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Joy Mining Machinery has developed a new generation of ultra-heavy shields for Anglo Coal Australia?s Moranbah North Mine in the Bowen Basin region of Queensland. These are the largest two-leg longwall shields yet produced by Joy. The longwall at Moranbah North posed a number of challenges, among them a thick, inclined, sometimes undulating seam with increasing depths. The result of this was the need for larger, heavier, more powerful roof supports. Knowing that future longwalls would be going deeper, mine management determined that shield yield ratings of at least 1,750 t (1,930 st) was what would be required.

Jan 1, 2011

Gaby Copper Mining?s Gabriela Mistral property is located in the Antofagasta region of northern Chile, at an altitude of 2,660 m (8,727 ft) above sea level. The reserve contains an estimated 562 Mt (620 million st) of oxide ore with an average grade of 0.41 percent total copper. The mine went into production in 2008. Gaby Copper faced the problem of having no reliable way to measure the solids level. This is a challenge that exists throughout the mining industry, where dust in the air and accumulation of solids on a sensor make accurate measurements difficult in areas such as transfer chutes, the rock box underneath crushers, silos and anywhere else that information is needed on the level of solids. The next-generation technology in the Sitrans LR560 radar from Siemens addresses this challenge. With a frequency of 78 GHz ? higher than previous generations of radar ? it provides a more robust signal for measuring in areas where there are high levels of dust accumulation. The Sitrans LR560 provides a signal beam angle of four degrees, significantly narrower than any other product on the market can offer.

Jan 1, 2014

By Konstantinos Komnitsas, Evangelos Petrakis, Emmanouil Varouchakis

The paper discusses the limitations of population balance modeling (PBM) in predicting particle size distribution in grinding systems. It introduces a nonlinear framework that transforms the batch grinding equation into the Rosin-Rammler distribution, providing more accurate analysis under different operating conditions. The study uses marble as test material and investigates the adaptability of the nonlinear model with different media sizes.

Oct 1, 2023

By Mehmet Mesutoglu, Ihsan Ozkan

This study investigates the feasibility of rock bolting support in an underground coal mine gallery with a thick coal seam. The Ömerler underground coal mine working area, owned by West Lignite Enterprise of Turkish Coal Enterprises, was selected for this purpose. Longwall top coal caving is implemented as the production method in the Ömerler underground coal mine. Field and laboratory studies were conducted to determine rock mass and rock material properties, followed by experimental, empirical and numerical analyses based on the acquired data. The obtained design results were evaluated using a resin-grouted rebar rock bolting (RBR) system and steel arch support (SAS) pilot application areas. The numerical modeling results conducted using the fast Lagrangian analysis of the Continua 3D (FLAC 3D v6.0) program indicated less displacement and secondary stress change in the RBR-supported zone compared to the SAS-supported zone. In situ measurements also demonstrated that RBR provided more successful support to the roof during coal production activities. The findings suggest that RBR is a more effective solution when evaluating the feasibility of rock bolting support systems in underground galleries with thick coal seams at the Ömerler Mine. This study emphasizes the importance of more sustainable and safe support systems to enhance operational efficiency in the coal mining industry.

Mar 1, 2025

By Connor Meinke, Shaihroz Khan, Kevin Erwin, Rajiv Chandramohan, Muhammad Usman Siddiqui

A geometallurgy study aims to link metallurgy and geology to reduce technical risk and enhance the economic performance of a mineral-processing plant. It does so by accounting for variability in a deposit to develop cash-flow models with variable throughput rates. High-quality sample selection for metallurgical test work that is representative of the deposit is an essential component of a geometallurgy study, but the large multidimensional data set makes sample selection a daunting task, as classifying the data set while respecting its heterogeneity is difficult. This paper presents a streamlined approach for sample selection, using statistical analysis techniques in Python. It cuts down time to select samples from around 1,200 s per drillhole to about 60 s for data classification and from 12 h to 8 h for handpicking samples from the classified data set, translating to cost savings. The cumulative sum method and k-means clustering method are used in the methodology to elegantly classify the data and select representative samples. The effectiveness of the methodology is demonstrated by presenting data from a prefeasibility study of a copper-iron mine in which 40 samples were selected for flotation test work.

