Search Documents

The Boliden Aitik concentrator in Sweden processes 2,000 tph of low grade copper ore. The plant consists of five grinding lines feeding four bulk flotation banks with a scavenger concentrate regrind mill, and a column cleaner circuit with a regrind mill. The authors installed a model-based expert, optimizing control system to maximize copper recovery in the bulk flotation circuit while maintaining an appropriate copper grade in the cleaner feed. The optimizing control system uses on-line assays and calculates and implements set points for cell pulp levels, air rates and reagent addition rates. It combines the power of a dynamic population balance model which estimates mineral liberation in each stream, an optimizer which computes appropriate set points and a rule-based module which implements the strategy. The benefits have been evaluated over three months. The model-based expert, optimizing control system generates a measurable increase in copper recovery, around 0.5 per cent and an optimized bulk concentrate grade. The need to maintain the optimizing control system and other practical aspects are discussed.

Jan 1, 1998

By V. T. McLemore

NMBGMR has been collecting data on uranium mining districts, mines and mills since it was created in 1927 and has converted years of historical data into a relational database that can be imported in ArcMap. The database includes information on mining districts, mines, mills, geochemistry, photographs, and bibliography. The available data includes location, production, reserves, geologic, geochemical, resource potential, and other data. The NURE stream-sediment data provides geochemical analyses for >27,000 samples collected in New Mexico during 1970s. The NURE hydrogeochemical data provides analyses for water samples. ArcMap includes location of individual ore bodies as polygons and incorporates the mines and NURE data as individual site locations. The purposes of these databases are to provide computerized data that will aid in identifying and evaluating resource potential, resource development and management, production, and possible environmental concerns, such as physical hazards (i.e. hazardous mine openings), indoor radon, regional exposure to radiation from the mines, background geochemical data and point-sources of possible pollution in areas of known mineral deposits.

Jan 1, 2010

By Kadri Dagdelen, Steven Hoerger

For gold mines, orebody uncertainty is one of the leading causes of differences between planned and actual production. Geostatistical conditional simulations create multiple equally probable orebody block model realizations which are conditional to the current drilling information and demonstrate the sampled grade distributions and spatial statistics. These simulated block models are key inputs for a stochastic evaluation to show the likely range of grades and cash flows to be delivered by a mine plan. The stochastic evaluation outputs can be used to compare different mine plans in terms of expected values and risks to planned grades, production, costs, Net Present Value (NPV) and other plan metrics. For the McLaughlin gold mine, risk profiles are demonstrated to show how different mine, cut-off and stockpile strategies can reduce risk and improve expected value. The strategies considered were effective in improving expected NPV and reducing or eliminating tonnage uncertainty, but the strategies had little impact on reducing the uncertainty of NPV’s or mill grades. The stochastic evaluation process is also used to compare the risk impact of orebody uncertainty against the risk of not achieving planned mining tonnages or vertical advance rates. Risks for plans created with and without stochastic mine plan optimization are also compared.

Feb 1, 2025

By X. Li, J. C. Stankus, J. Ma, H. Chen

Accurate evaluation of stress and geological conditions is critical to ground control design in underground openings. For a slope entry, the problem is more difficult, because a slope will transverse through many types of strata. Over the last few years, Keystone Mining Services LLC, an affiliate company of the Jennmar Corporation, has developed a new methodology designated the “Stress, geologic and support design system (SGS).” The method analyzes the stress, geology and support design for a mine slope. The method has been successfully applied in various new slopes across the United States, and ground control plans developed using SGS methodology has helped coal companies successfully pass review and/or hearings by state and federal regulatory agencies. With a case application in the U.S. Midwest, this paper details and demonstrates the main concepts of the methodology, including (1) analysis of stress and geology and identification of strong, fair and weak zones along the slope; (2) primary and supplemental support design; (3) long-term support design in the form of steel square sets or arches and (4) validation of the support design utilizing advanced finite element computer modeling.

