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By H. E. Mills

THE local auditorium of a little Alabama mining town was crowded with expectant men, women and children, as the bulletin board had announced the addition of visiting entertainers to supplement the local talent and motion pictures which usually made up the program of the regular monthly safety meeting. In the audience, near the stage, sat a group of bright-faced boys in boy scout uniforms, discussing the picture just completed. As the lights flashed on a crash and scream was heard from the outside, a shrill whistle and word of command from the scoutmaster, and five of the scouts ran out of the hall, while the mine super-intendent stepped on the stage and requested everyone to keep their seats. The scouts returned, three of them carrying a limp figure in their arms, while the other two cleared the doorway and aisle of excited spectators. They marched to the stage and, placing the apparently badly-injured boy on the floor, proceeded to give an expert demonstration of first aid to the injured. The scoutmaster then explained to the audience that the whole affair had been arranged for their benefit, and invited the local first-aid men to come up on the stage to examine and criticize the boys' work. This gave an opening for several talks on the value of first-aid training and accident prevention, which is the main object of the monthly meetings. This demonstration was given by the first-aid team of Troop One, and the entertainment was provided by members of Troop One and Twenty-eight of the Bir-mingham Scout Council, organized by the writer for the purpose of promoting interest in the welfare and safety meetings in the mining villages of the State. During the past year they have visited a number of such meet-ings and presented programs similar to the one men-tioned above. However, in order to assure a good attendance, entertainment features must also be pro-vided, and the serious part of the evening program was interspersed with excellent vocal and instrumental mu-sic, dancing and novelty acrobatic acts furnished by the visiting scouts. In addition to the numerous first-aid teams of the Birmingham Council, there are hundreds of scouts scat-tered throughout the mining district whose knowledge of first aid, safety first, life-saving, personal health and public health are a constant source of protection to their community. All of these subjects are covered by merit badge pamphlets and are required of an eagle scout.

Jan 2, 1927

By Jan E. Nesset

It is just over 100 years since the practice of blowing small bubbles into a mixture of ground ore and water revolutionized the mining industry, resulting in uneconomic deposits becoming highlyprofitable mines, along with the inevitable lawsuits over this new technology called froth flotation. To this day, the viability of many mining projects rests largely with the ability of flotation to effectively capture the valuable minerals and reject wastes. Remarkably, bubble behaviour in flotation has not been well understood until very recently with the advent of new sensor technologies that can be brought directly into the operating plants. This presentation will review the importance to the mining industry of understanding bubbles, highlight these new technologies and illustrate, with examples, how paying attention to your bubbles will pay off.

Jan 1, 2009

By Juan J. Monsalve, Nino Ripepi, Richard Bishop, Jon Baggett

"Terrestrial laser scanning (TLS) is a useful technology for rock mass characterization. A laser scanner produces a massive point cloud of a scanned area, such as an exposed rock surface in an underground tunnel, with millimeter precision. The density of the point cloud depends on several parameters from both the TLS operational conditions and the specifications of the project, such as the resolution and the quality of the laser scan, the section of the tunnel, the distance between scanning stations, and the purpose of the scans. One purpose of the scan can be to characterize the rock mass and statistically analyze the discontinuities that compose it for further discontinuous modeling. In these instances, additional data processing and a detailed analysis should be performed on the point cloud to extract the parameters to define a discrete fracture network (DFN) for each discontinuity set. I-Site Studio is a point cloud processing software that allows users to edit and process laser scans. This software contains a set of geotechnical analysis tools that assist engineers during the structural mapping process, allowing for greater and more representative data regarding the structural information of the rock mass, which may be used for generating DFNs. This paper presents the procedures used during a laser scan for characterizing discontinuities in an underground limestone mine and the results of the scan as applied to the generation of DFNs for further discontinuous modeling.INTRODUCTIONAccording to the Mine Health and Safety Administration (MSHA), between 2006 and 2016, the underground stone mining industry had the highest fatality rate in 4 out of 10 years, compared to any other kind of mining (MSHA, 2016). Additionally, during that same time, 40% of the fatalities were due to ground control issues, such as roof and rib collapses and pillar bursts. The National Institute for Occupational Safety and Health (NIOSH) developed guidelines for designing underground stone mines (Esterhuizen, Dolinar, Ellenberger, and Prosser, 2011). However, these guidelines do not apply to all underground stone mines.Monsalve, Baggett, Bishop, and Ripepi (2018) present a case study of an underground limestone mine experiencing a structurally controlled mode of failure. The authors analyze different methods to study that type of instability. They conclude that the integration of terrestrial laser scanning (TLS) with discrete element modelling (DEM) can be used to prevent rock falls in underground excavations to enhance worker safety. However, an adequate rock mass characterization and structural mapping must be performed in order to generate reliable models that allow the engineer to have a better understanding of the rock mass behavior."

