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By Samuel S. Wyer

THE following abbreviations have been used in, the text: Cassier's, Cassier's Magazine. Eng. Lond., The Engineer (London). Eng. Mag., Engineering Magazine. Eng. and Min. Jour., Engineering and Mining Journal. Eng. News, Engineering News. Eng. Rec., Engineering Record. Engng., Engineering. Engr., The Engineer (Chicago). J. I. and S. I., Journal of the Iron and Steel Institute. Jour. F. I., Journal of the Franklin Institute. Jour. Assn. Eng. Soc., Journal of the Association of Engineering Societies. Mar. Eng., Marine Engineering. . Mem, Soc. Ing. Civ., France, Memoires de la Society des Ingenieurs Civils, France. Prac. Eng., Practical Engineer. Proc. Digs. Soc. of W. Pa., Proceedings of the Engineers' Society of Western Pennsylvania. Proc. I. C. E., Proceedings of the Institute of Civil Engineers. Proc. I. 1M. E., Proceedings Institution of Mechanical Engineers. Trans. A. I. M. E., Transactions of the American Institute Mining Engineers. Sci. Am., Scientific American. Sci. Am. Sup., Scientific American Supplement. Zcitschr. d. V. D. Ing., Zeitschrift des Vereines Dentscher Ingcnieure.

Mar 1, 1905

By Miguel Arancibia

El presente trabajo nos permitirá conocer sobre la actual relación comercial que tienen los negocios locales -NNLL - de nuestra zona de influencia como Antauta con las empresas contratistas de la unidad minera de San Rafael y la importancia de cerrar brechas digitales dentro de los procesos comerciales que ambos gestionan. Minsur como parte de su estrategia de sostenibilidad busca contribuir al progreso de nuestros grupos de interés, impulsando oportunidades de desarrollo para todos, siendo un principio dentro del Consejo Internacional de Minería y Metales -ICMM- y guiados por nuestro propósito “Mejorar la vida transformando minerales en bienestar”.

Sep 29, 2023

By Charles Anema

The Mancarried and Helicopter Receivers were developed under the contract for trapped miner location. This program was a five phase program with 15 mancarried and 5 helicopter production receivers delivered under Phase IV and equipment documentation required under Phase V.

Jan 1, 1976

By M. L. Harris, J. Organiscak, S. Klima, I. E. Perera

"The Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health (NIOSH) conducted underground evaluations in an attempt to quantify respirable rock dust generation when using untreated rock dust and rock dust treated with an anticaking additive. Using personal dust monitors, these evaluations measured respirable rock dust levels arising from a flinger-type application of rock dust on rib and roof surfaces. Rock dust with a majority of the respirable component removed was also applied in NIOSH’s Bruceton Experimental Mine using a bantam duster. The respirable dust measurements obtained downwind from both of these tests are presented and discussed. This testing did not measure miners’ exposure to respirable coal mine dust under acceptable mining practices, but indicates the need for effective continuous administrative controls to be exercised when rock dusting to minimize the measured amount of rock dust in the sampling device IntroductionTwo recent regulations have modified operators’ rock dusting schedules in order to meet compliance standards. First, the 80 percent incombustible requirement in intake entries has increased both on-section and out by the- section rock dusting. Secondly, the recent change to the respirable dust regulation has increased the number of respirable dust samples taken per sampling cycle. Previously, when only five samples were needed bimonthly, rock dusting could be scheduled to not interfere with the respirable dust sampling schedule.The significant number of samples now required under new regulations, combined with the need to maintain 80 percent total incombustible content in active mining areas, require the schedules for respirable dust sampling and rock dusting to overlap. Although rock dust is considered a nuisance dust in relation to U.S. Mine Safety and Health Administration (MSHA) sampling, these overlapping schedules raise concerns about the amount of rock dust that potentially is included in the sample. Additionally, the respirable dust maximum was lowered from 2.0 mg/m3 to 1.5 mg/m3 effective Aug. 1, 2016, increasing concern that rock dust contamination may be an issue (MSHA, 2016). Currently, the acceptable practice is to apply administrative controls such as keeping the miners upwind during rock dust application, or to schedule rock dusting during a maintenance shift when the number of miners present is lower."