Jan 1, 2011

By E. R. Mueller

The natural lives of machines and components vary tremendously! Maintenance managers struggle constantly to maximize their equipment lives while minimizing their maintenance costs, but they normally lack the tools and techniques they need to do this properly. This paper proposes a methodology based on probabilities of failure and expected values for repairs that recognizes the variation among individual machines and components as well as the high costs associated with catastrophic failures. It enables a user to determine the optimum change-out intervals for many types of equipment. The approach proposed here is sophisticated enough to be reliable but simple enough to be applied by the maintenance staff on the shop floor. It will complement existing preventive and predictive maintenance programs.

Jan 1, 1995

By M. Downing

This paper gives a brief overview of impacts of coal blending on coal-fired power plants performance and discuses the preliminary results of an on-going study aimed at evaluating the effect of coal properties on the effectiveness, compatibility and thermal reactivity of coal blends. Plant survey studies reported no significant impacts on an existing plant designed for a high rank coal when switched to a blend of low-and high-rank coal. However, slight modification of some aspects (handling, fuel storage/stockpile, transportation, preparation, and general housekeeping) of plant design and operation may be necessary. The preliminary results of an on-going study at the Mineral Industry Research Laboratory shows that more compatible and better blends could be made from coals where ranks are closer than from those where ranks are far apart.

Jan 1, 1997

By M. Peters, P. Schmäh

The development of renewable energies and a sustainable power grid are the challenges for future energy supply. Underground cables will replace the vulnerable overhead lines, because of their safety benefits. Due to the public environmental awareness, smart tunnelling and trenchless solutions are required for inner-city and cross-country installations of underground cables, as well as for crossings and the landfall sections to connect offshore wind farms to the transmission grid. Methods from the tunnelling and pipeline industry provide a high flexibility in the planning of alignments, including versatile tunnel concepts and the installation of protective pipes with E-Power Pipe and Direct Pipe.

Jun 13, 2023

By Clark D. Harrison

This paper compares the ash slagging potential of Illinois No. 6 Seam coal: as raw coal; as commercially cleaned coal processed in a baum-jig plant; and as coal cleaned to a reduced ash specification at the Electric Power Research Institute's Coal Cleaning Test Facility. The comparison is based on: ? ASTM ash fusibility data ? A slagging index ? Gravity fractionation analyses of critical mineral matter compounds ? Comparative pilot combustion tests. The first three grounds of comparison are laboratory data; and the final comparison involves burning approximately 15 tons of each coal at CONOCO's 1.5 MBtu/hr (440 KW) test combustor. The evidence of these .four comparisons indicates that lowering the ash specification of coal before combustion can significantly improve the ash slagging characteristics of Illinois 90. 6 Seam coal.

Jan 1, 1984

By Walter B. Hester

All persons and communities that have experienced strong-motion earthquakes are convinced of the importance and complexity of earthquake problems thatmust be solved in order to reduce the personal hazards and property losses to a reasonable minimum. It is also clear that absolute elimination of all risks is impossible. Reduction of existing hazards and precautionary measures which will minimize chances for disaster can be accomplished by realistic appraisal of the effects of recent earth- quakes on modern structures and installations. Localities that have reason to expect so-called strong- motion earthquakes can anticipate these effects by taking appropriate steps. Valid earthquake information can only be obtained from earthquakes. Each earthquake contributes to the body of knowledge by additional facts and by clarification of previous observations. Rational interpretation of the data followed by practical application of the conclusions can contribute greatly to the safety of persons and property. The general public expects the architectural and engineering profession to accept this obligation and render this service. Most earthquake hazards are man-made and arise from the imperfections of the works of man and his failure to anticipate the consequences when the natural characteristics of his environment are ignored. If it is not given to man to prevent such natural phenomena as earthquakes, it is sometimes within his power to control their destructive effects and to reduce to a minimum the toll of life and human suffering.

