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By Swapan Bhattacharya

United States federal and state regulatory authorities require underground mine operators to adopt adequate measures to minimize material damage to the surface caused by nine subsidence. This paper presents an approach to define and determine the extent of material damage due to subsidence from underground coal mining. The basic steps involved in the development of adequate criteria have been enumerated together with the approaches and methodologies used.

Jan 1, 1984

By Richard R. Brochu

At the International Society ofExplosives Engineers Annual Conference held in Nashville, Tennessee in February 1995, a Seismograph Standards Committee was established. The purpose of this wmmittee was to develop objective performance specifications for vibration measurement instrumentation and field use practices. It was also understood that due to geology, temperature, and moisture in the soils, it is not possible to design and build an instrument to give ‘results which are absolutely comparable for ground vibration. It was, however, considered essential to standardize instrumentation by which vibration can be measured under closely defined conditions so that results obtained by users of seismographs are always the same ,&thin stated tolerances.

Jan 1, 1998

By Kenneth K. Eltschlager, Richard R. Brochu

At the International Society of Explosives Engineers Annual Conference held in Nashville, Tennessee in February 1995, a Seismograph Standards Committee was established. The purpose of this committee was to develop objective performance specifications for vibration measurement instrumentation and field use practices. It was also understood that due to geology, temperature, and moisture in the soils, it is not possible to design and build an instrument to give results which are absolutely comparable for ground vibration. It was, however, considered essential to standardize instrumentation by which vibration can be measured under closely defined conditions so that results obtained by users of seismographs are always the same within stated tolerances.

Jan 1, 1999

By Dave Minney

The South African mines health and safety regulations require that mine management establish a quality management system for rock support material. Quality control of resin capsules used as a support medium in South Africa is specified under SA National Standards No 1534. Experience has shown that this specification, while addressing the chemical and physical aspects of the products, but does not address the required performance criteria. In order to address this shortcoming, the industry has put a lot of emphasis on short encapsulation pull tests, performed insitu, in the underground workings of the mine. This is also fraught with many shortcomings, particularly as regards site availability, cost and repeatability of results. To try and address these issues, the Department of Mechanical and Aeronautical Engineering at Pretoria University were approached to develop equipment and machinery that could produce reliable, repeatable results in a laboratory environment which reasonably simulates installation practice underground. The test method is based on the ASTM F432-95 Strength Index test, but modified to use push test rather than pull tests. The paper describes development of the test method and the preliminary results and findings of the work.

Jan 1, 2007

By M. Piard

The scarcity of literature referring to mines in the Rockies has compelled the writer to co-ordinate information and advice taken at the very source. Help was gladly given by active inspectors and mine bosses. Although the field is unimportant at the present time, due to its distance from markets for raw coal, it is quite worthy of the attention it is receiving from two continents; for, with the commercial synthesis of liquid fuels, it would become the largest fuel laboratory in the world, provided, of course, that freight cost drops to a low comparative level. As explained below, there are no obstacles to economical and safe operation under anything like the typical outcrop shown in Figure 1. Although coal dust is probably more dangerous in the Rockies than anywhere else, the damp outcrops afford means of control. The abundant gas may be bled to the open air, and the rigid roof will settle gradually under a wide span of opened outcropping. The Panel Retreating Wall The Measures: Coal measures having an attitude similar to that shown in cross-section in Figure x are characteristic of the active coalfield on the Alberta side of the Rockies, and they are also found on large tracts of undeveloped land west of the divide. The small anticlines, not shown in the cross-section, do not affect the progress of a pillar line, provided their crests are connected to the atmosphere by drainage bore-holes.

