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By Aert Driessen

Australia has large resources of rare earths -- 4.35 Mt of contained rare-earth oxides (REO) in the demonstrated category and 1.69 Kt in the inferred category. Australia's demonstrated REO resources are contained in about equal proportions in placer deposits, which also host Australia's titanium and zircon resources, and in hard-rock deposits. The largest single deposit of rare earths, at Mount Weld in Western Australia, is contained in regolith overlying a carbonatite pipe. It has a demonstrated resource of 1.73 Mt of contained REO and yttrium oxide. The largest demonstrated resources of REOs in placer deposits are in the Murray Bash, southeastern Australia -- a total of 1.90 Mt of contained RE0 in six deposits. However, the REO-bearing minerals (monazite and xenotime) are of secondary importance and their recovery will be determined by the market for titanium dioxide and zircon. The Murray Basin and other pre-Pleistocene basins offer the greatest potential for discovering more REO resources. Australia produces about 7000 t/year of REO in monazite and xenotime nearly all from Western Australia, as by-product of mineral-sand mining; monazite production is about 12 000 t/year (6600 t REO) and intermittent xenotime production is about 50 t/year (25 t REO). About 8000 t/year of monazite containing about 4400 t REO is not recovered separately, or is lost in tailings, as is an unknown but smaller amount of xenotime.

Jan 1, 1992

By Mayer Cori

El trabajo técnico que se describe en este artículo estuvo orientado a ubicar indicadores de productividad y eficiencia en las principales actividades de operaciones mineras subterráneas, con el objeto de diseñar e implementar la herramienta Business Inteligencie (BI), basada en un modelo de minería de datos de estructura ramificada (técnica ERPC) y un proceso analítico en línea (OLAP) que sintetiza la información en forma de reportes y cuadros de mando. La herramienta no solo hace posible tomar decisiones de manera fácil, oportuna y asertiva, sino también realizar consultas y reportes a la medida.

Apr 30, 2019

By O. C. Blade

This report on the properties of motor fuels sold through service stations in the United states was made in accordance with a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United states Department of the Interior. This paper is a continuation of a series made in cooperation with the Coordinating Fuel Research (CFR) Committee of the Coordinating Research Council (CRC), Inc. The first of this series of reports presented data on motor gaso1ines sold during the winter of 1935-36, and succeeding reports described motor gasolines sold during the summers and winters to and including the summer of 1941.3/ No reports were made on motor gasolines sold during the winter of 1941-42 and during the summer of 1942. However, starting with the winter of 1942-43, the semiannual reports were resumed

Jan 1, 1948

By A. W. Bryson, S. P. Fox, S. A. Godorr

"This work is an extension of a previous investigation on the development of surface roughness during electrodeposition of copper. A comprehensive model based on diffusion and migration in a force field together with surface diffusion and sticking probabilities is used to generate profiles which are compared to those produced experimentally. The roughness is characterized by using the technique of fractal geometry which is shown to describe both qualitatively and 9uantitatively the development of surface morphology during electrodeposition.The work is extended to the deposition of copper in the presence of various concentrations of thiourea. The development of roughness is observed experimentally on the edge of a thin copper disc mounted between two glass plates. This enables photographs to be taken at various stages during growth. The surface outline is digitized using an image analyzer which enables the fractal dimension to be determined as growth proceeds. As expected, the presence of thiourea at low concentrations produces a fractal dimension which is closer to unity (i.e. the surface becomes smoother).IntroductionThe development of surface morphology during electrodeposition has far-reaching implications for copper plating in the electrowinning and electrorefining processes. Short circuits as the cathode surface grows unevenly require operator intervention in a dangerous environment and imply processing delays, and the inclusion of electrolyte in small gaps in the plated cathode have implications in downstream processing of the cathode. Higher current densities are obviously desirable, as they result in greater production rates, but as shown by Ettel et. al.(l), Harvey et. al.(2), Cook (3), and Harvey et. al.(4), it is not possible to operate near the projected economically optimum conditions because the electrodeposition of copper from sulphate and acid solutions is a mass transfer controlled process. It has been shown (Ettel et. al.(l), Harvey et. al.(2)) that the closer a system operates to mass transfer limiting conditions, the poorer the resulting cathode quality. One solution is to use agitation techniques to increase the limiting current density. Another is to add surface active additives to the electrolyte which has been shown by Ettel et. al.(l), Harveyet. al.(2) and Afifi et. a1.(5) to allow higher rates of production without decreasing cathode quality. The second proposed solution is of interest in this work, since there is very little knowledge of the conditions under which these additives operate effectively, and little fundamental understanding of the mechanism by which they operate. The current work seeks to contribute to this field by correlating a simulation model with experimental results to describe the development of surface morphology in the electrodeposition process."

