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By Charles D. Walcott

Jan 1, 1901

By James Westfield

Following is a resume of activities of the Division of Coal-Mine Inspection that have had a favorable effect on health, safety, and the reduction o1 injuries at coal mines: 1. The Federal Mine Safety Code for Bituminous Coal and Lignite Mines of the United States was issued originally by the Director of the Bureau of Mines July 24, 1946, after consultation with management and labor representatives of the coal-mining industry. The code has been used by Federal coal-mine inspectors while inspecting bituminous coal and lignite mines as a basis for determining the existence of unhealthful and unsafe conditions and practices in these mines. A revised code was issued by the Secretary of the Interior October 8, 1953, after further consultations with representatives of management and mine workers and was incorporated by reference in the 1952 and subsequent bituminous coal wage agreements. The agreement of May 29, 1946, between the Secretary of the Interior, acting as Coal Mines Administrator under authority of Executive Order 9728, and the United Mine Workers of America, covering bitumi¬nous coal and lignite mines in Government possession, charged Federal coal-mine inspectors with the responsibility of making periodic investigations of the mines and reporting to the Coal Mines Administrator any violations of the Federal Mine Safety Code. Federal coal-mine inspectors also had temporary authority to close mines found to be imminently dangerous, but such authority (under Executive Order 9728) was removed June 30, 1947, when Government control of the mines was terminated.

Jan 1, 1959

By D. R. Tesarik

Researchers from the National Institute for Occupational Safety and Health (NIOSH)1 and engineers from Placer Dome, Inc.2, conducted an underground rockfill span test at the Turquoise Ridge Mine near Golconda, Nevada, USA with the purpose of improving safety and increasing productivity by using a bulk mining method instead of drift and fill. A rockfill sill was constructed by mining and backfilling six adjacent, parallel drifts and then undercutting the sill with a 13.7 m (45 ft) wide and 30.5 m (100 ft) long room. Displacement measurements from vertical borehole extensometers installed in the mine roof and rockfill indicated that the sill remained stable with a maximum vertical deformation of less than 5 mm (0.2 in). These results were confirmed by visual observations and calculations from a validated three-dimensional numeric model of the sill. The numeric model was also used to simulate load on the sill produced by dislodged roof material in the shape of a 11.0 m- (36 ft-) high triangular prism with base measurements equal to those of the sill. Failure in the bottom third of the sill occurred with this additional load.

May 1, 2007

By Marcelo de Oliveira, Antoine Allanore, Dennis P. Chen, Davide Ciceri

Potassium fertilizers (potash) are mined in a handful of countries in the Northern Hemisphere. Potash is either expensive or unavailable to the farmers of the Southern Hemisphere. Alkaline alteration of K-feldspar rock (ultrapotassic syenite) in autoclave in the presence of Ca2+ generates a mixture of K-bearing calcium-aluminum-silicate-hydrate (C-A-S-H) minerals that potentially can be used as an alternative local fertilizer. This work investigates the effect of processing temperature (200 °C, 220 °C, and 230 °C) and time (from 0.5 to 3.0 h) on pH, mineralogy, and elemental availability of the C-A-S-H mineral mixture. Increasing temperature results in an increased conversion of K-feldspar and increased content of both the mineral tobermorite (Ca5Si6O16(OH)2·4H2O) and amorphous phase in the resulting C-A-S-H mixture; increasing time results in an increased conversion of α-dicalcium silicate hydrate into tobermorite. The amount of K leached from the mixture is relatively constant across all processing conditions. Hydrothermal alteration in autoclave of K-feldspar-bearing rocks such as ultrapotassic syenite permits the synthesis of a potential potassium fertilizer which alkalinity and mineralogy can be tailored according to soil requirements.

