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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 Artur Skoczylas, Paweł Stefaniak, Sergii Anufriiev, Wioletta Koperska, Maria Stachowiak

In many underground mines the excavated ore is produced during the blasting process. Drilling machines that are used to drill the blastholes, where later the explosives will be mounted, are crucial for this task. In order to optimize the currently used techniques, great emphasis is placed on increasing the efficiency and safety of blasthole drilling operations. The natural consequence is the development of monitoring systems and algorithms for processing operational and historical data. In this article, we present the result of the analysis of drilling data carried out as part of the IlluMINEation project. The paper proposes an algorithm for work cycle detection for drilling machines, together with the estimation of general operating parameters and diagnosing the drilling process on the basis of long-term data. Based on the available data, selected components of the drilling cycles have been indicated. Several approaches based on the parameters of the defined cycles are proposed. These approaches can be used in the future to create a full-fledged system for examining the effectiveness and safety of mining drilling rigs.

Jun 25, 2023

By Frederick McNeill, Mahmood Khwaja, Benjamin Lundsted, David Polcari, Michael S. Schultz, Timothy Clougherty

The City of Manchester, New Hampshire, is embarking on one of its largest public works projects in history to construct a 12,000 foot long, large-diameter, conveyance tunnel through downtown Manchester. This area has challenging geology with undulating bedrock (granite, schist, and gneiss) profile overlain by fluvial deposits. Understanding the subsurface conditions is key to mitigating project risks, establishing plan and profile for the tunnel, and selecting the most cost-sensitive and technically appropriate tunneling method. This paper presents the project team’s approach for conducting the ground investigation, developing preliminary subsurface profile, and the considerations for selecting the tunneling method.

Jun 13, 2023

By Earl G. Hoover

For most geologists and miners the term "asbestos" refers to a group of highly fibrous silicate minerals that readily separate into long, thin, strong fibers of sufficient flexibility to be woven, are heat resistant and chemically inert, and possess a high electric insulation and therefore are suitable for? uses where incombustible, nonconductive or chemically resistant material is required. The United States Mining Enforcement and Safety Administration (MESA) specifically refers to the naturally occurring minerals chrysotile. amosite, crocidolite, termolite asbestos, anthophyllite asbestos, and actinolite asbestos as "asbestos" if the individual crystal fragments have the following dimensions; length -greater than 5 micrometers, maximum diameter -less than 5 micrometers, and a length to diameter ratio of 3 or greater. Since asbestos has been identified as one of the ten most carcinogenic substances (a cancer causing agent) it has become, for many government regulatory agencies, a major issue concerning banning emissions to the environment.

Jan 1, 1978

By Irwan Halim, Young Jin Park

A new tunnel lining was designed for rehabilitation of the existing unlined Weehawken Tunnel in New Jersey. Structural assessment using beam spring models was performed for the lining design as a drained structure at the invert with a waterproofing umbrella. Empirical Federal Highway Administration (FHWA) guideline was typically adopted for estimating hydrostatic pressure, which recommends full hydrostatic pressure at the crown and ten or twenty-five percent gradual reduction from the initial pressure toward the invert. Finite element seepage analyses were conducted for the actual conditions based on anticipated drainage behind the lining and impact on the structural design. Considerations will be provided on the existing guideline for estimating hydrostatic pressures.

Dec 1, 2022

By P. M. Hawley

Kennecott Corporation, in joint venture with Galactic Resources Ltd., recently began operation of an open pit gold mining and milling facility near Columbia, South Carolina. The deposit consists of two ore bodies (North and South deposits) hosted in deformed and altered meta-volcanics and meta-sediments of the Carolina Slate Belt. This paper describes the rock mechanics and engineering geology investigations conducted for design of interim, ultimate and final reclamation slopes for the South Pit. Emphasis includes the successful use of drill core orientation techniques to confirm complex geologic structure at depth; the development of a three-dimensional rock mass competency model, incorporating surface mapping data, results of bench mapping documentation, field index testing and laboratory testing; and kinematic assessments for design of optimum slopes.

