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By G. W. Jones

In cooperation with the Edison Electric Illuminating Co. of Boston, Mass., and the Boston Consolidated Gas Co., a survey has been conducted continuously since 1929 by the Bureau of Mines to determine the general hazards of combustible gases and vapors in manholes of the Edison Electric Illuminating Co. The New England Telephone & Telegraph Co. also has cooperated in the investigation, and tests have been made in its manholes since May 1, 1933. Yearly reports6/ on the results obtained since the beginning of the survey have been published. The method and procedure of conducting the survey in 1936 were the same as heretofore.

Jan 1, 1938

By John Mastoris, Kostis Dragasakis, Kostas Kouklidis, Shkurtë Gashi, Halil Berisha, Jenuz Bulica

Titan Group’s environmental policy and Sharrcem’s Corporate Social Responsibility (CSR) are the driving forces behind the development and implementation of a comprehensive Rehabilitation Plan at Dimce Quarry, which is the main raw material source for Sharrcem Cement Plant since the 1970’s, located in the municipality of Hani i Elezit in Kosovo. Based on an Environmental Impact Assessment Study and the approved Mining Plan and also on the principles prescribed in the Guidelines on Quarry Rehabilitation, released by the Cement Sustainability Initiative of the World Business Council for Sustainable Development (WBCSD-CSI), Sharrcem has adopted a quarry operation and rehabilitation process in line with the best practices in the mining and cement sector. This paper discusses the background for the development of the rehabilitation plan and the results of rehabilitation activities, as have been implemented over the last few years. The main objective of the progressive rehabilitation plan at Dimce Quarry is to restore the depleted pit and return it back to the original land owners for resettlement. To date approx. 3,4Ha of former mining area has been restored by backfilling and levelling of the depleted closed pit and returned back to owners, who have built their houses and turned it into a living area again. This Quarry has turned out to be a real composition and practical example of preserving and returning back the natural resources in a state compatible with the surrounding environment and with respect to the needs of the local stakeholders. The motivation for business to engage in rehabilitation activities in the first place lies in the belief that the development and implementation of a progressive and practical Quarry rehabilitation plan and restitution of the land will deliver significant environmental and social benefits that outweigh the long-term rehabilitation costs, while maintaining the company’s reputation.

Jan 1, 2017

By Yeonuk Choi, Gus Van Weert

"In regular CIL circuits, activated carbon is used for two purposes: avoiding solid/liquid separation after cyanide leaching, and minimizing gold losses in the tails. The carbon distribution and gold profiles in the successive CIL stages are operating variables, not objectives. When the CIL feed contains a preg robbing constituent however, such as native carbon, there will be competition for gold cyanide and this conflicts with minimizing of losses of gold to CIL tails. This paper examines some of the limitations of activated carbon in CIL circuits handling preg robbing Carlin Trend ores.INTRODUCTION Carbon-In-Leach (CIL) has been a great success treating regular gold ores, but the technology is still challenged by preg robbing feedstocks. Little information is available in the gold milling literature on CIL gold extraction from “free” milling gold ores which are preg robbing, or on autoclave discharge (POX’ed) slurries of double refractory ores. Neither feedstock is readily available for experimentation. No literature reference could be found describing deliberate modifications to CIL operations or CIL circuits due to the presence of two types of carbon: “native” and activated. There is some literature on the gold cyanide adsorption activity of native carbons (Schmitz, Duyvesteyn, Johnson, Enloe & McMullen, 2001). Various tests have been devised to measure this activity, commensurate with CIP and CIL practices (Tretbar, Arehart & Graves). In this paper, the term “native” carbon indicates (severely) preg robbing carbonaceous materials found in gold ores. There is considerable literature on the gold cyanide adsorption activity of man-made “activated carbons”. Various tests have been devised to measure this activity, commensurate with CIP and CIL practices. These tests are comparative, i.e. results relate to a standard carbon and depend on the test methodology and carbon history. The test results are equilibrium oriented, hence of limited value to CIL circuit designers or plant operators handling preg robbing solids; in CIL circuits most carbons are not loaded to capacity. Information on gold cyanide adsorption and desorption kinetics might be more relevant and that is one subject explored in this paper."

