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By W. A. Van Dyk

Hydrophobic particles with diameters between 1 and 3 mm are poorly recovered by conventional flotation techniques. A novel reverse flotation technique is described whereby coarse particles with surfaces rendered highly hydrophobic, repel the bubble films in a froth and thus drop through the froth under gravity, to be recovered as a sink product. Conversely, gangue or hydrophilic particles are supported by the bubble films in the froth and are therefore recovered as a floating product. Tracer tests were conducted in the cell in order to study the dynamic behaviour of solid particles in the froth. The effects of hydrophobicity, density, particle size and particle shape were investigated experimentally. The higher the hydrophobicity of the particles, the lower the recovery of particles as a floating product, while the recovery of particles as a sink product increases with an increase in particle density. Furthermore, a decrease in particle size results in an increase recovery of hydrophobic particles as a floating product. When treating particles of the same mass-to-surface-area ratio in the froth, flat particles would be recovered as a floating product in preference to cubic, disc-shaped, cylindrical and spherical particles, in that order.

Jan 1, 1995

By P. Eger, D. Green

"The Soudan Mine was Minnesota’s first iron mine, operating from 1882 to 1962. The mine was donated to the State of Minnesota in 1963 and became a state park in 1965. The mine discharge contains elevated copper and cobalt concentrations and has been treated with an ion-exchange-resin-based system since 2009. The system includes flow equalization tanks, bag and cartridge filters, a carbon tank and two commercial ion exchange tanks. Although effective, the system’s high cost, inefficient removal of suspended material and substantial maintenance have been ongoing and troublesome issues.In November 2012, we initiated a pilot test using a peat-based sorption media. This media is produced from raw reed-sedge peat through a patented, low-temperature carbonization process that produces a hardened granular sorption material. The granules are uniform, have high hydraulic conductivity and maintain the high metal affinity of natural peat.Mine water was pumped through the peat-based sorption media without any pretreatment. Copper input concentrations typically ranged from 30 to 60 µg/L but increased to a high of 364 µg/L in the summer of 2013. Since startup, more than 60 million L (16 million gal or 32,000 bed volumes) have been treated, with average removal rates of 75 percent for particulate copper and 60 percent for dissolved copper. Backwash is required at about 4,000 bed volumes, but with a combination of air sparging and high-flow backwash, the suspended material is removedfrom the media.One tank of the peat-based sorption media was found to remove copper similarly to the first four components of the existing system. By reducing size and complexity, reductions in operation and maintenance costs are possible. A comparison of the estimated costs indicate that replacing the four initial components with the single media tank has the potential to reduce annual operating costs by more than half from around $163,000 to $70,000."

Jan 1, 2015

By Rustyn Sherer

Curis, the name of a new Arizona-based mineral development company, is an acronym which stands for ?Cu? (elemental symbol for copper), ?r? (recovery), ?is? (in situ, the Latin for ?in place?). The company was created specifically to advance the development of the Florence Copper Project in Florence, AZ and to pursue other next generation copper development projects in progressive jurisdictions around the world. ?We are extremely excited about this project,? said Curis Resources president and chief executive officer Michael McPhie. ?We?re here to set the standard for Greenfield in situ copper recovery (ISCR) operations in Arizona and around the world. We believe in our people, our technology and our process; and we are passionate about our commitment to environmental stewardship and community development. We?re making a long-term investment in Florence, and in Arizona.?

Jan 1, 2011

By David Chastka, Isidro Rivera, Shawna Von Stockhausen, Idit Zarchi

The City of Santa Cruz Water Department is replacing the existing Newell Creek Dam inlet/outlet works at Loch Lomond Reservoir in the San Lorenzo Valley. The project will improve the City’s overall operational efficiency, improve system performance, and improve the safety and reliability of storage for the City’s drinking water supply. The project comprises new inlet works* (three new inlets that control and convey flows into and out of the reservoir, and an intake control building), an inlet/outlet tunnel with a 48-inch conduit to convey flows into and out of the reservoir, and a new outlet structure at the toe of the dam. The outlet structure includes a release point for energy dissipation of emergency drawdown flows, a connection to Newell Creek Pipeline, and beneficial releases into Newell Creek. The project also includes a new dam seepage collection and monitoring system and appurtenant structures such as a culvert bridge over the spillway plunge pool to improve access to the new outlet. Notable complex project components include in-water work to connect the new intake shaft pipes to the three new inlets. The project includes one major milestone with a work window regulated by environmental permits that could only be amended/ extended with approvals from those agencies. If not met, the milestone work would have caused significant delays (potentially up to one year) to the project.