May 22, 2020

By I. Bhattacherya

Over the last three decades, the mining industry has been moving towards underground mechanized mining methods and the number of load haul dump (LHD) vehicles utilized has increased. The growth of mechanization and automation has benefited both workers and mining companies. However, due to the design constraints with LHD vehicles and the limitations of the operating environment, restrictions to operator visibility has contributed to a number of accidents, including fatal injuries. Past researchers have used the light filament technique to collect obscuration zones around mobile equipment and have produced 2D visibility charts (shadow diagrams) of this information. The light filament method involves manually collecting visibility data, which results in errors and is time consuming, requiring around three hours to complete. This research utilizes a MENSI GS100 laser scanner along with 3D modelling software (3Dipsos) to collect and process operator visibility profiles for underground mobile equipment. Results from this test work indicate that a laser scanner can be successfully used to rapidly collect this data and utilize this information for improved mobile equipment design from a visibility perspective. Nomenclature FERIC Forest Engineering Research Institute of Canada ISO International Organization for Standardization JACK Software for digital human modelling and ergonomics LHD Load haul dump vehicle LOS Line of sight MASHA Mines and Aggregates Safety and Health Association (based in Ontario, Canada) PVD Polar visibility diagram SAMMIE3D human modelling computer aided ergonomics design system WSIB Workplace Safety and Insurance Board

Jan 1, 2006

Dynamics of Three Phase Contact Line Motion in Liquid-Liquid-Solid Systems - Impact of Surface Roughness

Sep 13, 2010

By R. D. Currie

Haulage accidents in the anthracite region cause fewer fatal and lost-time accidents per million man-hours than similar accidents in bituminous mines, a fact that may be accounted for in several ways, but primarily because haulage, in a large part of the region, is restricted to haulage crews operating only on the gangways where most of the miners seldom come in contact with movement or handling of cars and locomotives. Generally in underground mines the number of men injured compared with the number killed is greater for haulage than for roof-fall accidents, while the number of men killed by haulage is second only to the number killed by roof falls.

Jan 1, 1939

By Valerie (Wollet) Rebar

Successful execution of fast-track projects is an arduous task at best. Effective and organized management, a comprehensive technical design with an independent check-and-balance system, and optimal schedule components all play major roles in project success, regardless of the required timeline. However, a fast-track schedule intensifies the significance of each of these elements due to the heightened time constraints.

Jan 1, 2008

By T. Tamagawa

A gaseous chlorination process for hydrometallurgical treatment of a chalcopyrite concentrate was investigated. The overall process is visualized to consist of low temperature chlorination-selective oxidation, followed by aqueous chloride leaching and SX-EW for producing electrolytic copper, elemental sulfur and ferric oxide. In this article, the chlorination phase of the processes is described. Initially, the chlorination behavior of chalcopyrite-concentrate micro-pellets was investigated using a small batch-type fluidized bed reactor. The optimum conditions thereby established was used in continuous chlorination tests. The chlorinated products thus prepared were used in the selective oxidation phase of the investigation.

Jan 1, 1999

By E. J. (Kirk) Conway

Thirty-five years ago underground coal mining equipment consisted of simple but rugged machines powered by electric motors and hydraulics. The machines were maintained by maintenance personnel armed with a basic knowledge of hydraulics, electricity, and mechanical design. Over the years the the machine has been transformed into powerful complex mining systems. The maintenance burden has also increased. During this period significant advances have been made in maintainability engineering and system design techniques. Many of these innovations and techniques are applicable to the design of underground mining equipment. The objectives of this project were to; (1) determine the extent to which maintainability design concepts and principles have been applied to the design of underground coal mining equipment, (2) try to assess the impact of equipment design for maintenance on productivity and safety, and (3) develop a maintainability design guideline to enhance the design of new or rebuilt equipment. An equipment design review was completed at ten operational coal mines. Interviews were also conducted with mine management, safety, and maintenance personnel to identify machine specific design advantages and problems. Visits were also made to six original equipment manufacturers to discuss the design of their equipment for maintenance. Volume I presents an overview of the protocol used and a summary of the findings. Volume II includes the maintainability design guide for underground mobile mining equipment.

Jan 1, 1989

By D. J. Stoops, H. Kato, M. D. Carver

The effects of impurity elements silicon , aluminum, copper , nitrogen , and manganese , at 50 to 300 ppm, on properties of the zirconium alloy Zircaloy 2 were investigated . Variations in microstructure , mechanical properties , and corrosion behavior in some inorganic acid and salt solutions were observed with variations in level of impurity element . Corrodents were solutions of sulfuric acid , phosphoric acid , copper chloride , and iron chloride . Silicon was found to modify annealed microstructures by spheroidizing and dispersion of secondphase material throughout grains . Silicon or manganese improved ultimate and yield strength of the alloy without loss in ductility . All five elements affected corrosion rates of the alloy , the effect being generally different for each element .