Jan 1, 2012

By C. H. Larsen

The results of a comprehensive investigation of conveyance arrestment devices (safety catches) in United States coal mines are presented. Availability and use, performance, inspection, maintenance, testing, procedures, and regulatory requirements were investigated. Information was obtained from equipment manufacturers, mine operators, and regulatory-agency personnel, as well as from studies of domestic and foreign mining safety regulations. Traditional mine hoists and commercial elevators for mine use were investigated. Results of this and an earlier study of wire-rope practice in United States coal mines show a continued need for conveyance arrestment devices. A wide variety of these devices are in use. Only two types have been proved reliable for stopping a conveyance without injuring passengers or equipment. These are elevator overspeed-actuated wedge-clamp (Type B) safeties and broken-rope-actuated devices for wooden guides using a single-tooth-dog design developed in Ontario as a braking element. Elevators are widely used in U. S. coal mines. When maintained according to American National Standards Institute (ANSI) Specifications A17. I and A17. 2, they appear to present no major arrestment problems. Of 42 coal-mine hoists used for man transport that were inspected, 30 are in vertical and 12 in inclined shafts. Twenty-four vertical shafts use wood guides; 6 use steel. The 12 inclined-shaft systems use flanged-wheel T-rail guidance. Two wood-guided vertical-shaft systems use the single-tooth Ontario-type dog; the other 22 use multi-toothed wedges, cams, or dogs that have been proved highly unreliable. The arrestment devices in the six steel-guided vertical-shaft systems and in six of the inclined-shaft systems cannot be evaluated because performance data are lacking. The remaining six inclined-shaft systems have no arrestment devices at all. Of the 36 hoists with arrestment devices, the devices of 16 are never tested, the devices of 10 are actuated periodically with the conveyance at rest, and the devices of the other 10 are actuated periodically with a slow-moving conveyance. Although high speed is as probable as low speed in an emergency and would provide the best test of arrestment capability, no tests are performed in the United States which demonstrate the ability of an arrestment device to stop a loaded conveyance from high speed. Mine operators indicate little confidence in their conveyance arrestment devices, and manufacturers recognize a need to improve their products. Neither state nor Federal regulations provide a guide to this improvement. Mine operators, manufacturers, and state and Federal regulatory agency personnel would welcome specific guidance. In view of this, a set of application, design, actuation, stopping-performance, and testing and inspection criteria is presented as a guide to eliminating the inadequacies of these devices. Recommendations are included for improving hoist controls and machinery directly affecting conveyance safety.

Jan 1, 1972

By Mark X. Haley

Foundation design and construction in Boston has changed dramatically during the past 10 years. Prior to 1985, the primary foundation element in Boston, where deep foundations are required, was driven end-bearing piles. Since 1985, drilled or excavated high capacity foundation elements have been utilized more frequently. This paper will provide a historic perspective of their use and a summary of design parameters for elements installed and founded in the bedrock. TOPOGRAPHY Boston was founded in 1630 by the Massachusetts Bay Company of John Winthrop and his hearty band of Puritans. The settlement was chosen for: ? its safe harbor, ? abundant source of fresh water, and ? peninsula setting offering protection of the ocean on almost all sides with high ground for fortification. These three factors were a direct result of past geologic processes that created the Boston Basin by erosion of the soft bedrock underlying this area as compared to the harder granite rock to the north, west and south. As the glacial ice sheets melted and moved northward, various soil types were deposited. During ice sheet re-advancement the hills and islands of Boston took on their precolonial shapes. The Trimont, consisting of Beacon, Mt. Vernon and Pemberton Hill, rose to 150 ft above sea level with the smaller Copps and Fort Hill to the north and south.

