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By George A. Savanick

Borehole (slurry) mining, in which a tool incorporating a water-jet cutter and a downhole slurry pump mines phosphate through a borehole, was field tested in northeastern Florida as part of a Bureau of Mines program to increase the domestic availability of critical minerals. Approximately 1700 tons (1.54x106 kg) of phosphate ore were mined at 40 tph (10.1 kg/s) from a depth of 250 ft (76 m). The borehole was filled with water during mining for roof support and to assist slurry pumping. Underwater cutting was enhanced with an air-shrouded water jet. Mined cavities were backfilled to prevent subsidence after abandonment. Roof subsidence during mining was avoided only when the cavity was filled with water. Environmental monitoring before, during, and after mining included hydrological studies and measurements of water quality. Significant water quality changes occurred only in the zone being mined and were confined to the immediate area of the borehole.

Jan 1, 1983

By Thomas E. Weyand

Prior to 1975, lead-based paints were commonly used in protecting steel structures. Because of the toxic effects of lead on human health and the environment, their use has been significantly reduced. However, problems with these paints persist when they are removed during normal maintenance by pneumatic blasting with mineral abrasives. Technologies are developed to contain the spent abrasive and paint during blasting operations. This paper reports on A study to identify beneficial reuses for the spent blasting material. Nine samples were gathered from different projects within Pennsylvania. The samples were thoroughly characterized with regard to composition, morphology, and EP and TCLP leach test performance. Potential reuse applications will be reviewed with regard to technical adequacy, economics, and environmental constraints.

Jan 1, 1992

In the present work, the flotation behaviours of zircon, rutile and ilmenite using sodium oleate as collector in absence and presence of depressants were thoroughly investigated. The maximum in the flotation recovery of any of the above minerals falls within similar pH ranges. A range of inorganic and polymer depressants were examined in order to improve the separation of zircon from rutile and ilmenite. Optimum values of conditioning pH and depressant concentration to achieve maximum recovery and best selective floatability of zircon were obtained. Selective flotation of zircon from Ti-bearing minerals was anticipated from single mineral experiments under different pH values, depressant and collector conditions.

Jan 1, 2014

By L. A. Morley

Electricity is a major cause of lost-time accidents and fatalities in the mining industry. Major hazards and unsafe practices that contribute to electrical hazards are identified in this paper. Recommendations for reducing electrical accidents in surface mining are given and are directed toward the following three areas: preventing equipment contact with overhead lines, preventing maintenance related accidents, and defining system protection techniques.

Jan 1, 1986

By M. N. Mathabathe, A. S. Bolokang, C. W. Siyasiya, R. J. Mostert, G. Govender

The b-solidifying g-TiAl intermetallic alloys of nominal composition Ti-48Al (binary alloy), Ti-48Al-2Nb (ternary alloy), Ti-48Al-2Nb-0.7Cr (quaternary alloy), and Ti-48Al-2Nb-0.7Cr-0.3Si (quinary alloy) (in at.%) were developed. The materials produced were tensile tested at room temperature. The as-cast microstructures and fracture surfaces of the tensile tested specimens were examined using conventional metallographic methods. Microstructural examination indicated that the alloys were comprised of lamellar structures (a2+g) embedded in columnar dendritic cores in the as-cast condition. However, the quinary alloy contained a Ti5Si3 second phase. The alloys exhibited no detectable ductility during tensile deformation, indicating the brittleness of all the materials. The fracture surfaces revealed that the alloys failed by translamellar fracture with correspondingly few cleavage facets.

Apr 1, 2021

By M Yahyaei, F Reyes, R Lage, V Jokovic

Equipment wear is strongly related to the performance of grinding circuits. In particular, SAG mills are subjected to the wear of their shell liners and grates. Changes in lifter height and face angle impact mill performance, while classification at the mill discharge is also affected as grates wear out. Moreover, liner mass loss caused by wear affects how operators interpret readings of sensors such as load cells or bearings pressure. Automating and optimising grinding circuits under these constrain becomes challenging due to the nonlinear and dynamic nature of the system. The operation of SAG mill grinding circuits remains largely dependent on human intervention, which frequently results in inconsistencies in performance across shifts, reflecting the operator’s personal preferences, experience, and other human factors. The influence of human factors can be reduced by careful training of operators as well as by automation using advanced supervisory control. The latter approaches could benefit from the development of dynamic process models that consider the effects of wear on the performance of equipment over time. This paper presents detailed industrial data showing the effects of wear on SAG mill performance. Additionally, a dynamic SAG mill model that accounts for these phenomena is proposed and demonstrated in a simulated environment. This model is shown to mimic the effect of wear on the performance of industrial scale mills and the operational constraints they are subject to, thus extending traditional SAG mill models. Incorporating wear into modelling and simulation platforms can improve the understanding of the effects that wear can have on the performance of key assets in comminution circuits and may allow the development of more robust model-based advanced process control strategies.

