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Between 1985-1986, the Bureau of Mines reviewed the mining history and minerals information for areas in and near the San Isabel National Forest to appraise the mineral resources present and determine the types of deposits, and their location in the Forest, that could be mined economically if sufficient demand and metal prices existed. The two major metallic deposit-types that are of national mineral resource significance within the Forest are stockwork- molybdenum (with tungsten and tin) and carbonate-replacement zinc-lead-silver deposits. Historically, small gold placers, gold-quartz veins, silver-quartz veins, skarn iron and copper deposits, volcanogenic copper-zinc-precious metal deposits, and base- and precious-metal veins have been mined. Barite, carbonate rocks, gypsum, other non-metallic deposits, and pegmatites, have also been mined. Sand and gravel, present in large volumes, occurs along and has been mined outside the Forest along the upper Arkansas River valley. Turquoise and gemstones are present in small amounts and are of interest to collectors and jewelers. Geologically, sediment-hosted uranium and copper are present in small occurrences but no resources have been identified. Geothermal resources are related to the Rio Grande rift which parallels the central part of the Forest. Four hot spring areas are present - two of these are within the Forest. Because of the low power requirements of the region, and the presence of other generating facilities, these geothermal resources have had only limited local use. Evaluation of mine models that may be found in the region show that base-metal deposits require a high precious-metal component to be economic. Although molybdenum can be produced at economically competitive prices, there is little demand for the product. Capital costs to start new molybdenum mines would be very high and it is not likely that new mines will be put into production in the near future.

Jan 1, 1989

By Christopher J. Farrow

This paper describes the grinding circuits installed at two remote sites in northern Canada. One is Cominco's Polaris Project at Little Cornwallis Island; a barge-mounted lead/zinc concentrator. The other is Echo Bay Mines' Lupin Project at Contwoyto Lake, 400 km northeast of Yellowknife, a gold mine, all components of which had to be flown to the site. Logistics and considerations of operating and maintenance presented challenges which were met by innovative design. The evolution of the grinding circuits is discussed. Both plants are operating at design throughput.

Jan 1, 1983

By Bernard Lewis

This report on the research and technical studies conducted by the Explosives Branch of the Bureau of Mines covers the 2-year period July 1, 1946, to June 30, 1948. A report for the fiscal year 1947 was omitted because of the large amount of work still in an unfinished state. The material presented herein is based largely upon more comprehensive reports prepared under the authorship of members of the branch staff.

Jan 1, 1949

By V. R. Spironello

One of the primary objectives of the Bureau of Mines solid waste utilization program is the recycling of the magnetic fraction of municipal solid waste called raw refuse scrap. In this investigation, several types of scrap of differing quality, including refuse and turnings, were melted in a 1-ton electric-arc furnace in various combinations to produce steel in noncritical (construction) grades. In-formation on furnace operation and on the behavior of tramp and alloying elements was obtained. The research showed that it is possible to produce acceptable steel from a variety of steel scrap. Although some scrap is routinely used in steelmaking, it was found that up to 50 to 55 pct of the scrap charge can be ref-use, provided it is combined with higher quality scrap. The chemistry of the steels was generally acceptable, and all of them were rolled without difficulty. The specification (ASTM 615) for the steels produced was grade 40 or grade 60, containing 0.30 or 0.40 pct C, with mini-mum yield strengths of 40,000 or 60,000-psi, respectively. Most of the steels met the specification requirements. In-formation on typical microstructures of some of the steels is included. The composition of some furnace dusts showed high levels of Sn, Pb, and Zn.

Jan 1, 1981

By Antonio Mendoza

El presente texto describe el sistema de manejo de agua y aire, las actividades integradoras, preventivas, de análisis y ejecución realizadas para describir la respuesta a los retos del futuro inmediato para alcanzar los objetivos ambientales en la mina Antamina.

Jan 1, 2012

By D. Eugene Rannels, Yu-Chen Lee, John W. Swisher

"Inhaled dust particles of appropriate size contact cells of the alveolar region.' The acute response to coal dust appears to involve a variety of cell types, including alveolar epithelial cells, interstitial fibroblasts, both resident and recruited macrophages, and cells of the immune system. Direct and indirect effects of dust, which may be mediated by soluble factors,'' can initiate acute and long-term lung injury. While it appears that epithelial cell growth and differentiation, along with integrity of the epithelial basement membrane, may play a role in the long-term response to dust exposure, little is known of the role the alveolar epithelium may play in the progression of injury. The broad hypothesis that underlies these experiments is that short- and long-term consequences of coal dust exposure involve changes in structure and function of the alveolar epithelium and the underlying extracellular matrix. Recent studies show that coal dusts exert direct effects to modify pulmonary epithelial cell-extracellular matrix interactions in vitro.3EXPERIMENTAL PROCEDURESType II cells isolated on day 0 by density centrifugation and differential attachment4 were plated overnight in D MEM containing 10% fetal calf serum before exposure to anthracite dust PSOC 867 sonicated into culture medium (750 ug/mL).3 Synthesis of extracellular matrix proteins was determined on day 3 of primary culture, as detailed elsewhere. 5 Cells were removed from extracellular matrix by extraction with NH4OH and high salt. Extracellular matrix synthesis and fibronectin content were evaluated based on radiolabeling with 3 H-leucine and on Western blot analysis, respectively. Additional analytical methods and calculations are detailed elsewhere.3-5"