Jan 1, 1994

By D. E. Macdonald

"Approximately 2.0 million tonnes of phosphate rock is imported from the U.S. to Alberta annually and is used in the production of agricultural fertilizers. No phosphate rock is presently mined in Canada, although sources of igneous phosphate have been mined in the past. Sedimentary phosphate rock is found in nine geological units within the Cordilleran Foothills and Front Ranges region of Alberta. The Devonian-Mississippian Exshaw Formation, Permo-Pennsylvanian Rocky Mountain Supergroup, and the Jurassic Fernie Formation have the best potential f or future development. Most of the phosphate rock in Alberta is of low grade and lies within restricted land use areas. The best over-all resource potential lies in the Fernie basin area of southeastern British Columbia, in the Fernie Formation. The possibility of deep phosphate rock deposits in the plains region should be examined.Phosphate rock is mined in Idaho, Utah, Montana and Florida, and is shipped to Canadian fertilizer plants for processing. Raw phosphate rock is acidified, usually with sulphuric acid, by a wet process. Varying amounts of ammonia are added, and the fertilizer is pelletized. Future research, in western Canada, is needed in the beneficiating of low-grade ores and in the area of in situ mining. At the present time, phosphate rock sells for around US$50Itonne, and Alberta fertilizer companies probably pay in the range of C$7D-$85Itonne for U.S. phosphate rock delivered to the plant. Environmental concerns about phosphate rock processing are centred around gypsum tailing ponds, and radioactive wastes.U.S. supplies of phosphate rock are secure until the year 2000; however, by this time, the richer deposits in the U.S. may be exhausted. Alternate deposits, such as the ones in Alberta and British Columbia, might then be considered. Phosphate byproducts, such as uranium, vanadium, fluorine and rare earth elements, may help in making the processing of low-grade Canadian phosphates economically feasible."

Jan 1, 1988

By Games Slayter

NO reasonably well-informed person believes that the role of minerals, both metallic and nonmetallic, will be any less important in the future than it has been in the past. The contrary is true. Industrialization is based on mineral resources and man's ability to make use of them. A nation's standard of living, its political and military power, will continue to depend largely upon the extent to which it is industrialized-and minerals are the raw materials both of the machine and the power to run the machine. Minerals are also the raw materials of human health and stamina. The world's healthiest, most vigorous, and most long-lived peoples have always been those that have lived in regions of the globe where the earth is rich, and kept rich, in the phosphates and other minerals required for the production of the so-called growth foods. Only a small proportion of the land surface of the globe is suitable under any circumstances for large-scale production of these and other essential foods. As things stand, only a part of this land is capable of such production either because the soil minerals have been exhausted by cultivation, or because they never existed in the soil in sufficient quantities.

Jan 1, 1943

The main asset of a mining company is the mineral resource; without resources there is no mining business and the infrastructure is useless. In this context the role of the mining geologist is to always keep the resource inventory to an optimum level for the mining business and to maximise the transformation of the resources into reserves in a multi- disciplinary work environment. In short, a ægood mining geologist has to always provide the best ore to the millÆ.To do his/her work properly, several technical skills are needed: to know how to observe and describe nature in order to optimise the data acquisition process, particularly when mapping; to have a good understanding of natural variability in order to develop proper sampling strategies and sample preparation protocols to minimise all the errors generated by the sampling process; to have a good understanding of assaying practices: their limitations as well as their assaying errors; to carefully and properly store the geological data and information and to preserve the geological patrimony; to fully understand ore forming processes to generate the best possible geoscientific models, which are fundamental for the mining business; to fully understand the consequences of the geoscientific models along the value chain from rock to cathodes; and to continuously validate and improve geological practices and models by continuous data collection and observation of geo- mining-metallurgy processes. Some very important behavioural competencies are also needed:long-term vision, passion for excellence and value generation, strategic influence, systemic and innovative thinking, and knowledge and experience transfer. Last but not least, it is important to point out that a deep knowledge of the mining business is essential to add value by using geology best practices.