Jan 1, 1991

By T. Qiu

"The purpose of this study is to investigate the effect of the dosage of sodium hypochlorite as activator on the flotations of depressed marmatite and depressed chalcopyrite, with a focus on activation-flotation kinetics. Four flotation kinetic models were applied to test data using 1stOpt statistical analysis software to estimate the relationships between the maximum flotation recovery rates for the depressed marmatite and depressed chalcopyrite, the flotation rate constants and the sodium hypochlorite dosages. Within the range investigated, the highest flotation performances of depressed marmatite and depressed chalcopyrite were obtained at 2.5 mL/L sodium hypochlorite with zinc recovery rate of 93.8 percent and 3 mL/L sodium hypochlorite with copper recovery rate of 94.6 percent, respectively, after four minutes of flotation. A second-order model with rectangular distribution of flotabilities gave the best fit to test data collected at various sodium hypochlorite dosages. For the highest flotation performances of depressed marmatite and depressed chalcopyrite, the respective equations of their flotation models were derived and presented.IntroductionCyanidation tailings are the solid residues generated by gold plants that use cyanide to extract gold (Lv, Ding and Qian, 2015; Zhang, Li and Yu, 2013). Because of increasing demand for gold, the Chinese gold industry has developed rapidly, with production amounting to 451.799 tons in 2014, an increase of 5.5 percent from 2013. Chinese gold production has been the highest in the world for eight consecutive years. As a result, more than 2.45 million tons of cyanidation tailings are estimated to be discharged into tailings ponds every year (Li et al., 2010; Lv, Ding and Qian et al., 2015; Wang et al., 2015; Zhang, Li and Yu, 2013; Zhang, Li and Yu, 2012), and approximately 300 million tons of cyanide tailings are stockpiled in China, with the potential to cause serious environmental pollution as well as death to wildlife (Adams and Lloyd, 2008; Donato et al., 2007; Hewitt, Breuer and Jeffery, 2012; Velasquez-Lopez et al., 2011; Stephen et al., 2009; Zagury, Oudjehani and Deschenes, 2004). Concerns over cyanidation tailings are not exclusively environmental but also economic, as tailings occupy considerable land area, and tailings storage facilities increase the production costs of gold enterprises (Donato et al., 2007). Tailings often contain other valuable metals such as zinc, lead and copper. For example, the cyanidation tailings of Gaoyao Hetai Gold Plant in Guangdong Province contain 2.5 percent copper (Cu), 0.31 percent lead (Pb), 0.23 percent zinc (Zn) and 15.36 percent iron (Fe) (Shi, 2008), and the tailings of Tianshui Gold Plant in Gansu Province contain 1.94 percent Cu, 5.96 percent Pb, 0.27 percent Zn and 24.62 percent Fe. Cyanidation tailings have therefore been increasingly viewed as a secondary resource rather than waste."

Jan 1, 2016

By Thomas W. Mitcham

A program of geological research in support of mineral exploration efforts is outlined. Specific goals are stated, approaches to accomplish their attainment are described, and the type of useful results to be expected are outlined. Because mineral exploration or prospecting has intensely practical goals, research in support of it must be applied research, applied to the problem of maintaining or increasing the discovery rate of the exploration effort. To attain research goals, attention to personnel selection, group structure, and program are critically important, and in about that order. A large percentage of the professional personnel should have had experience in mining geology or mineral exploration, and they all should be prospector-oriented. Structuring in the group should be at a minimum, with wide allowance for the kind of independent research which is essential to the nurturing of on-target creativity. The program should be field-oriented, and it should include a wide representation of those subdisciplines of geology which are applicable to mineral exploration. The types of results to be anticipated include improved or new conceptual models for various types of orebodies and their settings from which new ore guides can be derived, new exploration techniques, and the development of a knowledge bank for various aspects of the exploration effort.

