must be produced with manufactured sand. The bedrock of Sweden consists mainly of granites and gneisses, rock types mainly composed of various amounts of quartz, feldspar and mica. Manufactured sand from these materials generally contains rather flaky and elongated grains, and there are few types of granite that can be used as manufactured sand in concrete without increasing the amount of cement by eight to ten per cent. A Vertical Shaft Impact crusher (VSI) is commonly used to improve the shape of coarse aggregate particles. Research has shown that it is even possible to improve the shape in aggregate fractions less than 1 mm for some rock types. The aim of this project was to investigate which geological parameters control the improvement of manufactured sand when using VSI-crushers instead of the traditionally used cone crusher. In order to do this eight rock types of granitic composition were investigated. The selection of rock materials for the tests was based on grain size and mica content. A 4 - 8 mm fraction of each material was used for the tests. The characterisation of the shape of the material was performed using image analysis applied on microscopic images. The results showed that the VSI-crusher had improved the shape of all materials down to 0.036 mm, except for one rock sample. According to these results granites with low mica content and relatively high content of feldspars have the best prerequisites to produce manufactured sand for concrete with suitable geometric characteristics, and if these materials are crushed with a VSI crusher they almost show the same characteristics as natural sand.

Sep 13, 2010

By W. W. Adams

"The seventh National Safety Competition, that for 1931, conducted by the United States Bureau of Mines, was participated in by 350 mines and quarries operating in 34 States. Tables 1 to 5 show the relative standing of the various plants, Bronze trophies, known as the ""Sentinels of Safety,"" which were provided by The Explosives Engineer magazine to be awarded annually by the Bureau of Mines were awarded to five companies, each company having established the best accident—prevention record within one of the five classes into which all companies were divided — namely, anthracite mining companies, bituminous—coal mining companies, metal—mining companies, operators of nonmetallic mineral mines other than coal mines, and quarries or open—cut mines. The trophies are awarded for one year and are then transferred to the winners of the succeeding year's contest.The outstanding feature of the contest of 1931 was the operation of a bituminous coal mine without a lost—time injury to any employee. While accident—tree records had previously been made by certain quarries, metal mines, and nonmetallic mineral mines, never before has such a feat been accomplished by a bituminous coal mine in the National Safety Competition. Whether or not such a record has been made by a bituminous—coal mining company not enrolled is the competition the writer does not know, but it is believed that the case referred to is unique among large coal—mining companies. The mine to which reference is made is No. 1 mine of the Phelps Dodge Corporation, at Dawson, N. Mex. To that company belongs the distinction not only of being the first coal—mining company among those enrolled in these yearly safety contents to operate its mine without an accident but also of occasioning the 'Sentinels of Safety' trophy for a bituminous mine to take its first journey west of the Mississippi River. For the past six years the trophy has been in West Virginia, Alabama, or Pennsylvania."

Jun 1, 1932

By F. -J. Wodopia

Sustainability of energy supplies has been an issue of general interest for a long time. Whilst in the past the continuous productive use of natural commodities was in the fore, its compatibility with the environment and climate and ultimately also social aspects have recently gained more and more attention. Today many discussions focus on the climate compatibility of individual options to act. Fossil fuels, in particular coal and lignite, are generally challenged because coal use makes a significant contribution to global man-made CO2 emissions. The drastic increase in the consumption of fossil fuels is not explained by the fact that coal utilisation technologies are not or cannot be sustainable but rather by the growing world population and the endeavours numerous national economies trying to catch up economically. Coal is the world’s No. 1 fuel and, in the view of many experts, will keep this position also in the foreseeable future. The access to its deposits plays a significant role for the economies of the emerging countries. Consequently the aspects of energy security and economic efficiency need to be considered at eye level with climate compatibility. In Germany, however, the public acceptance of fossil fuels and of large industrial projects is in the focus of attention.

Jan 1, 2011

Edward A. UehlinG, New York City (communication to the Secretary*):—Mr. Baker's paper is one that brings up a subject of great importance, and if full statistics could be collectecl of the number of furnace-linings ruined by reason of bad distribution by skip-hoists, it would be found an astonishing array. Unfortunately a universal remedy has not yet been found. The fact that Mr. Baker has apparently succeeded in overcoming the trouble at Sydney, is no guarantee that the same remedy applied at another plant, where very different or even slightly different conditions prevail, mould cure the trouble. That it requires but a slight continuous difference of penetrability in the column of the descending stock of one section, over another, to produce channeling, is clearly demonstrated by Mr. Baker's experiments, by which he reversed the channeling from front to rear instead of remedying the trouble. Every change in the physical make-up of the charge necessarily requires a specific adjustment; even supposing this feasible, the regular working of the furnace is by no means assured, because with the high pressures now customary, the tendency of the ascending gases to plow their way through in a direct course, prevails, and having once opened up a passage, they will persist and cause trouble. Homogeneous filling-, hard driving and regularity of working are incompatible. The higher the furnace, the greater the

Jan 1, 1905

A subsurface study of the Maria Lode and associated hydrothermal alteration of andesites within the Karangahake epithermal gold-silver deposit defined the local evolutionary sequence in the once active geothermal system.   Some implications for mining of epithermal deposits arise as a result.

Jan 1, 1984

By Jamal Rostami, Levent Ozdemir, Amund Bruland, Filip Dahl

Cerchar Abrasivity Index (CAI) is one of the commonly used tests to evaluate rock abrasiveness for cutter life/cost estimations of TBM projects. There are at least 3 style machines, 2 different pin hardness, and the test could be run on fresh rock surface VS a sawn surface. Each of these parameters has a meaningful effect on the results, but its impacts were not fully understood nor its implications well explored. This paper reviews the current practice of Cerchar testing and its implications on geotechnical investigations related to TBM tunnels and provide a set of guidelines on testing and reporting of the test results for future projects.

Jan 1, 2005

By J Wesseloo and Y Kim, Y Potvin, G Mungur, D Grant

At the previous MassMin conference held in Sudbury in 2012, the authors proposed a new framework going beyond dilution and equivalent linear overbreak sloughing (ELOS) for stope reconciliation in relation to the planned stope design. More specifically, the new process investigates performance outcomes including rock overbreak (OB) and fill overbreak (FOB), rock underbreak (UB) as well as geomechanical and operational aspects such as blasting, fragmentation and other production data.Based on the findings of the original 2012 study, a comprehensive data gathering program has been undertaken involving design and reconciliation data from 43 stopes mined between September 2012 and October 2014 at BHP Billiton’s Olympic Dam (OD) operation. The new database structure was based on four types of data:stope definition and performance datastope geometrygeotechnical parametersoperational parameters.The new database allows a more in-depth investigation of stope performance. It is now possible to quantify and analyse UB and OB performance from each wall individually as well as the crown. In this paper, the influence of several parameters on recent stope performance at OD is analysed. The underlying reasons for stope wall performance outcomes are discussed in this paper.CITATION:Potvin, Y, Grant, D, Mungur, G, Wesseloo, J and Kim, Y, 2016. Practical stope reconciliation in large-scale operations part 2, Olympic Dam, South Australia, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 501–510 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016