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By Jake Gibson

"As one of the most pressing and important political debates of this century, climate change has captured global attention and is forcing governments to take action toward decreasing greenhouse gas (GHG) and carbon emission levels below what was previously thought to be necessary. With the ever-increasing price of diesel fuel, accompanied by the popular topic of carbon taxes and greenhouse gas emissions, the mining industry is looking to industry specialists for assistance. The benefits of a no-idle policy reach far beyond carbon reduction and fuel savings, ranging from decreased maintenance to increased engine life. With products like battery-powered ac systems and diesel-fired heaters, going noidle is easier today than ever before. With both systems being manufactured to withstand the harsh environments of the mining industry, the end user will see a seamless change from conventional, inefficient belt-driven systems to future, standalone mobile equipment HVAC.The history of GHGs and climate changeIn 1896, Svante Arrhenius first claimed that the combustion of fossil fuels may eventually result in enhanced global warming, but not until 1955 did Gilbert Plass draw global attention to global warming by summarizing that adding carbon dioxide to the atmosphere would intercept infrared radiation and thus warm the earth. Then in the early 1960s, Charles Keeling developed modern technology to produce concentration curves for atmospheric CO2 (Fig.1).In 1988, the Intergovernmental Panel on Climate Change (IPCC) was founded by the United Nations after acknowledgment of a rising global annual temperature. The IPCC consists of more than 2,500 scientific and technical experts from more than 60 countries. Because climate change could not be solved by a single country, the Kyoto Protocol was negotiated in 1998, requiring all participating countries to reduce their GHG emissions by at least 5 percent from the 1990 levels. The Protocol was signed by 186 countries in 2001 (since then several countries have retreated from the agreement, including the United States). In 2002, the Bush administration announced a policy for climate change relying on domestic, voluntary actions to reduce the "greenhouse gas intensity" of the United States economy by 18 percent by 2012. The U.S. still attends the Kyoto conference of parties (COPs) but does not participate in negotiations, as it is not bound by its terms."

Jan 1, 2014

By Charles K. Presley

This paper deals with drilling large diameter shafts for the mining and construction industry with diameters in excess of 3 feet to more than 20 feet in diameter. It discusses appropriate applications of the rotary drill method, linings for large diameter shafts, circulation systems,, and the limitations of the method. Each specific rotary drill method is determined by the geology of the area, the depth to be drilled and the formation fluids encountered. Shaft lining or casing must be improved to result in lighter weight, higher strength and lower cost. All phases of rotary drilling equipment must be improved to drill shafts in excess of 10 feet in diameter. As these goals are reached, more shafts of large diameter will be drilled by the rotary method for the mining and construction industry.

Jan 1, 1967

By Paul H. Rylund

Substantial priming was a considered necessity for proper initiation of ammonium nitrate-fuel oil mixes as ANFO began to carve its niche in the mining industry in the latter fifties. Heavy priming accompanied the introduction of prills and oil to many blasting operations, large charges of high explosives were commonly used at the bottom, top and frequent intervals through-out the column. As the quality of ammonium nitrate improved and operators became more experienced, primer costs began to diminish. Increased experimentation continued with reduced primer costs a main objective. Cast primers were introduced and became accepted as an excellent companion for ANFO. Although the trend toward larger diameter boreholes became increasingly popular, emphasis on lower and lower priming costs continued. A primer was simply required to produce any type of initiation within the ANFO column to be considered adequate. Suddenly ANFO priming had digressed from excessive to marginal. Early experimental data developed at "test site" and laboratory locations indicated that ANFO had a tendency to react inefficiently in the initiation region of the column unless substantially primed. This was evidenced by the presence of unstable reaction rates detected with newly developed detonation velocity measuring equipment. These 10" order or "transient" velocities were believed to originate because of inadequate primer strength or a primer diameter to column diameter mismatch. How-

