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By G. D. Markland

The Moose Mountain mine is located in a belt of Precambrian volcanic rocks situated 20 miles north of Sudbury, Ontario. It was the first iron mining operation in the Archean iron-formations of the Canadian Shield. The ore is believed to have been formed in an environment of active volcanism, being part of a pyroclastic and volcanic series where only the iron-formation and chert qualify as chemical sediments. The volcanic environment, subsequent regional tectonics and metamorphism produced orebodies which differ from the main sedimentary iron ranges of the world in such features as continuity, grade, structure and metallurgical characteristics. The orebodies occur as relatively small lenses which have been complexly folded, faulted and intruded by acidic and basic dykes.

Feb 1, 1966

By A. E. Hunt

Over the past twenty-live years since large scale truck haulage in open-pit mining began, the periodic introduction of Larger capacity vehicles has provided increased productivity and reduced costs. WISEDA Ltd. has introduced a 220 ton capacity, two-axle rear dump, diesel-electric truck for the world-wide large open-pit mining industry. Design features and components selected in the development of this vehicle will be presented along with operating experience and a brief history of rear dump truck evolution.

Jan 1, 1983

By Earl F. Hastings

The Pilgrim mine, operated by the Pioneer Gold Mining Co., is 9-1/2 miles west of Chloride in the Pilgrim mining district on the eastern slope of the Black Mountains, or River Range, Mohave County, Ariz. In March 1937, 100 tons of gold ore per day were being mined and milled at the property by a total force of 5i men. Climatic conditions allow year-round operations. Due to present activity in the county there is an ample supply of labor for the requirements of the mine. The Pilgrim is the only producing property within s radius of 6 miles; recently, however, the South Pilgrim Mining Co. has launched a development campaign on claims that adjoin the Pioneer Co. property to the south.

Jan 1, 1937

By A. Holland, T. Krumins, E. Olin, J. F. M. Castilleja, J. Geldart, C. Fleming, I. Jackman

A flowsheet has been developed to treat the flotation tailings from a copper mine in Mexico to recover gold and silver by cyanidation and carbon-in-pulp (CIP). The plant will treat ~15,000 t/day of a 60:40 blend of current flotation tailings and the mine’s historic tailings. The tailings also contain a significant amount of cyanide-soluble copper, and the economic viability of the project is strengthened by recovering most of the copper and cyanide associated with this process. The solution and solid phases in the CIP tailings will be separated in a counter current decantation (CCD) circuit and the CCD solution overflow will be treated by a SART Process. Copper precipitates as a salable copper sulphide product in the SART Process and the cyanide that is associated with the copper complex is regenerated as free cyanide. After SART, a portion of the SART product solution will be recycled to leach to reuse the free cyanide, while the remaining solution will be used as wash water in the CCD circuit. Incorporation of the SART Process in the flowsheet allows the CIP circuit to be operated aggressively as a gold plant, which means most of the silver in solution passes through CIP to SART. Silver co-precipitates with copper in SART and is recovered very efficiently with the copper sulphide by-product. Incorporation of SART also allows the leach and CIP circuits to be operated with relatively high levels of free cyanide, which enhances silver leach kinetics and helps keep copper from loading onto the carbon in CIP. The flowsheet was developed in the laboratory and successfully demonstrated in a fully-integrated pilot plant in 2018.

