Search Documents

By P. A. Dimas

A new family of sulfide flotation collectors has been developed in our laboratory. These formulations are comprised of novel renewable materials combined with conventional reagents. The resulting diversity permits tunability of collector chemistry to meet a range of flotation problems. Several attributes of the new collectors are presented.

Jan 1, 2012

Collaboration between education providers is the key to long-term sustainability and improved quality in mining education. The mining industry is now, more than ever, an industry doing business on a global basis. Staff are recruited by global mining companies in many different countries and can find themselves deployed anywhere in the world. The mining engineer of tomorrow must be willing to take on this international challenge, and must be educated to a level where he or she has a comprehensive grounding in technical aspects of mining engineering, but also a well-founded appreciation of management, social, environmental and cultural issues which may be encountered around the world. In order to deliver such an education, academic providers must collaborate at both a national and international level. This paper provides an overview of progress that has been made in Australia through the national joint venture ? Mining Education Australia (MEA). Supported by the mining industry in Australia, through the Minerals Council of Australia (MCA), MEA has now been operational since 2007 and is seeing the development of a range of innovative courses and delivery methods, together with a high level of staff co-operation across the country. MEA has also now commenced some international teaching initiatives which are seen as a catalyst for a far greater degree of international collaboration in the future. Such activity is not only to the benefit of the students who are taught by experts from around the world, but it also ensures that individual university programs remain viable in terms of staffing numbers and financial performance. The paper also presents some statistics on recent upward trends in mining engineering student numbers from around the world, in response to the global shortage of mining engineers.

Jan 1, 2009

By C. D. Anderson

A variety of processing technologies exist for recovery from both primary and secondary sources of rhenium. Currently, there are no known primary rhenium deposits, thus, the method in which primary rhenium is produced is dependent on the commodity of which it is a byproduct, e.g., copper, molybdenum, uranium, etc. In addition, focus on the recovery of rhenium from secondary sources, such as alloy scraps and catalysts, is continually growing. This paper presents a review of both primary and secondary processing technologies for the recovery of rhenium. Key Words: Rhenium, Ammonium Perrhenate, Extractive Metallurgy

Feb 27, 2013

By R. L. Virta

Four companies mined ball clay in four States during2004. They were H.C. Spinks Clay (owned by Franklin Minerals) Kentucky-Tennessee Clay (owned by Imerys),Old Hickory Clay and Unimin. Production was estimated to be 1.46 Mt (1.61 million st) valued at about $56.9 million, based on a preliminary survey of the ball clay industry. In 2003, production was 1.31 Mt (1.44 million st) valued at $56.2 million. Tennessee was the leading producer state with 61 percent of production. It was followed by Texas, Kentucky and Mississippi.

Jan 1, 2005

By L. F. Ruppert, P. A. Freeman, R. C. Milici, S. J. Tewalt, L. J. Bragg

The U.S. Geological Survey has completed a dig-ital coal resource assessment of six of the top-producing coal beds and coal zones in the northern and central Appalachian Basin coal regions. These include the Pennsylvanian-aged Pittsburgh, Upper Freeport, Lower Kittanning, Fire Clay, Pond Creek, and Pocahontas No. 3 coal beds and coal zones. Resources were calculated on all of the coalbeds/zones, with the exception of the Lower Kittanning coal bed. Preliminary original resources are estimated at about 93 billion short tons (84 billion tonnes), of which about 66 billion short tons (60billion tonnes) remain. Much of the remaining coal in all five coal beds/zones is thinner [<3.5 ft (1.07m)] and deeper [>1,000 ft (305 m)] than the coal that has been mined, but economic resources are still available and mining in each coal bed/zones will continue throughout this decade and into the next given current market conditions.