Jan 1, 1968

By Brian V. Roulston

Potash is Canada's leading industrial mineral in terms of value of production, with 11.1 M tonnes of muriate of potash produced in 1992 for a value in excess of $1 billion U.S. Each tonne of potash produced generates about 2 tonnes of waste salt, together with slimes and brine. The disposal of these waste products, particularly the salt and slimes which are discharged on the surface, has recently become an environmental concern. This concern is forcing companies and regulatory authorities to review disposal practices. In New Brunswick, on Canada's east coast, Potash Company of America operates a mine at which 2 M tonnes of potash ore and 0.5 M tonnes of rock salt are mined each year. The mine is situated in an environmentally sensitive area, noted for its dairy farming and salmon angling. In such an area it was recognized that the storage of waste on surface would be unacceptable, and the mine was designed around this principle. Three main waste streams - salt, slimes, and brine - must be managed as an integral part of the mining system. Around 1.5 M tonnes of fine salt tailings from the milling process and the rock salt screening operation, are sent directly to the active cut-and-fill potash stopes to be used as backfill. Slimes and excess brine from the mill are piped underground as a slurry to be discharged into one of the basin shaped stopes created by mining of the rock salt. While the slimes settle out, the clarified brine is withdrawn from part of the stope to be pumped to surface as a feedstock for the evaporator - a process which recovers the contained potash values in the brine. By designing a system which integrates the mining, processing and disposal of all product streams, and by careful production planning, it has been shown that zero effluent potash mining is possible and points the way for the industry in the future.

Jan 1, 1995

By Hemendra N. Kalia

Several attempts have been made in the past sixty or so years to commerciliaze the vast oil shale deposits of the United States of America. However, the industry has yet to become viable and economic. To date, it has not been possible to produce oil from the oil shales at a competitive price when compared to the oil produced from oilfields by conventional methods. However, the development work has been quite fruitful in furthering the art of thick bed mining and technology of in situ retorting. The in situ method has the potential of recovering oil from thick beds and the resource recovery potential is much greater than that from underground mining and surface retorting. In situ methods require that the shales/ marlstones be fragmented ' in place to induce adequate porosity and permeability to allow in situ' heating of the fragmented shales. This can be accomplished by using explosives. However, it has been found that the existing blasting systems, though very efficient, are somewhat lacking. The explosive become insensitive when shot in multiple vertical decks. They can also become insensitive when spaced horizontally at close proximity to other charges. Also, since the blasting is done in a very limited free face, this limits the delay time that can be allowed between charges. Consequently it is not always possible to predict the performance of the blasting system on a routine basis. Furthermore, since it is not possible to undertake secodary blasting, it is imperative that the blast design function properly. Recent, successful retorting by Occidental Petroleum Company of retorts seven and eight suggests that some of these problems may have been overcome. This paper addresses some aspects of in situ retorting and problems those have impeded the development of a viable oil shale industry in the U.S.A.

Jan 1, 1983

By T. Dombrowski

Acid-activated montmorillonite is used worldwide as a catalyst and as a sorbent for the enhancement and purification of petroleum products as well as vegetable and animal-based fats. The solid-acid character of the activated montmorillonite is imparted by the manufacturing process, giving it unique properties that are exploited in these industries. Several international companies and a multitude of local clay producers are focusing on improving the efficiency of their standard and specialized products. This paper will describe the use of acid-activated montmorillonite in traditional sorbent applications, as a solid acid catalyst, and other new uses.

Jan 1, 1997

By Jose F. T. Agapito

The mining engineer must be able to predict the structural behavior of the rock around underground openings so that he can answer questions relating to safety and economics. With the present status of rock mechanics knowledge, exact predictions cannot be attained and approximate idealizations are made. As a first approximation, structural design makes use of theory, laboratory testing of rock properties, and available experience from excavations in similar rock formations. However, realistic design can usually be obtained only after in-situ observations and measurements are made. After all the information is collected, judgement and experience play a most important role in the final formulation of the design. This paper describes part of a geotechnical program which was instrumental in obtaining information for the design of large oil shale pillars. The work was carried out during 1971 and 1972 in the experimental mine of the Colony Development Operation. Colony is an oil shale venture formed between Atlantic Richfield Company, Operator, The Oil Shale Corporation, Cleveland-Cliffs Iron Company, and Sohio Petroleum Company to conduct research and development in mining and retorting of oil shale, The property is located in the southern edge of the Piceance Creek Basin in northwestern Colorado, approximately 250 miles west of Denver (Figure 1) . Mining was conducted by the room-and-pillar method in a 60-ft high portion of the Green River Formation at a depth of 600 to 850 ft, Pillar dimensions are approximately 60 ft by 60 ft. The mine site is in the eastern face of the canyon containing the Middle Fork of Parachute Creek, The distance from the mine to the side of the mountain varies from 500 to 1,200 ft, and its height above the stream floor is approximately 700 ft.

