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By Ulf B. Andersson, Christina Dahnér-Lindkvist, Bruno Figueiredo, Jessa Vatcher, Jonny Sjöberg, Joel Andersson

Hydraulic fracturing to precondition the rock mass in high seismic risk environments has great potential. Unfortunately, there are many unanswered questions about how to best implement a hydraulic fracturing program at individual mine sites, and even how to best use our engineering tools to evaluate these plans. To give the hydraulic fracturing field tests at LKAB’s Kiirunavaara Mine the best chance of success, fully-coupled, discontinuum numerical modelling Itasca’s 3DEC code was used together with statistical simulations of the fracture network. For modelling purposes, it was assumed that hydraulic fracturing successfully reduces seismic risk through 1) the creation of hydraulic fractures along a plane at each injection site, and 2) activation of existing discontinuities. A variety of scenarios for the mine were evaluated, which focused on site specific uncertainties (such as the spacing of the pre-existing discontinuities) and practical solutions (such as the hydraulic fracture spacing, selection of injection medium, and hydraulic fracture site location relative to production). The discrete fracture network (DFN) realizations were developed using available statistical data for discontinuities near where hydraulic fracturing was planned.

Apr 26, 2022

By Roger Best

In the mining industry, where some of the vehicles are larger than a one-story house, tire maintenance cannot be accomplished by the tire shop alone. It takes an army of people to maintain a fleet of 100 trucks that may be transporting gold, iron ore, oil sand, copper or coal from an openpit to a refinery and eventually delivering the product to a customer. Everyone working in and around these mammoth machines has a duty to help with the maintenance of the tires, whether they know it or not. These responsibilities comprise observation and reporting hazards up to and including changing out a tire and recording the information in a tire-tracking program such as TreadStat.

Jan 2, 2010

By Z. Sample

"INTRODUCTION This past year commodity prices continued their dip with increased volatility causing market values to slide another 16% putting increased pressure on even the largest companies to improve their free cash flow.[1] Without a recovery in commodity prices in sight, companies must find a sustainable method to improve returns in the current economic climate. In an effort to improve plant sustainability, the mineral processing industry is investing in advanced automation technologies and innovative processing methods that are both more reliable and more efficient than ever before. One such breakthrough technology is Heap Leaching (HL). This method of extraction has certain advantages over traditional metallurgical methods making previously unsustainable operations economically feasible. While HL is already seeing use in the gold and copper industries among others, recent developments may allow for the use of HL to process primary sulfide ores which make up about 80% of today’s ores.[2] For this reason, this emerging technology is poised for exciting growth. Unfortunately, as with any process change, the implementation of HL projects requires significant training on both the control system as well as the underlying process, and further, due to the complex nature of the HL process, this can be a particularly difficult task. DEMOGRAPHIC TIME BOMB Even before the implementation of these new technologies, the availability of the skilled workforce has already become a significant problem for the mining and mineral processing industries. From a survey of 912 mining professionals, Stratum International found that a mere 0.4% of senior level candidates were between the ages of 25 and 34 and a similar proportion aged over 75 years.[3] This indicates that there is both a deficiency of young skilled workers and a skilled workforce that is retiring earlier than the previous generation. Combined with data published by the US Department of Labor stating that the median age of the mining workforce is approaching 50 years old, research suggests that up to 50% of skilled mining and mineral process professionals are expected to retire in the next 5 years, leaving with their irreplaceable knowledge and experience.[4] While it is projected that the labor pool will be sufficient to fill open positions, the real question is if this young workforce will have necessary skill sets and experiences. In addition to a rapidly aging workforce and an inexperienced labor pool, a study done by the Oil and Gas Journal showed that it takes about 7 years, on average, for new workers to achieve a level of competency that permits them to assess risks and appropriately make decisions.[5] Not only is this figure is in direct conflict with the typical tenure of 5 years in one position meaning that the thinly spread skilled labor will be required to become senior staff before they are able to achieve competency in their current role, this also means that these millennials are not given the opportunity to become competent in their role before the retirement of the more experienced workforce."

Jan 1, 2016

By R. M. Hays

Jan 1, 1980

By Yi Luo, Jian Yang, Hua Jiang

Surface subsidence induced by underground coal mining activities, especially longwall mining operations, can cause various problems to interstate highways ranging from structural integrity, drivability to safety. Accurate subsidence prediction, correct influence assessments, and effective mitigation measures are the keys to ensure the safety of highway traffic. The surface subsidence prediction program, called comprehensive and integrated subsidence prediction model (CISPM), was developed based on the principle of influence function method and has been validated with a large number of subsidence measurements. In this paper, the techniques to use the predicted final surface movements and deformations for assessing their influence on the integrity and functionality of highway structures (e.g., road surface pavements, concrete slabs, transverse joints, etc.), vehicle dynamics, comfort level, and drivability are presented. A number of mitigation measures to protect the highway structures and to ensure traffic safety are proposed along with an application case.