Jan 1, 1997

Jan 1, 1947

By Jeffrey C. Wynn

Since the early 1970's, the U.S. Geological Survey (USGS) has carried out exploration geophysical research on non-basemetal strategic mineral commodities, including uranium, lithium, gold, potash, and chromite. The chromite study (largely completed) and the potash study (still going on) carried out during the past 4 years have not been aimed at the discovery of new ore reserves, but instead were designed to complement exploration by private mining companies. The USGS has carried out research not normally conducted by these companies, but which can be used by them in their efforts to increase production of strategic minerals. Results of the chromite and potash studies highlight the importance of: 1) a laboratory-research phase (petrophysical and petrographic studies) at the beginning of work on any new commodity; 2) an operative or functional ore-deposition model to serve as a conceptual framework, and the necessity to continually test, refine, and modify it during the study; 3) indirect geologic/geochemical indicators, secondary associations, and the use of multiple physical properties; and 4) the use of a systematic inverse-cost sequential-exploration (i.e. lowest resolution and lowest cost first) strategy to keen the exploration economically reasonable. The keystone to the success of the study is frequent and substantive dialogue among geologists, geophysicists, and geochemists.

Jan 1, 1981

By P. Eadington

I feel sure that the apparent anomolies between his findings and ours arise as a result of the different experimental methods used. The modem oxygen electrode method he used is sensitive to nano moles of oxygen uptake whereas the method we used was only sensitive to micro moles at best. Furthermore, our experimental method did not permit measurements to be made in the first ten to fifteen minutes of reaction, the very time he is observing. Direct comparison of his data to ours is made difficult because of not knowing the specific area of the samples he used. However, we found that precipitation of PbS using sodium sulphide gave rise to samples of area approximately 30 m2 g - 1. Noticing the rapid decline in oxidation rate over ten minutes, as reported in Table 1, one can conclude that we could not measure the rate after ten minutes using our method. Taking the above area I estimate that at these rates only a small fraction of surface would be oxidised in a period of hours. I can only conclude that at some point a change in oxidation mechanisms occurs giving rise to a much faster rate such as we observed. Finally, I would like to comment on the apparent inertness of the homogeneously precipitated lead sulphide sample 11. This method of preparation we found to give specific areas of 20 to 30 times less than other methods and this would account for the very low oxidation rate.

Jan 1, 1982

By I. Nolet

Matte tapping is one of the most critical operations of a matte smelter. Every smelter has developed particular matte tapping practices and tap-hole repair strategies that are often based on the experience of the smelter personnel. As a result, very little information has been published on these critical topics. This paper aims at providing the information gathered from a survey conducted in the PGM and Ni industries on matte tapping practices and tap-hole maintenance strategies for different PGM-Ni matte smelting operations.

Jan 1, 2014

By F. Halverson

"The theory of flocculation usually is in a state of flux, involves many diverse phenomena, and is complex and sometimes contradictory in details. Instead of attempting a general discourse, I shall discuss selected observations made at our Stamford Laboratories, which impinge on theoretical aspects in two somewhat distinct areas of flocculation. Since some of you many not be familiar with flocculation, and :.n order that we all attach the same meaning to the jargon used, I first would like to review briefly a generalized picture of what goes on.Assume we have a suspension of particles in water, with a distribution in the sizes of particles. The surfaces of the particles interact to some extent with the water--· tending to alter the extent of hydration, may generate some ion exchange, all being somewhat variable with time--developing a surface condition which is very complex in details. We refer to this suspension as the ""substrate.""In the usual situation, if the suspension is allowed to stand quietly, the large particles settle out first, with somewhat smaller particles settling more slowly, and then there is a portion of very fine material which takes a long time or doesn't settle out at all. This resistance to settling t~ the very fine particles results from many factors, but all relate back to the size and density of the particles, to their surface properties, and to the other components in the aqueous suspending medium."