Jan 1, 2018

By James Y. Oldshue

"Very seldom is it possible when contacting a gas with a slurry to measure the dissolved gas concentration in the slurry, and even were it possible, seldom are equilibrium data available with a suitable Henry’s law constant.In general, by assuming a reasonable value for the dissolved gas concentration in the slurry and a corresponding equilibrium gas partial pressure P*, Kga values can be calculated for the pilot plant and scaled up. Then, with the same P* value at various reaction conditions, a mixer can be designed which is quite satisfactory, having a reasonable design factor for full-scale performance.We will take as an example a slurry of a known solids composition and use a continuous 4 tank system. By assuming a percentage saturation of the dissolved gas in the first tank, the dissolved gas concentration can be obtained in the other three tanks. It usually is possible to measure the off-gas composition in each of the 4 tanks. If the top of the tanks is connected in the form of a multi-compartmented horizontal autoclave, then a modified top off-gas composition in each compartment must be used."

Jan 1, 2003

By E. B. Spice

"IntroductionExperience at Eldorado has been gained with a variety of mill feeds. That is, the actual mode of occurrence of the pitchblende varies to such an extent that gravity concentration has at times been decidedly unattractive and at others highly successful. Because of this, the type of ore necessary for economic recovery of pitchblende have become well known. Also, those types which do not lend themselves to gravity concentration have become familiar. In general, it may be said that when the pitchblende occurs free, to a large extent, from sulphides or arsenides of high specific gravity, and when the bulk of the pitchblende is localized rather than disseminated, excellent recoveries, high ratios of concentration, and good grades of concentrates , will result from proper gravity concentration. On the other hand, if the ore contains pitchblende intimately or otherwise mixed with large quantities of arsenides or sulphides, or if the pitchblende is finely disseminated, gravity concentration alone will yield high recoveries only at the expense of very low-grade concentrates and low ratios of concentration.According to Taggart, the ease with which gravity separation may be effected is determined by the value of the following ratio: []It is stated that when the ratio is above 1.75, gravity separation can be expected to be easy. Thus with pure U308 (S.G. over 9) and gangue consisting chiefly of siliceous material, the process can he expected to be entirely successful even when carried on at very fine sizes. Unfortunately, the term pitchblende covers a great diversity of material. Although some of the mineral occurs pure enough to have a specific gravity of about 7, the average is much lower than this and is probably well under 5. Some of the pitchblende particles have a specific gravity so low that gravity concentration fails completely. It may also be said that no degree of grinding will produce free pitchblende of sufficient density from such particles. This, then, represents the most important limitation to the application of gravity separation to pitchblende ores."

Jan 1, 1950

By B. R. Eichbaum

To develop technology to assure an ample supply of zinc and to reduce environmental pollution, the U.S. Bureau of Mines investigated alternatives to the roast-leach process for treating complex sulfide concentrates. Previous studies proved that low-grade zinc sulfide (ZnS) concentrates could be leached using chlorine-oxygen to produce zinc chloride (ZnCI2). The process involves high energy requirements for evaporating the pregnant solution to produce anhydrous ZnCl2 needed for electrolytic cell feed. An efficient hydrometallurgical process would facilitate treatment of lower grade ores than can be used in conventional processing and would render roasting unnecessary. An alternative method was devised for recovering ZnCl2 from solution. Zinc diammine chloride [Zn(NH3)2CI2] was precipitated from solution by adding ammonium chloride (NH4CI) and sparging with ammonia (NH3) to a pH of 6 to 7.5. The spent solution was treated with calcium hydroxide [Ca(OH)21 at 60° to 80° C for 1 to 4 h to remove remaining zinc and NH3. The Zn(NH3)2CI2 was heated to 300° to 400° C to remove NH3 and produce anhydrous ZnCI2. A possible flowsheet was devised and is included.