Jan 1, 2006

By T. J. Haddon

For the mining industry in general and gold mining in particular the past few years have been difficult. Economic conditions coupled with growing regulatory restrictions have led to increasingly important reasons for managing assets wisely. From a public company perspective this makes sense because it ultimately provides for an increase in shareholder wealth and that's what we're in business to do. Regardless of whether a company is public or not, assets must be managed effectively to remain a player in today's competitive environment. So, as the CEO of a gold mining company, how do we manage our assets to ensure that we are satisfying our obligations to our customer --the Amax: Gold shareholder? Let me tell you. As I said earlier, the gold industry has been under siege. We have just completed our third year of average prices below $400 per ounce. When you add finding and/ or acquisition costs and development costs to operating costs, there isn't much of a profit margin left. What this environment provides, however, is opportunities for growth. In the gold business, you either grow or you die. Today, most North American gold producers have at most a 10 year mine life. We are all scrambling to add reserves so we don't become extinct. As prices remain low, opportunities for increasing diminishing reserves abound. This is the time for the opportunistic company to take advantages of market conditions and that's precisely what we, at Amax: Gold, have done!

Jan 1, 1992

By W L. Lane, T R. Yanske

The Doe Run Company and its predecessors have been mining for over 130 years utilising the room and pillar mining method. This method has left approximately 20 per cent of the orebody in the remaining pillars. The original design and planning for the mines did not include extensive pillar extraction. This paper summarises the introduction of the pillar extraction and backfill techniques which have been implemented since 1991. These techniques include the use of low cost fill walls up to 20 m in height and the use of slinger trucks for topping off the fill. In conjunction with these accomplishments, much experience and confidence has been gained in the use of numerical modelling as a method of predicting pillar stability as the mining of pillars progresses. These advances have led to pillar extraction becoming a major portion of the overall production and have added to the mine life of Doe RunÆs six operating mines.

Jan 1, 1998

By Liam Bussey, Graham Speirs

Si bien la automatización de plantas de proceso es quizás la norma actual en la minería, la adopción de esta en la minería subterránea se ha retrasado. En este artículo se compartirán algunas ideas de cómo implementar los sistemas de automatización en la mina subterránea y se explicará cómo la tecnología puede mejorar la operación, de manera que las minas sean más seguras y sus operaciones más competitivas. Se discutirán diversos aspectos tales como los sistemas de comunicación, los sistemas de seguridad, los equipos de producción, los servicios mineros y la gestión de operaciones.

Sep 20, 2019

By Maybee Vásquez, Robert Santos, Marco Jáuregui

El presente trabajo técnico nace de la necesidad que tenía Minera Yanacocha de ubicar los sectores más importantes para la realización de sondajes diamantinos, los cuales ayudarían a la confirmación o adición de nuevos recursos para el proyecto Chaquicocha Subterráneo, así como para establecer la línea base para operar la futura mina. Así, se analizan tanto los riesgos identificados como los controles a tener en cuenta durante el desarrollo de excavaciones mineras subterráneas en ambientes con alto contenido de azufre nativo y se confirma que es posible desarrollar excavaciones seguras en estos ambientes, a la vez que se establecen lineamientos generales para el desarrollo de este tipo de proyectos.

Sep 20, 2019

By Antonio Fernández, Javier Cáceres, Enrique Ramírez, Camila Yepez

El sector minero es una de las pocas industrias que depende de los precios de mercado para producir. Por lo cual, mantener ventaja competitiva y garantizar la eficacia del proceso para alcanzar las metas propuestas por la empresa minera representan un desafío constante. Esta investigación tecnológica tiene como objetivo maximizar la eficacia en los procesos de transporte y perforación manteniendo los costos más bajos en su proceso productivo. La investigación presentó dos desafíos durante la etapa de prueba que fueron la especialización del personal y modificación progresiva de los equipos para cada actividad específica.