Jan 1, 2019

By S. Bhattacharaya, S. Aich, B. K. Nandi

"At present scenario, there has been an increasing demand in the usage of blend coal in power sector; regardless of how, specific knowledge on burning and ignition characteristics and their interactive effects is stingy. In this work a detailed investigation was therefore taken up to study in detail the combustion characteristics of selected coal samples and their blends. Certain parameters were believed to have significant effects on combustion characteristics of individual coal and their blend. Major parameters identified for this purpose included proximate analysis, combustion conditions, heating rate, reaction regions, blending ratios, ignition condition, reactivity (or reaction rate) and burnout temperatures. With the help of these parameters, thermal features and reaction kinetics of the individual and blended samples were investigated through a qualitative and quantitative thermo-gravimetric analysis of two different individual coals and their blend carried out in an oxygen atmosphere from ambient to 800 0C at a constant heating rate of 10 K/min. A significant difference in terms of rate of mass loss with temperature correlated from Arrhenius expression along with coal-coal blend interactions and deviation from their expected behaviour, have been observed between the kinetics of individual and blend samples, the latter showing better ignition performance and comprehensive combustion phase. It was also found that particles having the lowest percentages of volatile matter and ash could possibly be blended with particles having high ash and volatile matter to meet the required burning condition which can be effective in terms of cost savings, improved fuel economy, reduced undesirable exhaust emissions and improved safety of coal burning equipment. Experimental results further indicated that individual samples and coal blend samples have different combustion features in terms of residue left, peak temperatures and activation energies. Thermodynamic activation parameters such as activation energy, pre-exponential factor and order of reaction were computed from the thermal data using the modified form of non-isothermal methods. INTRODUCTION Coal has been the most significant source of energy for India and would remain so at least for the next few decades. About 60-65% of the electricity produced in India is from coal fired power plants. Indian coal is of drift origin and of high ash content. Ash content of the coal burnt in power plants in India is in the range of 30-45%, most of it being Run-of-Mine coal. Most of the power plants in India source their coal from number of mines, most common being multiple sourcing. Usually coal from each source [1] is burnt separately. For various reasons mostly associated with logistics, burning of blended coal is rarely practiced. Blending of coal is practised mainly for improving the quality of available coal and meets the shortage of coal supply. Blending technique is generally practised in power industries to reduce the cost of power generation along with mitigating combustion performance or slagging problem ensuring consistency in as fired coal quality and also for environmental compliance. Blending good quality imported coal can improve coal quality and helps in preserving indigenous coal resources for longer period [2]. Use of blended coal shall reduce load on all boiler components (Mill, CHP, Boiler, AHP) & reduce O&M cost and increase the availability. The main purpose of blending is to get a blended as fired coal having ash, volatile matter and gross calorific value close to design coal and the two coals are to be blended in such ratio proportions that resultant coal blend have desired ash, volatile matter and gross calorific value [3]. For a coal to be blended certain parameters have to be considered to get compatibility with respect to combustibility ( Burn ability) of coal, grindability ( HGI), ash fusion behavior, swelling characteristics of coal, need to be checked"

Jan 1, 2017

By H. H. Schrenk

One phase of Bureau of Mines work in health and safety is promotion of the use of safe, satisfactory, and reliable respiratory protective devices. To insure that such devices will be. available, the Bureau has established schedules of minimum requirements for oxygen breathing apparatus,3/ gas masks,/ supplied-air respirators (hose masks, air-line, respirators, and abrasive blasting helmets, hoods, or masks),5/ and dispersoid (dust, fume, and mist)

Jan 1, 1943

By E. P. Evert

Profitable marketing of most minerals is dependent upon the total delivered cost to the user. Transportation costs are often greater than the value of the mineral f.o.b. the mine or processing facility. In some cases, transportation costs are three to five times the mineral cost. For many years, transportation costs were controlled by a complex system involving the transportation companies and supervised by regulatory agencies. This paper will deal with the effects of deregulation on rail costs and outline the major changes in transportation economics.

Jan 1, 1985

By Jannie van Deventer

"Innovation in the minerals industry has been lagging behind comparable industries like oil and gas. An incremental innovation culture that tolerates long lead times between invention and adoption has been exacerbated by a research grant structure that inhibits radical idea generation. Entrepreneurs who can make the link between ore source, technology and finance will cause a shift in innovation culture and open up substantial opportunities in the minerals industry of the future. By extrapolating existing trends in technology within and outside mineral processing, a crystal ball vision of future innovation is shaped with the aim to lower energy and water demand, reduce CO2 emissions, decrease operating and capital costs, reduce environmental impact, and secure a social licence to operate. Advances in nanotechnology, advanced materials and biotechnology will impact mineral processing, but the initiative for technology transfer must come from mineral processors. Laminates of graphene oxide can offer efficient filtration and separation media, while microfluidic devices will be used for desalination, solvent extraction and analysis. Substantial progress is expected on benign lixiviants and separation agents, such as nanoscale supramolecular hosts that can serve as high-capacity, selective and recyclable ligands and sorbents, and solid aminobiphosphonate-based adsorbents. Radical ideas for the recovery of precious metals from non-assayable ores and the generation of energy above unity will be adopted in selected minerals projects. In-situ mining in which microbes generate lixiviants at mineral surfaces will simplify processing circuits. Specific ores will be subjected to microwave processing and electropulse liberation to enhance recovery. Ultrafine grinding using devices of low energy consumption will be done mainly dry, followed by dry separation. New flotation cells will remove efficiently either coarse particles or ultra-fine particles, with mineral surfaces being modified not just by new reagents but also by selective microbes. Innovation in mineral processing indeed has a bright future."