Jun 13, 2021

By Charles M. Pelanne

Without insulation we could not survive on this planet. This may sound like a self-serving statement but it is a fact. The blanket of air which surrounds us is a very effective insulating blanket, allowing some shortwave solar radiation to warm us during the day while retaining the longer infrared radiation at night. Our life on earth is very much dependent on materials performing an insulating function without being thought of as insulation, clothing, fur, window glass, the ice of an igloo etc. The mechanisms of heat transfer involved in these materials are analogous to those involved in engineered insulations - Engineered insulations are designed for maximum effectiveness for given conditions within the applicable retraints. Engineered insulations are very effective! As an illustration let us consider this graph (Figure 1). It represents: 1. The radiative heat transfer between two 1 foot2 (0.0932) radiantly black surfaces, one at 100F (38C) and the other at the temperature indicated on the bottom scale. This does not include the convective and conductive heat flow of the air, both of which are significant but small in comparison. 2. The heat transfer resulting from the placement of 1 inch (25.4 mm) of insulation [10 pcf (160 kg/m3) ceramic fiber] between these two plates.

Jan 1, 1976

By G. A. Doyle

The quality of water in mine pit lakes depends in part on the physical limnology, including such factors as thermal and chemical stratification, turnover and the development of anoxic conditions with depth. Limnologic data collected from four existing pit lakes in Montana and Saskatchewan indicate that pit lakes develop a thermocline (temperature stratification) in the upper 10 to 30 m (33 to 100 ft) of the water column. Two o f the pit lakes, 26- and 55-m (85 and 180 ft) deep, undergo seasonal turnover of the entire water column, whereas two deeper, pit lakes, 110 and 240-m (360- to 790 ft) deep, undergo seasonal turnover of only the upper portion of the water column. In the deeper lakes, seasonal mixing does not extend through the entire water column, and a distinct chemocline develops with depth.

Jan 1, 1997

By C. S. Boland

The Copper Range Company's mining properties are located in the Upper Penisula of Michigan. (Fig.). Early work indicated the presence of copper ore in a bedded deposit, confined to the base of the Upper Keweenawan Nonesuch shale, and exploitation of this deposit on a portion of the Company's property was undertaken by White Pine Copper Company. Diamond drilling of the White Pine orebody indicated that a major fault pattern terminated the values to the South-west. Further drilling Southwest of the fault zone proved a downward displacement of the ore bearing horizon some 1,500 feet and a lateral displacement of approximately 4,000 feet; and in this area an ore deposit was outlined in a large asymmetrical syncline locally plunging to the South-west. (Figs. 2 and 3)

Jan 1, 1962

By Rob Thomas

It is generally agreed that standing support should be installed in roadways that will for various reasons, be holed through with a longwall. Considering the magnitude of the associated abutment loading in conjunction with the need to ensure that the material used is cuttable, some form of cementitious support is often used.

By III Westbrook

Although calcium sulfate dihydrate, commonly referred to as gypsum, has been utilized for some time in fiberglass reinforced polyester (FRP) applications, it does not have the fire retardant filler recognition of ATH. Gypsum is more commonly known for application in cement, soil and water treatment, plaster, and wall-board. Inherent characteristics of gypsum limit its use to low temperature and, until recently, non-aqueous applications. However, as a plentiful, naturally occurring hydrated mineral, the cost effectiveness of calcium sulfate dihydrate has prompted development and yielded success in the areas of FRP spray-up and latex carpet backing.