Aug 24, 2022

By N. D. Schupp

The Doe Run Company's Herculaneum, Missouri lead smelter has existed in continuous operation since 1892. Throughout the history of the plant extensive developments have been made to improve throughput, increase productivity, decrease operational costs and improve technology, while remaining an environmentally responsible producer of high quality primary lead in the international market. This paper provides an overview of the Herculaneum smelter, focusing on the most recent configuration of the operations. The paper includes discussion on all the aspects of primary lead production at the Herculaneum smelter.

Jan 1, 2000

By Matthew T. Mowry

As the mining industry continues to hire young professionals to supplant the growing number of retirees, a well-developed engineering curriculum, coupled with practical, real-world training, can prepare mining engineering graduates to make meaningful contributions in the industry. Successful companies can be measured not only by their reserve base and annual production but also by their retention of mining engineering graduates with zero to five years of operational experience. My personal experience in the industry during the last five years has been varied and rewarding. The knowledge and experience I have gained have taught me valuable lessons that prepared me for my current role.

Nov 1, 2013

By V. R. Bovino

In the early 80's, the cover of a major weekly magazine proclaimed the "Death of Mining." A few years ago, mining conventions, similar to this, around the country sported the theme, "The Survival of Mining." Today, the SME announces that "Mining is Alive." Being part of an industry that is simply alive is not very exciting. We can do better! Our challenge must be to flourish, blossom, maximize our potential and expand our horizons. The pace of rejuvenating this industry is still woefully inadequate. The new generation of mining industry leaders recognizes the urgent need for bold operational changes?changes in the way we deal with our employees? changes in the way we achieve productivity? and changes in the way we reward our employees for productivity.

Jan 1, 1991

It is no longer adequate when starting a new mine to simply select the best equipment. Today's competitive international commodity markets demand superior efficiency which requires systematic involvement of people in continual improvement of production and commercial processes. True Total Quality of Management (True TQM) principles provide an operating philosophy for maximising productivity and minimising unit costs of output. The presentation will show the practical and successful use of these principles. This paper will introduce the case study and provide background material on True TQM.

Jan 1, 1995

It is no longer adequate when starting a new mine to simply select the best equipment. Today's competitive international commodity markets demand superior efficiency which requires systematic involvement of people in continual improvement of production and commercial processes. True Total Quality of Management (True TQM) principles provide an operating philosophy for maximising productivity and minimising unit costs of output. The presentation will show the practical and successful use of these principles. This paper will introduce the case study and provide background material on True TQM.

Jan 1, 1995

By Jack F. B. Silman

Proving up any large, open pit ore deposit by normal exploration drilling under the best of conditions is a noteworthy accomplishment. But, when adverse conditions preclude standard drilling methods, and the same end result is achieved by a relatively new and little known type of drilling, special comment is in order. Three major problems confronted exploration drilling at the Questa molybdenite mine of the Molybdenum Corporation of America-sampling, terrain and time. Surface and underground longhole drilling provided the needed solutions, thus making the greatest single contribution to an exploration and development program that was successful in proving a major, open pit molybdenum deposit.

Jan 5, 1965

By Marcus Neves, Eventomar Junior, Adilson Castro, Leandro Silveira, Sérgio Augusto

The collapse of the Vale S.A. mining tailings dam in 2019, a tragic event that shook Brazil and the world, had consequences that transcended the immediate pain and devastation. Among them, the suspension of rock blasting activities in several mines in the Quadrilátero Ferrífero region of Minas Gerais, Brazil. This measure, taken as a precaution and with the aim of ensuring the safety of nearby geotechnical structures and the population, had a significant impact on the mining production chain. To overcome these challenges and resume blasting activities in a safe and sustainable manner, the mining industry has been dedicated to developing and improving solutions. One of the promising alternatives is the signature hole technique, used in conjunction with attenuation laws. The complex geology of the Quadrilátero Ferrífero, with lenses of compact ores immersed in friable materials, the presence of discontinuity families, and the emergence of geological faults, requires detailed analyses and specific adaptations of the signature hole technique and constant monitoring of the vibrations to calibrate the attenuation laws to ensure compliance with permissible limits and safety of the operations. To demonstrate the methodology, a case study in Abóboras Mine was described. Additionally, the challenge of achieving the desired level of production while controlling vibration and slope damage has driven the development of new charging and timing techniques. To address this challenge, a comprehensive approach was undertaken. A substantial database containing more than 4,000 registers of blasting-induced vibration events from 520 blasts was meticulously compiled from 2020 to 2023, 6 different attenuation laws were established and continuously calibrated with 99.3% of compliance regarding permissible limits of vibrations. The successful implementation of these actions allowed for the resumption of blasting, increasing production from 10 million metric tons to 43 million metric tons per year assuring sustainable operation.