Jan 1, 1974

By Hemendra N. Kalia

To plan a safe and efficient coal mining operation, the design engineer should use all the available information regarding the property to be exploited. The reliability of the mining operation must be as high as possible so that the plants relying on the coal can operate at the maximum design capacity. A good design should incorporate all of the known geological characteristics of the deposit, the structural and physical properties of the coal, as well as the rock which will form the roof and floor of the mine openings. A systematic method is proposed as a guide to insure a mine design that will be safe, efficient and will minimize surface disturbances resulting from mining operations. It is anticipated that the method proposed will result in maximum extraction at perhaps minimum cost to the operator. In general, to develop a mining area, several factors are systematically reviewed: (1) determination of the economic minability of the deposit, (2) the computation of the coal reserves, (3) the marketability of the coal, and (4) the life of the property. In general, boreholes are drilled in a predetermined pattern and geophysical or geological methods are used to log the boreholes. The information so obtained is primarily used to determine the quality and the extent of the deposit and to determine to some extent such geological features as faults, barren areas, washouts, and channels.

Jan 1, 1973

By M. Bidart, V. Sawyer, M. Saunders Macdonald

A number of open pit gold mines in Nevada extract ore from areas that are below the natural groundwater elevations. This necessitates dewatering, which requires a method for the disposal of the extracted water. Some of these open pits extend well below, the water table with dewatering volumes greater than 10,000 gpm (38,000 L/min). Some mines with large volumes of dewatering water have constructed reinfiltration basins to reintroduce the water into the groundwater system at a point some distance from the pits. This paper presents an overview of the state of the art of reinfiltration projects, including the permit process for such projects in Nevada. The paper includes the necessary engineering considerations.

Jan 1, 1997

By Jessica M. Wempen

"Differential Interferometric Synthetic Aperture Radar (DInSAR), a satellite-based remote sensing technique, has application for monitoring subsidence with high resolution over short periods. DInSAR uses radar images to measure centimeter-level surface displacements. In the images, ground resolution can be relatively high, with each data point (pixel) representing the average displacement over an area of several square meters. The image data are acquired regularly which allows subsidence to be monitored sequentially over short periods; imaging periods typically range from weeks to months.Monitoring subsidence over short periods with high spatial resolution has potential to provide insight into the dynamics of subsidence and into relationships between mine advance and subsidence. In this study, for three longwall mines in the western United States, initial subsidence occurring at the start of longwall advance is quantified over short periods (12 to 72 days). C-band interferometric wide swath Synthetic Aperture Radar (SAR) images from the Sentinel satellites are used to quantify the subsidence. Overall, the data show initial development of subsidence, expansion of the subsidence trough, and the advance of subsidence in the direction of mining.INTRODUCTIONApplied Differential Interferometric Synthetic Aperture Radar (DInSAR)Differential Interferometric Synthetic Aperture Radar (DInSAR) is a satellite-based remote sensing technique that can be used to quantify small displacements of the Earth’s surface. Using data from the Seasat satellite, which was launched in 1978 (Jet Propulsion Laboratory, 2018), studies by Goldstein, Zebker, and Werner (1988) and by Gabriel, Goldstein, and Zebker (1989) applied Synthetic Aperture Radar (SAR) interferometry to topographic mapping and displacement monitoring. These studies established the potential for broader applications of radar interferometry. Studies by Foxall, Sweeney, and Walter (1998), Wright and Stow (1999), and Carnec and Delacourt (2000) represent some of the earliest evaluations of DInSAR for mine subsidence monitoring. All three of the studies demonstrated the application of DInSAR for quantifying mine subsidence. They also demonstrated difficulty accurately measuring subsidence over long periods due to data decorrelation. DInSAR continues to be evaluated as a tool to quantify surface deformation related to active and historic mining. For example, see Vervoort and Declercq (2018), Wempen and McCarter (2017a), Chen et al. (2013), and Liu et al. (2013). Technologies associated with SAR interferometry continue to develop. Recently launched satellites have relatively high spatial and temporal resolutions, and data processing methods and data accessibility are improving."

