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By A. Kalogeropoulos, T. Michalakopoulos

The DEM has been used in several studies to numerically simulate the response of rocks to the cutting action with drag tools. In this research, the aim is to realistically simulate the rock material and the cutting process by controlling the grain interlocking of the numerical assembly and streamlining the calibration process while focusing on the cutting force and the failure mechanism.

Apr 1, 2023

By K. Neumann

"INTRODUCTION For many automation and safety tasks in open cut and underground scenarios it is crucial to have highly reliable distance measurements at hand. These measurements can for instance be used to obtain the exact position of a machine in one-, two- or even three dimensions. Research and development has shown interest in the ultra-wide-band technology (UWB) in recent years. While for this technology short range, high speed data transfer is the current main research focus, the technology can also be used for highly accurate ranging applications. Due to the use of a very wide frequency band, it is robust against disturbances of many types (e.g. EMC, rain, dust etc.) and is therefore attractive for the use in mining applications. The wide frequency band also offers benefits for ranging applications. Especially in environments with strong multipath problems such as in underground mines it is possible to focus on the dominant signal propagation path, thus increasing the reliability of the measurements. [1] State-of-the-art UWB ranging equipment claims precision within the range of a couple of centimeters and working ranges of more than hundred meters. At the Institute for Mining and Metallurgical Machinery (IMR) at RWTH Aachen University in Germany a modern UWB system was examined in several laboratory and real life tests to examine the feasibility of UWB bases ranging equipment in mining applications. UWB TECHNOLOGY The term ultra-wide-band denotes radio systems that use an ultra-wide frequency band. A common definition for UWB radio systems is that it needs to work on a frequency bandwidth of more than 500 MHz or a bandwidth equal to 20% or more of the center frequency [1]. Due to the ultra-wide frequency bandwidth UWB systems overlap the frequency spectrum of narrow band radio technologies like Wi-Fi, Bluetooth and other mobile communication systems which use a defined carrier frequency onto which information is modulated on (e.g. by using frequency or phase modulation). In order to not conflict with these other radio applications, it needs to be ascertained that the transmission power of a UWB system on a given frequency is so low that narrow band systems are not affected by it. As opposed to this only a small fraction of the UWB system’s bandwidth is affected by the narrow band system. The unaffected remaining bandwidth is sufficient to reconstruct the original signal, even if additional noise is present. Figure 1 shows the power spectral densities of popular radio standards [6], [7], [8]. A significant driver of research and development of UWB systems has been wireless high bandwidth communication. Using an ultra-wide frequency band is highly desirable here, as the channel capacity is dependent on the bandwidth. So far systems have been realized especially for short distances (e.g. wireless USB or Wireless HDMI) but beyond that, communication systems for long distances (several kilometers) are possible [2]. Advances in semiconductor technology led to a reduction in power dissipation of such systems. This enabled higher integration levels which in turn facilitated smaller solution sizes for space constrained applications [3]. Nowadays, UWB is also used for high-precision ranging applications [4], [5]."

Jan 1, 2015

By M. G. Karfakis

Grouting has been used in underground mining for more than twenty years. Chemical grouting is often used as a remedial measure when the implemented ground control program is unable to completely prevent structural failures or when there is a need for preventing a structural member from unraveling. Utilization of the polyurethane grout currently being used is restricted by its limited range of physical and mechanical properties that restrict its utilization. To overcome some of the drawbacks of polyurethane, research has been conducted on a newly developed polyester based grout. The polyester resin, identified by Sandvik as StrataGrip, provides a number of features, including variable gel times and much reduced chemical hazard. Equally important are the mechanical properties of the product. The strength and deformability of any chemical grout must be compatible with the intended purpose of grouting and the expected deformation of the rock that is to be grouted. Assessment of the mechanical properties of polyester grout is the focus of this work. Field experiences and laboratory research have defined the properties of an effective grouting material. Experimental results indicate that the polyester grout meets or exceeds the recommended properties for many injection applications. Furthermore, the results suggest that the ability to adjust mechanical properties via resin formulation has the potential to expand the applicability of chemical grouting in ground control.