By Jacob Carr, Rebecca Knuth, Emily J. Haas, Marvin Cheng, Bob Bissonette

Many industries, including mining, are experiencing an increase in the use of robotic and other artificial intelligence (AI) systems to improve efficiency, productivity and precision. For example, a 2023 survey showed that mining industry executives wanted to integrate more autonomous equipment to improve productivity and alleviate workforce shortages (Haas, 2024). This feedback was coupled with an increased appetite to advance the types and uses of automation and AI in the workplace. However, there is also an increasing concern about the ways that robotic applications may unintentionally affect worker safety. Humanmachine interaction poses potential risks, especially when industrial robots operate near workers in specific environments (such as drilling, handling and transporting materials, equipment inspection and lifting heavy loads). Research has explored the unintended consequences of introducing new technologies or processes in the workplace to include incidents such as being struck by equipment and challenges around data privacy (Lööw et al., 2019; Khurram et al., 2025; Haas and DuCarme, 2015; Almeaibed et al., 2021; Zio and Miqueles, 2024). More recently, the use of digital twin technologies and simulations (hereafter referred to as digital twin systems) has been boasted as a tool that can help prevent unintended consequences around worker safety by identifying and mitigating risks before a worker completes a task in tandem with a robot or other new technology. Digital twin systems produce a virtual replica of a physical environment or process (Almeaibed et al., 2021; Zio and Miqueles, 2024; Saes, 2024). To this end, this article explores the potential role of digital twin systems in enhancing safety within mining and other similar environments. It will primarily focus on environments where robots and human workers may interact, although digital twin systems can be useful with other technology applications. First, we define digital twins and digital simulation as components of a system. Then, we highlight possible applications of digital twin systems in mining to replicate real-world processes, followed by potential benefits of their use and where more research may be needed.

Oct 1, 2025

By James J. Brady, Kenneth L. Faught, Chadi El Mohtar, Chaoshi Hu

"During construction of a 9.5-ft. diameter sanitary sewer tunnel, the City of Edmonton encountered a large pocket of flowing sand that flooded their TBM and caused significant surface subsidence, stopping further tunneling by the TBM through this zone. A unique collaborative effort ensued between the authors representing the city, consulting engineers and academic researchers to develop the optimal strategy for grouting the problematic soils. The site has a layer of very find sand between 20 and 30 ft. in depth with fines contents ranging from 5% to more than 40%. The collaboration extended from requesting additional site investigation efforts to shipping samples to the UT-Austin laboratories for grout testing plus ground and grouting characterization tests resulting in field recommendations for a full scale ground improvement program. New research information on the grouting of fine sands along with a collaborative framework for the design of in-situ grouting projects are the key topics presented. INTRODUCTION Encountering a large unexpected pocket of flowing sand with an open-faced TBM while excavating a tunnel below the groundwater table is never a good thing. This was certainly true for the City of Edmonton when one of their Lovat TBM’s became inundated by flowing sand while excavating the 9.5-ft. diameter Millwoods Double Barrel Replacement Tunnel in September 2013. However, since the City of Edmonton self-performed this work, a rare situation existed where the site could be investigated objectively, without the prejudice of contending parties selectively influencing how information was gathered and presented, to accurately examine site conditions with a goal of identifying the best remediation measures."

Jan 1, 2016

By Manuel S. Rivera

Abstract. Instrumentation in concentrators has evolved from a few isolated indicators to compu- terized control within twenty years. This evo- lution has caused a drastic change in the phil- osophy, personnel and equipment used in a pro- gram of servicing and utilization of present day automation.

Jan 1, 1980

By M. G. Eiselein, R. A. Smith, C. H. Sheerin

FMC Gold's Paradise Peak Mine was one of the top two producers of mercury metal in North America in 1988 and 1989. As a by-product, elemental mercury is produced from cyanide soluble mercury minerals, primarily to reduce the health risks incurred with the refining of precious metal precipitate containing elemental mercury and mercury amalgams. A discussion of the design, primarily the Merrill-Crowe units, and permitting for the safe production of mercury will be presented. Additionally, laboratory testwork to determine the effect of mercury on reagent requirements in the Merrill-Crowe process will be discussed.