Jan 1, 1991

By Katie Schumacher, Greg Roset, Dayle Flynn

The Columbus Processing Complex of the Stillwater Mining Company began operations at Columbus, Montana in 1990 based on electric furnace smelting treating a precious metals concentrate from the nearby Stillwater mine and mill. Since that time, the smelter plant has been expanded in stages in order to treat recycled materials in addition to the concentrate. This paper describes a number of changes made at the plant to effectively handle recycled materials.

Jan 1, 2014

By J. J. Gillman

"The coal deposits from Cape Perce on Cape Breton Island have been known to supply the coal requirements of the people living in or visiting the area for close to 300 years.A major block of coal has been identified off Cape Perce, which has several seams from which coal can be taken. The initial development by the Cape Breton Development Corporation will be in the Harbour Seam and constitutes the Donkin-Morien Development Project.The CBDC's confidence in this indicated resource is based on its knowledge of the Sydney Coal Field and from boreholes driven into the block during the summers of1977, 78 and 79. In 1980, further geological data were gathered from surface drilling and an intermediate-depth high-resolution seismic survey. The surface facilities for the Donkin-Morien Development Project will be located on the northern half of the cape, with access declines extending 3.9 km in a north-northeasterly direction to the Donkin block of coal reserves. The development has the potential of supplying all the coal needed f or the future electrical power generation requirements of Nova Scotia for many years to come.The planned mine, for which a project definition study has recently been completed, will have a production rate in excess of 3 million tonnes per year.IntroductionAt the Second CIM District 1 Meeting held in Halifax in October 1980, a background paper on Phase II of the Donkin-Morien Development Project was presented. The project involves a 3.2-million-tonne, saleable, underground coal mine. At that time, the chronological sequence of events had unfolded, starting with the initial boreholes through to the feasibility study, and on through site clearing and site preparation. This led to engineering design contracts for the portals and the two tunnels to be driven to intersect with the Harbour Seam close to 4 km from their entry point."

Jan 1, 1982

[Ferro Alloys Producers Association The South Africa Institute of Mining and Metallurgy www.saimm.co.za Mintek www.mintek.co.za Eskom www.eskom.co.za ]

Jan 1, 2004

Professor Sir John Cadman, K. C. M. G. (1918) D. Se., F. G. S., M. Inst. C. E., was for two years Technical Adviser' of the Chemical Warfare Department and Liaison Officer between British and French Forces. The Cross of Officer of the Legion of Honor was awarded him in 1917 by the President of the French Republic "in recognition of valuable services rendered by him in the cause of the Allies." At the moment, Sir John is Director of the Petroleum Executive and Chairman of the Inter-Allied Petroleum Conference. In 1915, he was Technical Adviser of the Trench Warfare Supply Department and was awarded C.'M. G. in 1916. J. Edwards-Leckie, C. M. G., D. S. 0., went to Valcartier as second in command of the 72d Regiment, Seaforth Highlanders of Canada, with rank of Major, and later sailed for France as second in command of the unit now known as the, 16th Battalion, the Canadian Scottish. He was promoted to Lieutenat-Colonel on Aug. 14, 1915, and returned to England to take command of the 2d Canadian Reserve Training Brigade at Shornecliffe. On Jan. 2, 1916, he was promoted to Colonel. R. G. Edwards-Leckie, Lieut.-Col. of the 72d Regiment, Seaforth Highlanders of Canada (which unit later became known as the 16th Battalion, The Canadian Scottish, and under that name distinguished itself in France), left Canada for "Over There" on Sept. 14, 1914. He was promoted in France to the rank of Brigadier-General on Aug. 14, 1915, and served until severely wounded in February, 1916. He was Acting Chief of the General Staff, Canadian Overseas Forces in England from September to December, 1916. He returned to Canada in May,