Jan 1, 1928

By M. Piard

Fires and explosions are not likely to originate in clean gobs above pillar faces steadily driven through a solid panel in order to effect a complete extraction. As. to the storage which such a process implies where the market is intermittent, its cost will never equal that of abandoning large pillars in a fully developed property. Much less will that cost, thanks to the big sizes obtained, ever approach that of cleaning wet and dirty crushings robbed at great expense from small pillars exposed to many years of roof pressure. Even thick seams under bad roof may be fully extracted without the help of filling material. Fatal accidents from falls of roof owing to the great height of excavations, losses in coal, and the danger from fire, have compelled operators in South Staffordshire, England, to discontinue the stall-and-pillar system at one time supreme in the district, and to successfully adopt the following plan: A retreating' longwall is run along the top coal, as the first working; the bottom coal is taken in the same manner, after the fallen roof has become sufficiently consolidated to allow the mine to be reopened. A similar plan is suggested in this paper in order to deal with the outcropping and pitching seams found in the Kootenay measures.

Jan 1, 1930

By Lawrence F. Johnsen, Marc J. Gallagher

"Micropiles are small diameter, bored, grouted-in-place piles incorporating steel casing and/or reinforcements. The omission of micropiles from most United States building codes has resulted in the application of varying standards for design and installation. The ADSC/DFI Micropile Committee has developed a proposed section for the 2006 edition of the International Building Code (IBC 2006) covering micropiles. The proposed IBC 2006 micropile code section is presented, along with comparisons to existing micropile codes and guidelines. A discussion section is provided to clarify sections of the proposed code. IntroductionMicropiles, defined as small diameter (typically less than 12 inches outer diameter), bored, grouted-in-place piles incorporating steel casing and/or reinforcements, are becoming common foundation elements for new construction, retrofits, and emergency repairs. Developed in Europe in the 1950's and used in United States practice since the late 1970's, micropiles are typically not addressed in building codes, particularly in the United States. As a result, micropiles are often reviewed by building officials to a variety of standards, including drilled shafts, caissons, cast-in-place bored piles, and concrete filled pipe piles. None of these adequately address the unique design and construction aspects of micropiles. Therefore, it became apparent to the foundation design and construction community that a micropile-specific code section was required.To that end, the International Association of Foundation Drilling and the Deep Foundations Institute (ADSC/DFI) Micropile Committee appointed a subcommittee in October 2003 to develop and submit a proposed micropile code section for the 2006 IBC. The subcommittee members included the two co-authors, as well as Tom Richards (Nicholson Construction Company), Tom Armour (DBM Contractors, Inc.), John Wolosick (Hayward Baker, Inc.), Allen Cadden (Schnabel Engineering) and Matt Niermann (Schnabel Foundation Company). At the time of the writing of this paper, the proposed code section has been presented at the IBC public hearing during which it was modified slightly. Final adoption (or rejection) will be determined by the IBC at the final action hearing in September 2005. The attached code section is the revised version following the public review hearings."

Jan 1, 2005

By R. E. Legg

This paper gives a brief outline of the mining and milling methods which will be used on the Stirling zinc-lead-copper ores by Stirling Mines, Limited, who have for the past two years been developing the Stirling mine in Richmond county, Nova Scotia, and who will bring the mine into production in November, 1929. No attempt has been made to give the paper a detailed technical character, for the main reason chat, since base-metal mining is something new in Nova Scotia, it is felt that a general description would be preferable before this Society, whose membership is mainly made up of chose engaged in the coal mining and associated industries. Furthermore, as both mining and milling operations will be governed to a certain degree by the experience gained after production commences, there are many points which cannot be definitely stated now. GEOLOGY Before discussing the mining methods, it is desirable to present a general picture of the geology and occurrence of the ore-bodies. The surface rocks in the vicinity of the mine consist of rhyolites of .pre-Cambrian age. These volcanic flows outcrop in very few places, usually along' the beds of creeks or on the shores of the numerous small lakes. Consequently, a detailed geological map is not available. The exploration work carried out to date has revealed a sheared zone extending through the volcanic flows for a distance of over 1,000 feet. Along this zone, there has been a replacement of the rhyolites by a carbonate rock for widths varying from 50 to 230 feet, and it is in this carbonate formation chat the mineralization at a later date took place.

