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By J. H. Rose

This paper describing the milling practice at the Magma Copper Co., Superior, Ariz., is one of a series being prepared by the Bureau of Mines on milling methods and costs in the various mining districts throughout the United States. ACKNOWLEDGMENT The authors wish to acknowledge their indebtedness to William Koerner, general manager of the Magma Copper Co., for permission to prepare this article; to J. S. Garrott, former mill superintendent, for the historical facts; and to Walter Cooksley, general foreman, for his assistance in obtaining the data.

Jan 1, 1930

By James A. Wasson, Harry R. Johnson, Dean W. Boley

The Cow Run sand was cored and electrical and radioactivity surveys were made in C. E. Vandevender well 35 in the Burning Springs pool of the Burning Springs oilfield , Wirt County , W. Va . Laboratory tests , reservoir - fluid analysis , well - log interpretation , and available field data indicate that a substantial quantity of oil may be recovered from this pressure - depleted reservoir by waterflooding . Two formations erroneously believed to be the First and Second Cow Run sands were similarly evaluated in A. E. Mackintosh well 8 , Anns Run Pool , Wirt County , W. Va . , but were found unsuitable for secondary - recovery operations .

Jan 1, 1964

By Zuhair A. Nawab, Muhammad A. Al-Marhqun, Mehmet Guney

"The Atlantis-Il-Deep is a stratified metalliferous deposit located along the median valley of the Red Sea at a water depth of about 2200 m. The metal-bearing mud contains sulphides of zinc, copper and iron with significant amounts of silver, gold and cobalt. A variety of oxide, siliceous and carbonaceous gangue material is also present. Long sediment cores indicate that the thickness of the deposit may reach 25 m, but the average kriged thickness of metal-rich sediments is about 11 m.Mining geostatistics was applied to estimate the Red Sea offshore mineral resources. Experimental semi-variograms were computed along 0 ± 180 degrees and then models were fitted to analyze the mineralization phenomenon. Kriging estimates indicate that 696.330 million t of bulk sediments contain 1.891 million t of zinc, 0.425 million t of copper and 3. 75 thousand t of silver. Gold and cobalt contents were calculated from the analysis of solids in flotation concentrates as 47 t and 5368 t respectively. The significant outcome of implementing geostatistics to the Red Sea brine precipitates is not only for the evaluation of metal resources, but it also provides a useful tool in the optimization of selective dredging of appropriate areas to be mined. IntroductionThe discovery and extensive exploration of hot brines and hydrothermal sediments in the Red Sea median valley revealed the fact that the Atlantis-II-Deep is a potentially exploitable metalliferous mud in the economic sense. Sediments in the mineralized deep are composed mainly of oxides, various types of silicates and sulphides with considerable concentrations of zinc, copper, cadmium, silver and gold. The mineral-rich deposit, located at a mean water depth of about 2000 m, has an average thickness of 11 m, and is covered by a brine layer having a temperature of 60°C."

Jan 1, 1988

By R. T. Dec

Current industrial compacting and briquetting practices are largely based on trial-and-error techniques. This paper introduces a two-dimensional finite element model of briquetting process in the roller press. Compared with other modeling techniques used in the past, finite element method offers the most versatile approach because it incorporates adequate information about powder behavior, geometry and frictional conditions and offers predictions for the density distribution, the velocity field, the stress distribution, roll force and torque. More over, when the model includes elasticity, it offers predictions on the internal stress state in the briquette after its exit from the roll. This enables to perform realistic computer experiments which are helpful for establishing the forming cavity geometry and process conditions necessary to produce briquettes with the desired properties. Three forming cavity profiles are analyzed. Results from model are verified on experimental roller press and best cavity profile is recommended for briquetting of sub bituminous coal fines.

Jan 1, 2014

By R. Brown, A. J. S. Spearing, M. Treinen, M. Theisinger

The mining and use of coal creates a significant amount of waste material that needs to be safely disposed of. It is likely that in the medium term, the Environmental Protection Agency (EPA) in the U.S. will categorize all such products as a new category – special waste. This would make the materials subject to many of the requirements for handling toxic waste, which will complicate the disposal of such products and significantly increase the disposal costs. Underground disposal would, therefore, seem to be the obvious solution, especially if the placed material can have low or no permeability, so that water table pollution does not present a serious long-term issue after placement. Significant additional advantages could be derived from this backfilling, including the reduction or elimination of surface subsidence, increased extraction, reduced surface waste disposal footprint and the elimination of explosion-proof seals in worked out areas. The research using a specific coal waste product as a typical example proved that the method of placing the backfill at a high density with low permeability is technically viable, but it must be made more cost effective and the other potential benefits quantified and costed in order to present a true comparison.