Jan 1, 1978

By Lawrence Addicks

F. N. FLYNN, Clifton, Ariz.-As a number-of my associates in Arizona know, for a great many years, I have felt that leaching was one of the coming problems. We are about to start experiments at Clifton, along the idea of leaching wet flotation concentrates direct, without roasting-differing in this respect from Mr. Addicks' suggestion. We are prompted in starting these investigations by the difficulty in. transporting and handling flotation concentrates, and consideration for drying and roasting dust losses. I have had the idea for 5 or 6 years past, that those very fine concentrates could best be treated by leaching at the concentrating plant, thus eliminating our transportation difficulties to the smelter, and dust losses at the smelter. Given flotation concentrate, if it must be dried and roasted, it would, in our case, undoubtedly be cheaper to smelt the calcine, but if it can be leached raw and wet and the drying difficulties- and dust loss eliminated, it would be very advantageous to leach it at the mill. I realize that it will be a difficult problem, and one which may take several years to develop, but if developed, it would pay for many years' expense of investigation, and we have been encouraged by our general manager to investigate its merits.

Jan 12, 1916

By J. F. Vynne

ABSTRACT This paper examines several of the systems and processes that have been developed over the past few years and are now being utilized by major mining companies on draglines in North America, Australia and South Africa. These technologies include production monitors and reporting systems, GPS navigation systems, structural integrity monitoring systems, structural analysis studies to increase the dragline rated suspended loads (RSLs) and inspection and response strategies. The use of these technologies provides significant increases in dragline production and reduces maintenance costs, downtime and the chance of a catastrophic failure.

Jan 1, 2010

By Ralph A. Sherman, John Blizard

The experimental investigation described in this paper was conducted to determine the relative combustibilities of different samples of blastfurnace coke when burned in a current of air in a small furnace. It was undertaken in connection with the work done by Perrottl and Kinney2 on the process of combustion in the blast-furnace hearth.3 Reference is often made to the "combustibility" of coke by blastfurnace men, but exactly what is meant by the term "combustibility" is somewhat vague. Brassert,4 in a paper before a meeting of blastfurnace men in 1914, refers to combustibility as follows: The value of the coke in relation to the heat reactions in the furnace is determined not only by the carbon content but even more so by its combustibility. This, in turn, is governed by its size, the physical and chemical composition of the carbonaceous substance forming the cell walls, and the interior and surface structure of the coke pieces. These properties are, in turn, influenced by the chemical and physical properties of the coals used for coking, the density of the cake of coal in the oven, the coking time, temperature and heat regulation of the ovens, and last, but not least, by the method of quenching, screening and handling the finished coke. What principally concerns the blast furnace is the rate of progression of the combustion, which depends not so much on the chemical analysis as on the physical qualities of the coke. It is this rate of progression that we term combustibility, which is the speed at which the carbon molecules in the coke combine with oxygen under given conditions. In general, what the blast furnace requires is a coke which will burn rapidly and with intensity at the tuyeres, yet which has a sufficiently strong structure and hard surface to resist abrasion and solution by CO2 in the upper part of the stack.

Jan 1, 1923

By John Blizard, Ralph A. Sherman

The experimental investigation described in this paper was conducted to determine the relative combustibilities of different samples of blastfurnace coke when burned in a current of air in a small furnace. It was undertaken in connection with the work done by Perrottl and Kinney2 on the process of combustion in the blast-furnace hearth.3 Reference is often made to the "combustibility" of coke by blastfurnace men, but exactly what is meant by the term "combustibility" is somewhat vague. Brassert,4 in a paper before a meeting of blastfurnace men in 1914, refers to combustibility as follows: The value of the coke in relation to the heat reactions in the furnace is determined not only by the carbon content but even more so by its combustibility. This, in turn, is governed by its size, the physical and chemical composition of the carbonaceous substance forming the cell walls, and the interior and surface structure of the coke pieces. These properties are, in turn, influenced by the chemical and physical properties of the coals used for coking, the density of the cake of coal in the oven, the coking time, temperature and heat regulation of the ovens, and last, but not least, by the method of quenching, screening and handling the finished coke. What principally concerns the blast furnace is the rate of progression of the combustion, which depends not so much on the chemical analysis as on the physical qualities of the coke. It is this rate of progression that we term combustibility, which is the speed at which the carbon molecules in the coke combine with oxygen under given conditions. In general, what the blast furnace requires is a coke which will burn rapidly and with intensity at the tuyeres, yet which has a sufficiently strong structure and hard surface to resist abrasion and solution by CO2 in the upper part of the stack.