Jan 1, 2001

Editor’s note: As usual, the June issue features an industrial minerals review. And some thanks are in order. Thank you to the industrial minerals annual-review editor, to the technical committees chair and vice chairs and to the authors of the individual commodity profiles. Jim Norman of GeoTrans Inc. is the industrial minerals annual-review editor. Lucy McCartan, US Geological Survey, was the chair of the SME industrial minerals technical committees. She also served as the vice chair for agricultural minerals. Other technical committee vice chairs were: •Gary Tomaino, Specialty Minerals Inc., ceramics and refractory materials. •Srinivas (Vas) Veeramasuneni, US Gypsum, chemical raw materials. •William Langer, US Geological Survey, construction materials. •Vanessa Santos, Independent, fillers and pigments. •Richard Berg, Montana College of Mineral Science and Technology, specialty minerals. Their help makes possible this June industrial minerals issue. On behalf of the readers, the editors thank them.

Jan 1, 2002

By M. Guney, A. R. Bell

In Mindola mine on the Zambian Copperbelt, there is a plan to extend the current production level of 1.2-1.5 km (3,900-4,900 ft) with five additional production levels. Research work indicated that the present total heat output of 38.6 MW will inevitably increase to 63.2 MW in 25 years. Estimated WB and DB temperatures, representing the total heat generation in stope faces and development headings during these same periods are predicted to increase to 33.8/40.2°C (93/104°F) and 35.3142.10C (95/108°F) respectively. It is assessed that the nominal refrigeration capacity needs to be progressively increased to 9, 000 MW.

Jan 3, 1984

By Kent von Maubeuge, Charles R. Landis

The global bentonite industry is a dynamic market balancing a range of end uses with an ever growing number of bentonite producers. In addition, markets in developed countries are elevating the level of detail and transparency for materials reporting in programs, such as the Registration, Evaluation, Authorization and restrictions of Chemicals (REACH) program in the European Union. Bentonite is impacted by programs of this nature. The majority of the bentonite products sold around the world are sodium bentonites. These sodium bentonites consist either of natural sodium bentonites, or naturally occurring bentonite dominated by divalent interlayer cations (Ca+2 andMg+2) subsequently exchanged with sodium cation. The latter variety is often called “sodium-activated“, or “soda-ash treated” bentonite. Once exchanged with sodium, these bentonites are often difficult to distinguish from natural sodium bentonites using common commercial testing protocols. Due to their similar colloidal and bulk chemical properties; the lack of test procedures designed specifically to identify this product feature; and the failure to completely or effectively explain their differences, sodium-activated bentonite is often considered to be identical to natural sodium bentonite in the industry. This article defines both general types of sodium bentonite and presents a technique that could serve the industry as a tool to confirm the variety of sodium bentonite in question. Specifically, geochemical properties such as carbon (C13/C12) and oxygen (O18/O16) isotopic ratios can distinguish activated, even slightly activated bentonites, from bentonites not introduced to additional sodium during manufacture.

Jan 1, 2004

By M. F. Bradley, G. M. Schoen

The Magmont Mine, a 50/50 venture between Cominco American Incorporated (the Operator) and Dresser Industries, Inc., (Halliburton), is a metallic mining and milling facility in the new lead belt of Missouri. The mine is located approximately 100 miles southwest of St. Louis. Legislation passed in 1992 by the Missouri legislature requires all metallic mining and processing facilities to apply for a Metallic Minerals Waste Management permit (MMWM) for their waste facilities. Regulations were subsequently promulgated by the Missouri Department of Natural Resources (DNR). Cominco obtained a MMWM permit (MM-006) from the Missouri DNR in 1992.