Jan 1, 2010

By K. C. Corin, Z. G. Song, J. G. Wiese

In the present study the effect of using different grinding media, viz, ceramic balls, forged steel balls, 15% Cr steel balls, stainless steel and mixture of stainless steel and 15% Cr steel balls (50:50) on the flotation performance of a Platinum Group Mineral (PGM) UG2 ore was investigated. Test work was conducted using a laboratory scale horizontal tumbling mill and a batch flotation cell. Power draw to achieve a specific P80 was determined for each media type. Changes in flotation behaviour were evaluated in terms of particle size distribution, water recovery, solid recovery and valuable mineral recovery. pH, Eh and DO levels were also measured. Grinding products of five different media produced similar solids and water recovery, which is indicative of the froth characteristics, but the grades and recoveries of PGE and chromite were different. The product obtained when using ceramic media showed the best flotation performance, producing the highest PGE recovery and the lowest Cr2O3 recovery. The products obtained when using stainless steel balls (SS) produced the lowest PGE recovery and highest Cr2O3 grade and recovery. The paper proposes possible reasons to explain these observations which may have significant importance for the operation of a PGM concentrator.

Jan 1, 2015

By S. M. Dar

The U.S. Bureau of Mines constructed a full-scale model of a 15-ft-wide coal mine entry to use in combination with finite-element analyses to investigate roof support systems and various types of roof bolts. The objective was to enhance understanding of the fundamental mechanics of the interaction between rock and supports and the relative integrity of bolted mine roof as a function of roof bolt type, length, spacing, and tension, and the basic characteristics of the roof strata. The laboratory test results, when correlated with computer simulations using fmite-element analysis and underground verification tests, should provide a basis for desigillng safer, more cost-effective roof control systems and help to establish guidelines for employing fully grouted resin and mechanically anchored bolting systems. The background for this research, the research approach, the methods and equipment employed, and the results are described in this report.

Jan 1, 1989

By Takahiro Kubo, Katsunori Yamaguchi, Hidehiro Sekimoto

Equilibrium relation between B2O3 slag, RExOy-B2O3 (RE = rare earths) slag and Fe-C alloy formed by melting treatment of neodymium magnet and B2O3 was investigated. When neodymium magnet was melted together with B2O3 and Fe-C alloy in carbon crucible, 3 liquid phases of B2O3 slag, RExOy-B2O3 slag and molten Fe-C alloy formed and clearly separated by the difference of the specific gravities. In the case that excess amount of Cu was also introduced in that system, molten Cu phase additionally formed. Almost all amount of RE were concentrated in RExOy-B2O3 slag. The concentration of RE in RExOy-B2O3 slag increased with the decrease of the melting temperature. While chromium, phosphorous, nickel, cobalt, and copper were concentrated in molten Fe-C alloy, silicon and aluminum were distributed in B2O3 slag and RE2O3-B2O3 slag.

Jan 1, 2014

By Weiguo Xie, MARK LAPUTKA

The pyrometallurgical industry plays a vital role in producing metals for our modern life. With growing demand of metals and declining grade of mineable ore, innovations become critical for many mining companies. It is necessary to conduct a review of recent improvements to the pyrometallurgical industry on analytical measurement techniques, process and equipment improvements, and computer-based modeling/simulations. Many of those innovations tend to be applied to wider metals, and not be restricted by a specific metal. Therefore, we tried to cover the wide applications of many improvements to wider range of metals to reflect this trend. The challenge of a lack of robust measurement techniques under high-temperature conditions within a furnace hinders optimization of a pyrometallurgical process. Some future opportunities in the pyrometallurgical industry on analytical measurement techniques, computer modeling, and processes and equipment have also been outlined and discussed.