Jan 1, 1972

By J. Kretschmann

Mining heritage can be of outstanding value for many regions around the world, because mining has been done for thousands of years for the benefit of mankind and its development. This paper presents an ongoing project creating a general guideline for the handling of mining heritage on the basis of experiences made in Germany. Interactions of stakeholders in the ?heritage network? as well as strategies for the technical proceeding will be described. An action plan for the sustainable handling of mining heritage has already been developed in part, which includes necessary measures. Best-practice recommendations will be derived. Keywords: m ining heritage / preservation / guidelines / action plan / Sustainability

Feb 27, 2013

By Gy. Deák Deák

The ECOMINING platform aims to develop a scientific and technical organization in order to promote within the natural resources industry a framework for environment-friendly exploitation technologies (on Best Available Technologies principle) and also to develop a solid basis for performing Research and Development projects. The ground of this project is the success of the First International Seminar: ECOMIN-ING - Europe in 21st Century1, organized by the Research and Development National Institute for Metals and Radioactive Resources Bucharest in co-operation with ITASCA Consultants GmbH Germany, the University of Petrosani and supported by the National Society of Salt Bucharest & Praid salt mine branch and the Ministry of Economy and Commerce. The platform provides a complex data base, for partners? selection and researchers? team structure. This can provide the scientific results with a high level of confidence for the projects of interest in the field of exploitation of mineral resources and for the participation on national and international project proposals competitions (i.e., target the 7th Framework Programme or any European / national programme, which can provide funds for the ECOMINING platform field of interest). The next step is the affiliation of the ECOMINING platform to the European ones, and to be compatible with them. The ECOMINING platform represents itself a 7th Framework Programme (FP) project idea.

Jan 1, 2007

By Raymond L. Jones

With the inauguration of the open pit operation in Bagdad, plans were formulated for a large scale leaching operation. Dump stockpiling was started almost immediately, but actual production was not initiated until the spring of 1961. Like all neophytes, we started something about which, on a commercial scale, we knew next to nothing, either dump preparation or leach procedure, and as a consequence, we are still paying the piper. True, we had been through an extensive laboratory pilot program, but it soon became apparent that there was considerably more to increasing solution volumes than simple multiplication. Had we initially possessed our present acumen, the Cyprus Bagdad plant could be operated more efficiently and at a better profit. During the past several years, the art of dump leaching of copper has improved in many ways, primarily because of the application of scientific principles gleaned from general mining practice. Rigid pH control and the use of atomic absorption techniques for rapid," accurate assaying have probably played a leading role in this respect, although we cannot overlook the other sophisticated electronic controls lending improvement to acid addition and pumping, better piping materials, and lastly, the more efficient use of our pregnant liquors. Thin too, the years of experience have given us a greater understanding of dump behavior in general; and, we can, to a greater extent, measure, predict, and avoid some of the idiosyncrasies inherent in every dump. However, it is my firm belief that we will still be confronted with unexplainable dump behavior as long as we are involved in leaching. We have found our dump to be a wonderful money bank, but one that is capable of yielding a wildly fluctuating profit.

Jan 1, 1975

By Kurt Wiener

A major process control system is in some ways like a complex organism. The extremities, (that is, field instruments) are exposed to many hazards and suffer malfunctions of relatively minor and repetitive nature. Here I equate a stuck valve or dead transmitter with a skin abrasion or cut. The maintenance and repair of the extremities can be done by technicians with basic but thorough knowledge of relatively few problems and their solutions. Here I equate with administering Band-Aids and aspirin. On the other extreme, when the master control device (such as a computer) fails, one does not attempt home remedies. A "brain" specialist is called in. It is, however, crucial that the patient be able to clearly describe his symptoms. Getting down to the case at hand, a complex system consisting of field instruments, instrument racks, interface equipment, and perhaps a computer, may require maintenance at all levels. At the field equipment end where physical damage, corrosive atmospheres, reconfiguration, and routine calibration checks are common, the customer has the opportunity to develop a competent staff of maintenance people. The relatively high maintenance activity assures competence through repetition.