Jan 1, 2001

By Samuel A. Reipas

Introduction The ore mining industry has been successful because of technological progress and huge sums of capital investment. But new technology and plants have not come cheap. The problem now is companies will run out of money before they run out of ideas. Survival Strategies Industry survival strategies demand restructuring and new plans. Inland&apos;s prescription for the future includes: • Continued emphasis on technological improvements to upgrade pellet quality and lower costs; • Effective use of human resources resulting in employee satisfaction and improved planning and productivity; • Deliberate, well planned, and documented cost-control programs for the short- and long-term; and • Capital investments to support the first three initiatives. Technology Technological changes are not only required by the need for operational improvements, but by product quality improvement dictated by the user - usually the blast furnace operator. Established ambient measurements of pellet quality, such as tumble index, compression strength, porosity, size distribution, and chemical composition, are no longer considered meaningful in predicting pellet performance in a blast furnace. New specifications, called low temperature and intermediate temperature properties, have been recently introduced. Low temperature specifications are characterized by disintegration of pellets in the 500°C (930°F) range in the upper portion of the granular zone during the hematite-to-magnetite transformation in blast furnace stack. Intermediate temperature properties (measured by 1000°C or 1800°F) are characterized by swelling, reducibility, and compression strength after reduction, reflecting conditions in the lower portion of the granular zone of the furnace. These new parameters are being used for pellet quality evaluation at Inland, and will be introduced at its Minorca mine for more routine analysis and correlation with the pellet furnace operation. With increased emphasis on quality, effective communication between the blast furnace operator, research, and the pellet plant operator is critical. At Inland, this is accomplished through technical meetings where the opportunity is provided to solve problems, establish a common understanding on the value of quality, and develop future quality standards and programs. With the degree of sophistication in determining pellet quality as it affects blast furnace operation, the future pellet plant operator will actually be producing a custom pellet. Human Resources Technological change has been a strong point at Inland, and will continue to be. However, human resource management is equally important. Is management giving sufficient attention to employee motivation and involvement? It is a way to improve productivity, reduce costs, and enhance employee job satisfaction. The industry is beginning to understand the principles and the potential for tapping employee brainpower. The payoff can be handsome. Management has to be willing to share both information and power if participative management is to live up to its potential. It has to become more flexible and be willing to adapt to change on the human side. Management should embrace rather than fear employee involvement. Given time, joint problem solving will replace adversarial attitudes and pay dividends for both sides. Productivity and product quality will improve and new dimensions of employee job satisfaction will be achieved. But, it will not happen overnight. Attitudinal change must permeate the organization from top to bottom. This change is needed to support the working relationships and give everyone a sense of direct and meaningful involvement.

Jan 11, 1983

By Rajive Ganguli

There are several elements of online pedagogy and information technology that are being used in the University of Alaska Fairbanks’(UAF) course “ES 201: Computer Techniques,” to enhance classroom teaching. The use of information technology in this class grew from a desire to make lecture notes available to students. This has grown to include a sophisticated, online delivery software package. It provides chat rooms, discussion groups, and online testing and grading. Online delivery aside, the class uses the telnet, e-mail and C++/FOR-TRAN compiler facilities of the university server during class to enhance learning. During class, for example, the students read the lecture notes on the Web browser, telnet to their university Unix accounts, check their e-mail and download programs (to be covered in class) sent by me, and then compile, run and modify the programs. The class, therefore, requires students to be active most of the time. This ensures their full attention and better learning due to the hands-on experience (Fig. 1).

Jan 1, 2000

By M. Galetakis, C. Roumpos

A sustainable coal industry needs to achieve a number objectives concerning mainly with superior utilisation of deposits and improved environmental performance. Modern quality control systems, which are greatly based on the on-line analysers, play an important role in achieving sustainability targets. This paper discusses the testing and application of on-line ash analysers installed in the Ptolemais and Megalopolis lignite mines in Greece and examines the possibility of using this type of analyser to control blending and homogenisation operations. The effect of the accuracy of on-line analyser to control process, when used for the characterization of low rank coals with complex and variable composition, such as greek lignites, is examined.