Jan 26, 2021

By Chee Theng

"Mineral processors know you can put in the best technology in the world but it won’t work optimally without the support of the operators. Conversely, you may have complete operator support but won’t get top results without the right technology. When the two come together, the returns can be phenomenal.The first day of talks at the 68th Annual Colorado MPD Conference, held April 26-28 at The Broadmoor in Colorado Springs, covered the ground on these industry wisdoms.Coming together as a team“Think of the people, not just the lab and the numbers. That makes all the difference,” said Dee Kippers, of FMI Henderson Mine, in her talk on “Process optimization during a market downturn (A Moly MacGyver story).” Kippers told an entertaining story of the journey she and her team took in tackling the issue of an annual spike in iron content in the product at Freeport- McMoRan’s Henderson primary molybdenum mine near Empire, CO.As the metallurgists tried one thing after another — cranking up the iron depressant, adjusting pH with sodium hydroxide and hydrated lime, modifying reagent levels — Kippers found that when she shared her results with the operators, communicated with them on what she was doing and got their input, they were more willing to work with her, and more understanding and supportive of her efforts.The results make the case for getting people on board and coming together as a team. The cost savings from their optimization efforts, with little capital investment, have been “enough to cover the annual salaries of our metallurgy department and then some,” Kippers said.Considering the environmentDavid Lemieux, of Dundee Sustainable Technologies (DST), talked next on “Cyanidefree process for gold extraction,” presenting the results obtained from a demonstration campaign of the company’s novel chlorination process for gold extraction and associated arsenic stabilization process. Developed at an investment cost of C$35 million, they are ready for commercialization, having been demonstrated on the laboratory, pilot and demonstration scales.The DST process is differentiated from the Plattner chlorination process, which was in use from 1851 to 1916, by moderate process conditions of atmospheric pressure and ambient temperature — the result of using sodium hypochlorite solution, or bleach, instead of direct injection of chlorine gas — and new, cheaper materials of construction, such as polymers, plastics, fiberreinforced plastics and Teflon, resulting in lower capital and operating expenditures."

Jan 7, 2018

By P. N. Lategan

Mining companies are challenged with increased difficulty in delivering capital projects on schedule and within budget. In 2005, PricewaterhouseCoopers global review of major capital projects in the mining industry only 2.5% of projects could be defined as successful when assessed across the four critical dimensions of scope, cost, schedule and business benefits. Thus 97.5% of major mining capital projects were not successful according to the criteria PricewaterhouseCoopers used. Normally if a project fails on all these criteria it indicates scope creep. Scope creep refers to the change in a project's scope after the project work has started. As a result, the projects drift away from their original design, timeline, and budget, and as a consequence destroy business benefits. The major reasons for scope creep are poor change control and the lack of proper front end loading. Change control and front end loading are based on project processes in the planning and monitoring & control process group of the Project Management Body of Knowledge1 (PMBOK). This paper will focus on key factors to consider during project scheduling/planning with special reference to cost and schedule (using Microsoft Project as a tool although the principal is universal)

Jan 1, 2009

By J P. Sykes, A Trench

"World-class mine projects are increasingly failing to become world-class mines. Non-technical, socio-political and environmental problems seem, in part, to be the cause. However, the intangible and qualitative nature of these problems means overcoming them will require a greater systemic understanding of how the various technical and non-technical factors interact. This is particularly important as the concept of sustainable development has changed the industry paradigm sufficiently that it is no longer clear what world-class means. Finally, this better systemic understanding of mine projects needs communicating back to the exploration sector to improve exploration targeting.However, a disconnect between the exploration and mining sectors and between geologists and mining’s other professional disciplines means this is currently not possible. The use of economic evaluation techniques to assess the risk and value presented by the various technical and non-technical factors can assist with this by giving the varied professions a common language and including inputs from all disciplines. This paper therefore suggests a theoretical framework for analysing the various technical and non-technical factors, particularly the most challenging intangible and qualitative ones, and incorporating them into the typical economic evaluation techniques used in the mining industry.Understanding the risk and value relating to both technical and non-technical risks, however, places a greater emphasis on mining geologists to be conversant with a wide range of disciplines. Mining geologists will have to develop three types of knowledge:focusedinter-disciplinarybroad. In addition, they will have to become systemic thinkers to connect these types of knowledge. This multidisciplinary approach will require the use of fundamental critical thinking skills, common sense, intuition, experience and quantitative modelling techniques, dependent on the situation. As a result, both companies and professional societies, such as the Australasian Institute of Mining and Metallurgy, will have to develop ways of improving mining geologists’ inter-disciplinary and broad knowledge.CITATION:Sykes, J P and Trench, A, 2014. Resources versus reserves – towards a systems-based understanding of exploration and mine project development and the role of the mining geologist, in Proceedings Ninth International Mining Geology Conference 2014 , pp 243–270 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 18, 2014

By R. R. Brandenthaler

The development of the Seminole area into one of the major oil-producing sections of the country has been accompanied by many innovations and departures from former methods of development. On July 1, 1929, two years and nine months from the date of discovery, 20,490 acres were considered proved, and additional acreage is constantly being developed. Because of its peculiar conditions, extent, and rapid rate of development, the Seminole area provided numerous problems, the solution of which necessitated research in connection with practical field operation; as a result, there was a radical departure from methods usually employed in the development of a new field in the Mid-Continent area.

