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"A cationic surfactant, tetradecyl tributyl phosphonium chloride (TTPC), was first used as a collector. Flotation characteristics of muscovite using TTPC have been investigated through flotation tests. And dodecyl trimethyl ammonium chloride (DTAC) was tested for comparison. Their adsorption mechanisms on muscovite surface were clarified using zeta potential measurement, DFT calculation and molecular dynamics (MD). The flotation results indicate that the recovery of muscovite decreases when the pH increases in the presence of surfactants. When a maximum of recovery was reached, the dosage of TTPC was 2×10-5mol/L which was half of that of DTAC. Zeta potential measurements confirm that the TTPC displays a stronger collecting power than DTAC and is a superior collector for the muscovite flotation. DFT calculation and MD simulations show that TTPC interacts with the muscovite mainly through electrostatic attraction and hydrogen-bonding. The conclusions drawn from purely theoretical computations matched remarkably well with the experimental results. Keywords: Quaternary phosphonium salts; Flotation collectors; Flotation INTRODUCTION Muscovite mica is widespread in igneous, sedimentary and metamorphic rocks. It has the general composition KAl2(AlSi3O10)(OH)2. Muscovite mica exhibits perfect cleavage along the (001) plane, which exposes interlayer potassium ions[1-3]. In aqueous suspensions, the potassium ions readily enter into solution, leading to the development of a net negative charge on the (001) plane[4-6]. The surface of the muscovite mica is negatively charged at all pH > 1[7]. Due to the negative charge surface over the whole pH range of 2–12, the muscovite mica would not be expected to respond to anionic collectors in the absence of an activator. Conversely, the mineral is readily recovered using cationic collectors. However, until now, various amines and their derivatives (with N atoms as the center) are still the only available cationic collectors which still had their shortcomings such as weak selectivity, low flotation speed. Since few types of cationic collectors could be used, in some sense, the limitations of collectors are increasing significantly and the cationic flotation is facing more and more challenges. Quaternary phosphonium salts, as novel cationic surfactants, are widely used in antimicrobial, catalysis and surface modification field due to their biological activities, hydrogen bonding capability, stability and superior group electrical property[8-10]. There are a number of processes where quaternary phosphonium salt surfactants have shown better properties than quaternary ammonium salts and amines. Although the adsorption of quaternary phosphonium salt surfactants at the bacterium–liquid interface has been studied thoroughly, the case of adsorption in mineral surface has not been investigated thus far."

Jan 1, 2016

By Hendrick A. D. Kirsten, A. Clayr Alexander

Stillwater Mining Company is currently developing a second underground palladium and platinum mine approximately 21 km (13 miles) west of their existing Nye operation in the Bear tooth Mountains of southern Montana. Portals for the two access tunnels required at the new site were excavated in limestone talus to accommodate4.6 m (15 feet) diameter tunnel boring machines. A review of the technical design, field conditions and construction of the portals is presented.

Jan 1, 2001

By Lewis V. Wade

This paper summarizes the results of the rock mechanics monitoring program performed as part of Old Ben Coal Company's longwall coal mining demonstration project conducted in cooperation with the United States Bureau of Mines. The work described herein included installation of instruments, collection of data and data analysis performed during mining of the first longwall panel in Mine No. 24. The rock mechanics monitoring program included both surface and underground instrumentation and was designed to achieve the following purposes: 1 -To provide the capability to observe unusual situations during mining so that remedial measures could be instituted quickly 2 -To formulate design guidelines for future longwall mining efforts; 3 -To evaluate surface subsidence, and its character, rate and potential effects on cultural features, and to develop criteria to assist in predicting subsidence for other mines having similar roof conditions. Six previous attempts with longwall methods in Old Ben Coal Company's Hine 21 had been unsuccessful due to roof control problems. A description of these attempts is given by Moroni (1973). In preparation for the present longwall operation a study was performed to review existing data on the previous unsuccessful attempts, to establish coa1-and floor-strata bearing capacities in Mines Nos. 21 and