Jan 1, 1980

By James A. Clem

Approximately 2,000 years ago, the Lord Admonished the Scribes (Lawyers) and Pharisees (Religious leaders of that time) that they had paid the tithe but had omitted the weightier matters of law, Judgement, Mercy, and Faith. (Matt. 23:23). I want to talk about "The Weightier Matters of Law." In a situation where big government is trying to have an effect on even small details of a work activity, otherwise simple situations become complex. Regulations are written to such detail that constant compliance with strict interpretations can be a nightmare--not to mention off the target of the intended purpose for the regulation. One soon re- cognizes the oneros characteristics of Federal statues

Jan 1, 1979

By Willard C. Lacy

Survival of the mining industry as a viable economic entity in the United States is being seriously threatened by declining grades of ore reserves, rising operational and capital costs, and increased governmental taxes, restrictions, and subsidizing of third world competition. Discovery of major high-grade deposits is becoming increasingly unlikely. International competitiveness of the U.S. deposits will depend upon 'Yankee Ingenuity', innovations in mining methods, metallurgical treatment, and financial arrangements, and a viable national strategy. This will require not only effective management for control of operations, but management that encourages breakthroughs in technology, financing, labor relations, and in public and governmental understanding. The mine geologist and the exploration geologist both have important roles to play in all aspects of this fight for survival of the industry.

Jan 1, 1984

By John R. Marks

Introduction An engineer is a builder and a problem solver. He uses knowledge of the properties of matter and energy to furnish the needs of society. Engineers form the bridge between scientific researchers and the general public, most of whom are technologically illiterate. Mining, metallurgical, and petroleum engineers extract minerals from the ground and process them into usable forms. Then, other engineers further process them into society's needs. Minerals engineers deal with more uncertainty than other engineers. Each ore deposit has its own personality and each ore is metallurgically unique. Minerals engineers, therefore, must be flexible, often applying larger safety factors and contingencies than other engineers, and frequently functioning as a jack of all trades. A minerals engineer can work in coal, oil, oil shale, base metals, ferrous metals, precious metals, industrial minerals, strategic minerals, or in exploration. Other mining jobs include banking and financing, education and research, marketing and sales, and government. As a minerals engineer, you may be among the first to work on the ocean floor or the moon. College Preparation A difference between college and industry is the type of problems to be solved. A typical college problem has an exact answer derived from given information. An industry problem is more apt to have a solution chosen from a number of alternatives. Information required for the solution is not given. It must be measured, calculated, looked-up, estimated, or otherwise derived. Solutions involve trade-offs, economics, and human factors, as well as application of physical laws and theory. When a college problem is answered, you move on to the next one. In industry, however, the headaches may just be starting with the implementation of the solution. Students often complain that they see little use for the theory they are learning. This is valid. A good professor will link theory and practice. Another difference between college and industry is the price of failure. In college, you can make a half-hearted effort in an assignment and take your C or D. On the job, however, poor engineering results in potentially effective projects being rejected and unsound projects being undertaken. Poor performance results in cost overruns, schedule holdups, oversights, disgruntled employees, irate bosses, unsafe structures, and unreliable systems. The costs are time, money, and possibly lives. The student pays the university for his work - not the other way around. So the rewards for good schoolwork often seem nebulous. But education must be viewed as an investment. Working for good grades will help you think better, learn more, receive better job offers, and perform more effectively on the job. There is no substitute for hard work. Avoid taking the easiest electives. If you desire a more liberal education or dislike rigorous physical sciences, mathematics, or engineering courses, change majors. Remember, you are training to be an engineer, not a computer programmer or market analyst. At least one summer of industry employment is necessary for minerals engineering students. The sooner you gain actual experience, the sooner you will know whether to change majors. Most large companies hire students during summer. It is best to send out applications around Christmas break. First and second year students usually work as laborers. Upper-classmen may work as engineering technicians. Students must sometimes choose between returning to a company at a higher position or trying a different company at a lower position, for more varied experience. Both alternatives have advantages. Do your best on these summer jobs. The company is watching. If you do well, the chances are good you will get a job offer when you graduate. Good references are important when you begin job hunting. Interviewing occurs near the end of your school career. The standard procedure is to send your resume with a cover letter to each company you are interested in. The resume for a graduating engineer with little experience need not exceed one page. The cover letter must be written for the individual company.

