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By D. W. Smith, Robert F. Mehl

It has been shown by numerous studies that the orientations of new metal crystals are determined by the orientations of the crystals in the original matrix, whether these new crystals are formed by recrystalliza-tion, by precipitation from solid solutions, or by transitions in the solid state. The orientations of crystals formed by recrystallization of cold-worked metals that bear preferred orientations are occasionally simply related to the initial preferred orientation; often, however, the relationship is not simple, but complicated and obscure in origin.1 The orientations of crystals formed by precipitation from solid solutions have been shown by many studies in this and other countries to be determined by the orientation of the crystals of the solid solution stable at the higher temperatures, though here again complicated cases have been found and no general theory is available.2 Related to this latter class are the relationships found in crystals formed by suppressed transforma-

Jan 1, 1935

This Bureau of Mines publication summarizes the industrial minerals industry of Idaho. It contains information on 119 principal deposits of 21 commodities in the State and describes the institutional and infrastructural factors affecting mineral development.

Jan 1, 1991

By S. Don Brown

Between 1987 and 1988, the Bureau of Mines studied the mineral resources of the White River National Forest and part of the Arapaho National Forest to appraise the resources present and to determine the types of deposits, and their location, that could be mined economically if sufficient demand and metal prices existed. The study included a comprehensive literature search and a limited amount of field investigation of minerals and mining activity in and near the Forest. Mineral resource information indicates that in the Gore Range the area between Tennessee Pass and Gilman may contain large base-and precious-metal deposits, and could be the focus of exploration activity in the near future. The Breckenridge mining district was found to have a moderate to high likelihood for mineral exploration and possible development of gold. Recent exploration and minor development work has occurred in several other areas: Montezuma, Kokomo-Tenmile, and Upper Blue River districts, and portions of the Sawatch Range. Limestone, marble, sand and gravel, rock for crushed aggregate, and other industrial rocks have been recently mined or Quarried in the Forrest, and will likely be mined or quarried in the near future. Currently coal is being produced at one mine in the Forest, and extensive identified coal resources are located in the Forest. Parts of four known gas fields lie within the Forest west of Glenwood Springs; there is current production at one field.

Jan 1, 1990

By B. Haimson

A new loading apparatus was fabricated and used to conduct true-triaxial compression tests on KTB amphibolite, a crystalline basement rock. Tests in dry jacketed samples reveal that the intermediate principal stress has a significant effect on the onset of dilatancy and on rock strength, contrary to the implicit assumption made by Mohr-type failure criteria. Failure is induced through a shear fracture that dips steeply in the direction of the least principal stress. Experimental results lead to a new generalized strength criterion in terms of all three principal stresses. Unjacketed KTB amphibolite specimens, exposed to confining fluid, are considerably weaker than the jacketed ones, despite the negligible porosity and permeability. Failure is facilitated by several closely spaced subparallel tensile cracks normal to the least stress direction. SEM analysis suggests that microcracks developed upon dilatancy onset are penetrated and extended by the confining fluid, bringing about the unexpected rock failure mechanism at reduced stress levels. Un nouveau dispositif à chargement fut fabriqué et utilisé afin de réaliser un vrai essai de compression tri-axial sur KTB amphibolite, une roche cristalline du sous-sol. Les essais effectués sur échantillons enveloppés et secs révèlent que les contraintes principales intermédiaires affectent considérablement le début de la dilatance et la résistance de la roche, contrairement à la supposition fondée sur le critère de rupture de Mohr. La rupture est produite grâce à une cassure de cisaillement très incliner en direction où la contrainte principale est moindre. Ces résultats expérimentaux indiquent un nouveau critère de rupture général en fonction des trois contraintes principales. Les échantillons de KTB amphibolites sans enveloppe, exposés à un liquide confiné, sont considérablement plus faibles que ceux enveloppés, malgré la porosité et la perméabilité négligeable. La rupture est facilitée par plusieurs fissures de traction adjacentes et sub-parallèles, normales à la plus petite contrainte principale. L’analyse SEM suggère que les micro-fissures développent suivant le début de la dilatance, elles sont pénétrées et agrandies par le liquide confiné, produisant un mécanisme de rupture de roche inattendu, ceci à un niveau de contrainte réduit. Ein neuer Ladungsapparat wurde hergestellt um real - triaxiale Druckfestigkeitsversuche in KTB Amphibolit, einem kristallinen Grundgebirgsgestein, durchzuführen. Messungen in trockenen, bedeckten Proben zeigen that die mittlere Hauptspannung eine bedeutende Wirkung auf das Einsetzen von Dilatanz und auf die Stärke des Gesteins hat, im Gegensatz zu der impliciten Annahme auf Grund von Mohr-ähnlichen Versagungskriterien. Versagen ist induziert durch eine Scherfraktur die sich steil in die Richtung der geringsten Haupspannung nach unten senkt. Messergebnisse führen zu einem neuen, verallgemeinerten Stärke Kriterium dass auf alle drei Hauptspannungen basiert ist. Unbedeckte KTB Amphibolit Proben, die unmittelbar den umgebenden Fluiden ausgesetzt sind, sind wesentlich schwächer als bedeckte, trotz geringfügiger Permeabilität und Porosität. Versagen wird gefördert durch mehrere, nebeneinander liegende, sub-parallele Spannungsbrüche, normal zu der geringsten Spannungsrichtung. SEM Analyse lässt vermuten dass Mikrobrüche, die sich beim Überschreiten der Dilatanzschwelle entwickeln, durch die umgebenden Fluiden fortgepflanzt und weiter verbreitet werden, und unerwartet, auf Grund der reduzierten Spannungswerte, den Versagungsmechanismus des Gesteins einleiten