Jan 1, 2014

By Leo R. Love

A comprehensive study of the environmental conditions of the area affected by the Colfax and Cheswick Power Stations is of extreme importance to Duquesne Light Company. The residents in the valley where the two plants are located have complained for many years about the emissions from the Colfax Plant which is of the 1920 to 1930 vintage and which has a capability of generating approxi¬mately 200 Mw. They were extremely happy to hear that the Company had plans for shutting it down, however, they were extremely unhappy to hear that we were planning to build another even larger one to take its place in the same vicinity, namely the Cheswick Plant with a capability of 570 Mw. They had visions of a plant twice the size of the Colfax Plant and belching out twice as much smoke. A few of the citizens from that area were most vehement at the public hearings that were held by the Allegheny County Air Pollution Bureau for obtaining an installation permit. With two power plants already existing in that area (Duquesne Light Company's Colfax Plant and West Penn Power's Springdale Plant), the primary concern of the Allegheny County Air Pollution Control Bureau was that the Cheswick Station might increase air pollution levels beyond what they considered to be dangerous limits. It became very evident that the Allegheny County Air Pollution Control Bureau would be extremely reluctant to grant installation and operating permits unless they were satisfied that the new plant would not increase local pollution levels and that we were taking sufficient steps to monitor the emissions from our plants and also the ambient air in the general area. We concluded that an extensive air pollution monitoring program must be conducted in the area to determine the effects of the operation of our plants. The program was conceived with our consultants, NUS Corporation of Rockville, Maryland, and was begun in June, 1968. It was designed to accomplish several things: 1. Determine the effect on the ambient air of the operation of each of

Jan 1, 1972

By Noel N. Moebs

The Bureau of Mines conducted five reconnaissance magnetometer traverses across a small abandoned chromite mine in the State Line district of Pennsylvania and Maryland to determine the geophysical response of the area. The results indicate that more extensive geophysical surveys of the region might establish some worthwhile guidelines for chromite exploration. While chromite only rarely can be detected directly by magnetic methods, there is a possibility that geophysical signatures in the adjacent host rock could provide some guidelines for further exploration. Prior to 1875, all the chromite produced in the United States came from the State Line district, and the potential for discovering additional podiform deposits could be significant. Virtually no state-of-the-art geuphysical or geochemical studies have been conducted in this district since World War II and sizable areas remain undeveloped and suitable for exploration. While the results reported in this paper are not supported by drilling, it may encourage others to investigate the area more fully for improved methods of detecting subsurface podiform chromite deposits. New theories on the emplacement of ophiolites also could contribute to an assessment of the chromite potential of the serpentinite belt.

Jan 1, 1991

By Edward J. Karkoska

The film you see is a slow motion view of a typical half million ton taconite blast at one of Erie's mines. This blast is made up of 220 drill holes and a total of 325 thousand pounds of blasting agent. The second view of the same shot is taken by a remote control hi speed camera located 1500' directly in front of the blast. Shortly you will see some violent camera movement as the air blast shock wave strikes the camera location. As the blasting sequence progresses the rock fly becomes evident, and if you will look closely amidst the clouds of smoke, rock fragments weighing up to 1/2 ton begin to cascade into view. These missles are the chief concern of blast security. The next camera shot at 4000 frames/second vividly describes the primacord firing lines detonating the blast. Travelling at 22,000 ft./sec., this white snake of fire travels to each hole, detonating the blasting agent. Before we get into the matter of blast security, let me locate our operation for those of you not acquainted with Minnesota's iron ranges and tell you something about our company.