Jan 1, 1997

By C. H. Cheh

The amount of fines in run-of-mine coal has been increasing and coal quality has been deteriorating as a result of the increased use of mechanized and continuous mining methods. Removing the mineral matter and pyritic sulfur from coal prior to combustion will lower transportation costs, improve power plant performance and reduce sulfur dioxide emissions. Since physical cleaning methods can only remove individual particles of mineral matter and pyrite, it is necessary to crush and grind coal to fine sizes to separate these contaminants so they can be removed by deep cleaning processes. The increased portion of fines in run-of-mine coal together with attempts to increase the mineral matter removal efficiency have stimulated interest in fine coal cleaning technology. However, there are many problems to be solved before fine coal cleaning can be applied to power plant coals. These problems include: 1. coal cleaning plant capacity is reduced when conventional cleaning circuits are modifies to deep clean coals; 2. existing equipment and technology is not suitable for cleaning fine coal; 3. coal recovery is reduced; and 4. fine coal is difficult to dewater, dry, handle, transport and store.

Jan 1, 1982

By Paul Culvenor, Brad Gyngell

Ensuring effective management of contractual processes is essential for maintaining profitability and operational efficiency in mining. However, due to limited capacity and resources, sites often struggle to manage these processes effectively, leading to oversights and financial losses. Recent advancements in Artificial Intelligence (AI) offer promising solutions to these challenges. Large Language Models (LLMs), like those powering ChatGPT, now enable machines to understand unstructured data like contracts. These can therefore be applied to address these challenges by taking some of the heavy lifting off of humans. In this paper, we analyze a real-world case study of the application of LLM tools for preventing a $400k contractual issue on an underground gold mine in Western Australia. We provide a gap analysis of the failure modes in existing processes that led to the issue. We then describe the application of LLM tools to flag it early and facilitate a collaborative solution between the operator and the supplier. This includes a comparative analysis of base case vs LLM case to evaluate the impact on project cost and time. Finally, we discuss how the integration of AI can foster improved relationships between clients and contractors across a broad range of potential contractual applications, allowing the time required for collaborative and proactive problem solving.

Feb 1, 2025

By John P. Weir

The coal industry is ever changing. This paper discusses some of the problems which must be faced and the projected economic effects. Challenges include a relatively mature technology, a resource base which has deteriorated significantly in some areas, rapidly escalating freight rates, and a constantly changing regulatory environment, wherein reduced sulfur emissions will probably be required.

Jan 1, 1984

By B. G. McNish

Neutron Activator Laboratory Analyzer used for Rapid Analysis for Ore Blending, Stripping, and Mine Control BAUXITE is a rock and not a mineral. Since it is a rock, its mineral content varies depending upon the parent material, the topographic location of the deposit and the severity of the weathering and oxidation processes which produced it. At Bauxite, Arkansas the major mineralogical constituent of the bauxite is gibbsite with ~IL- purities of silica, iron oxide, and titania minerals. Minor amounts of other minerals are found. Chemical composition varies from 45% to 60% alumina, 5% to 25% silica, 1% to 15% ferric oxide, and 1% to 3% titania. The Arkansas bauxite region is located entirely within the north- central area of the West Gulf Coastal Plain near the northwestern boundary with the Interior Highlands. The region trends northeast-southwest and is about 42 kilometers long. It is divided into two districts; one in Saline County and the other in Pulaski County. The Saline District is the most important since it has produced most of the bauxite. This district is located at Bauxite, Arkansas and the deposits are found around the flanks of the Saline Dome. It is roughly square-shaped and is about 190 square kilometers in area. The source rock for the deposits is a Late Cretaceous, grey, nepheline syenite.

Jan 1, 1979

By C. Bryce

Rhenium is primarily recovered as a by-product from molybdenum roasting circuits. However, rhenium is also present in copper heap leach solutions at very low concentrations and represents a potential new rhenium source. Freeport-McMoRan Copper & Gold has developed a new process using carbon adsorption followed by ion exchange or solvent extraction to concentrate rhenium from less than 1 ppm to 15 g/L. The product is compatible as a feed to an existing rhenium processing plant. A pilot plant operated at Freeport-McMoRan?s Sierrita mine has demonstrated the technical and financial feasibility of this new process.