Sep 30, 2022

By P. C. Thakur

Methane has been a hazard since the beginning of coal mining and has influenced, more or less, every aspect of coal mine design. It is receiving increased attention lately because the rate of methane emission in coal mines is increasing as increasing demand for coal leads to exploitation of deeper seams and the use of higher productivity equipment. Consequently, the government and private industries have directed a great deal of effort towards understanding and solving the problem of methane emission in coal mines. In the United States, Consolidation Coal Company has pioneered research in this area since the early 1950's.1 Currently this work is being expanded by Consol through the Mining Research Division of the parent company, Continental Oil (Conoca), to find new techniques for degasification of virgin areas as well as control of methane in gob areas. Basic reservoir properties of coal seams, such as gas content, reservoir pres-sure, diffusivity, porosity and permeability are better understood today largely through the efforts of the U. S. Bureau of Minese2,3,4 It is possible now to identify and model the basic mechanism of gas emission from coal and to forecast steady as well as unsteady state emission of methane in coal mines with some degree of reliability. Combining this knowledge with any ventilation simulator should often identify problem areas in advance and permit adequate methane control measures to be planned.5 Another recent innovation in methane control is the horizontal hole drilling technology. The U. S. Bureau of 1-1ines and the Mining Research Division of Conoco have independently developed techniques for drilling horizontal holes 300 to 600 m deep6 The Bureau's method employs a rotary drill string while Conoco uses a non-rotating string with a down hole drill motor. It is the authors' view that the latter provides more positive control on bore hole deviation both vertically and laterally and appears to be faster, though somewhat more difficult to operate. The rate of methane emission depends on a number of factors which can be broadly classified in two groups. These are (1) the basic reservoir properties of

Jan 1, 1977

By E. Lee Cameron

Summary Records of the past show that the first mineral production in what is now the Province of Manitoba consisted of salt, obtained about the year 1800 by the evaporation of brine. Also at an early time in our history, the Ordovician limestone at St. Andrews Locks, East Selkirk, and other localities was quarried for use as building scone in the construction of forts and fur trading posts. Both salt and building stone are still produced in Manitoba, although not from the original sources. In addition, there is now a substantial production of a variety of other industrial minerals and their products such as lime, crushed stone, gypsum, peat moss, and bentonite. The annual dollar value of production of the industrial mineral industry in Manitoba is today greater than at any time in our past and is derived from a greater variety of products. At the present time, exclusive of the various gravel pits operated by the Provincial Department of Public Works, twenty companies operating thirty-four separate pits, quarries, or mines are producing industrial mineral raw materials in Manitoba. This paper attempts to outline the development of the industry from its start about 1800 to the present, giving general information on the various materials produced. Some suggestions regarding the possibilities of establishing new industries based on other raw materials are given at the end of the paper.

Jan 1, 1949

By José Adachi

La ventilación de minas es un proceso relacionado a la dinámica de la mina que genera el acondicionamiento del aire circulante a través de las labores subterráneas. Como tal, los requerimientos de la mina se adecúan de acuerdo a la estructura física de la misma. En consecuencia, no existe un sistema de ventilación estático puesto que los sistemas requieren de constantes monitoreos y ajustes para alcanzar una ventilación óptima. Así, el presente trabajo señala los aspectos importantes del diseño de ventilación principal de la mina Condestable realizado entre el período de 1992 y 1993 por encargo de la compañía minera. La metodología empleada comprende mediciones de campo y el cálculo de requerimientos del caudal. Asi también está la construcción del modelo de red de ventilación y el diseño del nuevo ciricuito con ventilación forzada.