Jan 1, 1964

By D. H. Pulling

Statistics for copper consumption from various sources show that the importance of production from secondary sources is increasing. This is of particular significance in countries such as the U.K ., which are totally dependent on secondary material for the supply of home-produced copper . A brief survey of the U.K . industry has shown that, in the past, relatively high profit margins have not encouraged high cap ital investment and development of more sophisticated operating techniques, but set against a background of rapidly escalating operating and energy costs , together with an ever-increasing demand for copper , it is anticipated that the industry will see great changes in the near future. With this in mind, an experimental furnace for continuous smelting of copper-bearing scrap has been developed at the University of Birmingham. This furnace has been designed to combine the conventional operations of blast furnace or reverberatory smelting, usually followed by converting, in one unit, and incorporates many of the features of the WORGRA and Noranda processes for continuous primary smelting . It consists of a long, sloping channel, constructed of chrome-magnesite refractory, which: is churned near the top. Smelting is effected lower down the channel, where iron, etc., in the scrap is oxidized and slagged off with silica flux. Provision is made for oil injection to increase oxidation rates. Metal can flow from the bottom of the channel, and slag from the top, so that a counter-current flow is achieved. The approximate molten capacity is 25 kg. Various scrap charges, both synthetically made and as supplied from various industrial smelters, have been successfully smelted. Metal of 83 -95 % Cu has been produced, depending on the original charge composition and the degree of air injection, although air injection was also found to considerably increase the copper loss to slag. Recoveries of other valuable non-ferrous metals in the charge were good.

Jan 1, 1977

Although these subterranean cavities are common to the Broken Hill big lode, yet the Broken Hill Proprietary is the most prolific in their occurrence, loud they have been found of various dimensions almost from the surface down to the lowest levels yet attained in that mine. Many of these vugbs have contined valuable silver, copper and lead deposits, and some have been remarkable for the beautiful forms of crystallization pendant from the roofs and walls, and collected on the floors. The question arises, How are these caverns and fissures in the ore body formed? There are numerous theories more or less feasible, but that the causes are variant is demonstrated beyond doubt. That water in its passage leaving channels, is one ofthe chief factors for their production is assured, and their presence is likewise due to the shrinkage and dropping of the earth from varions causes, to the deposition of material forming ledges overhanging, and thus leaving spaces below, and also to chemical erosion and electrical action both of which latter are constantly at work in reconstructing, segregating and dissolving tlie mineral and metallic constituents of all ore bodies.One of the most remarkable vughs yet discovered in the big mine was that opened up about three months bitek in the' heart of the ironstone body on Block 11, and located about 40 feet below the 100 feet level of Weatherley's stopes, but now destroyed in the progress of work. Probably it was caused by chemical action, the eating out, so to speak, of a soft and soluble portion of the manganic iron, leaving a,hollow about 15 feet long, with a width and height, of say, 6 feet, carpeted with beautiful zinc with a modicum of limeincrustations, apparently produced by the percolation from around the carbonate waters holding these minerals in solution. This cavern was divided into, what might be termed, a double chamber, by big boulders of manganic iron, also coated with an aggregation of small crystals of zinc and lime although the actual proportion of the latter was not determined.

In Broken Hill, Northern Rhodesia, two water jacket lead furnaces have been in operation for the past three years. The furnaces were erected in war time, and only absolute essentials were procurable. The water for the jackets was obtained from wells adjacent to the works, in a dolomite formation. There being no water-softening plant, except a small one capable of treating water for the power plant only, this water was found to make a heavy scale in the jacket. During 1917 several jackets were burnt through, resulting in serious trouble and loss of output. In order to avoid this, furnaces were stopped twice a month for 8 hours and scale was removed as far as possible. In addition to the scale trouble during the summer months, a green slime grew in the supply tanks and occasionally became detached from the tank and collected in the cocks near the jackets. This caused risk to the jackets and was difficult to remove without a stoppage of the furnace. In 1918, bundles of wattle bark were placed in the hot well at the rate of one ton per month. These extracted the tannin and added from 0.5 to one part of tannin per 100,000 to the circulating water. The hot water was cooled over a brushwood cooling tower and returned to the supply tanks. The well water required to, make up the wastage was estimated at 40,000 gal per day.