Dec 1, 2024

By E. S. Bianchin

The more complex control needs of today's mineral processing plants combined with ever-changing digital technology have brought numerous improvements to process control systems. This paper discusses recent advancements in distributed control systems (DCS) which facilitate the implementation of process plant automation. Some of the topics of discussion include integrated function controllers, weigh scale and analyzer interfacing, operator interfacing, personal computers, process information management and process plant management.

Jan 1, 1988

From 2009 to 2012, Aker Wirth, in cooperation with the BGR (German Federal Institute for Geosciences and Natural Resources), developed a concept for the deep sea mining of manganese nodules, which it also examined by means of a profitability analysis. The study was undertaken for the German Federal Ministry of Economics and Technology. The increasing scarcity of resources, coupled with the continuous rise in resource prices, drive the search for new raw material deposits. As a result, the deep sea is coming increasingly under the spotlight. At depths of more than 1,000 m (3,280 ft), large deposits of ores and precious and high-tech metals, such as manganese, cobalt, nickel, copper and gold, along with rare earths (which are important for the high-tech industry), can be found. The extreme deep sea conditions ? enormous water pressure, ice-cold temperatures and complete darkness ? present huge financial and technical challenges to the mining industry when extracting these materials. Aker Wirth has recognized the potential of this important future market early on and advances the development of relevant products.

Jan 1, 2013

Caterpillar and Fortescue Metals Group have moved forward with the delivery, installation and support of a complete Cat MineStar System at Fortescue?s Solomon iron ore mine in the Pilbara region of Western Australia. The complete technology suite was implemented for the first phase of Solomon, the 20 Mt/a (22 million stpy) Firetail manned mine, in October 2012. As part of an autonomous mining solution for phase two, the 40-Mt/a (44-million stpy) Kings Mine, eight Command for hauling Cat 793F CMD trucks were commissioned and commenced operations in the second quarter of 2013. The mine plan calls for a progressive ramp up to 45 autonomous trucks during the next several years. In addition, other Cat MineStar System capability sets, Fleet, Terrain, Detect and Health, are being used across the mobile equipment fleet, including support equipment and light vehicles. Working closely with Fortescue and its mining contractor, Leighton Contractors, Caterpillar and the Cat dealer in Western Australia, WesTrac, are providing a full solution for managing, operating and supporting Cat MineStar System and Command for hauling. The greenfield Solomon Mine has brought together the skilled team from Caterpillar, Fortescue, Leighton Contractors and WesTrac to deliver an efficient, cost effective autonomous mining solution.

Nov 1, 2013

By JIAQI JIN, Chen-Luh Lin, Amanda N. Erskine, Jan D. Miller, Shijie Wang

The liberation and exposure of valuable mineral grains in ore particles are of significant importance in understanding the efficiency of flotation separations. A flotation feed sample from the Kensington concentrator was scanned by micro Xray computed tomography (micro-XCT), to determine the liberation and exposure of auriferous pyrite grains. The analysis results suggest a satisfying extent of liberation for particle sizes smaller than 212 μm. Theoretical flotation recovery of pyrite for selected particle size fractions was predicted from the three-dimensional liberation and exposure analysis. The plant flotation tail was also characterized by micro-XCT to identify liberated and partially liberated pyrite particles that might not be collected into the concentrate. However, liberation analysis of the tail sample revealed that the majority of liberated pyrite was recovered in the plant flotation circuit. Trainable Weka, a machine learning segmentation approach, was compared with the Watershed thresholding segmentation for the 106 × 45 μm particle size fraction scanned at a voxel size of 1.85 μm. Improved segmentation of small particles was found using the machine learning method.

Mar 1, 2024

By J. W. Currier

The compositions and natures of the materials charged to a blast furnace, as well as their respective distributions within the furnace, are known to int1uence furnace performance. However, fifteen years ago, there was little reason to believe that any significant variation of these parameters had been overlooked. Nor was there any particular reason to believe that olivine might be a particularly useful raw material for blast furnace applications.