Jan 1, 1923

By Michael D. Balen

The U.S. Bureau of Mines (Bureau) is currently conducting a four-year study to assess the mineral resources and the mineral development potential of the 5.7 million acre Valdez Creek Mining District (VCMD) located in southcentral Alaska. The VCMD study is part of the Bureau's ongoing statewide mining district evaluation program. This report is a summary of the 1988 field work. The field work involved collection of reconnaissance placer and rock samples, and also involved sampling and examination of the mines, prospects, and mineral occurrences which were identified by literature research of the geology, exploration history, and mining history of the district. During the 1988 field season, Bureau personnel spent a total of 11 weeks in the field, collected 1,006 rock and placer samples, and located, mapped, and sampled 106 of the known mineral occurrences. The Bureau has visited 243 of the 250 known mineral occurrences during the course of the VCMD project. Reconnaissance sampling for placer occurrences resulted in the identification of 4 previously unreported gold placer occurrences, and identification of 5 occurrences that contain detectable levels of platinum or palladium. Reconnaissance sampling for lode sources of base and precious metals resulted in the identification of 5 new Lode gold-silver occurrences, identification of 2 occurrences that contain elevated quantities of chromium, cobalt, nickel, palladium, and platinum, and identification of one occurrence that contains elevated quantities of copper, molybdenum, anti zinc.

Jan 1, 2011

By Jean-Pierre Hamelin

Ground movements induced by underground excavation are always of critical concern, particularly in urban areas. Compensation grouting now appears as a safe means to control these movements. The paper presents new advanced systems developed by the specialist contractor to bring, at all stages of the project, an efficient control of operations and presents a case history taken from the project at Tren Urbano, Rio Piedras Section, constructed beneath an historic commercial section of San Juan de Puerto Rico.

Jan 1, 2000

By K. W. Fritzsche

The prosperity of any nation depends, to a large extent, on its natural resources such as oil, coal, 'metal, timber, waterpower, and fertile soil. Each one of these resources forms the basis of a huge industry. The mining and smelting industry ranks among the first since it paves the way for a number of other industries. The mines and smelters provide a market for electric power, coal, timber, and agricultural products: other industries in turn provide a market for metals and non-metals. The real pioneering, however, is done by the prospector who goes into the wilderness to search for the ores from which the metals are to be extracted for the use of men. Prospecting is an interesting and fascinating occupation. There are many difficulties and hardships in the way but the lure of gold and the vision of finding an outcrop that may develop into a large bank account, within a reasonably short time, will urge the prospector forward. Thus, on the outskirts of this northern hemisphere hundreds of prospectors are searching and toiling and of whom nothing is known or heard until they reach civilization and announce a new discovery. Then a mad rush takes place and everybody who can afford to go will take a gamblers chance and plant stakes in the neighbourhood of the new discovery, or wherever an outcrop of mineralized rock can be found, with the hope of winning a fortune.

Jan 1, 1925

By W. E. Howlett, R. L. Slobod

Jan 1, 1965

By H. E. Sadler, B. Silliman

INTRODUCTORY NOTE. THE research here recorded was undertaken early in the present year, and has been prosecuted steadily for about eight months. While the work has been under my constant supervision and advice, the labor has all been performed by Mr. Sadler, to whom is chiefly due the development of the successive steps which have led to the final result. The process is better than I dared to hope, and we are able to place at the command of chemists and engineers interested in the matter an apparatus of continuous and uninterrupted action, and methods of analysis by which the daily averages of the two variable and inconstant factors of illuminating gas, ammonia and sulphur, may be determined with all needful accuracy, even by those little skilled in chemical manipulation, and with very little loss of time. This research has been carried out in the laboratory of the New Haven Gaslight Company. B. SILLIMAN. October 17th, 1876.