Jan 1, 1958

By Donald P. Tuchman, Justin R. Patts, Emanuele G. Cauda, Andrew B. Cecala, Elaine N. Rubinstein

Video techniques for monitoring exposure, such as NIOSH’s “Helmet-CAM,” employ both real-time dust monitors and mobile video cameras to assess workers’ respirable dust exposures. Many real-time personally worn dust monitors utilize light scattering sensing elements, which are subject to measurement biases as a function of dust type (size, composition, shape factor) and environmental conditions such as relative humidity. These biased and inaccurate dust measurements impair the monitor’s ability to properly represent actual respirable dust concentrations. In the testing described, instrument mass concentration data was collected using three different types of commonly used commercial off-the-shelf personal dust monitors and compared to a reference standard. This testing was performed in a calm air (Marple) dust chamber in which three units of each make and model (for a total of nine monitors) were used for each test. Equivalency factors (EF, a multiplier to match the Thermo TEOM 1400a reference instrument) ranged between 0.746 and 1.879 across all dusts and environmental conditions tested, and between 0.821 and 1.519 on the ISO test dust.

By D. J. Sweet, B. Seymour, T. M. Emery, M. Armatys, J. P. Bourgeois, W. Johnson

The Spokane Mining Research Division (SMRD) of the National Institute for Occupational Safety and Health (NIOSH) has partnered with a narrow vein, hard rock underground mine to research the effects of the binder content on the elasticity and post-peak ductility of cemented hydraulic backfill (CHB). This is part of a larger study to enhance the long-term integrity of ground support in underground mines. As mining advances deeper and stresses increase, CHB mix designs will benefit if they can be modified to handle higher levels of strain which are induced by an increased stope closure, typically affected by a reduction in stope width and increased mining depth, or through dynamic loading resulting from a local seismic event. This portion of the research examined the impact of reductions in binder and their impact on Young’s modulus, peak strength, and post-peak ductility.

Mar 2, 2022

By D. C. Shumway

Recently, the health of the cement industry has been threatened by the impact of environmental regulations, over-zealous state and federal agencies and radical environmental groups. Unfortunately, cement plant operations tend to trigger every environmental regulation and program promulgated, plus several programs designed specifically for the cement industry. These environmental burdens come at a time when the cement marketplace has been impacted by imports resulting in a situation where it has been difficult to increase prices to offset these increased environmental liabilities. The competitive world market forces the cement industry to seek creative ways to reduce costs. With additional major environmental programs coming down the pipe, like the Federal Clean Air Act Amendments of 1980 and EPA regulation of cement kiln dust, the cement industry has attempted to try innovative supplements to cement manufacturing. The cement industry has found that using waste tires, biosolids and other solid wastes in the cement manufacturing process can reduce costs and plant emissions.

Jan 1, 1996

By D. Keech

The Conveyor Equipment Manufacturers Association (CEMA) specification B105.1 “Welded Steel Conveyor Pulleys” adequately defines standard pulleys for most aggregate material handling applications. However, many aggregate applications demand pulleys of higher capacity and reliability than that offered by CEMA pulleys. This paper examines the CEMA Pulley Standard and pulley specifications for aggregate applications requiring greater capacity and reliability than the CEMA Pulley Standard. Higher reliability increases the uptime and has a lower total cost of ownership.

Jan 1, 2003

By B. Hearn, Malcolm J. McPhersqn

Since 1993 Inco Ltd. has been using wet shotcrete at Stobie Mine. Through an evolving process the mine has reduced the thickness and fiber content of its steel fiber reinforced (sfr) shotcrete. However, the shotcrete support is used without any other type of ground support. A process referred to as bolt less shotcrete. Boltless shotcrete is used as the primary ground support method in development headings when the sub level caving front passes through the development drifts which now serve as migrating ore draw points. Although there are references of drifts and tunnels supported by shortcrete only, written accounts are rare. The empirical nature of most underground support designs makes them of limited value in a boltless environment. Considerable amounts of material testing and insitu trials have been completed in order to estimate material property strengths. Material testing, for adhesion, flexural strengths and compressive strength along with observational insitu data have been used to evaluate the performance of shotcrete. Punch tests on panels have also been undertaken in order to gain insights on the limitations of the two dimensional testing common to the laboratory. All these design aspects have been successfully utilized to design an efficient ground support process.