Jan 1, 1993

By Pratt Rogers, Aaron Young

This paper considers the mining industry’s need for digital transformation (DT) and presents a three-part review of the foundational components of the DT process: ubiquitous data, connectivity and decision-making. It also provides a discussion on the future of DT in mining as well as a research direction, which identifies the need of academia to provide support for mining companies in the form of both research and the education of digitally literate, dynamically capable mining engineers into the coming decades.

By Jack G. Crump

Nuclear radiation systems for gauging solids content in process slurries and level in crushers has demonstrated acceptance in ore processing. The use of nuclear radiation for moisture analysis of bulk materials is presently receiving acceptance in beneficiating and agglomerating processes. On the horizon is the use of nuclear activation methods for continuous, qualatative and quantitative analysis of concentrate. The common characteristics of these uses of radiation is the non-contacting nature of the measurement. Unquestionably, this is the dominant reason for acceptance of nuclear methods in level and slurry-gauging. Moisture activation analysis of a product using nuclear methods retain this advantage. However, and: more importantly, they offer new solutions to old problems. The nuclear method in addition to being non-contacting, is non-destructive and provides a continuous measurement of the process variable. The system responds: to the fundamental makeup of matter, mass and elemental composition, not to secondary properties such as temperature, resistivity, or dielectric constant. Measurement is a volume rather than a surface phenomenon, thus the results can provide a truer pricture of the measured variable.

Jan 1, 1965

By Robert E. Goodwin

As man's need for minerals continues to grow and as the known mineral deposits become depleted, it may be expected that these increased demands will result in greater exploration for additional deposits and at continually increasing depths below the earth's surface. As labor and material costs continue to rise, the need for more economic material handling will be emphasized. The quest for heavier payloads, safely moved at faster speeds from deeper mines, will be vigorously pursued. Strenuous efforts are, therefore, being made in the wire rope industry to develop ropes with greater strength-to-weight ratios than presently available while maintaining the dependability and long life being received from the conventional rope manufactured today. For many years, high quality rope wire has been manufactured from rods of selected steel compositions. Carefully-controlled wire drawing combined with proper heat treatment has resulted in high quality wire and wire rope throughout this period. Refinements in the rod produced from specially-selected high carbon steels combined with the latest improvements in wire drawing and heat treatments have made it possible to manufacture higher strength rope wire of uniform composition and structure that is suitable for use in Special High Strength wire rope.

Jan 1, 1970

By T. J. De Mull

The Alligator Ridge Mine is located 70 miles northwest of Ely in White Pine County, Nevada. Development of the mine began in the late 1970's as a joint venture between Amselco Minerals, Inc. and Occidental Minerals Corporation, with Amselco as the operating partner. Early in 1983 Nerco Minerals Company acquired Occidental's share of the property. The mine and ore processing facility have operated at capacity since 1981 producing 680,000 tonnes of ore and 1,900 kg of gold per year. The gold ore deposits at Alligator Ridge consist of disseminated micron-size gold particles in a silicified siltstone matrix. The deposit comprises three separate but adjacent areas of mineralization that are designated as Vantage 1, Vantage 2, and Vantage 3 after the name of the basin in which the deposits lie.

Jan 1, 1983

By K. KAKLIS, O. SAUBI, Z. Agioutantis, R. JAMISOLA

Machine learning in the form of artificial neural networks was applied to investigate whether specimen load evolution can be predicted as a function of acoustic emission (AE) signals in the case of three-point bending (TPB) marble specimens instrumented with piezoelectric sensors. The ultimate objective of this study is to develop a model that can quantify rock behavior under loading that can lead to rock-failure prediction in underground structures subjected to bending, such as roof failure in development or production openings.

Nov 1, 2022

By J. D. McAteer

It is widely agreed throughout the mining community that federal mine safety and health legislation administered by the Mine Safety and Health Administration (MSHA) deserves significant credit for the past quarter-century's remarkable improvements in miner safety and health. Recently, however, it has been suggested that the mining industry in the United States has now evolved to a point that current mine safety and health law may be obsolete. This proposition deserves attention. Today, I propose to give it the close logical scrutiny that is its due. I conclude that the obsolescence of current mine safety and health law is not supported by the evidence. The existing mine safety and health law continues to serve as a critically important supplement to mine operators' safety programs at a modest cost to the taxpayer. At the same time, trends in a changing industry do call for responsive adaptations in the Federal mine safety and health program. I will argue that timely and appropriate responses to changing needs can be accomplished within the framework of existing legislation, provided federal officials avail themselves of the flexibility provided by existing law.