Jan 1, 1977

By D. M. Abbott

The problem with best practices occurs when they do not work. This happens when the seldom-stated assumptions underlying the practice are not met. This paper provides some examples for the mining industry: (1) when core splitting is inappropriate, (2) when the use of fire assays for placer samples is inappropriate, and (3) when high-grading may be acceptable. Geologic conclusions are, in the final analysis, expressions of judgment predicated upon knowledge and experience. A geologic conclusion, however, purports to be more than an arbitrary determination—it is reached as a consequence of method. No specific method is required, but the method used must be an orthodox method, in accordance with orthodox definition of terms, and the one best adapted to the dealing with the questions asked about the property in question. Whether the so-called “best practice” is really applicable to the job at hand must be decided on the basis of professional scientific judgment. When one decides to deviate from a published “best practice” for sound scientific reasons, describe in detail in the report what the so-called “best practice” is, why it was inappropriate for the project, and why the method used was better. If one becomes aware that a “best practice” is being proposed, actively urge those proposing it to include in its description the underlying assumptions that must be met in order for the “best practice” to be valid.

Jan 1, 2014

By George H. K. Schenck

The North American-based mining engineer needs to understand the differences that exist between mechanical mining or boring machines built on this continent and those built in Europe. The differences Ere most clearly seen when machines for large-sized openings--about 15 feet high-are considered. This report will focus on the innovations of European origin. The rock-breaking tool, drag bit, or roller cone that is efficient for a particular project is related directly to the strength of the rock involved. This strength is generally stated in reference to the rock's unconfined compressivee strength in pounds per square inch (psi) although it is well recognized that a rock's shear strength is also important. Compressive strength has been adopted because it is simple to test for and provides a convenient comparison. Table 1 relates cutter type to compressive strength and indicates the general nature of the machine innovation devel¬oped in Europe.

Jan 1, 1970

Semisoluble salt minerals are characterized by their ionic bonding and are distinguished from soluble salt minerals by their limited solubility in water. One group of semisoluble salt minerals being considered is the alkaline earth salt minerals, including fluorite (CaF2), calcite (CaCO3) and apatite (Ca5F (PO4)3), as well as celestite (SrSO4) and barite (BaSO4). Another group of semisoluble salt minerals being considered is the rare-earth salts, which include bastnaesite ((Ce, La) CO3F), monazite (CePO4) and xenotime (YPO4). Surface chemistry features of these selected semisoluble salt minerals are discussed with respect to flotation separations. First, the surface chemistry features of alkaline earth semisoluble salt minerals are reviewed, and then the surface chemistry features of rare-earth semisoluble salt minerals are examined. The discussion includes electrokinetic behavior, wetting characteristics and collector adsorption.

By P. W. Finck

Detailed mapping, using a large diameter diamond-drill in conjunction with high resolution reflection seismics, has increased known resources of kaolin clay and glass-grade silica sand from scattered deposits generally < 1 km2 to large areas of Cretaceous valley fill up to 130 m thick. Detailed chemical and physical analysis of drill core is presently underway. Silica sand deposits intersected in this study are up to 99.4 % SiO2 without beneficiation. Light grey to white kaolin clays identified by XRD and DT A have concentrations values (without beneficiation) up to 47.28% SiO2, 37.44% Al2O3, 0.45% Fe2O3, 0.49% K2O, 0.07% Nap, 0.07% CaO and 0.39% MgO.

Jan 1, 1996

By Steve Kral

The concept of sustainable development is not new to the mining industry. Many people involved with mining have argued that the industry throughout the world has always supported the communities where they operated. They say that the mining industry was employing sustainable development practices before the phrase became fashionable. The mines employed residents and supported the local economy through tax payments and the purchase of goods and services from local businesses. In many cases, mining companies have built medical facilities and contributed money, equipment and services to local schools. In modern times, mining companies have donated reclaimed land to the local communities for use as parks and recreational facilities.

Jan 1, 2004

By T. O. Kuhl

The Royal-Mountain King Project is 7.2 kilometers (4.5 miles) northwest of Copperopolis, California. Reserves of 8,250,000 t (9,100,000 st) at 2.32 g/t (0.068 oz/st) gold will be processed at 2500 t/d (2750 st/d) from three pits. Production is scheduled to begin the first quarter of 1989. District geology consists of northwest trending sequences of Jurassic meta-sedimentary and meta-volcanic rocks. Three ore bodies are located along the Hodson fault which trends northwest and dips 40 degrees northeast. The Gold Knoll and North Pit ore bodies are hosted in carbonate and silica altered meta-volcanic rocks whereas the Skyrocket ore body is hosted in quartz stockwork zones in meta-sedimentary rocks. Gold is present as inclusions and micro-veinlets in pyrite.