Jan 1, 1998

By J. Hanna

Four Ca-bentonitic clays from Alabama were evaluated for use in Diammonium Phosphate (DAP) or Urea Ammonium Nitrate (UAN) fertilizer suspensions. The viscosity and gel strength of suspensions prepared with different proportions of a Western bentonite clay and sodium exchanged Alabama clays, were measured as a function of clay content and dispersant concentration. The results obtained suggested that three of the Alabama Ca-bentonites would replace about 40% of the more expensive Western bentonite in UAN and DAP fertilizer suspensions. The performance of the Na-modified clays, prepared according to the TVA soda ash method, was as good or even better than those observed for the Mg-, Na/Mg-or K-modified clays. The TVA clay modification procedure appears to be reliable and cost effective.

Jan 1, 1989

By Y. Wang, G. Xu, N. A. Amoah, A. Kumar

Mining-induced coal dust causes various respiratory diseases to mine workers, such as coal workers’ pneumoconiosis (CWP). Current available underground monitors are expensive, heavy and only measure mass concentration. These disadvantages limit them for regulatory sample monitoring purposes only while personal exposure levels for most miners remain unknown, risking miners to potential overexposures. Low-cost light scattering PM sensors offer a potential solution to this problem with capability of high spatio-temporal resolution PM characterization. However, these sensors require careful calibration before they can be applied in mining environments. There is basically no comprehensive study in the literature using a standard protocol assessing these sensors for coal dust monitoring. With the aim of calibrating the PMS5003 sensors for coal dust monitoring, we design the calibration method and system to calibrate these low-cost PM sensors coal dust monitoring. Working principles of present coal dust monitor and low-cost sensors are presented in detail. The linear regression calibration model which is used for the sensor calibration is further described. Sensor calibration and evaluation protocols are comprehensively compared and discussed. This investigation reveals the feasibility of low-cost sensors for real-time personal coal dust monitoring in underground coal mines.

Mar 2, 2022

By C. D. Harrison, J. W. Parkinson

This paper compares the ash slagging potential of Illinois No. 6 seam coal as raw coal, as commercially cleaned coal processed in a baum-jig plant, and as coal cleaned to a reduced ash specification at the Electric Power Research Institute's (EPRI) Coal Cleaning Test Facility. The comparison is based on ASTM ash fusibility data, a slagging index, gravity fractionation analyses of critical mineral matter compounds, and comparative pilot combustion tests. The first three grounds of comparison are laboratory data. The final comparison involves burning about 13.6 t (15 st) of each coal at Conoco's 4.40-kW/h (1.5 million-Btu per hr) test combustor. The evidence of these four comparisons indicates that lowering the ash specification of coal before combustion can significantly improve the ash slagging characteristics of Illinois No. 6 seam coal.

Jan 1, 1987

By Eugene A. Hickok

Seismic surveys utilizing the MD-1 have been performed by Geophysical Specialties Company since 1957 in many parts of the, U. S. and Canada and in several foreign countries. These surveys have proven the refraction seismic technique to be applicable to a wide variety of engineering problems. The best known applications of the instrument have been in the, construction industry, where it is used for the delineation of material and mineral deposits and for bedrock depth determinations. Fast on-the-site depth determinations give reliable subsurface' information even in boulder-strewn soils. A widely publicized use of the MD-1 is to make rippability studies in which the instrument is used to determine the seismic velocity of the materials to be excavated. By use of special tables which correlate rippability with seismic velocities, such as those prepared by the Caterpillar Tractor Company using the MD-1, the rippability of-a specific material may be determined.