Jan 21, 2025

By Burton E. Gilpin, Dr. George W. Annadale

A two level risk analysis procedure which is specially designed for use in river environments, is presented. The first level risk assessment (Level I) is often adequate for purposes of most projects, and entails hazard assessment, exposure identification, consequence estimation, and risk characterization. Two unique features of the method are the Composite Hazard Rating system, which is used in hazard assessment, and a formalized decision model for risk characterization. The risk characterization procedure provides information on the acceptability of risks, can be used to distinguish between the relative severity of risks, and to evaluate whether more advanced risk assessment would be required.

Jan 1, 1992

By Ryan T. Smith, Anthony Sahj, Alexander T. Darnell

Every second can count when trying to board a departing flight or catch a ride-share to your final destination. Hartsfield-Jackson Atlanta International Airport is in the midst of a project that aims to cut about 13 seconds between automated people mover trains (Plane Train) that move passengers between the terminals and concourses. The project involves extending the Plane Train tunnel west from its existing terminus under the domestic terminal. Working from inside non-public areas of the terminal, Keller North America, Inc. (Keller) incorporated systems of micropile-supported steel beams and grillage to both underpin existing columns prior to tunneling and support open-cut excavation at the tie-in of the new to the existing tunnel. Dewatering aided in mining a challenging section at the start of the drive of the mixedface, sequentially excavated tunnel and an automated instrumentation system monitored the performance of the construction and its impact to the terminal. Cut and cover egress and ventilation tunnels required braced support of excavation.

Oct 1, 2022

By C. Dai, S Raathiv

The Waikato Expressway is one of the New Zealand Transport Agency’s (NZTA) seven roads of National Significance. Coffey is part of the City Edge Alliance engaged by NZTA for the Hamilton Section of the project. The 22km Hamilton Section is the largest and most geotechnically complex section of the Expressway. The Mangaonua gully in Sector 6 is the most challenging geotechnical area of the project for piling works. Together Coffey and Brian Perry Civil have carried out the temporary and permanent design and construction of embankments, piling works, retaining walls and soil improvement works for the bridge construction. The design and construction works were governed by weak alluvial layers and artesian pressure layers several meters beneath the ground level. This paper presents the action taken to improve the foundation of temporary platform, control the artesian pressure, prevent bentonite leakages into the highly permeable alluvial layer and challenges in the base grouting process. This paper summarises the key components in the construction and supervision of bored piling works and outlines innovative solutions for challenges which we faced during the construction.

Nov 1, 2022

By R Cooksey

The Globe-Progress Mine is an open pit gold mine that is part of the larger Reefton Goldfields deposit located on the West Coast of New Zealand. The regional geology comprises a series of north to south oriented fold structures that have undergone post-deformation mineralisation. The structural geology within the mine itself is more complex, with major shears hosting numerous high-grade mineralised quartz shoots and splays that have been historically mined.The selective mining of ore within the pit is challenging due to the orientations of the hanging wall and footwall areas of the main Globe shear zone, the lithologies of these areas which range from highly brecciated and sheared material to competent mineralised host rock, and in the hazards presented by the numerous old historic underground workings. The coordination of drilling, modelling and excavation of the ore requires careful planning to maximise recovery whilst operating with the pit design boundaries.Grade control packages are custom designed to reflect the orientation of the footwall and hanging wall mineralisation. The shear material in the footwall zone dips between 60° and 70° and requires angled drilling whereas the footwall mineralisation is contained in shallow dipping quartz veins sub parallel to bedding and can be vertically drilled to best intercept the mineralisation. Ore excavation is directed so that the contact between the footwall and hanging wall is mined in the correct direction so that any non-visual ore contacts can be safely mined and that the ore-waste dilution is reduced.The ongoing grade control and selective mining of the Globe Progress deposit continues to deliver high grade ore for processing by ensuring that waste and dilution of ore is reduced and that recovery is maximised.