Jan 1, 1989

By Steve Kral

The Northwest Mining Association (NWMA) has been an advocate for the U.S. mining industry since 1895. For several decades, the organization has represented mining members located mostly in the Northwest and some southwestern Canadian provinces. Today, though, the NWMA?s membership is located in 42 states and seven provinces and has become a national voice for the mining industry. So, during the association?s 119th and final meeting as the NWMA, a name change was announced. The organization is now called the American Exploration and Mining Association (AEMA). But that?s not all that has changed, according to the association. The new name reflects more closely the diversity and location of the AEMA?s membership. It will still be an advocate for the mining industry, dealing with land, environmental and community issues on state and federal levels. The conference, held in December 2013 in Reno, NV, attracted about 2,500 attendees. And the accompanying exhibit included 230 equipment and service suppliers in 246 booths. Technical programming ran the gamut of mining industry issues and technologies, including surface and underground mining; high technology systems and automation in mining, metallurgy and exploration; along with social issues, finance and safety. The following is a sample of some of the sessions.

Mar 1, 2014

With commodity prices rising again and market conditions stabilizing, the Metals Economics Group (MEG) found that most mining companies increased their exploration budgets in 2010. In the groups 21st edition of the Corporate Exploration Strategies (CES), MEG found a 44-percent rise in the estimated worldwide exploration total for 2010. MEG found that the estimated total 2010 budget for nonferrous metals exploration reached $12.1 billion, reinstating almost two-thirds of the industry?s $6 billion in cuts to exploration in 2009. Nonferrous exploration refers to expenditures related to precious and base metals, diamonds, uranium and some industrial minerals; it excludes iron ore, aluminum, coal, and oil and gas. In 2008, exploration budgets were at an all-time high of $14.4 billion. This capped a six-year run in which budgets rose. In 2009, nonferrous exploration budgets dropped 42 percent in 2009 as the global economic crisis and declining prices for almost all commodities took their toll on the industry. Metals prices - the primary driver of exploration spending - have improved markedly since bottoming in early 2009, and have traded well above their long-term trends throughout 2010. In response, major, intermediate and junior companies have all increased their aggregate exploration allocations in 2010. In particular, the significant improvement in the availability of equity financings for the juniors over the past 12 to 18 months has allowed this group to account for the largest share of the overall increase in exploration spending this year.

Jan 1, 2011

By Isabel Barton

This article describes and analyzes the history of research into the origins of the uranium-vanadium(-radium) deposits of the Paradox Basin. For several decades after their discovery in 1881, research was desultory and almost entirely descriptive, fluctuating with demand for vanadium and radium. Systematic geologic descriptions, accumulated between 1910 and 1950, supported rapid progress during a government-backed surge of research in the 1950s, when uranium was the chief commodity of interest. Most of the major theoretical innovations date from this decade, including the use of concepts from solution chemistry to identify the conditions and constrain the processes of deposit formation and alteration. Research from this time was highly influential in geology at large, providing the model for sandstone-hosted uranium deposits worldwide and numerous new minerals and mineral structures. After about 1960, mine production remained high but research dwindled, and most new advances were to the details of the hydrothermal model of ore formation rather than its core concepts. By the end of the 1960s, the deposits were understood to have formed at the mixing interface of an oxidized, metal-bearing water with a reducing fluid of debated origin. Research was desultory over the ensuing decades; the source of the metals and the nature of the chemicals constituting the trap were not clearly established. They remain questions today, as do factors like the relationship between ore mineralization and the geologic history of the basin. (More in the full paper.)

Jan 1, 2025

By C. L. Elmore

This paper describes a new development in the cyanidation of gold ores, which we expect will result in a major improvement in the way many gold ores are treated. The process has evolved through work at Hazen Research, Inc. for Kamyr, Inc. and in brief, the consists of utilizing oxygen rather than air in the carbon-in-1 each (CIL) process. We refer to this improved process for all ores amenable to cyanide leaching as carbon-in-1each with oxygen or CILO.