Jan 1, 1969

By K. S. Raja, F. Battick, B. Pesic

"CeO2 doped with lower valence cations, such as Y3+, Sm3+, Gd3+ etc. is considered as electrolyte material for low temperature SOFC. Doping introduces additional oxygen vacancies and improves ionic conductivity. This work describes the preparation of yttria-calcia doped-ceria precursor material, its sintering in DC and AC field methods, and characterization of sintered electrolytes with respect to the ionic conductivity. Doped precursor materials were prepared by a controlled co-precipitation process. Sintering of prepared, pelletized particulates was carried out using three different methods such as: 1) conventional; 2) spark plasma sintering; and 3) an alternating current field at 1125°C (AC assisted sintering). The mechanism involved in the conductivity improvement as a function of defect density, grain boundary area and phase stability will be discussed. INTRODUCTIONThe performance of SOFCs depends highly on the properties of materials. Subtle variations in the composition, microstructure, or density of SOFC components can considerably alter the power output capabilities of fuel cells. Early SOFCs utilized zirconia based electrolytes but efforts in lowering the operating temperatures of SOFCs have prompted investigations into several other oxygen ion conductors – often modified with dopants to either promote the formation of oxygen vacancies or to stabilize a vacancy rich high temperature phase – such as bismuth oxide, lanthanum gallate, and ceria.The transport of oxygen ions through the electrolyte first begins with diffusion into the material. While this is generally a surface kinetics phenomenon, it is safe to say that it is highly dependent on oxygen pressure and vacancy gradients. The role of the cathode in SOFCs is to reduce oxygen at the electrolyte surface creating an O2– ion gradient which induces permeation into the material. Once inside and under the influence of a potential field, O2– ions migrate by a vacancy hopping mechanism, Catlow, C.R.A. (1990), effectively exchanging positions throughout the matrix until they reach the anode and react, thus leaving the matrix."

Jan 1, 2012

By L Chaffey, M Buckland

The minerals industry has enormous potential to positively contribute to sustainable development and many leading companies have concluded that their long-term success is directly linked to their ability to leave a lasting positive legacy. While there are many examples of success, there have been failures as well and much work has been done in recent years to define the role of the minerals industry in sustainable development and identify the key elements for success. In the past, our sector could point to the taxes and royalties it paid, the exports it generated and employment it created and felt confident that its contribution would be recognised and duly acknowledged. This is no longer the case. Critics of the industry have highlighted resource-rich countries that have failed to capitalise on their resource wealth and have arguably lower standards of living than their resource-poor peers û the æresource curseÆ hypothesis. Recent research has done much to clarify the factors that contribute to a countryÆs success or failure and all stakeholders in the industry now need to include these learnings in their approaches going forward. We know that our long-term success relies on embedding a company- wide approach to sustainable development into all aspects of our business operations. In this paper we highlight BHP BillitonÆs experience in the development and implementation of policies and systems designed to enhance our contribution to sustainable development. We detail the business drivers for excellence in this area and the key external codes and initiatives that have shaped our approach. The values-based BHP Billiton Charter, Sustainable Development Policy and associated Health, Safety, Environment and Community (HSEC) Management Standards are central to our approach. Implementation is reviewed through our HSEC audit program. One area in which we have placed particular emphasis is our approach to community development. BHP Billiton has a corporate target to contribute one per cent of its pre-tax profit on a three year rolling average to voluntary community programs. As our profit stream has increased with the minerals boom this is approaching an A$100 million commitment. In our paper we detail how we are working to ensure we maximise the value of this contribution for our communities and our shareholders.