Aug 22, 2011

By T. Veneroso

Comminution is the process by which rock or ore is reduced to a size where the liberation of the minerals is maximized without changing the chemical or physical properties of the rock. Comminution accounts for about 50% of all energy that mines use (Klein et al., 2018). Growing demands from stakeholders and shareholders for sustainable development and CO2 reduction will increase the need for energy-efficient comminution. Ores with different mineralogical characteristics, textures, strengths, apparent stiffness, and mass-specific fracture energies need to be processed with a specific, new, and efficient comminution technology to increase the production and profitability of mining companies. The adoption of crusher wear parts built with new materials, such as non-Hadfield manganese steel or synthetic materials or traditional manganese with wear-resistant components, could improve the efficiency of the crushers, reduce downtime, increase production, improve the desired P80 (the aperture through which 80% of the product will pass) product size distribution, and enhance mine safety.

Feb 1, 2023

By William Gleason

At 6,898 ft below surface, the historic No. 9 shaft at Resolution Copper near Superior, AZ is now the second deepest single lift mine shaft in the United States and connects to the deepest single lift mine shaft in the U.S., Resolution Copper’s No. 10 Shaft (6,989 feet). The shafts serve as ventilation and access for future underground development of what could one day become one of the most significant copper mines in the United States. It is from the base of No. 9 and No. 10 shafts that hundreds of employees of Resolution Copper, a joint venture of Rio Tinto and BHP, hope will soon be given the go ahead to begin driving lateral tunnels to reach a copper deposit that is estimated to contain 28 Mt or 40 billion pounds of copper. Copper was recently added to the U.S. Geological Survey’s (UGGS) critical minerals list, in large part because of increasing demand. A study by S&P Global Energy & Market Intelligence “Copper in the age of AI: Challenges of electrification” released on Jan. 8, 2025, “identifies a transformative trajectory for copper demand, projecting a surge from 28 Mt (31 million st) in 2025 to 42 Mt (46.3 million st) by 2040 – a 50 percent increase that underscores the metal's pivotal role in multiple technological and economic domains.” The surge in demand is driven in large part by the global energy transition, electrification of vehicles, growth of artificial intelligence and data centers, and most recently robotics. Meanwhile, geopolitical tensions have increased the focus on the need for the United States to secure more of its own mineral supply chain. S&P Global’s report is one of many warnings that while copper demand has accelerated rapidly, future supply is being held back. Resolution Copper stands out as one example of a known mineral deposit remaining locked in the United States’ complex and lengthy permitting slog.

Feb 1, 2026

By M Thompson, N Vines, Z Hearne, S Lam, G A. Gomes-Sebastiaõ, D van der Spuy

Construction and commissioning of the Nova Copper-Nickel project of Independence Group was completed in late 2016. The plant is in the Fraser Range of Western Australia, about 120km east of Norseman and produces separate Copper and Nickel concentrates. Since the early feasibility phases of the project, the importance of automation and control was recognised and planned for to ensure the plant performance meets the design expectations. The site is well equipped with common as well as advanced instrumentation. It currently boasts the largest number of Blue Cube MQi (mineral quantifier inline) slurry grade analysers on a single plant worldwide. It was also decided that 25 Blue Cube TempoTracks would be installed on the flotation cells. The TempoTracks provide information on froth height and velocity, hence giving continuous, quantitative measurements of the froth that is pulled off each cell, rather than relying on infrequent, subjective visual inspections.The Nova concentrator consists of a differential flotation circuit whereby copper bearing mineral are selectively floated prior to nickel flotation. It is imperative that losses of copper to the nickel circuit, and vice versa, are minimised. The plant metallurgical team and Process IQ collaborated to develop and implement the advanced control strategy for the plant. This paper focusses on the optimisation of the copper concentrate that is pulled off the copper rougher and scavengers. This strategy was made possible by the additional measurements listed above. The control optimisation of the copper rougher and copper rougher scavenger circuit was implemented during August 2017 on the StarCSTM advanced control platform. It continuously optimises the level and air setpoints. The control philosophy incorporates several notable techniques which include: a variable mass pull target that is a function of the quantity and grade of material entering the circuit, integrated compensation to prevent inventory build-up in cells, balancing of the froth velocity over the lip of each cell to adaptive, modular system usage and advanced error handling. CITATION:Gomes-Sebastiaõ, G A, Hearne, Z, Lam, S, van der Spuy, D, Thompson, M and Vines, N, 2018. Nova copper-nickel project optimisation of the copper rougher-scavenger circuit through advanced measurement and control, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 77–92 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018