Jan 1, 1988

"With a longstanding reputation for engineering expertise, Weir Minerals continually develops solutions and technology to better serve the mining industry. Recognizing that throatbush wear rate has a major impact on the overall efficiency of slurry pumps, Weir Minerals has developed superior rotating and axial adjustment technology.In many applications, the pump’s throatbush is the component that has the shortest life compared to the impeller and liners, with considerable variability.Adjusting the gap between the throatbush and the impeller front shroud reduces hydraulic recirculation in the pump. This prevents localized wear on the throatbush, improves hydraulic efficiency and lowers the total ownership cost for the operator. To avoid impacting the plant’s production, these adjustments are often performed while the pump is operating. However, this can have safety implications for individuals working at the front of the pump unit.“Manually adjusting an alloy throatbush on a large pump requires several people and is laborintensive. It requires mechanical tools to adjust the four pusher bolts, one at a time, in order to reduce the gap between the throatbush and impeller. We wanted to find a safer and quicker way to extend the wear life of the pump with regular adjustments, which led us to development of this technology,” said Marcus Lane, global product manager for centrifugal pumps for Weir Minerals.“Our automated throatbush adjustment solutions are available for pumps fitted with either rubber or alloy throatbushes on Warman slurry pumps used in the most arduous applications, and have been designed with our customers’ safety and pump operation in mind. By mechanizing the adjustment procedure, personnel are removed from the line of fire, and the accuracy of axial movement is increased,” said Ron Bourgeois, director of slurry pumping technology group for Weir Minerals."

Mar 1, 2019

By Scott Donald, Barry Esford

Cameco Corp. operates uranium mills and tailings management facilities at its Key Lake and Rabbit Lake operations in Northern Saskatchewan, Canada. Development at both mine sites began in the 1970s, with initial tailings deposition occurring within above-ground impoundments, which was common for these facilities at the time. As open pits became available at each site, and mining continued at other orebodies in the area, tailings management shifted to in-pit facilities to meet stakeholder expectations and improve the long-term security and environmental performance of tailings management at these facilities. The in-pit facility at Rabbit Lake (receiving tailings since 1984; Fig. 1), was one of the first (if not the first) engineered in-pit tailings facilities in the world and adopted a full pervious surround design concept with subaerial deposition. Under this concept, permeable sand and coarse rock are placed at the base of the pit, around its perimeter, as well as overlying the tailings at closure to promote regional groundwater flow bypassing the lower-permeability tailings. In contrast, at Key Lake, the in-pit facility (receiving tailings since 1996) adopted a partial pervious surround design concept. Under this concept, permeable materials were again placed at the base of the pit, and partway up the side walls; although for the upper portion of the tailings, the material is placed directly against the natural geologic materials. In the Key Lake case, the natural geologic environment provided the required bypassing of the tailings deposit to achieve the desired environmental performance while the base drain again facilitated pumping during operations to achieve consolidation objectives (Fig. 2). In both the initial design of the facilities, and through more than several decades of operation, it is clear that although in-pit tailings facilities provide common benefits with respect to long-term geotechnical stability, it is critical that their design approach take into consideration site-specific conditions

Jul 1, 2025

There are many risks associated with the storage of nuclear or other toxic wastes. One of the major risks is the escape of material from the repository. No matter how well a storage facility is engineered, the potential escape of dangerous material must be studied. This kind of study will include some estimation of the "travel path" of the particles. The travel path of a radio-nuclide particle will depend on the geological and hydrological parameters of the surrounding rocks. These parameters must be estimated from a limited number of samples available within the study area. Any estimation will -of necessity -contain a certain amount of uncertainty or "estimation error". This uncertainty will be carried through to the analysis of potential movement of particles, so that the estimated travel path itself will be subject to some error. This paper discusses an approach which may lead to a quantification of the uncertainty on the predicted travel path.