Jan 5, 2017

By Winfried Rosenstock

AEBT has been available for a couple of years and is successfully applied in Australia. Up to now it was mainly used in coal surface mining at the Australian East- Coast. Presently, the proved results reach ~ 50 % reduction of Drilling & Blasting costs and a productivity increase of between 10 and 20 %. In 2003 it was for the first time used in surface metal-mining. The mine features for the time being an extremely difficult geological environment and had above to be carried out in the transition level waste/ore. Reductions of wall control, powder factor and vibrations were the main target.

Jan 1, 2004

By B. J. Kloppers, J. V. Z. Visser, C. J. Horn

"The long-term plan (LTP) in a mineral resource company is defined by the quality of the mineral resource and represents the result of a series of trade-offs to fulfil internal organizational as well as external business and legislative requirements, ensuring ultimate delivery on the defined organizational strategy.The LTP should as a whole align to a coherent and well-defined organizational strategy, working towards a clearly defined objective while still allowing a tactical response to short-term requirements of the organization. The ability to respond tactically to changes in environment, like the unprecedented five-month strike in 2014 on the platinum belt following the 2012 Marikana incident, is a measure of the flexibility of the plan given the agreed strategy.This paper describes the Lonmin process of linking company strategy with long-term planning, tactical planning, and the execution of the plan through an annual planning cycle to maximize organizational flexibility. This flexibility enables mining companies to respond to the many internal and external forces that impact on both strategy formulation and delivery of results that meet shareholder expectations."

Jan 1, 2015

By H. C. M. Gordon

IN every co al mine the hazard of fire in the underground workings is always present. This is a natural condition, because the mineral wrought and the supports normally used are themselves combustible and because underground fires may originate in many ways. The main causes of such fires are: (1) Open lights igniting gas, wood, or the coal itself. (2) Explosives igniting gas or coal. (3) Spontaneous combustion. (4) Electric sparks or short circuits igniting gas, wood, or coal. (5) Frictional heat igniting wood, coal, or oily material. (6) Explosions of gas or coal dust igniting wood or coal. The relative importance of these causes, and others less frequently met with, varies from district to district and depends to a great extent on the equipment and supplies used, on the training and discipline maintained among the workmen, and on the liability of the coal to heat spontaneously. It follows, therefore, that open lights should not be used and that, wherever there is the least possibility of methane being encountered, only locked safety lamps of an approved type should be allowed underground. It follows, also, that only 'permitted' explosives should be used and that the it use should be confined to conditions under which they are ?permitted?. Similarly, electric equipment should be of an approved type and all such stationary equipment should be housed in well-ventilated fireproof rooms. Such rooms, as well as entries to stables and oil houses, should be provided with doors which can be easily and tightly closed and which should be constructed of fireproof material.

Jan 1, 1937

By A. S. Block-Bolten

Two innovations in nickel-arsenic separation have been studied on a laboratory scale. The first requires only a nitric acid atmospheric leach without preliminary roasting and leads to favorable final conditions for precipitation of arsenic as highly stable FeAsO4, The second is an NaOH-H2O2 pressure leach which is an alternative to the known NaOH-O2 pressure leach. Either method offers the possibility of rapid and efficient separation of nickel from arsenic and is applicable, for example to the high grade niccolite deposits in the Great Slave Lake area of northern Canada.

Jan 1, 1982

The Australian industrial relations system is in a state of constant change. We are undergoing a transformation from a compulsory arbitration and an award based system to one which is fundamentally rooted in the concepts of enterprise bargaining. This is true both at the State and Federal level. The structural changes which facilitate the movement away from the predominance of Awards to enterprise agreements has been fostered by both sides of the political spectrum and is a cornerstone of their respective industrial relations platforms.In determining what form or combination of forms of industrial instrument(s) should apply to the individual enterprise, employers must have regard to the viability and sustainability of each form in the changing industrial climate. In particular employers should have regard to the needs and agendas of their employees and unions which may purport to represent Them.

Jan 1, 1998

By D. K. MACKAY

The production of oil and gas in Arkansas is confined to two distinct and widely separated regions of the state; namely: (1) South Arkansas in the Gulf coastal plain, where 49 fields-many containing two or more reservoirs or pools-yield oil, condensate and gas from beds in the Cretaceous and Jurassic, and (2) Northwest Arkansas, a part of the Arkansas Valley, where only dry gas is produced in 21 fields from sandstones of Pennsylvanian age. Exploration during the year 1945 centered largely in these two producing regions, but some of the geophysical surveys were made and wildcat drilling was done a considerable distance outside these regions.