Nov 24, 1993

By L. H. Michaud

"Albian Sands Energy (ASE), an oil sands surface mining and extraction operation, is currently undergoing start-up and is scheduled to ramp-up to full production by mid-2003. Startup includes the selection and implementation of over 75 IT systems or computer applications which include: engineering applications; systems required to control mining activities, maintenance, the processing plant and utilities; and also systems required to run the company, such as human resources, finances and inventory/ warehousing.This paper outlines the processes used for the selection, implementation and integration of these systems in order to optimize the use of information and to meet the technical, business and IT requirements of the company. The first step in ASE’s approach to identifying system requirements is the development of a business activity model, outlining all tasks involved in running the operations. The computer applications required to accomplish each task are then identified by having the IT team work closely with each technical and business unit. Historically, at some companies, the selection of systems has been led by the IT team or by consultants, with little input from the technical or business units. Typically, this results in products that do not meet the company’s expectations. To ensure a more positive outcome, ASE believes that it is imperative that the company’s technical and business people be closely involved in the selection process.Integration of the IT systems is also key, including linking all applications through a data warehouse and EDMS. Over 120 required integrations have been identified. This ensures the storage of all data in only one location, data security, and easy data and document retrieval for all requirements throughout the company"

Jan 1, 2003

By L. U. Spellman

Atlantic Cement Company's new multimillion dollar, 10,000,000 barrel per year cement plant went into full operation in February, 1962, bringing into reality a new concept in the distribution of Portland cement. The Cerro and Newmont Mining Corporations, well established in the mineral extraction and dressing industry, backed the venture. To take advantage of the, economics inherent in single production units of large capacity, it was necessary to first find a market' capable of absorbing such large quantities. Cement can be economically shipped by rail and truck about 200 miles. Beyond' that radius from the producing facility the freight costs become prohibitive. No single marker area within that radius exists which could absorb such a large volume of cement. However, water transportation provides a relatively inexpensive method of transporting bulk products many times over such a distance. Thus, it was decided to locate the producing facility near a deep water port which had ready access both to the Atlantic Ocean and, just as important, a good source of raw material. An extensive feasibility study was made and the site at Ravena, New York on the Hudson River near Albany was chosen. Here, vast quantities of limestone in the foothills of the Catskill Mountains are found within a short distance of-the deep-water Hudson River.

Jan 1, 1964

By D. S. Barr

Mineralogical, lithological, and metallurgical studies were conducted on various gold ore deposits currently controlled by Freeport-McMoRan Gold Company. Ore samples were first lithologically and mineralogically categorized, then subjected to chlorination, roasting, and autoclaving pretreatments to determine their effects on gold recovery in a subsequent alkaline cyanide carbon-in-leach extraction. The studies indicate that, while organic carbon and sulfide sulfur are the primary refractory components, their effect on process response must be interpreted with respect to the deposit's geology and mineralogy. This approach has proven to be an effective method for evaluating metallurgical alternatives and fore-casting future mill performance.

Jan 1, 1987

By C. W. Jr. Waterman

INTRODUCTION MY SUBJECT is one which would require several speakers and many hours of time for adequate presentation in all its many facets. Because of the widely varying market requirements and coal seams mined, the coal industry of the United States bas of necessity employed many types of preparation facilities to satisfy its needs. Predominance of Baum-type jigs, however, bas marked the mechanical cleaning installations since the early thirties, and these machines continue to hold the lead. CLEANING As a matter of record we find that, at the end of 1948, we had 480 mechanical cleaning plants in operation. Of these, 19 used air cleaners only,?400 used water washers only, . and 61 used dry and wet washers in combination . Due to the increased use of spray water underground on cutting and mechanical mining equipment, there has in recent years been a marked downward trend in dry cleaning installations. In fact, the moisture in dry-cleaned fines has been increased to such an extent by spraying that recent dry cleaning installations have incorporated thermal drying ahead of the dry cleaning units in an effort to overcome the varying and increasingly higher moisture percentages in their raw coal feeds. While on the subject of dry cleaning, it might be well to bring to your attention one of our most recent developments in this art. I refer to the McNally-Brusset vacuum jig.

Jan 1, 1951