Jan 1, 1989

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 S. K. Kawatra, J. A. Halt

"Low-grade iron ores are finely ground and processed to recover iron-bearing minerals. However, the iron-rich powder is too fine to be used directly in blast furnaces and most direct reduction furnaces, and must be agglomerated or pelletized into a usable product called “pellets.” Bentonite clay has traditionally been used as a binder to make iron ore concentrate pellets, but it is expensive and contaminates the pellets. Organic binders may be a viable alternative to bentonite clay. This manuscript reviews organic materials that have been used to make iron ore concentrate pellets. Included are discussions on the development of organic binders, common pros and cons to organic binder use, organic binder structure and its effects on agglomeration, and additives to organic binders.IntroductionIron ore agglomeration turns finely disseminated, low-grade iron ores into a usable product, called pellets. During pellet production, fine-grained, iron-rich minerals are liberated from low-grade ores, concentrated, and agglomerated into round balls that are thermally hardened or cold-bonded to form pellets. Pellets are then transported to blast furnaces or direct reduction operations where they are used to produce iron; iron is further refined and shaped into the wide variety of steel-based industrial and consumer products in use today.Over the years, pellet production has become increasingly more prevalent with the increased exploitation of low-grade iron ores and increased iron and steel consumption around the world. In 2010, world iron ore pellet production was 388 Mt. It could be argued that the current pellet production process has been enabled by the use of binders – practical experience has shown that it would be nearly impossible to agglomerate iron ore concentrates using rotary drums and discs without using a binder."

Jan 1, 2015

By Rodolfo Lagos, Nicos Pfeiffer, Ben Harding, Clayton V. Deutsch

This paper documents a probabilistic resource modeling workflow for the Round Mountain epithermal gold deposit. The set of categorical and continuous variable simulated realizations provides a model of variability and uncertainty given the current orebody knowledge. These realizations can be used to quantify and understand expected deviations in reconciliation during mining and provide a more accurate measure of expected gold than an estimated model. Gold mineralization at Round Mountain is primarily contained within tertiary tuff units, which dip gently to the west and thicken towards the southern part of the orebody. Domain boundaries are modeled as combinations of lithology and alteration; alteration domains are constrained to be within the tuffs. Large-scale geologic uncertainty is strongly influenced by parameter uncertainty, particularly the input histogram. The spatial bootstrap characterizes prior global uncertainty in the input histogram for categorical and continuous variables. Categorical models are generated using hierarchical truncated pluri-Gaussian (HTPG) simulation. Continuous variable simulation is carried out within the simulated domain boundaries using trend models to account for non-stationarity.

Aug 19, 2023

By R. K. Clifford

The formation of elemental sulfur on the surface of sphalerite in aqueous systems was investigated. Hallimond tube flotation tests showed that unoxidized sphalerite did not float well without a collector. Flotation recoveries of greater than 95 percent were obtained without the use of a collector or frother after the sphalerite had been reacted with oxygen under pressure and water at pH 2.8 at room temperature. High flotation recoveries also resulted when sphalerite was reacted in acidic solutions in the presence of platinum sponge, titanium sponge, 316 stainless steel, copper turnings, or [10-5M++]. Conditions which produced high flotation recoveries of sphalerite yielded contact angles of 37° to 40° and also produced elemental sulfur. The increase in elemental sulfur on the surface of sphalerite was detected by elemental sulfur extraction with petroleum ether, electron spectroscopy for chemical analysis (ESCA), and the electron beam microprobe. The quantity of elemental sulfur formed was insufficient to be detected by infrared or Raman spectroscopy, or by the optical microscope or by the scanning electron microscope. An electrochemical type reaction for the production of elemental sulfur in acidic solutions was proposed. The cathodic reduction of oxygen was the slow step which needed to be catalyzed. A chemical type reaction which produced H2S rather than elemental sulfur was evident in non-oxidizing conditions.