Jan 1, 1946

By M. Misra

The coral contaminated with plutonium at Johnston Atoll UA) was subjected to gravity and flotation separation processes at the Soil Washing Laboratory (SWL) and also at the Johnston Atoll UA) site. Tests were conducted with the contaminated coral fractions referred to as the "HP-l" ( hot particles) and the "sludge". The gravity process tested was centrifugal gravity separation and the flotation processes were conventional Denver mechanical flotation and tall column flotation. Flotation tests were conducted using both fresh and sea water. Industrial fatty acid (anionic collector) was chosen as collector to make plutonium-enriched particles hydrophobic. The use of flurosilicic acid and sodium silicate made the clean coral hydrophilic. The results show that each of the processed when tested with appropriate size fraction and operating conditions resulted in passing the success criteria. It was possible to obtain more than 80% weight of the original coral as "clean sand" having activity below the JA site "soil screening level" of 13.5 pCi/gm. The field tests spiked with plutonium particles showed remarkable success. The effect of depressants, flotation medium and the coral pretreatmentis described. Finally, a flowsheet developed by the University of Nevada, Reno to treat 8000 tons of HP-l pile presently stored at JA is presented.

Jan 1, 1996

The aspect ratio (mill diameter/mill length) of autogenous and semi autogenous mills varies widely and can be as high as three or as low as 0.5. The literature on the subject of what effect aspect ratio has on grinding mill performance or energy efficiency is almost non-existent. However, at the design stage of many grinding circuits the subject is often vigorously debated amongst metallurgists. In this paper the performance characteristics of mills with different aspect ratios are examined to determine whether process performance characteristics are a function of aspect ratio and whether high aspect ratio mills are any more or less energy efficient than low aspect ratio units. Data from both pilot and full-scale mills are used for this purpose in open and closed circuit configurations.

Jan 1, 2007

HAVING previously described the metals to you, before I proceed any farther I do not wish to fail to tell you, as I promised to do in the first chapter on metals, what I have learned through experience concerning the semiminerals, although this may seem to you outside our proposed subject. Since these are not produced by Nature as all rock or all metal they are called semiminerals by speculative physicians. Many kinds of these are found; those that resemble rocks are earthy, very difficult to liquefy, and much more adapted for adorning paintings than for anything else. Those that liquefy with fire, like sulphur, antimony, marcasite, [22] calamine, zaffre, manganese, and others, resemble the metals almost like brothers. Some others are more watery so that they dissolve in water, although they are fairly dense, and are obtained and reduced to their, perfection by means of water. These are the salts, vitriol, rock alum, and saltpeter. To these, as a watery thing, belongs also quicksilver, as it is commonly called because of its motion. Although it appears. not only liquid, but very liquid, this is not at all similar in its effects to any of the above. Indeed, it retains its same being until its very form is consumed. Since the reasons for its effects are almost impossible to investigate, I do not intend to speak of them here or to enter now this maze of speculation, because I wish to make definitely clear to you what this quicksilver really is. Therefore, leaving aside opinions and disputes, I shall take only those of the said semiminerals that I know are useful. First we shall see the method by which the semiminerals can be found and then how they are to be extracted from their matrices. These, perhaps, have no less need of effort and industry than the metals since they are substances completely hidden in the rocks or in the earth. For this reason some of these that are sought are made use of by means of fusion after they have been mined from their mother mountains, and some others need to be disposed by a certain maturative corruption, now with moisture and coldness, now with dryness and heat, as with waters, rains, frosts, or long baking in the sun, with fire, or even with a strong reheating within themselves. Most of them can finally be brought to the desired end by means of solution with water and fire.

Jan 1, 1942

By Asheim, Harald A.

Parameter estimates affect both the optimum field development decisions and the economic result. A general methodology for assessment of the effects of parameter uncertainty in offshore development decision situations is proposed, and used to analyze aspects of the initial development situation for the Statfjord field.

Jan 1, 1982

By P. K. Sims

Extensive mineralization in the basal part of the Duluth Complex of Middle Proterozoic (Keweenawan) age in northeast Minnesota has been explored during the past 30 years as a potential source of copper and nickel from sulfide-bearing assemblages. Very large resources of low grade and marginal material have been delineated by drilling and by test shafts sunk by at least five private mining companies, but none of the properties has yet been mined. With few exceptions, grade and tonnage figures for specific properties have not been released, but the magnitude of the resources has been estimated by the Minnesota Geological Survey and the Minnesota Dept. of Natural Resources as constituting several billion tons of low grade and marginal copper- and nickel-bearing material - a major combined copper-nickel resource of international importance.