Jan 1, 2005

By R. J. Boyd

SUMMARY The productivity of drill and blast methods of mining in hard rock is limited by the cyclic nature of the operation, and a plateau of performance has been reached, even with the most advanced equipment developments. Higher mine operating costs and lower metal prices have more than ever generated the need for breaking through these productivity barriers. After initial field testing The Robbins Company has designed and manufactured, on a joint venture basis with Mount Isa Mines, Ltd., Australia, a prototype "Mobile Miner" for continuous cutting of hard rock. This paper describes the cutting concept, the initial application of a completed 1,156 m (3792 ft.) long 14% decline, actual performance and delay analysis, developmental modifications, anticipated performances of a fully developed machine, and possible future applications. Sincere appreciation is expressed to the management of Mount Isa Mines, Ltd., for allowing access to the data used in this paper. The views expressed here are those of the author and not necessarily those of Mount Isa Mines, Ltd. INTRODUCTION A paper titled, "Design and Development of a Mobile Mining Machine", was presented by J.P. Kindsvater at the RETC, New York, in 1985. This paper described the evaluation of a test fixture in an andesite quarry near Seattle, followed by design, construction and

Jan 1, 1987

By Jamal Rostami, Richard Kastner, Ahmad Ramezanzadeh

Improving the accuracy of the performance prediction models for hard rock Tunnel Boring Machines (TBMs) is important in estimation of the schedule and cost of tunnelling in related projects. The effects of rock mass on performance of TBMs has been studied extensively, yet due to the complex nature of the process, impact of many parameters influencing machine advance rate are not very clear and there is still room for improvements. More accurate estimates can be obtained by better understanding of operating parameters in various geological conditions and can lead to matching machine specifications with job conditions, optimizing machine performance, and avoiding long delays and downtime for increased productivity. This paper will offer review of two case histories including Queens Water tunnel in New York and KCRC project in Hong Kong. The analysis of the available field data, including the geological back mapping and results of laboratory testing of rock mechanical properties, machine operational parameters and achieved rate of penetration will be presented. This includes statistical analysis of available field data to provide a better understanding of the influence of rock mass properties on performance of hard rock TBMs as well as related formulas to improve performance estimates.

Jan 1, 2005

By K. Hanumantha Rao, A. Nayak, K. S. Narasimhan, S. N. Mahapatra

B.A. Hancock It is not at all surprising that causticized potato and potato derived amylopectin starch solutions performed much better than their parent starches. Some preparation is required to rupture the starch granules to effect the polymeric adsorption and interparticle bridging necessary for selective flocculation. In laboratory work comparing the deslime performance of causticized and autoclave cooked laboratory corn starch solution preparations, it was found that higher deslime weight rejections, with attendant proportionally greater iron unit losses, occurred with the causticized starch. These results may be specific to the ore involved but they do suggest that cooking and causticizing cause different starch granule rupture and/or starch breakdown, which have an effect on desliming response. I calculated from the data in the article that the slimes product grades were high - 24.3% and 20.3% Fe when 53.7% and 54.5% Fe concentrate products were obtained, respectively, in Table 4, and 21% Fe with a 62.6% Fe concentrate in Table 5 - using the natural tailings sample, which had a head of 34.3% Fe. It may be advisable for the authors to consider different starch preparations in future investigations. The combination of upgrading and selectivity results presented in Table 4 are not as good as the authors suggest. The authors&apos; claim that a system has been developed to produce saleable concentrates from the Kudremukh tailings is quite disconcerting. There are many hurdles yet to be crossed before commercial application of selective flocculation becomes possible because differences between the very small-scale laboratory tests conducted and commercial application are rather large. Among the many differences are varying circuit feed grades that will occur from use of tailings, the apparent face that much lower tailings grades will be encountered in practice (it is much easier to achieve a high concentrate grade with reasonable recoveries using 34.3% Fe tailings as in the study rather than 25.3% Fe tailings grades that the plant apparently averages), the hydraulic nature of the thickeners used in operations compared to the static system used in laboratory tests, the different size distributions that will be obtained from a plant closed grinding-classification circuit, and differences in water used in a plant operation and the laboratory. The authors wrote that it was necessary to overgrind to be sure that the coarse gangue would not settle with the iron oxide floccules. This situation is likely to be exaggerated in commercial operations where it is assumed cyclones would be used for classification. Because cyclone classification is greatly influenced by particle densities, there will probably be an even greater difference in size between the iron and gangue particles in the plant, which would make the gangue slightly coarser still in relation to the iron. This would make the selective flocculation-desliming separations using the procedure employed by the authors even more difficult and, using the dispersant system the authors employed, greater overgrinding would be required. To grind finer to minimize the coarse gangue in the flocculated iron oxides is quite inefficient and appears not to broach the problem. The actual problem appears to be insufficient dispersion of the ground pulp. In this situation, addition of a dispersant would likely be required to attain a sufficiently high pulp dispersion level to efficiently effect a selective flocculation-desliming separation. Although the very coarse particles would still have a tendency to settle with the floccules, it probably would be found unnecessary to overgrind as much as indicated. Use of an optimum combination of dispersant and pH modifying reagents may also significantly improve the selectivity of desliming. Additionally, although it is possible that sufficient dispersion may be obtained by pH control alone in some situations, it is quite probable that added dispersity was obtained in the reported work from using distilled water. It is research experience that distilled water enhances dispersion. In commercial operations it may not be expected that sufficient dispersion will be obtained by pH control alone, unless the water used in the process is by nature quite dispersive. Overall, a change in the Kudremukh tailings dispersant scheme appears necessary where a dispersant is used in conjunction with a pH modifying reagent. With this change, different dispersion-flocculation responses will result that would have to be further evaluated. Therefore, it is still an open question whether an efficient and effective selective flocculation separation using Kudremukh tailings may be obtained that will produce saleable concentrates.