Jan 1, 1877

By S. Thibeault, P. Filiatreault, B. Straight, D. Castendyk, L. Cameron

"Unmanned aerial vehicles (UAV), or drones, capable of collecting and retrieving water samples from pit lakes, tailings ponds and other mine water basins will revolutionize environmental programs by lowering sampling costs and reducing safety related risks. Costs typically include a boat and associated equipment, boat transportation, road maintenance, water safety devices, water safety training, and additional staff. Typically, the total cost can exceed $20,000 USD per sampling event (excluding lab analyses). Hazards include potential for drowning, unstable pit walls, and unconsolidated sediment surrounding tailings ponds. Hatch has developed a novel device for aerial drones which currently enables the collection of water samples from depths up to 390 ft (119 m). This system only requires a pilot, a sample technician, and a safe operations point overlooking the water body. Hatch anticipates this will reduce monitoring cost by at least 50% while improving safety, reducing staffing requirements and accelerating data acquisition. This manuscript demonstrates profiling and sample collection from a 95 ft (29 m) deep reservoir and a 377 ft (115 m) deep pit lake, and highlights the potential of this emerging technology. INTRODUCTION Working on or near water at active, closed, or abandoned mine sites is inherently dangerous. Between 1996 and 1999, the United States Mine Safety and Health Administration (MSHA) reported 17 fatalities involving drowning at US metal, non-metal, and coal mines (MSHA, 2000). Open pit mines which fill with water following mine closure, called pit lakes, present numerous risks to environmental monitoring teams including drowning, hypothermia, falls to the ground from the top of high walls, and rock avalanches resulting from steep, unstable pit walls. Some pit lakes are simply not easily accessible for ongoing monitoring. However, the routine collection of water samples from the entire water column on at least an annual basis is required to monitor the evolution of water quality over time, to verify the accuracy of numerical predictions, and to manage lake water chemistry in order to produce “treatable” influent to water treatment plants, and ultimately, produce acceptable site discharge water quality. As a product of these risks and the need for water sample, mining companies spend considerable expense on pit lake safety as part of monitoring. This includes training personnel for “on water” duties and hazards, purchasing or hiring specialized equipment and personnel (such as boats, boat operators, personal floatation devices, and mustang suits), stabilizing pit walls and maintaining safe access roads to the lake surface, employing spotters with direct communication to emergency medical services to watch sampling activities (because cell phones and radio signals can be blocked by pit walls), and utilizing redundancy to prepare for unexpected incidents and accidents. For example, one Canadian mining company requires pit lake water samplers to hold Marine Emergency Duties (MED) training to ensure the entire boat crew is sufficient and competent for the safe operation of the vessel, and uses three boats for water sampling: two on the water at all times, and one on the shoreline, ready to deploy. The costs of these safety mechanisms greatly adds to the overall expense associated with pit lake sampling. Consequently, environmental programs may need to reduce the frequency of pit lake sampling in order to keep monitoring programs within an acceptable budget"

Jan 1, 2017

By S Zaffron, O Loffredi

A critical concern of any mining company today is its relationship with the different stakeholder groups impacted by the operational activity û communities, unions, vendors, local partners and competitors, local and federal governments, interest groups and non-government organisations. What ten years ago would have gone unnoticed, now, and even more so in the future, can drastically impact the profitability and even existence of a mining operation. This paper describes the development and delivery of a new paradigm for creating effective external stakeholder relationships. We report on the actual measurable results of an integrated and highly complex initiative led by Lonmin Plc (Lonmin) and Landmark Education Business Development (LEBD) that significantly altered the nature of the relationship with the stakeholders. Given the nature of the long-term investment required in a mining operation, any breakdowns or surprises in its relationship with external stakeholders brings with it the potential for major loss. The transformation of executive and senior management and community leadership was required to enable them to be effective in managing this complex set of circumstances.

Jan 1, 2006