Jan 1, 1991

By Peter Faust, Jeremy Zorne, Timothy Siegel, Diane Fiorelli

Professional sport venue construction follows a very simple rule. Once the decision has been made to move the team to a new place, construction shall begin immediately, so that not more than one or two seasons pass by stuck in the old home. Such tight construction schedules require a different approach than traditional design-bid-build contracts. Design is mostly done on the fly, the construction schedule becomes a main risk factor and an early contractor involvement is desired. As specialty contractors become more and more sophisticated, owners, their construction managers or the general contractor have realized the value of ideas and modern technology they can bring to the table for a successful and fast project completion. Local knowledge and experience in a variety of solutions play a key role in the specialty contractor’s ability to provide added value to the project. This is also true for the specialty foundation contractor, who needs to understand the complexity of such modern structures from its integrate foundation, over the delicate concrete structure to a potentially fancy movable stadium roof. Not to mention all the modern high tech equipment which shall make such a place a great customer experience. His expertise shall enable him to propose the most suitable foundation element for the given ground condition and application. Rather to build what others have designed, his strength is to propose alternate concepts which will be faster and (hopefully) more cost effective. This paper highlights different value engineering (VE) input a specialty foundation contractor had on 3 major sports arena projects in California. Together with the entire team from owner to GC, including the Geotechnical (GEOR) and the Structural Engineer of Record (SEOR), the most efficient and best performing foundation solution can be found every time. But such an approach also requires the open mind of the owner to entertain last minute changes when the permit drawing set has already been submitted for approval.

Jan 1, 2018

By Lynch A. J

The success of the Australian mining industry depends on the quality of its skills. High quality skills supported by a culture which demands success lead to innovations, good practices and prosperity. Average skills lead inevitably to mediocrity. Universities play an essential role in the development and use of skills but the crucial industry-university links have been subordinated to conventional academic interests in training mining and processing engineers. It is only in the area of post-graduate research degrees which are oriented towards the mineral industry that Australia can claim world leadership. Deficiencies are not due to lack of training resources, they are due to inadequate utilisation of the resources that are available. Australia can and should have the world's best mineral engineering school, with a branch in Asia where many of its customers are and close ties with South America where some of its production operations will be. Some steps which might be taken to achieve this are proposed.

Jan 1, 1995

By Robert F. Pettit

This paper on methods and costs of mining and milling iron ore at the Iron Mountain mine of Ozark Ore Co., St, Francois County, Mo., is one of a series of Bureau of Mines reports on methods, practices, and costs of mining and milling throughout the United States. The Iron Mountain operation is notable for its successful transition from open-pit to underground mining, for use underground of large earth-moving equipment, and for development of a multilevel room-and-pillar mining method. Milling methods also have undergone transitions - from hand sorting and log washing in the early days to gravity concentration. Milling ultimately may include flotation to recover additional iron from products now discarded as tailing,

Jan 1, 1957

By B. Asbury, M. Cigla, C. Balci

The Western Mining Resource Center (WMRC) at the Colorado School of Mines (CSM) received a grant from the National Institute for Occupational Safety and Health (NIOSH) to perform a study that will help reduce the amount of respirable dust generated from the cutting of coal. The study is based upon laboratory testing and field experience. This information is being used to develop a new cutterhead design in conjunction with Joy Mining Machinery. The new cutterhead design is being evaluated with existing computer models developed at CSM. The new continuous miner cutterhead will be tested at the Twenty Mile Coal Company’s Foidal Creek Mine. Baseline testing with the current cutterhead will also be performed. This paper presents laboratory test results, design methodology, and test results performed to date.

Jan 1, 2002

By Federico Chavez

The process for recovering lead from battery residues used in several Mexican Plants include lead blast furnace and rotary furnaces. The formers are basically fed with recycled batteries together with the necessary additives to produce metallic lead. One of the by-products generated in the blast furnace is a dust mainly formed by lead sulfide. The rotary furnace is used to recover lead .from lead batteries, dross from the refining-alloying process and the leady fines produced in the blast furnace. This paper describes thennodynamic analysis made to the rotary furnace process to understand the effect that each component of the system has upon the lead recovery. In order to enhance the process, the influence of iron chips composition and excess coke on slag viscosity is discussed. A computer optimization program . has been developed to design the furnace charge based on material and energy balances, .together with the thennodynamic equilibrium calculation.

Jan 1, 1995