Jan 9, 1986

By L. M. Dyer

Various attempts have been made to build leadership and management expertise with little success. There are numerous reasons these attempts have failed. Three reasons, along with suggested solutions, will be explored: 1) lack of ownership of the development process by those affected; 2) lack of congruence of the development process used and the business strategies of the organization; and 3) a comprehensive development process. We will discuss a development model applied inside a smelter and refining complex over one year involving all levels of management. The process was credited with helping to substantially reduce cost and enable breakthroughs in production, quality and safety results.

Jan 1, 2000

By R. Thornton

Montana Tech is located in the historic mining town of Butte, MT and is adjacent to the Orphan Boy mine. This abandoned underground mine will be the heat source for a down-hole heat exchanger (DHE)/heat pump system. The mine was abandoned in the 1950?s and has since filled with water to within approximately 30 m of the surface. The shaft is composed of a 245 m vertical shaft connected with horizontal crosscut drifts at 60 m and 150 m below the water level that connect to a large stope with approximately 1250 million liters of water at a consistent 75-78°F temperature. The intent is to build this heating system to augment or fully heat a newly built 2,000 m2 building on the Montana Tech campus. As designed the system uses ?off-the-shelf? parts making the basic configuration straightforward with the exception of the DHE?s which need to be placed into the vertical shaft. Because there is little or no examples of placing the heat exchangers in a vertical shaft, the primary focus of this work was to model the heat exchanger placement and configuration in the vertical shaft such that thermal currents develop between the stope and vertical shaft in, via the horizontal crosscut drifts, in order to move the water and thereby provide the required energy. This study includes the modeling of water flow, temperature profiles, and the heat contribution from the surrounding rock walls.

Feb 27, 2013

By K. Holmberg, D. Herriot

This paper by Mr Mclvor is yet another contribution to the eternal controversy surrounding the benefits, or otherwise, of high circulating loads in closed circuit grinding. Throughout the paper it is difficult to establish whether the author is referring to effects relating to the mill, classifier, or to the overall circuit. Table 1 is put forward as indicating the advantage of operating at high circulating loads. From the two (it would be interesting to see more) product sizing points provided in each case, the conclusions to be drawn are that cases one and two have very similar size analyses. The third case, however, indicates a much flatter curve, that is to say, higher fines production and a very wide spread of size ranges. If the objective of this circuit is to provide a closely sized product with minimum overground slimes to the downstream process, then it would appear to be the less "efficient" by far. No data is given for product pulp densities either. The term "efficiency" should never be used without a careful and clear definition. In this case, "efficiency" is used to express an apparent percentage reduction in operating work index (Bond) from the measured "standard" at 250% circulat¬ing load operation. The Bond calculation is itself based upon