Jan 1, 1930

By James J. Gusek

Passive-treatment systems that mitigate acid-rock drainage (ARD) from coal mines have operating since the mid-1980s. Large systems at metal mines are being contemplated. A 95L/sec (1500-gpm) capacity system is planned this year at an underground lead mine in Missouri. Mine, process and environmental managers need to understand how and why passive-treatment systems work. They must understand what operational limitations to expect, as well as the economics of construction and operation compared to the alternatives, like lime precipitation. Wetlands have been recognized as nature's method of improving water quality. Contaminant reductions can occur through the precipitation of metal hydroxides, sulfides and carbonates and pH adjustments. Local conditions, oxidation state and water and soil chemistries dictate whether these natural reactions will occur under oxidizing (aerobic) or reducing (anaerobic) conditions.

Jan 1, 1995

By William Catron

This paper is one of a series being prepared by the United States Bureau of Mines on mining methods, practices, and cuts in the various reining districts of the United States. The mining methods described are those used in the mines of the Cananea Consolidated Copper Co., a Mexico corporation whose holding company in the United States is the Greene Cananea Copper Co. The mines are at Cananea, Sonora, Mexico, 25 miles directly south of the international boundary, approximately in 31° nor to latitude and 110 to 130° west longitude. Cananea is connected with the boundary towns of Naco and Nogales, Ariz., by a standard-gage railroad.

Jan 1, 1930

By K Osten, N Scagliotta, G Lane

Oceana Gold (New Zealand) Limited operates the Macraes Gold Mine near Dunedin on the South Island of New Zealand. The orebody is mineralogically complex and comparatively low grade requiring a series of unit processes and resulting in a relatively complex plant. As part of Oceana GoldÆs ongoing Business Improvement program, a concerted effort has been made to focus on operational efficiency. One aspect of this has been the efficient use of energy in the gold recovery process. A benchmarking process has been developed for the Macraes operation that includes comparison with other operating mines and theoretical design. Criteria for determining operational efficiency have been developed. While benchmarking is, in theory, a simple process, this paper looks at putting benchmarking into practice by catering for variability in ore and associate processing methods. The unit processes discussed include the comminution circuit, flotation plant, pressure oxidation plant and gold recovery circuits.

Jan 1, 2004

By G. S. Pauley

Paper presented at a meeting on: Artificial intelligence in the minerals sector, held in Nottingham, UK, 20 April 1993 (original title: Case-based reasoning can be a catalyst for improvement). A new computer software technology known as Case Based Reasoning (CBR) can be used to produce small decision support systems that are economically viable. This is because the knowledge that they contain can be owned and maintained by their users. A CBR tool has been used to perform a pilot study with Anglesey Aluminium Metal Ltd. The results are encouraging. They suggest that a combination of CBR and participative design and implementation techniques (such as Checkland's Soft System Methodology) can achieve sustainable improvement in mineral processing functions. An explanation is presented of why traditional, rule based systems are often an ineffective way to implement support systems. It is shown that CBR may provide an appropriate technology solution. Methods of achieving sustainable benefit are indicated. The pilot study with Anglesey Aluminium Metal is used as a practical illustration of the development of a CBR application. A review of potential application areas and some observations about the implementation are presented