Jan 1, 2003

Despite the fact that mined minerals and gemstones have allowed human beings to continuously improve their standard of living throughout the ages, mining has also been implicated in violent conflict for two principle reasons. The first is that mineral resources have been used or traded to conduct or finance violent conflict from small to large scales. The second is the substantial social, economic and environmental changes that occur in a community or a region as a result of mining activity which can either precipitate or re-awaken latent conflict. A modern complication of mining-related violent conflict is the trend for activists, international NGOs and intergovernmental organisations (e.g. the United Nations) to regard any human consequences of resource extraction in terms of Human Rights violations. Acknowledging but not labouring the Human Rights implications of mining-related violent conflict, this paper explores whether or not there is a relationship between the actual or perceived value of mineral resources and the level of violence that occurs in mining-related conflicts. Key to the investigation is a mapping exercise of mining related conflict from 2005 ? 2012: to see where mining related conflict is happening; to identify precipitant causes of mining related conflict; and, to discover what correlation ? if any ? there might be in the degree of violence and the value of the mineral(s) implicated. Findings of the analysis are presented in this conference paper.

Aug 1, 2013

By G. Goellner

The thick alluvial sand and gravel deposits along the base of the San Gabriel mountain range in Southern California area have been mined for construction aggregates for over 100 years. Encroachment of high-density urban populations in this area has led to concentrated mining in a handful of open pit mines with single production faces reaching up to 55 m (175 ft) in height, and long transportation distances from the pit to the processing plant. Aggregate producers have responded to these challenges by developing innovative mining systems which enable low-cost, full-face mining of the alluvial material, and low cost delivery of this material to the plant.

Jan 1, 2004

By Allen Chung, John Twomey, Christopher J. Greet

"It is widely accepted that the type of grinding media has an impact on the grinding chemistry and subsequent flotation behaviour of the sulphide minerals being separated. There are countless laboratory investigations demonstrating that inert grinding media produces more oxidising pulp potentials, reduced levels of grinding media corrosion products and superior concentrate grades and valuable metal recoveries. However, taking these results to industrial scale has proven difficult.Work conducted at the Ernest Henry Mine, in north western Queensland, Australia, at laboratory and pilot plant scale clearly indicated that using a high chrome grinding media resulted in significant improvements in both copper and gold recoveries. However, advancing this work to plant trial represented considerable financial and technical risk to the mine.This paper provides details of the protocol developed and used during the high chrome grinding media plant trial. It describes the test regime employed to measure changes in pulp chemistry, and the statistical methodology utilised to interpret the results. The work also highlighted the need for close cooperation between the metallurgists on site and the researchers conducting the trial.To date, the trial has produced excellent results: indicating that the copper recovery has improved by about 2 percent. The successful application of high chrome grinding media to the Ernest Henry ore has increased metal value by $18.7 million USD per annum based on current spot price for copper.INTRODUCTIONTheoryThe application of electrochemically inert grinding media to mineral systems has been extensively studied (Table 1). Broadly, these studies indicate that most sulphide minerals are more noble than the grinding media used during comminution. Therefore, the sulphide minerals are cathodic with respect to the forged steel grinding media, and the following reactions apply:"

Jan 1, 2011

By J. R. Goode

Up to one half of neodymium and praseodymium production, key ingredients in permanent magnets, is produced illegally. About 60% of cobalt production, critical in lithium-ion batteries and other applications, comes from central African states, and much of it is produced illegally. Tantalum, important in modern electronics, is also primarily sourced from central Africa and, again, much of it illegally. Illegal mineral production, as exemplified here, is often used to fund armed conflict. Furthermore, it is typically conducted with scant regard for human rights and environmental protection. It also leads to depressed prices which in turn limits the possibility of legitimate producers entering the market. Systems of traceability and provenance, along with cooperative supply chain participants can limit the production of illegitimate material and thereby improve conditions in the countries of origin and reduce downward pressure on prices.