Jan 8, 1918

By Mark S. Greenleaf, Alec D. Smith, Mary Vittoria-Bertrand, Heather B. Scranton, Jean Louis Z. Locsin

"Rhode Island’s new $163.7 million, 2,265 ft (690 m) long, four-lane Sakonnet River Bridge sits just south of the existing bridge in Portsmouth/Tiverton. The bridge, a critical transportation system link between Massachusetts and Rhode Island, has a steel I-girder main span and concrete New England Bulb Tee approach spans. The foundation work was done between October 2009 and July 2010, and the bridge was completed in February 2014.Foundation design and construction challenges make the project noteworthy. There were thick layers of silty glacial soils with bedrock as deep as 400 ft (122 m) below the waterline, coupled with high foundation capacity demands at the river piers in 50 ft (15 m) of water. The Sakonnet was one of the first major bridge projects in the country to incorporate AASHTO Load and Resistance Factor Design (LRFD) guidelines for foundation design and construction. Because of these and other challenges, the engineers conducted two design-phase load test programs on several foundation elements. These programs were successful and allowed the engineers to adjust the final foundation design prior to the start of construction. During construction, the contractors drove thirty 6 ft (1.8 m) diameter steel pipe piles, each with a novel recessed steel plate insert, to depths of 130 to 200 ft (40 to 61 m) at the three river piers. The insert provided increased resistance of the steel pipe piles and saved about $9 million. Also, 457 14x117 en bearing or friction H-section piles were driven to between 50 and 190 ft (15 to 58 m) at five land piers. All piles were driven relatively close to the existing bridge, which remained in service during construction, due to the project team’s precautionary use of instrumentation and the installation of a jacking system.Area GeologyThe Sakonnet River is up to 60 ft (18 m) deep along the bridge alignment and is underlain by a deep bedrock valley. The bedrock valley is buried by at least 350 ft (107 m) of soil, which includes a complex sequence of interbedded glacial soils (glacial till, glaciolacustrine deposits and glaciofluvial deposits), overlain by geologically recent estuarine deposits. The soils having the greatest impact on the foundation resistance are the glaciolacustrine (fine sandy silt or silt) and glaciofluvial (silty sand with gravel, cobbles, and occasional boulders less than about 2.5 ft [0.8 m] in size). The soil overburden decreases toward the east and west banks of the river, as the bedrock surface rises."

Jan 1, 2015

By John V. Beall

One Sunday night last month the phone rang and it was George Schenck from Penn State. How would we like to see a big scrap operation, he wanted to know. A few days later we were on the Connecticut turnpike headed for New Haven to visit a large scrap operation, M. Schiavone and Sons. George had a large clam basket in the back which he explained was for collecting trophies. The car shredder, he said, turns out some fancy metal shapes. In fact, they have gained a certain acceptance as objets d’art among George's friends and relatives. He thinks there may be a small, but possibly lucrative secondary market for shredded cars in the art world if the idea is imaginatively promoted. On the way to New Haven we received a briefing on the scrap industry. The scrap business grew from humble beginnings. Mostly it was started by a few immigrant Jews who collected junk in hand- or horse-drawn carts. The fortunate one might even have had a truck. Before proceeding further, we hasten to point out that the word "junk" is strictly taboo among scrap people, who prefer to refer to their industry as the "secondary metals industry."

Jan 1, 1970

By J. H. Kempton

Refinement of environmental procedures can produce significant cost savings at most mines. Grouting permeable aquifers reduces water pumping and disposal costs. Stable groundwater quality supports reduced groundwater monitoring; and for contaminated groundwater, in-situ or natural restoration should be evaluated. Waste-rock characterization can be minimized using fewer (but more representative) samples, inexpensive surrogate analyses (e.g., NAG instead of humidity cells), and appropriate tests (e.g., avoid meteoric tests on sulfide). Selective waste-rock handling should be compared to random emplacement, which is often cheaper and more stable. Finally, incorporating schedule uncertainty in modeling allows the flexibility to revise mine plans within permits.