Jan 1, 1929

By Staff

Introduction As the Sherritt Gordon property is still in the development stage, . it is rather difficult to write a proper account of the mining methods and milling practice that will be used. While the general scheme of operation will remain the same, there will undoubtedly be many minor changes to meet special conditions which we cannot forsee at the present time. Most of the work accomplished to date has followed the usual routine of preliminary development in the Canadian North. However, we have learned a few things which might be of use to others operating under similar conditions. The most important of these is the saving in power cost made possible by the use of Diesels as against steam power when using wood fuel, and the movement of freight by tractors when rail transportation is not available. Location The property i6 located about 90 miles north of The Pas, or 40 miles northeast of the Flin Flon mine. A branch line from Cranberry Portage, on the?C. N. railway, between Flin Flon and The Pas, connects the property with the outside.

Jan 1, 1930

By B Bamford

High speed diamond cutting has extensive applications in civil and mining engineering. A project involving the diamond sawing of black granite is investigating the nature of the diamond cutting process. A sawing machine was devised to adjust the cutting load and measure cutting speed. Cuttings were collected for size distribution analysis. The surface produced by interaction between diamond. grits and the rock was subjected to microscopic investigation. Increasing load prompts the proportional increase in the cutting rate. But the mean size of cuttings shows little change. The photomicrographs of the cutting tracks indicate neither patterns of crack formation nor signs of the ductile behaviour of the rock. A diamond cutting model for hard rock is formulated on these observations. Diamond cutting is a process of surface failure, which advances in four stages. The polycrystalline characteristics of a hard rock and the action of high-speed diamond grits guarantee the creation of crack nuclei which develop into cracks in various directions. This network crisscrossing cracks enable the stripping of this surface layer from the rock.

Jan 1, 1992

By Palmer King

The increased emphasis on environmental protection, together with the exorbitant costs, or in many urban areas the complete unavailability of surface space, has resulted in a burgeoning demand for greater use of underground space. More and more, those considering new or expanded facilities are looking toward the possibility of utilizing underground space for communications installations, for transportation of people, industrial products, water, sewage and energy, and for industrial installations. Happily, this growing demand for use of underground space is accompanied by fast forward strides looking toward more efficient underground excavation techniques. The tunnel boring machine is already here and where ground conditions are suitable for its use it can greatly reduce the cost of underground excavations, savings of one-third or more often being realized. Research is underway involving excavation by use of laser beams, jetting, vibrations, improvement of tunnel boring machines to make possible the excavation of harder rock, and other advanced techniques. The Engineering Foundation estimated in 1973 that tunneling costs can be reduced as much as 30 percent by rapid excavation methods which are expected to be developed through ongoing research programs in the next few years. Your American Society of Civil Engineers reported in 1973 that $60 billion per year, or 15 percent of the gross national product, could be saved if facilities required to support life were located in the subsurface. Studies looking toward improved contracting practices are going on under the sponsorship of the National Academy of Sciences, and Mr. Al Mathews who is heading this program will address you during this session on the status of this project. I myself am a member of Mr. Mathews' study group and, considering the human element involved, it is too early to make predictions as to what can be accomplished in the way of savings in costs of

Jan 1, 1974

By R. H. King

This paper describes the results of an underground coal mine trial installation of a shielded trailing cable. The cable was a three conductor, round, type SHC-GC, and was installed on a shuttle car in a conventional room and pillar mining section. The purpose of presenting the information is to prepare mine operators for proposed legislation that will require shielding on low-voltage trailing cables. Specifically, machine modifications are required to cable reels, packing glands, and couplers. Cable splicing is not as complex as expected but additional materials are needed in the kit and splice training is necessary. Even though shielding will cause some problems for the mine operator, it can reduce the hazard of electrical shock to mine workers. This paper will present information that mine operators can use to solve most of the problems that will be encountered if they are required to install shielded cables. The in-mine evaluation was funded by the U.S. Bureau of Mines.