Jan 2, 1985

By E. Stolarski

The circulating fluid bed (CFB) technology can proudly point to its history of more than a quarter of a century of commercial operations. Over 80 CFB units operate in aluminum calcining, coal combustion and gold roasting. This paper describes the invention of the circulating fluid bed and chronicles its development and evolution from calcining through coal combustion to gold roasting. It presents performance data of Lurgi's CFB units in operation and highlights the six gold roasting plants currently operating throughout the world.

Jan 1, 1998

By J. Kretschmann, O. Drusche, S. Krause

Mining companies are caught between the growing international relevance of ESG (Environmental, Social and Governance) investments and the need to secure their “social license to operate” by considering the needs of their stakeholders. In the search for sustainable business models, the concept of the circular economy (CE) is gaining momentum among practitioners and scholars, as it enables the creation of shared value and thus strengthens the trust of investors and stakeholder relationships. However, there is a lack of a sectorspecific CE framework providing guidance to decision-makers in evaluating promising activities. A gap, which this contribution aims to address.

Mar 2, 2022

By Vladimir Nikolić, Alex Doll

The Bond ball mill grindability test is one of the most common metrics used in the mining industry for ore hardness measurements. The test is an important part of the Bond work index methodology for designing and measuring the efficiency of mineral grinding circuits. In spite of being called “Bond’s Law,” the work index equations are not a law of nature; but rather an empirically measured regression of a large data set collected by the Allis- Chalmers corporation in the period between 1930 and 1952. As a regression, it is valid within a specific “calibration space,” and great care is required when deviating the test procedures or observing results that are outside of that calibration space. This paper is a collected summary of other works by the Authors that describe feed sizes, product sizes, quality control checks, and other information about interpreting the test and using its results. Examples of adjustments that are sometimes required when using the test are: changing the test product (P80), and coping with a feed that is too fine to apply the “proper” feed preparation steps (such as is sometimes observed from HPGR or SAGDesign product testing). Related metrics, like the Morrell Mib value and Levin B value will be discussed, along with recommendations for their use on design projects. The intended audience is any user of laboratory work index test data.

Feb 1, 2024

By Yassine Lahmadi, Edoardo Trivellato, Christian Chereau, Bénédicte Robert

Within the framework of the adaptation of the South-East European Technicentre (Technicentre Sud-Est Européen TSEE), SNCF Voyageurs appointed Pini with the project management mission (MOE) for the design and construction monitoring of a road tunnel. This investment has a dual function: during the site transformation phase, it facilitates the work logistics (and shorten traffic flows); and in the operating phase, it is intended to ease all movements on the site over the long term. This is a limited-length gallery (50 meters) to be performed in conventional excavation below Poniatowski Avenue (Paris 12e). The excavation, crossing the entire width of the boulevard, constitutes a major challenge, given the very low coverage (less than 5.5 m), and the surrounding main infrastructures. The same project mis- sion includes the design of the tunnel accesses, via reinforced-concrete frame structures. The targeted design questions several aspects of its execution framework, and particularly, continuous operation must be guaranteed to the neighboring networks during the works. The installation of an umbrella- pipe all along the excavation profile, the progression in divided sub-sections, and the implementation of a complex monitoring system are hence key elements for limiting and controlling any deformation. An exhaustive 3D finite element modelling was performed, taking into account the detailed phasing of construction (pre-support, excavation in divided section, preliminary support and definitive lining), to dimen- sion the structures, and, overall, to analyze the impacts on the neighboring structures and facilities. During the execution phase (planned for mid-2024), monitoring activities with back-analyses as close as possible to the works are planned.