By G. M. Bond

Reduction of the emissions of greenhouse gases, such as CO,, is currently the subject of extensive research. A novel strategy is put forward here, based on a biomimetic approach providing accelerated deposition into carbonate form for long-term sequestration. It offers the advantages of a process that: does not require concentration of CO, from flue gases; could potentially be used in an on-site scrubber to provide a plant-by-plant solution to reducing CO, emissions; is an environmentally benign procss with an environmentally benign product; and is based on readily available, low-cost reagents (except perhaps the catalyst).

Jan 1, 1999

By Reinhardt Thiessen

Views and conceptions of the origin, composition, and general nature of coal differ so widely that to determine the real extent of actual knowledge is no easy matter. The chemist finds difficulty in attacking the chemical problems and the engineer lacks a broad chemical basis for the study of his problems. Thus the economical and efficient utilization of coal in the industries suffers from a lack of knowledge of the composition of coal itself. Most scientists interested in this matter, as has been brought out in discussions during the recent investigation of coal problems, appear to have only a vague idea of the components of coal and their origin. Some are even in doubt as to whether substances derived from the wood and resins of plants form a part of coal; and few seem to have more than the dimmest idea of what are the components of coal, the condition in which these now exist, and the transformations that they haye undergone. Although during the paiilt century or more many co.rrect observations have been made and recorded, these were falsely or inadequately interpreted, so that many of the interpretations rendered are contradictory. As a result there has been great confusion. Many of the observations made in the past, although accurate and correct, could not be explained, because the principles involved in a correct solution of the problem were not then known. For example, Parkinson, Hutton, Petzhold, Guembel, and others made valuable discoveries regarding the processes by which plant substances are transformed into coal, but as the principles involved are those of colloidal chemistry, a science not known to the scientific world of that time, the observed facts could not be interpreted and the solution of the whole problem was blocked. The explanation of the true meaning of the alternating bright and dull bands so familiar in all ordinary bituminous coals afforCls another example. This banding has been observed and recorded from the earliest times, and has led to the forming of many false theories. Some gAologists, for example, have endeavored to explain the bands as due to alternating climatic conditions during the coal-forming period. Had the geologists known the true nature of coal they could not have made this mistake nor many others made in the past. To fill in a few of these gaps and to clarify some of the existing confusion is the aim of this paper. The immediate cause that led the author to investigate further the composition of coal and the origin and structure of its constituents was that when an attempt was made to discover the meaning of the coking and noncoking properties of coal a more exact knowledge of the nature of coal was required than was then available.

Jan 1, 1920

By G. W. Josephson

JUDGING by the progressive atmosphere prevailing in the nonmetallic mineral industries during the past year, postwar conditions were healthful though inflationary. Demand for most industrial mineral products has been exceptionally high and many new production records were attained. Severe shortages of some commodities existed, especially building materials and fertilizers. Production costs and prices increased and profitable operation was general. Under these conditions expansion programs were the order of the day. Ample funds were available to finance the purchase of good equipment; and, as wages and other operating costs were increasing, primary emphasis was placed on attaining maximum efficiency in new installations. These efforts were hampered by shortages and slow delivery of desirable equipment, so compromises in design were often necessary. However, on the whole, production practice improved.