Jan 1, 1980

As REVISED IN CONFERENCE FEB. 17, 1931 REPORT OF SUBCOMMITTEE ON MINE VENTILATION CODE OF A, I. M. E. COMMITTEE ON VENTILATION ALFRED W. HESSE, Chairman THOMAS G. FEAR GEORGE S. RICE E. A. HOLBROOK WILLIAM A. ROWE HOWARD ECKFELDT R. V. NORRIS CADWALLADER EVANS, JR. H..1. SMITH, Secretary REALIZING, from the safety and health standpoint, the need of furnishing air of good quality to workers underground and of diluting and carrying away dangerous and noxious gases, the following code is offered to unify regulatory measures in coal mine ventilation, so far as is practicable, in the United States of America.

Jan 1, 1931

By E. E. AGGER, Arthur Notman

THE proposal has been made in a bill introduced into Congress at the last session by Representative Jones of Michigan that an import duty of 6 c. per lb. shall be placed on copper. This action is urged after eighty years of prosperity for the industry in this country; during most of which copper has been on the free list, and during all of which a tariff would have been without real effect. To comprehend the general situation upon which this action would be imposed, we must refer to the past history of the industry and its trends at the present time. The following table supplies us with a picture of the physical growth of the industry in this country and its relation to that of the world as a whole down to Jan. 1, 1921:

Jan 1, 1925

By Michael Altepeter

Big River Zinc Corporation, located in Sauget, Illinois, operates a neutral leach residue circuit. The residue produced in the circuit is sold to lead smelters for subsequent recovery of valuable metals. A research program was initiated several years ago to find a means of treating the residue at Big River Zinc to recover the valuable metals. The Ausmelt submerged lance reactor was selected as the best alternative for the first step of the process. Pilot scale tests were conducted at Ausmelt's facilities in Melbourne, Australia. Separations were excellent. 99%+ of the Zn, Pb, Cd, and Ag contained in the residue reported to the oxide fume. 99%+ of the SiO2,, Fe, Mg, and Ca in the residue reported to the slag which passed the EPA TCLP test. Subsequent leaching of the oxide fumes and purification of the leach solutions using conventional procedures produced solUtions suitable for zinc electrowinning and an upgraded lead sulfate cake for sale.

Jan 1, 1992

By Edgar Trask

EACH branch of engineering seems to depend on the cooperation and contribution of some other branches to enable it to produce more efficient methods and appliances for man to use. The purpose of this paper is to show approximately the gain in efficiency of self-propelled merchant ships when steel of greater elasticity is substituted for mild steel in some of the strength members and alu-minum alloy is substituted in some of the parts where strength is not essential. The new steel will have some greater strength and a much greater elastic limit in the as-rolled condition, and must be readily weld-able under ordinary conditions of shipbuilding. Naturally, its cost may be more than mild steel, but if the demand is great that excess cost may be reduced to an amount that will make its use more economical than that of the present mild steel. There appears to be a well defined axiom in engineering today that to use the least power to carry a given load the weight of the carrier must be reduced to a minimum. This minimum must be, of course, consistent with the necessary strength, rigidity and durability and it must not be attained at an excessive cost where the fixed charges of the carrier will exceed the savings in, operating the motive power. Recent railroad equipment is a notable example of this, and in these trains alloy steels and aluminum together with less weight per horsepower of the power plant are reducing the weight of the carrier and hence the total power required for moving the paying load. Before considering the application of these metals to shipbuilding, it is well to explain some of the fundamentals of ship design.

Jan 1, 1936

By Sidney Cornell

THE technical- advantages of adding oxygen to air and producer gas, or using it as a reactive agent, producing 400 B.t.u. gas instead of. the present 150 B.t.u., with higher flame temperatures and a reducing flame possible, with a smaller volume of gases passing through a furnace, will result in quicker melting, sharp working, and the production of a higher quality steel. Probably electric-furnace quality steel can be produced in an open-hearth furnace using oxygen. A modern, standard, 100-ton open-hearth furnace, with all equipment, costs from $350,000 to $500,000; there are about 1000 open-hearth furnaces in this country. When considering the use of oxygen in the open-hearth furnace, it is necessary to study: (1) The use of oxygen in the present furnaces, such that modification of existing furnaces and equipment cost the minimum, although the full advantages of oxygen are not thus obtainable. (2) The use of oxygen in a furnace designed for its use, producing quality and quantity steel at the lowest possible cost. This entails the junking of approximately one-half the value in existing equipment-writing off $250,000,000. The basis of such an estimate is the present cost of manufacturing open-hearth steel. Objection may be taken to some of the unit prices here given, but while some companies obtain their ores for much less, the prices quoted are -market price. They are used to show the maximum economy obtained by oxygen at that point.