Jan 1, 2000

By Jocemir da Silva Santos, Alberto Vicente Belezia, Matheus Neves Lana

A regulação ambiental de processos industriais que geram efluentes contendo fluoretos é mundialmente restrita devido à alta toxicidade do íon. Na Ternium, a água de resfriamento recirculada no spray do Lingotamento Contínuo (WTP#2) dissolve parte do pó fluxante, resultando em concentrações de 20 a 30 mg/L de fluoreto. Para desenvolvimento do processo de tratamento de fluoreto que atendesse a legislação, mantendo no efluente tratado concentração de Fluoreto menor que 10mg/L e Alumínio menor que 3,0mg/L, foi realizada uma pesquisa utilizando um equipamento de Jar Teste convencional totalizando 165 ensaios. Os ensaios foram planejados segundo revisões bibliográficas descrevendo o método da precipitação química de fluoreto de cálcio, auxiliado por Cátions de Alumínio. Na conclusão da pesquisa, foi desenvolvida uma Rota Tecnológica para tratamento do efluente gerado na purga do sistema WTP#2 atendendo a legislação, atingindo uma remoção de 70% a 80% de Fluoreto. Ao final foi realizada uma etapa de otimização das dosagens, cujo resultado foi a redução do número de etapas de tratamento e uma redução na quantidade de produtos químicos utilizados, consequentemente reduzindo o custo de tratamento. A redução do custo de tratamento foi da ordem de 3 milhões de reais anuais, mantendo o efluente tratado com as concentrações dos contaminantes abaixo dos limites da regulação ambiental.

Aug 1, 2019

By Eric Kelley

Having been retained as a legal expert for the fatality at the Canberra, Australia project, it made me aware of how good intended blasters profess to be implosion experts. Owners and contractors can be misled by these representations, seeing a video of Directionalized Structures constructed of reinforced concrete may be impressive to watch, but lack sound evidence of the true mechanics of an actual “implosion”; on steel structures more prevalently. If any well intended blaster comes to a determination that he can implode a structure, it should be not be construed he cannot. It should be well investigated that the specific blaster has verifiable experience. What happened in Australia reflects on all end users of explosives. I have heard a direct quote in our project in Alberta, “We don’t want to have what happened in Canberra”. Such a tragedy could have, and should have been avoided. Simple by using the “Right Tool for the Job”. We should sideline egos and economics. Would any competent blaster compromise his or her reputation, company or insurability? More importantly, have an honest conscience knowing that if the proper explosive is available, use it, don’t shortcut it. If possible expand the schedule. Better, yet, examine all avenues before the project, and last, cancel the project. A human life is our best asset and should not be compromised.

Jan 1, 1999

By J. Um, B. Morin, P. H. S. W. Kulatilake

Development of a three-dimensional mine visualization model for a section of the mine is addressed first. Discontinuity orientation and location information was taken from this visualization model for use in slope stability analyses. Estimated shear strength properties of discontinuities and mechanical properties of intact rock from the rock mass samples obtained from the mine are discussed next. The paper is then focused on the calculated maximum safe slope angles based on the performed kinematic and block theory analyses using the mapped discontinuities at the mine. Finally, the effects of water that exist in the rock mass, tension cracks, slope face inclination, overall wedge height and double benching on factor of safety of wedge stability are illustrated through limit equilibrium slope stability analyses.

Jan 1, 2002

By Jie Zhou

Mining mobile equipment is becoming larger in order to lower operation cost and increase productivity; however, their performance characteristics are often limited by the tire capabilities. Although considerable progress has been made in the field of tire research, the lack of comprehensive knowledge on tire performance characteristics impedes the advancement of off-the-road tires. Longer haul roads, and a severe operating environment make tires more vulnerable than other components of a vehicle. Furthermore, due to a limited availability of large tires, mines are facing shortages. Thus mines and tire service companies are keen to improve tire performance, extend tire life and hence lower operating costs. This paper reviews the relevant tire performance research, analyzes tire interactions with the surrounding environment, tire maintenance practices and operational issues using a case study based on data collected during an ongoing project with Fountain Tire.