Feb 23, 2014

By Joseph W. Johnson

General Electric introduced electric drive systems on 85 ton Off-Highway mining trucks in the early sixties. Due to favorable economics, trucks have increased in size to handle larger payloads. Series Motorized Wheel systems were developed to meet this demand. When the technology was available, General Electric switched from use of Series motors to separately excited motors with the added benefits of static exciters and simplified control. Over 20 years of electric drive experience have been incorporated in the STATEX drive systems, which covers truck sizes from 85 to 220 tons. This paper traces the drive system developments from the early stages to the present and takes a look at what's ahead.

Jan 1, 1983

By Art Hamid, Manfred Wong, Carlos Jaramillo, Greg Raines, John Caulfield

"The Central Bayside System Improvement Project (CBSIP) is a critical element of the Sewer System Im-provement Program (SSIP), a 20-year, $6.9-billion investment by the San Francisco Public Utilities Commis-sion (SFPUC) to upgrade San Francisco’s 100+ years old seismically vulnerable combined sewer system. The CBSIP’s centerpiece, a proposed 10,000-foot-long (3,048-meter-long) Channel Tunnel, will provide reliable and redundant gravity conveyance and storage of combined wastewater flows from the northern and central parts of San Francisco to the Southeast Water Pollution Control Plant (SEP) while ensuring compliance with regulatory requirements for combined sewer discharges to the Bay. A tunnel with a diameter of 23 to 30 feet (7 to 9 meter) is being planned using pressurized-face tunnel boring machine technology. Project challenges include tunneling through Franciscan Bedrock, mixed ground conditions in close proximity to the Bay, connector tunnels and shafts, construction in congested urban environment, and challenging real estate issues for shaft access. BACKGROUND AND NEED FOR TUNNEL The City of San Francisco is one of the most beautiful cities in the world. About 850,000 people live in the city and many more come to work, for tourism, and for attending conferences. The SFPUC is a department of the City and County of San Francisco that provides energy, drinking water and wastewater services to San Francisco, wholesale water to three Bay Area counties, and green hydro-electrical and solar power to San Francisco municipal departments. The SFPUC wastewater system includes tunnels, large storage/transport boxes, 1000 miles of collection sewers, 28 pump stations, and three wastewater treatment plants. San Francisco’s combined sewer system collects both wastewater and stormwater in the same sewers, which is then pumped, treated to stringent state standards and discharged into the San Francisco Bay and Pacific Ocean. After decades of service, much of the sewer system is nearing end of its working life. During the 1989 Loma Prieta earthquake, damage to SFPUC water and wastewater infrastructure was extensive. The 11,200-foot-long (3,400-meter-long), 66-inch-diameter (1,676-mm-diameter) Channel Force Main, built in 1976, and a critical component of the SF wastewater system was also damaged. This force main carries 70 percent of the bayside dry weather sewage flow from the northern and central part of the city to the SEP. The force main is at the end of its life and was not constructed to the current seismic code; in addition it has no redundancy. Figure 1 shows the project background and the force main that will be provided redundancy by the new gravity tunnel."

Jan 1, 2016

By Herbert S. Richey

Two hundred years ago next April, our forebears embarked upon the difficult path to national independence. They succeeded, and shook off the yoke of foreign domination. In the ensuing two centuries, the country was mobilized several times to protect that political and economic independence from foreign domination. These efforts were also successful. Thus, as we stand here on the threshold of our third century of political independence, we can thank previous generations and congratulate ourselves for establishing and maintaining the world's oldest republic. Now -- once again -- the United States faces the challenge of foreign intervention into our economy. This time the battleground is resource avail- ability. America has been blessed with enormous resources. Whether we speak of minerals or timber or water or "amber waves of grain," this nation has benefitted from a resource base that is the envy of the world. This asset, coupled with a political system that permitted us to develop it, has been the physical backbone of our independence. Without the economic independence that this resource base has given us, the political independence we fought for would have been tenuous, at best.

Jan 1, 1975

By V. L. Zajakowski, J. D. Gargulak

The current political climate has forced multinational cement manufacturers to consider technology that minimizes GO, emissions. Along with this environmental issue, individual manufacturing facilities are under constant pressure to increase productivity and lower costs. The use of processing or functional additions can help address these difficult demands by maximizing the extender content in blended cements. Recently, cement standards have been modified such that additions can be employed to improve quality. By using these "cement performance enhancers," the cement manufacturer can maximize extender content of cement thus optimizing plant economics, while meeting local quality standards and minimizing greenhouse gas emissions.