Apr 1, 1994

By N. H. Snyder

Coal analyses help to describe the character of coal as it lies in the ground of as it may he delivered to the user Analyses of samples of coal collected from the face of the bed in mines are plentiful, but available analyses of delivered coal are relatively few, and there is a distinct difference between "mine samples" and "delivered samples.” Mine samples are collected actor drag to a standard method. 13 The sampler cuts a channel. 2 by 6 or 3 by 4 inches from roof to, floor in the face of the bed, and excludes from the sample all partings more than 3/8 inch thick, and any lenses or concretions of sulphur or other impurities more than 2 inches in maximum diameter and 2 inch thick. Analyses of mine samples form a permanent and scientific record of the coal bed at the point sampled, they ale important in determining the character of the coal in any given mine or district These analyses, when the samples are taken by a standard method, are valuable to the operator When compared with analyses of delivered coal they show him whether his mine is being worked efficiently or whether the coal is being properly prepared, which involves the ques¬tion ii Nether he has suitable mechanical appliances for separating the impurities sties. In the purchase of coal, mine samples may serve as a sufficient guide for the experienced buyer who has knowledge of the impurities in the bed, and the degree to which these are eliminated in mining and preparing the coal To the average purchaser, however, unacquainted with these details, dependence on mine samples may be misleading The quality of coal indicated by the base samples call rarely, if ever, be attained in the delivered coal Certain impurities that are eliminated from the formally prepared mine sample may not be eliminated by the miner Some of the roof and floor may also be included if these are soft or flaky When coal prices are high and competition is lessened it is easy for the miner and the management to lower the standards of preparation, and a return to rigid stand¬ards is always difficult. In sampling delivered coal the Bureau of Mines follows a definite procedure. 14 A sample of not leas than 1000 pounds is systematically

Jan 1, 1928

By Robert A. Siokler

Approximately 75 percentage of the earth's land surface is comprised of shale or shale-like materials. Shale itself is composed of the residue from an almost infinite variety of weathered parent materials which have undergone deformations ranging from intense to negligible. Under standard test procedures, shales exhibit a very wide range of physical properties particularly if the test specimen is subjected to a change in moisture content, when the original test values may vary from 0 to 100 percentage. It is this wide variation in physical property values compounded by its ubiquitous presence that makes shale such a problem material to engineers. In reviewing the literature relating to shale, it is evident that the "problem" has been approached from many directions. In order to understand why shales behave as they do, investigators have sought mineralogical, geological, chemical, electrical, and physical answers. Each study yields valuable academic information, but few contribute much of value to the engineer in the field. Many valid relationships between shale strength or competency and clay type, clay content, organic content, water content, grain size, cementation, density, porosity, etc, have been established. Yet it is very difficult to extend these understandings to the in situ condition with results that can be used by the field engineer. One major reason earlier work has not produced better information lies in the ambiguity of the definition of shale. It is apparent that no one laboratory parameter can be successfully used to provide sufficient engineering information to properly describe in situ conditions. For example; shale with swelling clays will produce low strength values provided: the swelling clay is in sufficient quantity, the clay is dispersed throughout the medium involved, and there is a low value of cementation. Shales with high unconfined compressive strengths have been found with very low shear strengths. Sandy shales often provide as many ground control problems as clay shales. Shales of similar nature may provide good roof conditions in one part of a mine yet in another part of the same mine the apparently identical shale may cause substantial problems. A clear need exists to classify shale in a manner which will enable the engineer to better predict the strength and durability of shale-like materials. Studies at the University of Missouri-Rolla (UMR) have focused on finding parameters which influence durability and competency, while being discretely discernible through uncomplicated testing. Initial research concentrated on distinguishing shale8 on the basis of standard physical tests such as: unconfirmed compression, triaxial shear, and slake durability. As results accumulated, however, it became evident that moisture content played a much greater role in determining competency than had been recognized previously. As a result the focus of the research turned to developing tests which would evaluate the influence of moisture on shale behavior. The above work then became a foundation for a second phase of investigation in which a suite of standardized tests were developed to provide a classification procedure. From this study five tests were identified as being critical: Moisture Activity, Atterberg Limits, Submersion, Unconfined Compression, and Shore Hardness.

Jan 1, 1986

By Micah Nehring, MEHMET KIZIL, Farzad Sotoudeh, Amin Mousavi, PETER KNIGHTS

Production scheduling in underground mines is one of the most important and complex processes in maximising the economic value of an operation over the life of the mine. Due to increasing energy, transportation, processing and smelting costs and reducing water availability, the extraction of ore deposits through underground operations has become more expensive and challenging. A potential productive and efficient solution to mitigate these issues is to integrate pre-concentration systems into the existing mining system to increase ore grades through a preliminary process of rejecting some waste before sending the ore to the energy intensive mineral processing plant. Further benefit of such systems includes the utilisation of the waste and low-grade material in backfilling of open stopes to reduce the transportation costs and surface environmental impact such as reduction of CO2 emissions and waste transportation. The objective of this paper is to present a new mathematical model to optimise the production schedule of underground metalliferous mining operations in the presence of a pre-concentration system. The proposed model optimises the production schedule and sequencing of stopes within a sublevel stoping operation. The results of this study illustrate the potential economic benefits of using a pre-concentration system prior to a mineral processing operation as a result of increased net present value.

Nov 16, 2023