Jun 23, 2024

By Saverio Agresti, Giuseppe Lunardi, Donato Basta, Roberto Trapasso

"At a distance of 10 years from the first application of the Nazzano Method, the widening under traffic of a tube of an existing motorway tunnel was realized near Ancona, along the A14 Motorway in Italy. This paper describes the works for the enlargement with conventional method of the second tube, very close to that already widened under traffic.This enlargement was realized very fast, taking into account the advantages of some interesting technological improvements of the Final Design proved in the first tube.INTRODUCTION TO THE WIDENING OF EXISTING MOTORWAY TUNNELSThe widening of a twin-bore motorway tunnel usually considers the double option of creating a third bore as an alternative or closure to traffic of one of the two bores with the resulting reduction in the level of service for users.On the contrary, the extension in situ of a road, motorway, railway or underground tunnel in the presence of traffic, made possible by an inspired idea of Prof. Pietro Lunardi, enables the level of service of the infrastructure to be maintained without the need to resort to alternative routes to create new permanent or temporary bores, not always feasible because of the lack of the necessary space.This construction technique, known as the ‘Nazzano Method’, is part of the technologies refined and offered by the ADECO-RS approach to tunnel design and construction (Lunardi P., 2008) which is increasingly used in the world, leading to the industrialisation of tunnelling (meaning respect for the times and costs set out during detailed design) both in conventional and mechanised (through TBM) excavations.The first true experimentation of the ‘Nazzano Method’ was carried out between 2004 and 2007 to enlarge the two-bore ‘Nazzano’ tunnel (Italy, Milan-Rome A1 motorway) in the presence of traffic, widening it to house from two to four lanes in each direction (Lunardi P. et al., 2007). Following the success achieved in this first application, the Nazzano Method was strengthened considering all the possible suggestions arising from the previous experience and then taken up to enlarge the north bore of the ‘Montedomini’ two-bore tunnel (Italy, Bologna-Taranto A14 motorway), in situ and the presence of traffic."

Jan 1, 2016

By A. A. El-Midany, R. M. Farag, A. M. Salem, S. E. El-Mofty

Bentonite represents one of the main players in the stability of the drilling mud. Its particle size and particle size distribution affect the physical properties of the drilling mud especially the rheological properties. Therefore, a specific particle size distribution was recommended by American Petroleum Institute (API) for use in drilling mud. To clarify the effect of individual size and size distribution, in this study, the bentonite sample was classified into different size fractions. Each size fraction was tested separately in terms of controlling properties such as filtration loss, plastic viscosity, gel strength, cake thickness, and packing density. The effect of each size fraction on the rheological properties of the suspension was correlated to the behavior of the whole particle size distribution in the bentonite sample. The results indicate that the coarser the particles, the higher the rheological properties; in this case, the API mixture is the highest. The filtration loss and cake thickness for the API mixture are lower than that of the individual size fractions due to its wider size distribution due to the filling of voids between larger particles with smaller ones, which lead to bed compaction and consequently lower fluid loss and cake thickness.

By Shemek Oginski, MARK C. JOHNSON

All Rights Reserved. Printed in the United States of America. Information contained in this work has been obtained by SME, Inc. from sources believed to be reliable. However, neither SME nor its authors guarantee the accuracy or completeness of any information published herein, and neither SME nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SME and its authors are supplying information but are not attempting to render engineering or other professional services. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Any statement or views presented here are those of individual authors and are not necessarily those of the SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2015