Jan 1, 2003

By Z. Sartowski, M. J. Pearse

The authors present laboratory and plant results illustrating the benefits to be gained by using chemical additives, namely flocculants and surfactant dewatering aids, in the Bayer process. Advantages of synthetic flocculants over starch are illustrated in terms of more efficient solid/liquid separation in both the initial settling of blow-down slurries and in the CCD wash train. In addition, it is shown that the use of synthetic flocculants considerably reduce the levels of organic contaminants present in the process liquor. Secondly, very significant improvements in moisture removal were obtained by the application of dewatering aids to hydrate filtration/ washing operations.

Jan 1, 1984

By Brad Simser

Several case histories from Glencore’s Sudbury Operations show how passive seismic monitoring data is used for geotechnical decision making. The data comes from three different seismic arrays monitoring two open stoping deposits, and a narrow vein cut and fill/blasthole operation. Mining depths range between 1000 to 1680m below surface. The deposits are hosted in hard igneous rocks typical of the Sudbury basin, with characteristically high horizontal stress (approximately 1.8 times the depth of overburden). Rockbursting is the main geotechnical risk, due to the strong brittle nature of the rock and local high mining extraction. Fault related seismicity includes both fault slip events, and the stress channelling effect as the mining front approaches a major fault structure. Planar data trends generally line up with known faults and often indicate early stage fault activation. The structures are risk ranked based on their seismic response. This has been particularly useful at the Nickel Rim South Mine (NRS) where the structural fabric (jointing and small-scale faulting) is generally parallel to the more through going faults. The persistence of structures is difficult to measure, and the NRS faults generally have low offsets and thin gouge. The visual difference between the more persistent structures that occasionally generate large seismic events (up Mw 2.9 to date) and localised joints/slips is often minor. The seismic monitoring data clearly shows the more active structures. This information is highlighted on mine plans to help guide enhanced ground support and seismic re-entry protocol barricade locations. Pillar loading/yielding is a key element to the blasthole operations where a primary/secondary mining sequence is used. The secondary pillars are mined in a yielded state with just-in-time development. An example of the seismic signature of a secondary stope is shown with emphasis on the need for high location accuracy given the stope widths of 12.5 to 15m. The ratio of the shear wave energy to primary wave energy (Es/Ep) has long been used as a method to estimate source mechanisms; the higher the ratio, the more likely the event is fault slip versus rock fracturing. Data sets are filtered on Es/Ep ratios to highlight both fault slip populations and stress fracturing mechanisms. Examples of seismic data quality checks, high stress development, and re-entry protocols are also shown in the case histories.

Apr 26, 2022

By R. E. Miller

Hoisting coal using water and air is a technology which has potential to improve the economics and safety of transporting coal. The Coal Air-Lift Hydrohoist is a prototype coal hoisting system developed by the U.S. Bureau of Mines (USBM). This paper discusses the method used to regulate the supply of water to the 50-m-high hydrohoist U-tube such that the pressure difference at the bottom of the U-tube is held constant. Maintaining a constant pressure difference results in a steady flow of slurry out of the hydrohoist.

Jan 1, 1995

By R. Hogg

A standard procedure for determining size-specific gravity distributions of fine coal (including the -400 mesh fractions) by sieving and centrifugal sink-float separation is described. The significance of using a centrifugal sink-float technique and the effect of the magnitude of the centrifugal force on the separation of fine coal are confirmed in the present study. The relative merits of cumulative versus incremental sink-float are discussed. The procedure is evaluated quantitatively using data obtained for the products of froth flotation of -100 mesh coal.

Jan 1, 1994

By Ademar Lopes, Victor Silva, Heitor Silva, Gustavo Usero, Roberto Rolo, Lucas Pereira, Gabriel Moreira, João Lague, Arthur Endlein, Matheus Feitosa

Grade control models are supposed to provide a higher resolution than long-term or interim models. However, available grids from diamond or reverse circulation drilling do not provide that required resolution. In this study, a geostatistical workflow is proposed to integrate available grade data from production blastholes with its operational parameters taken when drilling downhole. The step of geological logging can be replaced by machine learning models for classifying blastholes into lithologies and hardness classes. Next, indicator and ordinary kriging use the classified blastholes and previous data for estimating the model domains and the grades within each one. The workflow is applied in a world class iron ore mine in Brazil.