Jan 1, 1962

By Ed Sullivan

"Australia is one of the richest continents when it comes to mineral extraction, ranging from exotic projects like the Olympic Dam — a copper, silver and uranium mine believed to have the world’s largest uranium resource — to the extensive iron ore, nickel, coal and gemstone formations that provide many of the country’s most rewarding exports.Among the challenges to succeed in this industry is the ability to provide efficient “pitto- port” infrastructure performance, which essentially means ensuring that minerals move seamlessly from the point of extraction to the facilities that can then move them to international market destinations.To provide such efficiencies, avoid human error and facilitate automated mining functions, producers are increasingly turning to fiber optic cable suppliers for “end-to-end” communications and control solutions. Many such solutions include ruggedized cable and connectors that ensure the survival of fiber-based DCS/PLC automation/ control architectures for various types of mining operations, even in the harshest environments.Integrating the solutionAs industrial Ethernet and fiber optic cable emerges as the medium of choice in many industrial arenas, communication and control integration using the most appropriate products for a specific application is increasingly important.“This whole ‘pit-to-port’ performance concept is focused on control and process automation,” says Boyd McDonald, Founder and Managing Director at Datalek Systems & Electrical, Rockhampton Area, Australia. “It also means bringing reliability to networks and providing the needed bandwidth. An appropriate plug-and-play solution is also important because it takes human error out of the equation.”Datalek Systems & Electrical, is responsible for the design, installation and maintenance of numerous fiber optic communications systems including those that involve automation, security, access control an CCTV systems for open-pit and underground mining operations as well as LNG and coal seam gas facilities."

Jan 1, 2015

By G. van Eck, H. Smit, L. Meyer

The Cook Islands (CI) possesses within its Exclusive Economic Zone (EEZ) a massive field of polymetallic nodules representing one of the world’s largest undeveloped cobalt deposits, along with large quantities of other metals critical to achieving global energy transition targets. In February of 2022 the Seabed Minerals Authority (SBMA) of the CI granted Moana Minerals a license to conduct our nodule exploration program. This paper describes how Moana Minerals chose to approach conducting exploration activities, one of the greatest challenges to Deep Sea Mining (DSM) development and the securing of the social license to advance to eventual mining of the resources, in an unconventional manner. The remote location of the project poses logistical challenges in mobilizing to and operating in the region and is a significant cost driver. Historically, exploration campaigns mobilized large vessels from mainland Europe, the Americas, and Asia as this model works well when contemplating long duration and widely temporally spaced campaigns without the need to revisit. Moana Minerals, when considering these challenges determined a multi-year deep sea mining (DSM) exploration program conducted in such a remote location can be better optimized by the deployment of a smaller yet highly capable “exploration optimized” vessel that is dedicated to the task and is based full time in the Cook Islands. INTRODUCTION The paper describes the challenges of exploration in remote regions including the South Pacific, and how an unconventional consideration of the problem led to the solution. Completion of an Environmental and Social Impact Assessment begins with a detailed environmental scoping study, resource update sampling requirements, and engineering data and sample requirements, which identifies the exploration goals of the project and technology needed to accomplish those goals. The method walks the reader through vessel and technology selection, discusses the challenges of equipment selection considering size and capability, describes the final arrangement, and provides results from the initial exploration campaigns. We followed the project from conception through the shipyard conversion, mobilization, and initial operations in the Cook Islands. The result shows how a smaller vessel with limited budget makes a large impact on the exploration capabilities in the region while building public trust. The Anuanua Moana is the first dedicated deep sea minerals exploration vessel modified with a suite of technologies that allow it to compete technically with existing ships but operate locally in the smaller ports of the South Pacific. The unique combination of size and technical capability gives the Anuanua Moana advantages over other vessels. This paper shows the importance of the Anuanua Moana in the development of offshore exploration strategies in the emerging deep sea minerals space.

Feb 22, 2026