Jan 11, 1924

By N H. Jansen, H L. Bridgwater

Field portable X-ray fluorescence (XRF) and near infrared (NIR) instruments are proven technologies in the minerals industry. The in-field results of these instruments can add value early in the project life, leading to cost-effective decision-making compared to their equivalent laboratory based techniques. However, in order to add value to a project, it is crucial that the instruments are employed correctly.Orientation studies should be carried out prior to initiating a sampling program to achieve the highest level of quality assurance and control for the results. Hence, an appropriate sampling workflow begins with considering what outcomes are required, including level of precision, accuracy, reliability for elements and minerals of interest, and sampling errors. The workflows proposed include soil sampling and reverse circulation and diamond drilling sampling techniques, and laboratory based techniques. They are practical and flexible workflows using available portable XRF and NIR technologies that can be applied to current sampling and drilling methods.The combined technologies have the ability to create large, integrated geochemical and mineralogical data sets that can provide cost savings for every stage of the mining chain from exploration to prefeasibility, mineral processing and environmental remediation.CITATION:Jansen, N H and Bridgwater, H L, 2017. Proposed workflows for portable X-ray fluorescence and near infrared instruments for soil and drill hole sampling, in Proceedings Eighth World Conference on Sampling and Blending , pp 219–228 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

The development of research activities at Risdon and the implementing of a policy of instrumentation in plant processes have, in recent years, entailed a considerable increase in research staff and created an urgent need for more space and modern laboratory facilities. The existing laboratories have been in use for 25 years and are now inadequate. New buildings have been authorized.The new buildings will comprise, firstly, a laboratory building of three floors giving a totai .floor space of approximately 11,000 sq.ft., and a pilot plant building as an annexe to the laboratory building, of approximately 4,900 sq.ft. The laboratory building will accommodate from 20 to 22 research workers, and additional plant operatives will be used for the control of processes in the pilot plant building. The new buildings are designed to provide facilities for three principal functions; the investigation and improvementof existing processes, the development of new processes up to the pilot plant stage, and the control and maintenance of instruments.LOCALITY AND ORIENTATION OF BUILDINGSThe site of the buildings is elevated ground on the eastern side of the main plant, near the main entrance and general office building. There will be no obstruction to sunshine at any time of the day, and the laboratory building will command views of wide radius from wooded hills across the River Derwentto the open sea on the south-eastern quarter.The buildings are located to provide space for future extensions. The main laboratory building faces approx...

Jan 1, 1949

By Fabio Andre Brand

As empresas de classe mundial, para atingir a excelência, buscam inovações para maximizar a utilização dos seus ativos. Para estas empresas, os departamentos de manutenção assumem uma função estratégica e a utilização de metodologias como a Manutenção Centrada em Confiabilidade (MCC) tem contribuído muito para a obtenção de um desempenho positivo em seu sistema produtivo. Apesar das inúmeras vantagens da aplicação da MCC, identificou-se uma oportunidade de melhoria nesta metodologia, na etapa de aplicação do diagrama de decisão para escolha das tarefas de manutenção. Pois é dentro deste contexto que se insere o presente trabalho, que busca consolidar o processo de implementação da MCC, com a introdução de melhorias na etapa mencionada, voltadas principalmente para a sua utilização na indústria siderúrgica. Inicialmente, apresenta-se uma abordagem sobre os conceitos e métodos empregados na MCC tradicional. Em seguida, as melhorias propostas foram detalhadas junto com um estudo de caso, onde a MCC, já contendo os métodos elaborados neste trabalho, foi aplicada em uma empresa siderúrgica, sendo que os resultados obtidos demonstraram a adequação desta proposta às necessidades deste ramo industrial.

Oct 30, 2017