Jan 1, 1948

By David R. Macedon

"Through the years, a wide variety of dust control methods have been utilized at mineral processing operations. While some have been successful, many have been highly ineffective. Dust Control systems currently in use include baghouse systems, fog systems, surfactant spray systems, and foam dust suppression. While baghouse systems can be effective, they are capitalintensive and costly to operate and maintain. Chemical dust control programs can be very effective. However, if applied incorrectly, they can have detrimental effect on mineral recovery. Thus, many operations utilize a combination of baghouses and water, often with limited success.Recent advancements in surfactant and polymer chemistry have resulted in substantially improved chemical dust suppression programs. These products range from non-corrosive surfactant/humectant combinations for road dust control to foam-based systems for crushers and transfer points, to advanced polymers for pile binding and soil stabilization. These advances are discussed in detail, citing results from fieldwork in the precious and base metals industries.INTRODUCTIONThe global nature of the mineral processing industry presents a unique set of challenges. Traditional thinking would tell us what works in one place should work in another. This could not be further from the truth in the area of dust control. We learn very quickly that there are a number of factors that can affect the efficiency and success of a dust control program and that these factors are not all chemical or equipment related. Some of these factors include facility maintenance, product selection, water quality and characteristics, and economic considerations.What has been learned from past experience is that each mineral processing plant presents a unique set of factors that will affect the ability to create an optimal dust control program. This paper presents a myriad of treatment options that will highlight the advancements in chemical dust suppression products and equipment."

Jan 1, 2004

By Paul L. Russell

Interest in the western oil shales of the US began in about 1908, with the first retort in Colorado constructed in 1917. The most successful early developments were near Elko, NV, where the Catlin Shale Products Co. produced more than 1.9 dam3 (12 000 bbl) of shale oil during 1920-1924 and at Rulison, CO, where a US government operation produced about 570 in 3 (3 600 bbl) of shale oil during 1926-1929. Plentiful low-cost crude oil was developed about this time and shale oil was of little or no interest until after World War II. From 1944 to about 1972, several companies, and the US government, operated shale oil mines and recovery plants in Colorado. While technical successes were achieved and an estimated 40-56 clam' (250 000-350 000 bbl) of shale oil were produced, economics were not favorable and commercial production was not achieved. In recent years domestic production of crude oil supplies has not kept pace with US consumption. The growing shortfall has been met with imports. The cost of imported oil has continued to escalate and increased US dependence on petroleum imports are national concerns, because of the negative impact on US balance of payments and an increasing dependence on other nations for US energy needs. In 1978, petroleum imports equaled about 44% of demand, up from 23% in 1970, but down from 48% in 1977 because of availability of Alaskan North Slope crude oil. Reduced domestic consumption and other factors have reduced current imports to about 40-45% of de¬wand-but at ever increasing cost. The growing shortage of crude petroleum and its increasing cost have resulted in renewed worldwide interest in oil shales. In the past, the main obstacle to oil shale development (progress toward commercial production) has been economics-shale oil cost too much to develop and thus could not compete with conventional petroleum crudes. Even with today's inflated energy prices, some experts say the production of synthetic crude oil from oil shale is, at best, marginally economic. The 1973-74 Arab oil embargo and increased crude oil costs-along with the federal government's offer to lease oil shale lands-resulted in renewed

Jan 1, 1981

By T Hirsi, M Weatherseed, T Ritasalo

Cooling tower design has not advanced significantly in the last decade. Recognising this, Outotec has developed an innovative horizontal outflow cooling tower with increased performance compared to conventional design cooling towers.Outotec® Cooling Towers operate today in applications such as spent electrolyte cooling in zinc plants and for gypsum removal before copper solvent extraction. In such applications the use of this latest design has enabled increased production and lower maintenance costs in the downstream operations.In actual operations, the cooling performance has been confirmed at start-up, and has demonstrated that the towers operate in accordance with the CFD modelling. In the last three years these towers have proven themselves in commercial operation to operate with high efficiency and availability.This case study will outline comparative data, collected over two years at a site where both Outotec and conventional cooling towers are operating. The data shows that Outotec cooling towers require less than half the maintenance time of conventional cooling towers, when adjusted to a total solution flow basis. A close partnership approach with the site has allowed continual development, ensuring high availability and high performance.Experience with previous cooling tower installations guided the development of maintenance philosophies and procedures; this resulted in a design where maintenance intensive components were accessible from the top of the cooling tower. This allows safe access to components and maintenance with little or no downtime.CITATION:Hirsi, T, Ritasalo, T and Weatherseed, M, 2015. Improving cooling tower performance with innovative horizontal outflow design, in Proceedings MetPlant 2015, pp 396–402 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By Deepak Vidyarthi

This paper deals with the significance of Explosive Energy in the optimization of blast design parameters, and the benefits emerging out of it. It is based on the original work done by the author in developing and successfully implementing a site-specific software package on ‘Blast Design Optimization’ at Kudremukh Iron Ore Mine in India with a production level of 22.5 million tonnes of crude ore and off-take of Explosives of approximately 5500 tonnes per annum. The software package has yielded tangible results in effecting reduction in Explosive Consumption, substantial savings in the Cost of Explosive, besides Environmental Improvements by way of attenuation of Blast Induced Ground Vibrations as well as Air-Blasts. By carrying out regular ‘Regression Analysis’, and determination of the Rock Constants, it has been possible to further develop software packages as well as prediction curves for prediction of Peak Particle Velocity, Safe Charge of Explosive, Air-Blasts etc. A model has also been developed for the prediction of ‘Fly Rock’ although at KIOCL, fly rock does not pose any problem.