Jan 1, 1920

By R. J. Kendall

As we enter the new millennium, the South African mining industry has to ensure that it becomes more competitive if it is to survive in the ever more demanding global environment. Traditionally, mechanization in narrow stopes has been limited to the use of scraper winches, and numerous mechanization attempts have been restricted to pilot projects operated on an extremely limited scale (with varying degrees of success). The benefits of hydropower are well documented, and Northam Platinum has shown these benefits to be achievable on a mine-wide basis. However, the equipment originally developed for hydropower systems has followed the traditional labour-intensive approach commonly used in deep level narrow stoping operations. The problems experienced with the hydropower system are discussed and the rationale for developing alternate technologies is explored. The hydropower system has shown to be a versatile powering medium which can be harnessed for a diversity of uses. It (hydropower) enables the mining engineer to change traditional paradigms and to design an entirely new approach for optimizing the mining operation based on explosive techniques. The system developed for Northam consists of the following: ?Purpose-built stope drill rig operated off the hydropower system with special features to ensure accurate drilling patterns throughout the length of the blast hole ?Purpose-built high rate cleaning system for rapid transfer of fractured ore to the stope orepass ?Redesigned stope layout to facilitate in-stope water control and to recover fines from the run-off water ?Purpose-built drill rig for rapid establishment of reef raises and advanced strike gullies ?Purpose-built drill rig for flat end development. On both types of development end rig, emphasis is placed on ensuring accurate drilling patterns throughout the length of the hole to maximize linear advance per blast. The paper discusses the implementation of the Northam system on a large scale as well as current initiatives to further improve on the efficiencies of mining operations. It concludes by emphasizing that mechanized hydropowered stope technologies are in their infancy and thus offer unlimited scope in progressing beyond today?s paradigms to present as yet unthought of solutions for optimizing deep level ore extraction.

Jan 1, 2000

By M. W. Lewis

A mine's inherent capacity is dictated by factors such as equipment, design, people, processes, and environment. Actual production may approach, but never surpass, the inherent capacity limit. The inherent capacity ceiling can only be increased through re-engineering. Autonomous haulage systems have the potential to significantly increase a mine ’s inherent and realized capacity. Realized capacity may be maximized through the optimization of soft factors such as the processes, behaviours, and organizational systems, controlling asset utilization, availability, and performance. Truck shovel dispatching systems revolutionized the utilization of mobile assets. High-precision global positioning systems (HP-GPS) are increasingly being adopted to optimize equipment performance. Real-time maintenance management systems have the potential to revolutionize equipment availability and significantly reduce cash costs. This paper explores some of the solutions available to mines to increase their inherent capacity and maximize their realized capacity.

Jan 1, 2004

By M. W. Lewis, B. Sambirsky, J. Werner

A mine’s inherent capacity is dictated by factors such as equipment, design, people, processes, and environment. Actual production may approach, but never surpass, the inherent capacity limit. The inherent capacity ceiling can only be increased through re-engineering. Autonomous haulage systems have the potential to significantly increase a mine’s inherent and realized capacity. Realized capacity may be maximized through the optimization of soft factors such as the processes, behaviours, and organizational systems, controlling asset utilization, availability, and performance. Truck shovel dispatching systems revolutionized the utilization of mobile assets. High-precision global positioning systems (HP-GPS) are increasingly being adopted to optimize equipment performance. Real-time maintenance management systems have the potential to revolutionize equipment availability and significantly reduce cash costs. This paper explores some of the solutions available to mines to increase their inherent capacity and maximize their realized capacity.

Jan 1, 2004

The intent of this manual is to provide guidelines for inspectors of drilled shaft construction otherwise referred to as drilled piers, caissons or bored piles. It should also be helpful to train beginning geotechnical engineers with limited first hand experience or for geotechnical engineers who are training inspectors. It is expected that the general guidelines and procedures described here will be supplemented by local geotechnical engineers working in a particular region based on local practice and experience. Since drilled shaft construction procedures vary widely based on local geology and size of project, an all-inclusive manual is not considered practical. This manual focuses on traditional topside inspection for routine drilled shaft construction. Other inspection and evaluation methods that rely on electronic equipment are available, but these methods require extensive training and experience in the interpretation of results. These more sophisticated methods of drilled shaft inspection and evaluation are common in construction, but they are usually provided by specialty subconsultants. The subconsultant will typically submit a report for each shaft, which will be reviewed by the geotechnical engineer. Other manuals are available to describe the electronic methods of drilled shaft inspection.