Jan 1, 1989

By Richard R. Klimpel

Introduction Froth flotation is one of the most common unit engineering operations in use today. Its aim is to upgrade the quality of coal by removing ash/pyrite and separating selected minerals from undesired gangue materials. Flotation has been successfully practiced at the industrial scale for more than 50 years. Its use is increasing due to the ever decreasing feed grades of the coals and minerals being processed. Flotation has also shown itself to be a flexible process that lends itself well to many solid/solid separations. Thus, with surprisingly little equipment modification, separations can involve very different particle sizes and densities, and relative weight ratios of materials to be separated. In addition, the flotation process is economic, especially when compared to size reduction, its associated precursor process. Flotation also lends itself to continuous operations with a given equipment configuration. The operation must exhibit an ability to vary feed rate of solid to the process by as much as 50% without a total collapse of separating efficiency. In addition, the mechanical flotation cell is scaleable from 2.8 to 57 or 85 m3 (100 to 2000 or 3000 cu ft) with surprising ease relative to other unit engineering operations over the same relative size increase. The separating medium used is water. Most of the chemicals required - pH regulators, frothers, collectors, activators, and depressants - are all relatively inexpensive and common. They are not usually used in large quantities. Froth flotation is certainly one of the most versatile and forgiving unit operations in the chemical, mining, and agricultural industries. The problem with the industrial flotation process is that it is fairly easy to get reasonable results and relatively difficult to get excellent results. Why is it so difficult to fine tune the froth flotation process? There are some obvious reasons and a few not-so-obvious factors. The obvious category would certainly contain the tendency of natural feed materials (ores and raw coals) to have variable physical, metallurgical, and surface properties. This occurs even when special care is taken to minimize such differences with blending. There is another obvious reason for difficulty. An inherent broadness of the feed particle size range to flotation results from using any of the common industrial-scalefine grinding devices - ball-, rod-, or autogenous mills. Research has been done into the chemical reagent and equipment aspects of flotation. It has shown strong interactions (limitations) of chemical reagents and equipment on larger and smaller particles. The point is that current flotation practice works best on average- or medium-sized feed particles. The greater the amount of large or small particles, or of both large and small, the more difficult it is to achieve excellent flotation results. Other reasonably obvious factors include: • variations in mineral type and liberation sizes; • water chemistry variations such as those involving Ca", C03, or Fe", or various soluble metal cations; • the presence of stray organic materials such as returning soluble reagents or partially degraded reagents in reuse water; • the lack of reliable on-line instrumentation for monitoring and control; • frequent equipment malfunctions of all types; • excessive feed rates for installed plant capacity; • poor operator interaction with the process; and • poor reagent dosage control. There are less obvious, but real limitations to flotation. These are inherent in the design and operating characteristics of the most common cell design in use today - the mechanical flotation cell. Individual performance attributes of the chemical reagents used, along with their manner of use, also carry limitations. The bulk of this paper will deal with chemical reagents and their use. Chemical reagents In 1979, the author and his co-workers were asked to invent and implement, at the industrial scale, new flotation reagent chemistry. After reviewing some of the literature (Sutherland and Wark, 1955; Klassen and Mokrousov, 1959; M. Fuerstenau, 1962; D. Fuerstenau, 1976; and Leja, 1982), a series of carefully controlled plant scale tests were set up. These tests were designed to understand existing reagent scale-up from the laboratory to the plant. They were to quantify at the plant level the effect of some of the more important, controllable chemical reagent factors (frother and collector type, frother and collector dosage, pH effects). This is a learning experience that all researchers involved in flotation theory should experience. It quickly became apparent that: • because a factor is important

Jan 12, 1988

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&apos;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