Jan 1, 1990

By D. M. Hausen

A quantitative x-ray diffraction method has been developed for the analysis of alteration minerals in wallrock. Alteration data are plotted and contoured (analogous to geochemical data). Alteration trends outlined by this technique correlate closely with geochemical anomalies, and in some cases attend well beyond the perimeter of anomalous base metal values. "Monomineralic contouring," applied originally to porphyry-type mineralization, has been extended to other types of mineralization, including volcanogenic massive sulfide deposits. Equipment and techniques used in the quantitative measurement of alteration mineralogy are discussed.

Jan 1, 1978

By Jürgen Brune

This is a shortened version of the paper ?The Methane-Air Explosion Hazard Within Coal Mine Gobs published in the 2013 volume of SME Transactions (Brune, 2013, pp. 376-390). This paper analyzes the explosion hazard resulting from the formation of methane-air mixtures in the mined-out gobs of underground longwall coal mines. Evidence from numerous mine explosions suggests that explosive methane zones can form within longwall gobs. Explosions and fires resulting from these methane accumulations have led to severe and fatal injuries to the miners, including the explosion of the Upper Big Branch Mine in West Virginia, where 29 miners lost their lives April 5, 2010.The paper also reviews current research on numerical modeling of gas flows in longwall gobs and outlines how targeted injection of nitrogen into gobs can effectively reduce the volume of such explosive methane zones. The paper concludes that comprehensive monitoring of gas compositions, along the accessible fringes of the gobs along with inertization, improved ventilation schemes and further research are necessary to control this explosion hazard and make mining operations safe. Keywords: Longwall, gob, methane, EGZ, explosive gas zones, underground, coal, explosion, fire

Feb 1, 2014

By M. D. Bishop

Early solvent extraction circuits in the uranium industry utilized bona fide kerosenes as diluents for extractant chemicals. These kerosenes were used successfully in the uranium industry; however, at least one plant was destroyed by fire resulting from the use of a low flash point kerosene. Although the term "kerosene" is used throughout the solvent extraction industry, the authors have been unable to find any use of kerosene in copper solvent extraction circuits. A term that is occasionally used with reference to diluents is "metallurgical kerosene." Such a term is unrecognizable in the petroleum industry. Kerosene [or kerosine] is a flammable hydrocarbon mixture that is less volatile than gasoline. It is produced for combustion purposes and may have variable compositions of organic compounds including alkanes, alkenes, alkines, and aromatics. Diluents are constant composition hydrocarbon mixtures developed specifically for use in solvent extraction processes. These products usually have much lower vapor pressures and higher flash points than kerosene. In solvent extraction systems, they typically comprise 70 to 95 v/o percent of the circuit organic. The primary purpose of the diluent is to adjust the extractant concentration to the working range of the operation. The diluent and extractant must be completely soluble or miscible with each other. Secondary diluent effects are to promote transfer kinetics, optimize phase disengagement, and minimize both organic in aqueous and aqueous in organic entrainment.

Jan 1, 1996

By R. Gilges

The implementation of effective techniques for meeting the maintenance requirements of the new Utah Copper Division smelter, one of the largest in the Western Hemisphere, is a goal of the smelter management and supervisory personnel. Kennecott's Metal Mining Division Computing Center has been working with smelter personnel to implement a computer program to provide instantaneous access to equipment specifications, maintenance and cost histories, spare parts, preventive maintenance scheddes, etc. for several hundred pieces of equipment. This information will be available to all smelter personnel via visual display terminals. The system will dramatically reduce the time now spent in search of pertinent information required in effectively performing the maintenance functions. It will also be used to analyze practices, detect trends, prepare budgets, and substantially reduce the paper work normally associated with the running of a large and complex maintenance organization.

Jan 1, 1977

By Y. J. Zhang

This paper presents the results of a recent study on the development of an in-situ testing method for determining the coal strength in mine pillars. The strength testing is performed in the horizontal holes drilled into the coal rib using the penetrometer. It is a hydraulically powered device that uses an indenter to press the surface of the borehole until the load reaches the failure point of coal. The pressure and the penetration of the loading pin are recorded by the data acquisition unit. The results collected from several coal mines indicate that this testing method is ideally suited for the realistic coal strength measurements. The new testing system not only improves the accuracy of pillar strength determination, but it is more cost efficient than the conventional method.