Jan 1, 1989

By Edie Trimmer

Utah statute defines sovereign lands as "those lands lying below the ordinary high water mark of navigable bodies of water at the date of statehood, and owned by the state by virtue of its sovereignty." The lands within the bed of Great Salt Lake (GSL) are, by this definition, sovereign lands, acquired at statehood in 1896 in accordance with the "equal footing" doctrine, granting each state control and ownership of navigable waters and the lands underneath those waters within its borders. Under public trust doctrine, the state, as trustee for the people, bears responsibility for preserving and protecting the right of the public to use of the waters for navigation, commerce, fishing, recreation, and wildlife habitat. Also by statute, sovereign lands are defined as "state lands," to be managed by "multiple use sustained-yield principles." The Division of Forestry, Fire and State Lands is given management authority for sovereign lands and, as manager, has responsibility to prepare comprehensive plans, initiate studies of the lake and its resources, implement comprehensive plans through state and local entities, and coordinate the activities of various divisions within the Department of Natural Resources (DNR). The Division of Forestry, Fire and State Lands also has responsibility for management of mineral leasing on sovereign lands. The many resources on the lake--water, minerals, wildlife, recreation, archeological and historical values--are managed by as many state agencies which occasionally creates conflicts. The brines of GSL contain several ions that crystalize into valuable minerals during evaporation. The major ions in the lake are, in order of relative abundance, chloride, sodium, sulfate, magnesium, and potassium. Mineral products which are currently extracted from lake brines are sodium chloride, magnesium chloride brine which can be sold as flake magnesium chloride or further processed into magnesium and chlorine gas, and potassium sulfate. Mineral products which have potential for extraction include gypsum, sodium sulfate, and trace amounts of lithium, boron, and bromine. The GSL contained an estimated 4.3 billion short tons (st) (3.9 billion metric tons [mt]) of dissolved salts in 1998. Utah Geological Survey (UGS) estimates of the dissolved salt content in GSL have fluctuated from 4.0 to 5.5 billion st (3.6 to 5.0 billion mt) due to the dynamic conditions in the lake as salts are precipitated and redissolved, and due to the diversion of brines from GSL, such as the West Desert Pumping Project. The lake has four areas of varying salinity, separated by dikes or other man-made structures: north arm and Stansbury Bay brines at near saturation (25 to 27 percent total dissolved solids [TDS]); the main body of the south arm with concentrations ranging from 7 to 15 percent TDS as lake elevations fluctuate; the waters in Farmington Bay at approximately 3 to 5 percent TDS; and Bear River Bay at <1 to 7 percent TDS. The percent TDS in Bear River Bay fluctuates with lake level, and changes in Bear River inflow. The transfer of salts from the south arm to the north arm has raised questions about the viability of the mineral and brine shrimp industries. The UGS and the U.S. Geological Survey (USGS) continue to monitor salinities at designated sites on the lake to document changing lake salinity. A recurrent theme is that placement of dikes and diversions can have significant and rapid impacts on various conditions in the lake. Hydrocarbon resources on the lake are significant, but presently undeveloped. The hydrocarbons are low gravity (4 to 9 degree API) and tar-like, contain high nitrogen concentrations, and up to 12 percent sulfur. The unusual characteristics of the oil have been the subject of studies by chemists at Weber State University and University Louis Pasteur de Strasbourg. However, these resources are difficult, and at present, uneconomic to extract using current technology because of the nature of the hydrocarbons, and production in "an offshore, highly saline environment." Oolitic sand deposits make up many of the beaches and shorelines around the lake. Because of their high calcium carbonate content, oolites have been used by Magnesium Corporation of America (MagCorp) and its predecessors for acid neutralization and dike construction. Oolites are also used in very minor amounts in flower drying. The Utah Division of Oil, Gas and Mining reports up to 130,000 st (118,000 mt) mined annually by MagCorp from U.S. Bureau of Land Management (BLM) lands adjacent to GSL. Currently, there are twelve producing mineral leases which generated slightly more than $1,000,000 in royalties during calendar year 1998. IMC Kalium Ogden Corp. (IMC Kalium) produces potassium sulfate and magnesium chloride from brines concentrated through solar evaporation in Bear River Bay and Clyman Bay. By-product sodium chloride is transferred to IMC Salt, which packages and sells the salt. MagCorp produces magnesium metal from brines concentrated in Stansbury Bay. Cargill Salt produces sodium chloride from brines provided by MagCorp under a lease agreement. Morton Salt produces salt at the southeast end of Stansbury Island. Lastly, North Shore Limited produces cocentrated brines for use in dietary and mineral/vitamin supplements near Spring Bay in the north arm of the lake. Producers of magnesium, potash, and salt from GSL contribute significantly to the value of metals and industrial minerals in Utah. Together these companies contribute approximately $240 million in gross value, or 18 percent of the value of the state&apos;s nonfuel mineral production. Most of this production is exported.