Jan 1, 1996

By Valerio Violo, Antonio Raschilla, George Kafantaris

"The Cityringen project in Copenhagen, Denmark will form a new circular line in the city center and will consist of 21 new stations (17 + four transfer stations) and approximately 31 km (19 miles) of earth pressure balance (EPB) twin-bored tunnels.The new tunnels passed under the historical building of Magasin du Nord, McDonald’s and two pubs in the heart of the city with a minimum cover of about 4 m (13 ft).To minimize the movements, a complex system of compensation grouting and jet grouting soil treatment was performed. A detailed action plan between the parties involved allowed coping with the critical tunnel boring machine’s (TBM) successful passage.The Cityringen is an extension of the existing metro line underground Copenhagen and will include the City Circle Line, 15 km (9.5 miles) of twin tunnels looping around the city. The City Circle Line will form a new circular track inside the city center and will intersect the existing M1 and M2 lines at Kongens Nytorv and Frederiksberg stations, as well as suburban train services at København H, Østerport and Nørrebro. It will extend the Metro network to the Nørrebro, Østerbro areas and the central station at København H (Fig.1). The two new lines M3 and M4 will run on the same tracks, but the M3 will be a circle route running around the entire line, whereas the M4 will drive from the station to the north side of the city.The €1.5 billion design-build contract was awarded by Metroselskabet in January 2011 to the Copenhagen Metro Team (CMT), a joint venture (JV) between the Italian companies Salini, Tecnimont Civil construction and Seli SpA. Since the bankruptcy of Seli SpA and Tecnimont, Salini Impregilo now owns 100 percent of the JV shares. Seli Tunneling Denmark ApS, a subcontractor to CMT, was initially constituted as a Seli SpA subsidiary and, following the economic difficulties of Seli SpA, was acquired in 2015 by Salini Impregilo. Seli Denmark is in charge of the tunnels excavation and lining and owns the four 5.84-m (19-ft) diameter Seli/Kawasaki earth pressure balance machines."

Jan 5, 2017

By Wei Zhang, Jinhong Zhang

An atomic force microscopy (AFM) image analysis has been applied to study in situ the adsorption of hydroxamic acid collector, i.e., octanohydroxamic acid (OHA), on malachite in aqueous solutions. AFM images show that hydroxamic acid collector adsorbs strongly on malachite mainly in the form of insoluble copper hydroxamate complex. Increasing the collectors’ concentration and the adsorption time both increase the adsorption of hydroxamic collectors on malachite. Results from the attenuated total reflectance–Fourier transform infrared spectrometry (ATR-FTIR) also show that the collector adsorbs strongly onto malachite, with strong absorbance spectra being detected, and the ATR-FTIR results confirm those as obtained by AFM. This specific adsorption mechanism explains that a high selectivity with a moderate collectivity will be achieved with a hydroxamic acid collector for the flotation of malachite. The findings of present study also show that AFM image analysis is a powerful tool for the study of the hydroxamic acid collectors’ adsorption on malachite surface and it can help with the development of novel collectors for malachite flotation.

Feb 1, 2025

By Paul Culvenor, Brad Gyngell

Large language models (LLMs) have generated a lot of hype since ChatGPT was released in early 2023. In essence, they allow people to interact with computer systems through natural language and have the ability to generate highly complex text, images and videos (Patil and Gudivada, 2024). It is clear that this technology has significant potential, however most mining companies have not yet found practical applications for it within their operations. In this paper, we present a range of such applications along with the tactical considerations associated with developing and implementing them. We have identified use cases across a variety of operational and functional areas within the mining industry and evaluated them based on their potential business value and ease of implementation. Firstly, we provide an overview of how LLMs work and a review of how LLMs are being applied in other industries to provide best practice inspiration for mining. Next, we present a list of possible applications in mining and a critical assessment of each use case. This section also includes a technical deep dive into the different methodologies for developing the technologies as well as an analysis of barriers to adoption within mining organizations. Finally, we share a discussion of the potential path forward for LLMs in mining and the impact they could have on the industry. We analyze the potential differences between early adopters and laggards in the artificial intelligence (AI) space. This research draws on interviews and surveys with artificial intelligence experts as well as mining subject matter experts to connect cutting edge thought leadership with the specific problems faced by our industry.