Jan 1, 2006

Mining education has received almost continuous discussion since its inception and most people engaged in the mining industry and in mining education feel at some time the urge and necessity to express their views. This paper is not a comprehensive survey of past and present practices and accepted principles, but a personal opinion of the form mining education should take at university level. It is expressed because of a dissatisfaction with the existing courses offered to students. It is hoped to provoke discussionand bring forth guidance to those engaged in mining education. After all, students spend four or five years at a university and it is desirable that the graduate should be something more than just those many years older at the end of his course.POST GRADUATE EMPLOYMENTThe first problem confronting the university should, be to discover what the mining industry wants and expects or graduates. This must influence the university course and yet universities have done little to seek this information, and if suggestions have been offered by industry; universities appear to have made little use of them. University mining curricula are basically what they were 50, 100 and even 200 years ago. (See Appendix.) Whether this reflects the unchanging problems of mining the wisdom of early professors, the conservatism of subsequent professors or inability to apprectate necessity for changes, is debatable.Unfortunately there is no uniformity in the type of employment offered to new graduates: Some mining...

Jan 1, 1959

By NEWTON C. MARSHALL

AS every school boy knows, the Andes mountain range forms the backbone of South America, extending the full length of the continent along its western edge and fairly close to the Pacific coast. But in Colombia these mountains are divided into three distinct ranges known as the Western, Central and Eastern ranges of the Andes. United at the southern end, they spread out like three fingers in a northerly direction across the Republic of Colombia. These great natural barriers have only in recent years been tarried by railroads or wagon roads, and they have had their effect upon the history of the country, both political and ethnological. Each of the three ranges dies out and dwindles away before reaching the boundary of Colombia on the Caribbean Sea. When I studied my geography as a youngster 1 used to think that the

Jan 1, 1935

By Mayfield P. L J, Honeyands T. A

BHP's two million tonne per annum nominal capacity Hot Briquetted Iron (HBI) plant at Port Hedland in the Pilbara region of Western Australia is based on FINMET¦¦ direct reduction technology. The FINMET¦¦ process produces direct reduced iron (DRI) by reacting fine iron ore with reformed natural gas in a series of fluid bed reactors and then hot briquetting this DRI into dense, high quality iron briquettes. The Port Hedland HBI project represents a major investment in the chemical processing of Australian minerals to higher value products prior to export to Asian markets. This paper describes the FINMET" process and technical aspects of the high-quality HBI product, and provides an update of the current status of the project.

Jan 1, 1999

By Carlos Soria

El presente texto describe los Sistemas de Gerencia de la Información y su aplicación en la industria minera con el objetivo de optimizar la gestión total de la empresa. Dichos sistemas manejan información del proceso y sus valores de producción, cálculos, consumos de energia, emisiones de plantas, tiempos de funcionamiento de equipos, eventos, alarmas, mediciones de laboratorio y control estadístico, etc. De forma que dicha información pueda ser reunida y consolidada, convirtiéndose en materia de significado y relevancia disponible en base a análisis, reportes, listas, tendencias y gráficos para que el usuario final de una planta o en sus oficina pueda tomar mejores decisiones.

Jul 17, 2000

By R. Sweennen, A. Vervoort, J. Caers

A case study is presented of the mechanical behaviour of fractures in the Westphalian A and B siliciclastic succession of mud-, silt- and sandstones with intercalating coal layers in the Campine basin of northeast Belgium. Mining ceased in the area in 1992 and a pilot well was drilled to assess the feasibility of methane extraction by hydraulic fracturing. Work was carried out to study the influence of types of cement fill in fractures on the shear behaviour of the rocks by comparison with that of the coal seams. X-ray computerised tomography was used for visual appraisal and selection of jointed rocks before destructive shear testing was carried out. Two major type of veins were found to be present, one cemented with carbonate and the other with kaolinite or kaolinite/carbonate. Uniaxial compressive strength and shear tests showed that differentiation of the two types of veins was vital in evaluating the strength of the sandstones, as cementing of the fractures by rigid carbonate minerals can reinstate the strength of the rock masses to that of the intact material. Kaolinite was more susceptible to plastic deformation than carbonates

Jun 19, 1905