Jan 1, 2004

By Peter C. Jones

The paper gives a broad view of the maintenance procedures at the Cassiar Asbestos Corporation property. Comparisons are drawn to indicate the changes in facilities and approach that have evolved over the last 25 years while coping with the northern British Columbia climatic conditions. Special emphasis has been placed on the importance of the support groups providing services for both the mine site and the town.

Jan 1, 1978

By Clarence Hall, Spencer P. Howell

Among the more important factors involved in the use of high explosives in blasting operations is the means employed to bring about the detonation of the charge. When flame is applied to high explosives many of them may burn if not confined; but all of them when burning under certain conditions of confinement may detonate. Detonation may also be effected by mechanical means, such as frictional impact caused by a blow or by rubbing between surfaces. By this means, however, the full effect of the explosive charge may not be developed, so that a partial detonation, often accompanied by the burning of the explosive, results. When nitroglycerin was first used it was fired by the application of flame, but considerable difficulty was experienced in exploding it with certainty and in obtaining uniform resl'llts. In 1864 Allred Noble, a Swedish engineer, discovered that nitroglycerin could be surely and completely detonated by exploding in contact with it a small quantity of an initiatory explosive. Mercury fulminate was the substance then found capable of producing the best results There are many other fulminates and other substances that will produce complete detonation of commercial" high" explosives, but detonators or electric detonators containing mercury fulminate as the characteristic ingredient are still almost exclusively used in this country. The term" detonator" is used in the publications of the Bureau of Mines to designate what the miner calls a "blasting cap "-a copper capsule containing a small quantity of some detonating compound that is ignited by a fuse. The term" electric detonator" is applied to a blasting cap that is similar except for being ignited by means of a small wire which is heated to incandescence or fused by the passage of an electric current. One of the conditions prescribed by the Bureau of Mines for a permissible explosive a is that it shall be :fired by a detonator, or preferably an electric detonator, having a charge equivalent to that of the standard detonator used at the Pittsburgh testing station. A further requirement is that this charge shall consist by weight of 90 parts of mercury fulminate and 10 parts of potassium chlorate (or their equivalents). At the request of a manufacturer of permissible explosives, an investigation was undertaken by the bureau to determine the relative strength of detonators and electric detonators having different compositions. The tests of electric detonators herein reported were conducted by H. F. Braddock, junior chemist; J. W. Koster, J. E. Tiffany, junior mining engineers; and A. S. Crossfield, junior explosives chemist, at the Pittsburgh testing station of the bureau. Similar tests of detonators were not conducted because it was believed that the results would not show sufficient variation to warrant such tests. It is hoped that the conclusions drawn from the tests made will be of service to those using explosives by enabling them to select the grade of detonator or electric detonator that will insure the most effective results. The conclusions are given in this bulletin, which is published by the Bureau of Mines as one of a series of publications dealing with the testing of explosives and the precautions that should be taken to increase safety and efficiency in the use of explosives in mining operations. The results of tho experiments described in this bulletin show that the average percentage of failures of explosives to detonate was increased more than 20 per cent when the lower grades of electric detonators were used instead of No. 6 electric detonators, and was increased more than 50 per cent when these lower grades were used instead of No. 8 electric detonators. It is noteworthy, however, that when sensitive explosives, such as 40 per cent strength ammonia dynamite (p. 33), were tested under conditions ideal for detonation, the same energy was developed irrespective of the electric detonator used. When tests were made with a less sensitive explosive, such as a 40 per cent strength ammonia dynamite containing nitrosubstitution compounds (p. 32), the energy developed increased with the grade of the electric detonator used. For example, the average efficiency of four different explosives was increased 10.4 per cent when a No.6 electric detonator was used instead of a No.4 electric detonator, and 14.9 per cent when aN 0.8 electric detonator was used (see tabulation onp.45). The results of the tests emphasize the importance of using explosives in a fresh condition, but as fresh explosives can not always be had in mining work, strong detonators should be used in order to offset any deterioration of explosives from age.

Jan 1, 1913