Jan 1, 2001

By Brett P. Spigarelli

"To meet the growing need for CO2 capture and storage technology, Michigan Technological University is studying CO2 capture using alkali-based solvents. The objective of the present study was to find a way to increase the absorption rate of CO2 into an alkali solution without reducing the absorption capacity of the solution. One approach to increasing absorption rate is to use a surfactant to chemically alter the gas bubble size. The surfactant chosen for the study was a neutral-charge polypropylene glycol methyl ether (PPGME) with a molecular weight of 200. Experiments were conducted to study the absorption rate of CO2 at varying surfactant concentrations. Results showed that as the concentration of PPGME increased in solution, the absorption rate also increased. The CO2 absorption rate increased from 3.45 x 10-3 mol/min CO2 at 0g/L PPGME to 3.92 x 10-3 mol/min CO2 at 0.48 g/L PPGME. This amounted to a 14% increase in the CO2 absorption rate with no decrease in the absorption capacity of the solution. IntroductionChemical absorption using an amine solvent is currently the most mature carbon capture and storage technology available. Amines are advantageous in that they have a fast CO2 absorption rate, which leads to a high CO2 removal efficiency. However, amine absorption has some considerable drawbacks, such as high energy requirements, high equipment corrosion rates, amine degradation in the presence of oxygen, high waste generation and a large increase in plant footprint if new equipment is constructed (Herzog and Golomb, 2004; D’Alessandro et al., 2010). Due to these drawbacks, Michigan Technological University (MTU) is studying CO2 absorption using alkali-based solvents, which address the above disadvantages of amine solvents."

Jan 1, 2015

By William Gleason

"Despite the difficult economic climate for the mining industry, more than 6,300 people joined SME for its 2016 Annual Conference & Expo in Phoenix, AZ, Feb. 21-24.Nearly every commodity has been bruised and battered during the past year, leading to one of the more difficult cycles for the industry in the past decade. Coal has taken some of the hardest hits and other commodities, such as copper and iron ore, have felt the sting of a slower growth in China and an oversupply on the market.The difficult conditions could not be ignored, but they did not deter SME from offering a forum for the industry to share knowledge, network with peers and learn about the best products and practices while visiting the sold-out exhibit hall (844 booths and 627 vendors) or while attending any of the 121 technical sessions that were offered.The current state of the industry was one of the overriding themes of the conference and during the challenging times there are often cutbacks as operations look to become leaner and more efficient, however, there is one area that cannot be cut – health and safety.The conference kicked off with a fascinating presentation from Colonel Mike Mullane, a former NASA astronaut who, in 1978, was selected as a Mission Specialist Astronaut in the first group of space shuttle astronauts. He completed three space missions and logged 356 hours in space aboard the shuttles Discovery and Atlantis before retiring from NASA and the U.S. Air Force in 1990.In his speech to a packed audience, he warned of the dangers of cutting corners to get the job done more quickly by guarding against the “normalization of deviance.”Normalization of deviance is a long-term phenomenon in which individuals or teams repeatedly accept a lower standard of performance until that lower standard becomes the norm. Usually, the acceptance of the lower standard occurs because the individual or team is under pressure (budget, schedule, etc.) and perceives it will be too difficult to adhere to the original higher standard. Their intention may be to revert back to the higher standard when this period of pressure passes. However, by getting away with the deviation from the higher standard, it is likely they will do the same thing when the same stressful circumstances arise again. Over time, the individual/team fails to see their actions as deviant."

Apr 1, 2016