Jan 1, 2019

By Mason L. Dicks

For many years The Hanna Mining Company has been investigating the flotation of the non-magnetic iron ores located in the Western Mesabi Range of Minnesota.1 During the 1950's a number of anionic iron procedures were evaluated and in the late 1950's and early 1960's the anionic silica floats and the cationic silica floats were tested with improved results.2 The cationic float became more attractive and effective by the use of the improved ether amines. About 1962 a desliming process by selective flocculation was developed by the U.S. Bureau of Hines at Minneapolis', Minnesota.3, 4, 5 This is a very efficient method of desliming and was first tried with the anionic silica float and then the more practical cationic silica float. In the mid 1960's The Hanna Research Laboratory began studies to optimize the selective flocculation process for our ores. This was followed by studies to optimize the cationic silica float after desliming by selective flocculation. This testwork was done on large, 500 to 1000 tonne bulk samples of oxidized taconite which were later successfully piloted at .68t/h (1500 Lbs. /hr.). A program was then begun to test the oxidized portions of numerous taconite drill holes to outline the ore bodies and develop mining plans. This paper will discuss our optimization results of both the selective flocculation and the cationic silica float as applied to our various ores. In addition the pilot plant studies and drill core testwork will be discussed.

Jan 1, 1978

By J. A. Marts

Reservoir properties including porosity and permeability distributions in longwall coal mine gobs have direct application to modeling the flow patterns and gas distributions in the gobs. Proper assessment of these distributions is required to assess gob gas hazards such as spontaneous combustion and explosive methane mixtures and to optimize gob gas venthole operation and nitrogen inertization. Determining the reservoir properties is difficult given that the gob is inaccessible and direct measurements cannot be easily taken. Several techniques have been used by previous researchers and will be discussed. This paper will present the methodology used to model the gob compaction by simulating the sequential extraction of coal. Two Western US coal mines were used for case studies. By determining volumetric strain, the porosity and permeability distributions in the gob can be calculated. The geo-mechanical model predicts an axisymmetric volumetric strain distribution with a steeper slope near the start-up room and a shallower slope near the active face.

Feb 23, 2014

By Brett Schug, Caelen Anderson, Sohail Nazari, Carlos Cristoffanini

"The Haile gold mine in South Carolina is increasing the automation level of its processing plant in order to improve operational stability. One step toward this goal is the application of a digital twin concept to provide virtual instruments. Haile has engaged Andritz to implement virtual instruments at its grinding area hydrocyclones and at its tailing thickener underflow pump. These virtual instruments provide density values in a traditionally difficult location for reliable slurry density measurement. The digital twin is a first-principles integrated design engineering with advanced simulation (IDEAS) simulation model, connected in real time to the control system. Results have been promising, with the virtual instrument values matching the physical instrument under normal operating conditions and showing better prediction under upset conditions. Haile plans to use the virtual instruments as optional process control parameters.OceanaGold’s Haile gold mine is located near Kershaw, SC, about 80 km (50 miles) southeast of Charlotte, NC. This location was first mined in 1827 and has produced gold through several operating periods since then, including a heap leaching operation from 1985 through 1992. In October 2015, OceanaGold acquired Romarco Minerals, the previous owner of the Haile operation.The current operation began in 2017 as an openpit mine with additional underground resources. The nameplate throughput is 5,760 t/d (6,350 stpd) ore, and 2017 production was 3,345 kg (118,000 oz) gold, with 3,968 to 4,384 kg (140,000 to 155,000 oz) gold expected in 2018. Proven and probable reserves exceed 85 t (3 million oz) gold at a grade of 2 g/t (0.06 oz/st) gold. The process, as shown in Fig. 1, includes a primary jaw crusher, comminution with a semiautogonous grinding (SAG) mill and ball mill circuit, flash flotation, rougher flotation, regrinding, pre-aeration, carbon-inleach leaching, carbon elution and regeneration, cyanide recovery, electrowinning and refining. The Haile operation’s inaugural gold pour took place Jan. 20, 2017. Mine life is expected through the year 2030."