Jan 1, 2006

By Juan M. Pestana-Nascimento, Robert G. Bea, Hamed Hamedifar, Emery M. Roe

The current State-of-the-Practice is grounded heavily on deterministic characterization and assessment of the performance of civil engineering infrastructure. In particular, flood defense systems, such as levees, have been evaluated within the context of the Factor-of-Safety where the computed capacity of the system is compared with the code specified demand forces. Uncertainties associated with the capacity and demand forces render deterministic modeling incomplete. In particular, two structures with the same Factor of Safety can have vastly different probabilities of failure. While efforts have been made to assess levee vulnerability, results from traditional engineering approaches omit important factors because they do not account for uncertainties included in analytical modeling, and natural variabilities, or human and organization factors. This paper utilizes risk assessment methods to advance methods for quantifying the contribution of uncertainties to engineering analyses, and thereby provide additional information to help assess sustainability of geotechnically engineered systems. The probability of failure of a geotechnically engineered system is directly impacted by how well the system is understood, and how uncertainties are incorporated in development of understanding of the system. This paper presents methods to evaluate two types of uncertainties for three potential failure modes of flood protection levees: underseepage, slope (or levee) instability, and overtopping/erosion. These analyses account for two types of uncertainty: 1) Type I – inherent uncertainty, 2) Type II – analytical modeling uncertainty. Human and organizational task performance and information development and utilization uncertainties are not included in these analyses. This paper focuses on the behavior of the flood protection levee system for Sherman Island, a western island in California’s Delta. Sherman Island is of critical importance to California because of the very important infrastructure systems that pass under, on, over, and adjacent to Sherman Island, including: natural gas pipelines, regional and interregional electricity transmission lines and telecommunication facilities, two deepwater shipping channels; and State Highway 160, a link between major transportation expressways. The work evaluates current (year 2010) and future conditions (year 2100) and incorporates variations in capacity and demand arising from projected human response activities and global climate change.

Jan 1, 2017

By Xianjun Lyu, Junxiang Wang, Peng Wu, Minjie Lian

"In recent years, the efficient cementation of mine tailings is a new way to manage mine solid wastes. The traditional cement materials have a slow setting time, large dosage and poor cementation strength for fine aggregate such as mine tailings. Therefore, the preparation of new type cementitious materials for the cementation of fine tailings has great potential in the treatment of mine waste solids. The paper mainly focuses on exploring the critical factors affecting the cementing performance of granulated blast furnace slag and its performance in the cementation of fine aggregate. Results indicate that the fineness of slag has a significant effect on its cementitious activity and Portland cement clinker has a better stimulation effect on the cementitious properties of slag than lime. And, anhydrite has a better early stimulation effect on the cementitious properties of alkali-activated slag compared to semi-hydrated gypsum and dihydrate gypsum. According to a series of tests on the cementation of fine iron tailings, the optimal ratio of slag, Portland cement clinker and anhydrite is determined as 60:30:10. Compared with P.O 42.5 ordinary Portland cement, the new slag based cementitious material shows much better cementing performance on fine tailings sample. Under the dosage of 12%, the compressive strength of fine tailings mortar using slag-based cementitious material in 3 curing days is increased to 168% that of using P.O 42.5 ordinary Portland cement, while the compressive strength in 28 days curing period is increased to 194%."

Jan 1, 2018

By D. J. Rose

The San Miguel Mine is owned by San Miguel Electrical Cooperative, Inc. and operated by Atascosa Mining Company, a wholly-owned subsidiary of Morrison-Knudsen Company, Inc. This multiseam, single-zone lignite surface mine is located near Jourdanton, Texas, 110 kilometers (68 miles) south of San Antonio. Lignite extracted from four closely-spaced seams is used to fuel the 400-MW San Miguel Power Plant. Recovery depths range from 7 to 37 meters (25 to 120 feet). The mine began stripping operations in the spring of 1980 and now produces approximately 2.5 million tonnes (2.8 million tons) of lignite annually. Atascosa Mining Company is responsible for production, maintenance, engineering, and management services. Production responsibilities include topsoil removal, overburden removal, lignite mining, spoil pile regrading and topsoil replacement, as well as ash disposal and construction and maintenance of water retention and diversion facilities.

Jan 1, 1984

By G. M. Hutt

Introduction The major development of industrial minerals in Manitoba has been in building materials. 'The building-stone industry is developed far beyond the needs of the Province, and the well known Tyndall limestone is marketed over a wide area throughout the other provinces to Canada. Similarly, gypsum and gypsum products are produced in excess of local requirements and are exported to adjacent provinces. The crushed-stone, sand and gravel, limestone, and lime industries are sufficiently developed to supply the needs of the Province and, notably in the case of lime and lime-stone, there is a surplus for export to the adjacent provinces and to the United States. The manufacture of common brick is well established, but for face-brick and other clay products the Province is dependent largely on importations. Production of silica-sand will increase as Canadian markets become available through recognition of the utility value of the Black Island sand as foundry-sand and for other purposes. There is some possibility of the export of feldspar, of lithium ore and concentrates, and perhaps of salt. A considerable part of the Province has not been seriously prospected for industrial minerals and it may be expected that, as time goes on, other deposits of non-metallic minerals will be discovered and opened up, especially as the prairie provinces become more industrialized. At the present time, there is some activity in the southern part of the Province based on gas and oil indications. Whatever may be the outcome of this work, it should yield valuable information concerning the geological structure of the area.