Feb 1, 2025

By Stephen H. Hall

INTRODUCTION At some point in the design and development stage of a mineral venture, the assay laboratory building, its interior layout, and major pieces of analytical equipment must be specified for construction or purchase. Even the most experienced chemist would have difficulty in proposing useful specifications without a good deal of investigation into the kinds of analytical tasks that the laboratory will be expected to address, the probable workload, and the operating time constraints. This chapter will provide a logical approach to laboratory design that starts with such an investigation. Specific examples throughout the chapter are drawn from the author's tenure as Chief Chemist at Barrick Mercur Gold Mines, Mercur, Utah, from 1982 to 1985. It is necessary to understand the nature of a modern production laboratory, and to recognize that its operations bear more resemblance to its parent processing plant than to a research, teaching, or custom analytical laboratory. The assay lab is a processing facility unto itself, where samples and reagents are the raw materials, and assay results are the final product. Its most efficient operating mode is as an assembly line, treating samples in a nearly continuous flow. Nevertheless , there are important differences between the lab and the process plant. The products - assays - are individually unknown quantities until they are "produced.' This can vastly complicate quality control compared to the process plant. Capital costs are general 1 y small compared to the plant, but the ratio of operating costs to capital costs for a laboratory is often very much higher than for the plant. This is due to the labor intensive nature of analytical work. For instance, during Fiscal Year 1984 at Barrick Mercur Gold Mines, labor costs for the laboratory staff represented about five percent of the total labor budget, while the laboratory building and equipment represented only about six-tenths of one percent of the original start-up capital. Failure to recognize both the similarities and differences between laboratory and plant operations is the foremost cause of difficulty encountered in designing a laboratory. The

Jan 1, 1986

By E. Siami-Irdemoosa, S. R. Dindarloo

"Pareto analysis was used to investigate the failures database of a Hitachi EX1900 hydraulic shovel over one year of continuous operation. The hydraulic system and hydraulic links, hoses and piping were identified as the most critical system and subsystem, respectively. A three-parameter gamma distribution function was identified as the best fit for a probabilistic modeling of the time between failures (TBFs). This distribution was used in a Monte Carlo reliability analysis of the hydraulic system. Autoregressive integrated moving average (ARIMA), within the context of a time series analysis of the TBFs, was proposed as a viable alternative to the traditional technique of distribution fitting. The mean absolute percentage error (MAPE) metric was used to compare the two models. The MAPE value that resulted from the ARIMA was 66 percent smaller than that from the traditional technique in predicting the TBFs. Resumen ¦ Se usó análisis Pareto para investigar la base de datos de fallas de una pala hidráulica Hitachi EX1900 durante un periodo de un año de operación continua. Se identificó al sistema hidráulico y a los enlaces hidráulicos, mangueras y tuberías como el sistema y subsistema más importantes, respectivamente. Se identificó una función de distribución de tres parámetros gamma como el más apto para un modelado de probabilidades del tiempo transcurrido entre las fallas (Tabes por sus siglas en inglés). Esta distribución fue usada en un análisis de confiabilidad Monte Carlo para un sistema hidráulico. El promedio de movimiento integrado auto-regresivo (ARIMA por sus siglas en inglés), dentro del contexto de análisis de serie temporal de los TBFs, fue propuesto como una alternativa viable a la tradicional técnica de ajuste de distribución. Se usó el porcentaje de la media absoluta de error (MAPE) para comparar los dos modelos. El valor MAPE que resultó de la ARIMA fue 66 por ciento menor que el resultado obtenido con la técnica tradicional de predicción de TBFs."

Jan 1, 2015