Jan 1, 1974

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

Ease of excavation or rippability, also called diggability or excavatibility, is a critical decision-making parameter in the selection of both the overburden removal method and the required equipment in surface mining and geotechnical engineering projects. The most widely used method of estimating rippability is rock mass classification. Although there are different classification schemes in the literature, all of them have the two major limitations of sharp transitions at class boundaries and subjective uncertainties in decision making. In this study, the decision trees method was employed as a classification tool for estimating ground rippability, using the four rock mass parameters of weathering degree, uniaxial compressive strength, joint spacing and bedding spacing. The results were compared with those of the widely used method of diggability index rating (DIR) and a fuzzy-based DIR. The problem of subjective uncertainty was resolved in the proposed decision trees method, as the tree rules were derived automatically from the training data sets. Compared with fuzzy-DIR, a decision tree classifier is simpler, needs less computational time and is more appreciable by industry practitioners. Nevertheless, the proposed method is not flawless and, similar to both the conventional and fuzzy DIR methods, yielded poor estimations in particular instances. The limitations of the three methods are discussed.

Jan 1, 2015

By L. O’Connor, E. Tarshizi

The objective of this work is to provide a detailed review and a list of references in chronological order, comprising 80 recent technical papers, on the use of discrete-event simulation (DES) modeling in mining engineering. In this article, the review papers of published mine simulation projects through 2007 are summarized, and then a comprehensive review of individual articles published from 2008 to 2015 is presented. This survey work also includes analyses of the simulation tools used in the published projects, mining types and applications in order to assess these key features and evaluate the recent state of research in mine DES simulation. In addition, an interactive map visualization for the locations of the simulated projects is made available on a website to benefit current and prospective scholars in the field. The results of this investigation revealed that the most common application of DES in mining had been mining equipment selection and analysis, while ore processing and risk management projects were less frequently reported. The results also showed that modeling surface mines were in the majority, but the trend of publications for underground mine simulations had also increased. According to the results, ARENA was the most popular simulation software package, but several simulation tools that were only used once or twice in the mining projects are also included in this review.

Jan 1, 2018

By L. O’Connor, E. Tarshizi

The objective of this work is to provide a detailed review and a list of references in chronological order, comprising 80 recent technical papers, on the use of discrete-event simulation (DES) modeling in mining engineering. In this article, the review papers of published mine simulation projects through 2007 are summarized, and then a comprehensive review of individual articles published from 2008 to 2015 is presented. This survey work also includes analyses of the simulation tools used in the published projects, mining types and applications in order to assess these key features and evaluate the recent state of research in mine DES simulation. In addition, an interactive map visualization for the locations of the simulated projects is made available on a website to benefit current and prospective scholars in the field. The results of this investigation revealed that the most common application of DES in mining had been mining equipment selection and analysis, while ore processing and risk management projects were less frequently reported. The results also showed that modeling surface mines were in the majority, but the trend of publications for underground mine simulations had also increased. According to the results, ARENA was the most popular simulation software package, but several simulation tools that were only used once or twice in the mining projects are also included in this review.

Jan 1, 2017

By Simon Hille, Rein Raudsepp

Since 1991, the Porgera Joint Venture has processed refractory sulphide flotation concentrate by pressure oxidation with subse­quent gold recovery from the washed residue, by a conventional leach/carbon-in-pulp (CIP) circuit. The capacity of the plant has been progressively increased in five stages of development. In December 1995, a third oxygen plant was commissioned, raising the total oxygen production to 750 t/d and thus allowing for an increase in the oxidation capacity of the four autoclaves. The daily sulphur oxidation rate in 1995 was 192 t/d with 99.5% oxidation, as compared to 293 t/d in 1996 with 99.0% oxidation. This paper details the performance of the pressure oxidation circuit through 1995 and 1996, and compares measured plant parameters with the original Sherritt (now Dynatec) process design criteria.