Jan 1, 1995

By J. C. Irvine

A recent development in underground drilling has been the introduction of the down-the-hole drill, an old and very familiar tool to the surface operator. The idea of moving such a rig underground is not new. Tests were conducted at INCO in Canada and Mt. Isa, Australia in the early 1960's, and St. Joe used one for underground exploration in their Missouri lead mines in the mid-1960's. However, the trend to full scale production programs did not start until the mid-1970's. The first successful North American test was at INGO in early 1973. This led to a large-scale pillar recovery and open stoping program which en¬compassed 25 drilling units by mid-1976. Meramec Mining Company tested a unit using air boosted up to 200 psi (140, 000 kg(m2) in the summer of 1973 which by 1976 led to an open stope and pillar drilling program using 12 units. By mid-1976, production units using boosted air were also in use at Pilot Knob in Missouri and at St. Joe in Balmat, New York. Experimental and utility units were in use in several other mines and down-the-hole drills were being seriously considered for at least one major new underground mine.

Jan 1, 1976

By V. B. Achanti

This paper deals with the effect of various bit geometric parameters on failure characteristics of rock material. Improvement of rock cutting efficiency of continuous mining machines has been an interesting research topic for the last few decades. In the current study, an automated rotary rock cutting simulator, duplicating a continuous miner, was utilized to study these parameters in the laboratory. Improvement of bit performance in terms of its life, cutting efficiency, dust production and energy consumption has drawn wide spread attention over the years. Research shows that optimizing bit parameters can result in efficient fragmentation of rock. Indiana limestone rock material was utilized in this study while bit tip angle, bit tip size, bit spacing, depth of cut and cutting velocity of rotary drum were varied to investigate the failure characteristics. The cutting pressure, penetrating pressure and the depth of cut were monitored on the simulator during the cutting process. Air borne dust and settled dust were measured for each experiment. Then, the specific airborne dust and specific energy were determined for the each type of bit. Triaxial tests were carried out to correlate the failure angle of the rock in static case to dynamic cutting process failure. The physical and mechanical properties of the rock were also determined in order to assess their influence on the wear characteristics of each bit.

Jan 1, 1998

By M. G. Premo

The McKinley Mine is located in the northwest New Mexico, in McKinley County, approximately 25 miles from Gallup. The mine is operated by The Pittsburg & Midway Coal Mining Co. (P&M), a wholly owned subsidiary of the Chevron Corporation. P&M is headquartered in Englewood, Colorado. Since the McKinley Mine began operations in 1962 a total of 83,391,000 metric tons of coal have been sold through 1990. The 1991 production was approximately 5.000.000 metric tons. The mine operations are contained on a 109.000 square kilometers lease area of which 44.000 square kilometers are on the Navajo Nation. The present customer base consists of four utilities and one industrial account, all of which are located in Arizona. The utility customers are the Arizona Public Service Co. Cholla Station at Joseph City, The Salt River Project. Coronado Generating Station near Joseph City, and The Tucson Electric Company, Irvington Generating Station in Tucson. The industrial customer is the Stone Container Corporation, Snowflake Paper Mill.

Jan 1, 1992

By J. Iannicelli

Spray drying is the principal drying method used in the production of over six million tons annually of beneficiated kaolin in Georgia. Thirty-three dryers in the Georgia Kaolin belt comprise the highest concentration of large tonnage spray dryers in the world. The steady growth of spray drying in the U.S. kaolin industry is paced by advances in design and development of large spray dryers which have led to large scale new applications in mining and related industries.

Jan 1, 1982

By NARAYAN K. BHAGAT, ARVIND K. MISHRA, Aditya Rana, M. M. Singh

The paper presents an innovative directional controlled blasting (DCB) technique for excavating unstable slopes along the Konkan railway in India without disturbing the traffic. New empirical formulae for small geometry blasting to estimate burden and throw were developed. A unique sequence of firing and excavation with powder factor varying between 0.04 and 0.39 kg/m3, irrespective of the actual free face, was used for rock blasting. The process controlled the throw of blasted material over the track and resulted in a smooth and stable wall. The slope angle was changed from 80–82 to 45–47 degrees, and possible wedge, planar and toppling failures were eliminated. No incident of rockfall and slope failure along these slopes has been observed after the stabilization.

By R. Ribeiro

The designers of the new Arafertil concentrator in Brazil provided for complete automatic control of the grinding circuit to meet the operating objective of maximum throughput at a specified grind. Analog control methods were selected because of proven reliability and simple maintenance, and in order to minimize commissioning time and effort. This paper summarizes the step-by-step effort required to progress from local loop control of certain individual parameters to an integrated system capable of achieving the design goal. Emphasis is placed on the practical aspects of commissioning a control system.

Jan 1, 1979