Jun 25, 2023

By R. Yang

This paper presents a kinematic approach for blast modeling with examples of blast models that were developed previously. A kinematic approach was applied successfully in developing blasting models that can simulate all blast design parameters for field applications. Several applied blasting models have been developed and applied widely in the world. A kinematic approach to blast modeling refers to using measurements of kinematic quantities such as the velocity, strain, or displacement and well-established assumptions to model blasting phenomena, rather than being restricted to use first principal of physics, such as, the stress- and material-constitutive relations. The kinematic quantities are easy to measure in the field. Due to the complexity and inhomogeneity of rock mass properties, using first principles of physics, many parameters of rock and explosive properties must be involved, which are hard or impossible to quantify. This creates a major impediment when trying to simulate the total process of blasting based upon first principles of physics. The 3D kinematic model for muckpile formation was developed and applied to open pit blasts. The multiple blasthole fragmentation model developed during recent years has been applied successfully to many mine sites around the globe. These models are typical examples of blast modeling using the kinematic approach, which enables the models to catch major trends of the blasting process and explicitly simulate full blast design parameters and complex geometries. Blast modeling using the kinematic approach results in easy model calibration and validation against field measurements and effective applications to practical problems. Using kinematic models of the muckpile formation and the multiple blasthole fragmentation model, this paper demonstrates the merits of the kinematic approach for blast modeling. New developments of the models were also presented in the paper, which illustrate the potential of the kinematic modelling approach.

Mar 2, 2022

By Corey Vaughan

Unplanned shutdowns from abrasive wear part failure in crushers, chutes, and slurry pipe assets can cost millions in lost production and reactive maintenance. 2Censor patented sensor technology enables real time abrasive wear monitoring of mineral processing equipment, turning passive assets into smart, data driven components. Wireless sensors embedded in liners and pipework transmit wear data live to operators, allowing for predictive maintenance, safer scheduling, and optimized asset life. This paper will present global case studies showing reductions in downtime, increased throughput, and improved maintenance accuracy. The system is ready to retrofit, neutral to original equipment manufacturers, and proven across more than twelve countries in abrasive wear liners and slurry pipe applications.

Feb 22, 2026

By W. R. Reed, S. Klima, J. Driscoll, T. W. Beck

"Tests were conducted to determine properties of four foam agents for their potential use in longwall mining dust control. Foam has been tried in underground mining in the past for dust control and is currently being reconsidered for use in underground coal longwall operations in order to help those operations comply with the Mine Safety and Health Administration’s lower coal mine respirable dust standard of 1.5 mg/m3. Foams were generated using two different methods. One method used compressed air and water pressure to generate foam, while the other method used low-pressure air generated by a blower and water pressure using a foam generator developed by the U.S. National Institute for Occupational Safety and Health. Foam property tests, consisting of a foam expansion ratio test and a water drainage test, were conducted to classify foams. Compressed-air-generated foams tended to have low expansion ratios, from 10 to 19, with high water drainage. Blower-air-generated foams had higher foam expansion ratios, from 30 to 60, with lower water drainage. Foams produced within these ranges of expansion ratios are stable and potentially suitable for dust control. The test results eliminated two foam agents for future testing because they had poor expansion ratios. The remaining two foam agents seem to have properties adequate for dust control. These material property tests can be used to classify foams for their potential use in longwall mining dust control. IntroductionAbout one-half of U.S. underground coal is produced by longwall mining, which allows for mining high volumes of coal but generates significant amounts of coal mine dust. This can lead to overexposures for longwall miners and possibly occupational respiratory diseases, including black lung and silicosis, which have no cure and can be disabling or fatal. The only method to avoid these occupational illnesses is through elimination of exposure to respirable coal mine dust and crystalline silica (quartz). The current occupational exposure limit for respirable coal mine dust is 1.5 mg/m3 during each shift that a miner is exposed in the active workings of the mine or in mine facilities (Mine Safety and Health Administration (MSHA), 2015a). When respirable quartz is present, the mine must maintain average concentrations at or below 0.1 mg/m3. If the mine exceeds the 0.1 mg/m3 respirable quartz dust concentration, then the applicable respirable dust standard is reduced, calculated as 10 divided by the percent quartz present (MSHA, 2015b)."

Jan 1, 2018