Jan 1, 1998

You have been involved with research activities in froth flotation and size reduction. What do you think the future holds for these technologies? Froth flotation and size reduction are essential processing steps common to almost all current mineral-processing operations. The most significant recent advances in both of these technologies have been in the increased size of equipment and in some alternative machine designs, such as the column cells and the high-pressure roller mills. I believe that the next major area of improvement in size reduction will be at least partially driven by an improved awareness of controlling the conditions that influence the efficiency of particle breakage. This would include factors such as water-chemistry influences, the influence of fines from classification, chemical grinding additives and better rheology control. In froth flotation, significant changes are currently taking place in the plant use of frothers. Also, there will be an increasing number of new collector chemistries for certain types of flotation, such as with oxide minerals, oxidized mineral recovery in sulfide systems and improved selectivity with certain sulfide mineral systems. You have been active in implementing new engineering technology in industry. What do you think will be the technological future of mineral processing? Being involved in the invention and industrial implementation of new technology has been one of the most positive experiences of my career. I also have had the unique experience of working in the chemical and petroleum industries as well as in mineral processing. In my opinion, the future of mineral processing will be an exciting, wonderful work area in which to be involved. The development of new technology in minerals processing offers a special challenge compared, for example, to that of chemistry or chemical engineering. In successful industrial innovation involving minerals, having a sound theory is not enough. Instead, what is required is a valid blend of a good idea, meaningful laboratory characterization and, most key, the experience necessary to adjust the plant in such a way to incorporate the idea. The complexity of engineering systems that contain solids, liquids and gases, as well as highly variable natural mineral properties, means that nothing new comes easily. In some cases, it has been difficult to explain how processes practiced in industry for decades actually work, in terms of physical and chemical fundamentals. On the other hand, when a new idea is successfully implemented, the economic and professional returns can be very rewarding. I know of no more challenging field of engineering than minerals processing. What is your view of the future of the minerals industry in general? The need for minerals, metals and coal will be with us for decades to come. In many aspects, the minerals industry became global much earlier than some of the other industrial sectors that are currently experiencing globalization. I believe that fair international competition is beneficial to the users of minerals, metals and coals and to those involved in producing such materials. The key word here for a global economy to work is "fair." So the various playing fields involved such as finance, profit return, regulation and labor should be relatively level for all the players involved. Competition is an amazing driving force for innovation. This has been true in the minerals industry during the last few decades. The mining industry is producing more at less cost per unit than ever before in our history. I anticipate that this trend will continue as long as the global political situation remains relatively stable.

Jan 1, 1997

By J. A. Herbst

Mineral liberation modeling can be traced back to the early work 0fA.M. Gaudin up through more recent population balance modeling by R.p. King, J.A. Herbst and G.T. Adel. A more micro-scopic look was taken at the University of Utah in the form of the J.E. Sepulveda and J.D. Miller Pargen model which permits the creation of an arbitrary shape, multiphase particle made up of discrete grains. Recent work on image analysis and tomographic analysis by J.D. Miller and C.L. Lin have laid the experimental ground work for model validation, but until now it hasn&apos;t been possible to include the necessary physics of the particle stressing process to allow the development of a &apos;ffirstprinciples"mode1 which does not presuppose a "mode” of liberation (e.g., random or by detachment). Recent developments in discrete grain breakage (DGB) modeling now make a generalized physics based model feasible. This paper describes current work that is being done to develop a physics based discrete grain liberation (DGL) model. Two-dimensional and three dimensional simulation results exploring the effects of particle size, phase properties and loading type are presented. Relationships between energy based liberation efficiency, degree of random liberation and material properties are identified.

Jan 1, 2005

By Göksel Hızlı, Selim Ertürk, Ayşegül Bilen, Raşit Sezer, Cüneyt Arslan

The carbothermic reduction of celestite is the first step in producing many strontium products. The way materials move in the rotary kiln has an essential effect on the carbothermic reduction efficiency as well as the temperature. In this study, the reduction of celestite ore and excess carbon blend in a laboratory-scale rotary kiln was investigated. In the experiments carried out at three different temperatures, the rotational speed and slope of the furnace tube were altered, and their effects on the reaction efficiency were examined. The leachability of the reduced powders and the content of the unburned coke indicated the optimal parameters for the reaction.When the speed was increased to 10 rpm, the powders weremoremobile in the stack and could react more easily with the furnace atmosphere. According to the results, celestite can be reduced by carbon at temperatures of 1000–1200 °C, at rates of between 5% and 75%. The maximumreaction yield (75%) was obtained with a slope of 2° and a rotational speed of 6 rpm at 1100 °C.

May 7, 2020