Jan 1, 1934

By V. Rajaram

A mine fire or roof collapse may necessitate the reversal of main fans to isolate the fire or provide an escapeway. Hence, to assist the mine operator in estimating the flow and pressure during reversal, Engineers International, Inc. conducted a laboratory and field study of the reverse performance characteristics of main mine fans. Laboratory tests were performed using a 96-inch (2.4 m) diameter vane axial fan to establish the forward and reverse performance characteristics under controlled conditions. Subsequently, a field test was conducted in a Colorado oil shale mine during which two 79-inch (2 m) diameter fans were reversed. The data obtained indicate that reverse performance characteristics are dependent upon the blade angle and the hub to tip ratio. The quantity in the reverse mode ranged from 30 to 65% less than in the forward mode, and the static pressure was directly proportional to the square of the quantity.

Jan 1, 1985

By S Dorrington, J Olsen, N Kinkaid

Several studies have been conducted on the economic analysis of mining near-Earth asteroids for resources for use in Earth orbit. While these studies use detailed economic figures of merit, they often use many invalid assumptions in the trajectory design. Factors such as the energy and propellant requirements are estimated with analytic methods, however, the stay-time at the asteroid and the spacing of repeated launch opportunities are not taken into account. The work outlined in this paper attempts to combine detailed trajectory design methods with newly defined economic figures of merit to improve the economic assessment of asteroid mining missions. The study focuses on asteroid 2014 EK24, a near-Earth asteroid with very Earth-similar orbital properties.CITATION:Dorrington, S, Kinkaid, N and Olsen, J, 2015. Trajectory design and economic analysis of asteroid mining missions to asteroid 2014 EK24, in Proceedings Third International Future Mining Conference, pp 281–288 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By S. Mohanta, S. Chakraborty, B. C. Meikap

"An air dense medium fluidized bed separator is an efficient dry process for the removal of undesirable gangue material from run-of-mine coal. Its cleaning performance depends on a variety of operating parameters that are interrelated in unknown, complex ways. A literature review showed that these parameters' effects had been experimentally investigated using a traditional one-variable-at-a-time approach, which is highly inefficient and sometimes misleading because many of the parameters often interact with each other to alter the overall equipment performance. Also, it is realized that the interrelationship among these parameters can have a significant effect on equipment performance. Therefore, to correctly evaluate the effects of individual parameters as well as their interactional effects on the separation performance of an air dense medium fluidized bed, we conducted a scientific study based on response surface methodology. Empirical models for two key response variables, namely, product ash and combustible recovery, were developed and subsequently used for identifying an appropriate operating region to achieve optimum separation performance. Furthermore, the optimum performances predicted from the empirical models were validated against experimental data. Preliminary results show a strong interaction among the operating parameters investigated in this test program.IntroductionFluidization is widely applied in industry for its various useful features. In the coal industry, it is used in the air dense medium fluidized bed (ADMFB) separator for the beneficiation of run-of-mine coal. In this separator, a medium is created by suspending fine magnetite particles in an upward air flow, and this pseudo-fluid is used as the beneficiation medium, with the lighter coal particles floating to the medium’s surface while heavier particles sink to the bottom. This separation technique had been receiving a significant amount of attention worldwide in recent times for its specific advantages of low operating cost and less restriction for small capacities (Luo and Chen, 2001; Sahu et al., 2009; Dwari and Hanumantha Rao, 2007; Van Houwelingen and de Jong, 2004), but it is still not a well-established industrial practice because of the availability of efficient wet processing technology. However, with a revival of interest in the dry beneficiation of coal, in general, and ADMFB, in particular, there is once again a concerted effort to improve the efficiency of the ADMFB process, and successive improvements have been made to make this process a competitive and viable option. The existing literature reveals that most of these research efforts had been essentially focused on the identification of a single parameter that has a key influence on separation performance, without taking notice of parameter interactional effect. For example, Luo et al. (2004) proposed a pressure drop number to distinguish separation performance without considering the bed height and gas velocity, which are intimately related to this proposed pressure drop number."

Jan 1, 2015