By T. R. Jr. McMillan

Introduction Examining the short- and long-term job prospects for engineers in the coal industry might include looking at coal tonnage projections, future export markets, federal regulations, and the decrease in overall graduates. But coal is the US most competitive basic industry. As such, why not go back to basics? That is, there are three basic challenges that need to be faced by students, faculty, and members of the coal industry. These challenges are counseling, career placement, and professionalism. Counseling Counseling can include elementary, high school, and college students, as well as individuals already employed. But what happens to students after they have selected a course of study at a particular university? As shown in Fig. 1, only 87,000, or 7.25% of our graduates have technical degrees. Generally, there is a strong market projected for these engineering graduates. However, many students who have majored in other nontechnical curriculums, have to scramble for jobs. This says something about our ability to make students aware of where the real job opportunities are. As a student spends four or five years pursuing a degree, he or she is looking for professional guidance. The student has the right to expect "real world" counseling - counseling that is not "the way it should be" but "the way it is." The influence of faculty members is significant. They should take this long opportunity to tell students not what they want to hear or what the problem's of academia or the industry are, but what the real job market is all about. If faculty do not use this opportunity, they in-advertently-through omission - mislead their students. Once a student graduates and is a working alumnus, faculty should take advantage of their relationship with the student and continue to stimulate conversation leading to a two-way exchange of ideas and information. Faculty should also encourage and solicit financial support for their mining departments from their alumni. These monies, in many cases, will be matched dollar for dollar or more, depending on the company the alumnus works for. In the private sector, the responsibility is to communicate with faculty and students. Alumni can be effective by participating in this two-way dialogue with their professors at meetings, technical seminars, and conventions. In many cases, alumni will employ summer or co-op students in their organizations. While getting to know these students, industry members should level with them on where the true opportunities are and what it takes to be successful. It is important to communicate with both faculty and students candidly on both the posi-

Jan 2, 1985

By Yues Bertube

Molybdenite and chalcopyrite are two often-associated minerals. In Quebec, the Gaspe Copper Company, a subsidiary of the Noranda group, currently operates a molybdenite flotation circuit to recover a one percent trace of this mineral in the chalcopyrite concentrate. The low levels of molybdeni 2 preclude the use of flotation to remove molybdenum directly from the ore while scavenging of chalcopyrite concentrate for molybdenite yields a concentrate of the latter of somewhat inadequate quality. Such a situation could possibly best be solved by hydrometallurgical means, if molybdenite could be leached selectively from the chalcopyrite concentrate. Work in the field of extractive metallurgy was initiated about 22 years ago in the laboratory of the department of mining and metallurgy at Laval University, Quebec. Following a literature search, two objectives were selected. The present talk will outline some of the results obtained to-date and it is hoped the ensuing discussion of the paper can raise questions of immediate assistance to us for the future. First, as an immediate objective of-practical use, the oxidation rates for molybdenite and chalcopyrite in alkaline media would be studied under conditions of possible industrial application. Secondly, the kinetics of mass transfer of gases in pressure reactor are to be studied. Solubility data for various gases in aqueous solutions have been gathered by a few investigators, to mention the work of Pray1, Wadsworth2, Pawlek3 and Gerlach. Scattering in experimental results and discrepancies between authors are ominously present. Kinetics of mass transfer have somewhat been more neglected. A systematic investigation by the school of Berlin has greatly helped in the design of impeller most suitable for gas dispersion, without much reference however to the solid dispersing ability of the various designs. Variables affecting rates of gas transfer to the solution have not been studied. Studies on the aqueous oxidation of sulfide minerals are much more numerous. While molybdenite has been relatively less studied, work has been carried in two areas namely in alkaline oxidation of MoS2 , work performed by Dresher2 and Wadsworth, and in the hypochlorite leach of molybdenite by Bhappu4 and co-workers, These two methods showed appreciable rates of leaching for molybdenite. In general, comparisons between rates of oxidation of this sulfide with that for chalcopyrite have not been made.

Jan 1, 1972

By H. Sevim

Placement of coal combustion byproducts into abandoned sections of underground coal mines for the purpose of subsidence mitigation has been investigated in Illinois. Several handling and transportation systems have been examined. Prototype pneumatic and hydraulic placement systems have been developed and demonstrated. The demonstration site, Peabody No. 10 mine in Pawnee Illinois, is selected as a case study. It is found that, for a project of 5 years, transporting 150,000 tons of byproduct annually from a power plant located 32 km (20 miles) to the mine would cost $1.80 per ton and placement into underground would cost $3.07 per ton.

Jan 1, 1998