May 1, 2006

Large mining operations need equipment that consistently performs as expected. The most effective way of ensuring this is to have a defined life cycle with an optimised maintenance strategy. The determination of this life cycle is an economic decision, influenced by the construction and utilisation of the equipment. An effective life cycle costing (LCC) tool must be able to process the many variable factors involved.Many factors influence the costs that are associated with a machine over its life. The most variable of these are the costs of maintaining the equipment. Maintenance costs are dependant not only on the utilisation of the machine, but also on the strategy that has been developed to support the machine through its life. A combination of supplier support, component changes, regular servicing and unscheduled maintenance needs to be modelled, based on a variety of drivers. Traditionally spreadsheets have been used to model these factors, but the increasing complexity of the situation can make spreadsheets unwieldy and difficult to manage. A database solution that breaks each activity into its constituent components, links them to an associated mine plan driver and then aggregates the result is the ideal tool to provide a time based cost profile. The evaluation of a number of scenarios, representing different maintenance strategies/life cycles can be rapidly undertaken. Auditability through inbuilt tools is required to provide easy tracing of data. Use of the host company's account structure allows for reporting against the standard chart of accounts.

Dec 6, 2010

By M. J. Gula, S. S. Xue, E. P. Horwitz, J. T. Harvey

A study has been conducted to control iron in copper electrolyte streams using Eichrom Industries’s new Monophosphonic /sulphonic acid resin. The resin strongly and selectively extracts ferric ion over copper and cobalt from highly acidic copper electrolytes. The resin has a loading capacity of 27 g/L of iron and can be readily regenerated. In addition, the new resin can be easily synthesized using commercially available starting materials. This paper presents the experimental results for iron control in copper electrolyte streams using the new resin and discusses its potential applications to other hydro-metallurgical streams.

Jan 1, 2000

By P. N. Erasmus, M. Heyns, M. J. Pretorius

The characteristic of stope supports plays a vital role in the design of the supports. This paper deals with the characterisation of both cellular lightweight concrete and timber supports since both supports absorb and dissipate the energy in different ways. The behaviour of the support and hence its performance is simulated for different loading conditions by constructing a model consisting of various mechanical components like springs, dampers and blow-off valves. When the force exerted by the stope support increases significantly during deformation of the support, the stresses in the hangingwall could exceed values where failure of the hangingwall may occur. There is a need to understand this phenomena and the work presented in this paper is a first attempt to start with the characterisation of the stope support. Les caractéristiques des supports de taille jouent un rôle vital dans la conception des supports. L’étude présente traite de la caractérisation des supports cellulaires en béton léger et en bois, puisque ces deux types absorbent et dissipent l’énergie de façons différentes. Le comportement du support et par conséquent sa performance est simulée pour des conditions différentes de chargement en construisant un modèle qui consiste en des organes mécaniques variés tels que ressorts, registres et valves d’échappement. Quand la force exercée par le support de taille augmente considérablement pendant la déformation du support, les contraintes dans le toit peuvent dépasser des valeurs qui pourraient entraîner la défaillance du toit. Il est nécessaire de comprendre ce phénomène et l’étude ici présentée constitue un premier essai dans la caractérisation du support de taille. Die Charakteristika der Strossenunterstützung spielt im Design von Unterstützungen eine vitale Rolle. Diese Arbeit befaßt sich mit der Charaketerisierung sowohl der porösen Leichtgewichtbeton- als auch mit der Holzunterstützung, da beide Unterstützungen Energien auf verschiedene Art und Weise absorbieren und auflösen. Das Verhalten der Unterstützung und folglich seine Leistung wird für unterschiedliche Ladezustände simuliert, indem ein Model konstruiert wird, welches verschiedene mechanische Komponenten wie Federn, Dämpfer und Ausblaseventile enthält. Wenn die von Strossenunterstützung während einer Unterstützungsdeformation aufgebotene Kraft signifikant ansteigt, könnten die Spannungen im Bereiche des Stollenfirstes Werte überschreiten wo ein Versagen des Stollenfirstes eintreten kann. Es besteht die Notwendigkeit dieses Phänomen zu verstehen, und die Arbeit, die in diesem Elaborat dargestellt wird, ist ein erster Versuch, mit der Charaketerisierung der Strossenunterstützung zu beginnen.

Jan 1, 2003