Dec 1, 2018

By A. Tordoir, S. S. Kanchibotla, W. Rogers, E. Engmann, B. Bisiaux, S. Ako

Blast-induced rock mass displacement can have a significant impact on ore loss and dilution. The mischaracterization of the grade boundaries both prior to, as well as a result of, blasting can lead to significant financial losses due to ore loss and dilution. Ore dilution occurs when waste material is miscategorized as ore and sent for processing or stockpiling, diluting the run-of-mine head grade and recovery. Ore loss takes place when valuable mineral is miscategorized as waste and sent to the waste dumps, thus never being processed and recovered. Extensive research has been conducted at the University of Queensland over the last fifteen years to understand the impact of blast movement on ore loss and dilution. Recent outcomes of this research have led to the development of innovative tools and techniques to measure and model blast movement. These techniques have been implemented at the Ahafo gold mine in Ghana to understand blast movement dynamics and to implement solutions to reduce blast-induced ore loss and dilution. These solutions are validated through controlled trials and have been incorporated into site standard operating procedures.

Jan 1, 2012

By Erik S. Bernard

"INTRODUCTION Reinforced Concrete (RC) members such as beams and columns are usually required to include stirrups to maintain post-crack shear capacity, and some may include stirrups that act as confining steel to maintain structural integrity during a seismic event (eg. NZS3101, ACI 318). To achieve seismic resistance, the spacing between stirrups is usually required to be much closer than is ordinarily prescribed for non-seismically resistant structures. Each stirrup must also fully enclose the longitudinal reinforcement with long end-hooks to ensure that the contained concrete is sufficiently restrained during reverse-cycle loading and the reinforcing bars are confined to prevent buckling. The close spacing between stirrups can lead to congestion of reinforcement within members, and can also be expensive to construct due to the labor-intensive nature of steel fixing. A possible alternative to closely-spaced stirrups is the use of fibers to provide restraint and confinement during a seismic event, although this is not yet recognized in codes. Previous experimental research (Jiuru et al, 1992; Filiatrault et al, 1995; Bayasi and Gebman, 2002; Billington and Yoon, 2004) has demonstrated that steel fibers are relatively effective in this application, but suffer the problem that their stiffness can make them difficult to consolidate within an already tight reinforcement cage, especially if they are relatively long (>40 mm). Moreover, steel fiber reinforced concrete (SFRC) is subject to embrittlement with the passage of time, leading to a steady loss of ductility beyond crack widths of 1-2 mm (Banthia and Trottier, 1994; Bernard and Hanke, 2002; Bernard, 2014; Bjontegaard et al, 2014; Bernard, 2015). Since cracks during seismic events are generally much larger than this, embrittlement may present a challenge to the long-term efficacy of SFRC during seismic events. An alternative to steel fibers for enhancement of seismic resistance is the use of macro-synthetic fibers. This type of fiber usually offers the advantage of being flexible so that consolidation is easier between reinforcing bars. They also offer superior durability compared to steel fibers and can reduce flexural crack widths (Bernard, 2016). Several recent small-scale investigations (Ma et al, 2012; Carnovale, 2012; Osorio et al, 2014) have indicated that macro-synthetic fibers can produce meaningful improvements in seismic resistance if used in combination with conventional steel reinforcing bars. The present investigation has extended research in this field by examining whether embossed macro-synthetic fibers can be used to increase the spacing between stirrups while maintaining seismic resistance."

Jan 1, 2016