Jan 1, 1998

By R. Rosenblum, J. Y. Kim, D. Shink, K. G. Stowe

"A small scale continuous flotation cell was designed and constructed at the Noranda Technology Centre to develop a mobile testing flotation circuit located next to the production circuit. This mobile small scale flotation pilot plant can easily and economically be set up at any circuit in a mill and used to evaluate and predict plant performance against a given flotation condition. The main feature of the cell, beside the provisions of automatic pulp level and feed rate control, is to provide a reduced surface to volume ratio approaching to that of an industrial machine.This paper describes the basic design and the results of various testwork carried out to date including aeration, conditioning, reagents, recirculation, flotation gas, etc. are presented in comparison with the plant production results. INTRODUCTIONStudy of the behaviour of an ore during concentration by flotation process starts, in general, with a series of tests in laboratory cells. Given the discontinuous nature of these tests, the information obtained by such a study is somewhat limited. It has long been recognized that laboratory test results are not always reproducible in pilot plant tests and subsequently, the pilot plant results do not always predict plant performance. The differences are often blamed on batch vs continuous operations, grinding media, size distribution, aging (oxidation), water quality, equipment, operator's skills, etc."

Jan 1, 1992

By H. EI-shall

In this paper, the results of bench scale testing of five different flotation processes to separate dolomite from phosphate are discussed. The effectiveness of each process interms of phosphate recovery and MgO content in the concentrate is used together with the reagent consumption as the basis of comparison. The water quality is found to play a major role in the performance of these processes. Effect of water hardness as well as other parameters are discussed.

Jan 1, 1995

By M. Carrales, C. J. Jirik, W. D. Dietzman

In view of the developments and recent interest in recovering heavy oil , this report was prepared to present general information on more than 2,000 heavy oil reservoirs in more than 1,500 fields in 26 states . Information given on each heavy - oil deposit includes the following items : Field and formation , location , average or range of depth , average API gravity of oil , average thickness of formation , areal extent of field , total productive wells drilled in field , discovery date of field , field status in 1963 , cumulative production to Jan. 1 , 1964 , and all known types of secondary - recovery operations initiated ( active and terminated ) in the reservoirs . The geographical location of heavy oil accumulations in the United States is shown by a map , and a brief discussion of 14 different areas is given in the text . As of Jan. 1 , 1964 , 75 percent of the heavy oil reservoirs in the United States had produced more than 10 billion barrels of oil and are estimated to contain over 90 billion barrels of oil in place . It is also estimated that if the deposits which have had little or no production history , such as the one in Missouri , were included , the total remaining heavy oil in place would be in excess of 150 billion barrels . To find economical ways of recovering this vast reserve of heavy oil , industry is developing technology in several types of thermal - recovery methods . Some of the general considerations and more suitable limitations in selecting a prospect to study for thermal - recovery techniques are : Lithology , depth , viscosity of reservoir fluids , gravity of oil , reservoir thickness , oil in place , and permeability and porosity .

Jan 1, 1965

By Peter N. Gabby

A mineral purvey of 40,000 acres of the 42,213-acre Little Humboldt River Wilderness Study Area was conducted by the U.S. Bureau of Mines in 1985 at the request of the U.S. Bureau of Land Management. There are no identified mineral resources but anomalous gold, silver, mercury, and arsenic concentrations were found. The study area is located in Elko County, NV, in the Owyhee Upland geomorphic subprovince. It is underlain by mid- to late-Miocene-age rhyolite, basalt, tuff, vitric ash, and tuffaceous siltstone. On the south side and partly within the study area, a mining company recently (January 1986) located 125 contiguous claims over an area of hydrothermally-altered volcanic rocks that have anomalous surface concentrations of gold, mercury, arsenic, and silver. Anomalous gold-silver concentrations in altered rocks were encountered at several other widely scattered localities in the study area. These elevated metal concentrations and associated hydrothermal alteration indicate gold resources may be present in the study area. A 20-ft-thick bed of diatomaceous earth, which contains 60 to 85 percent diatoms, crops out 0.3 mi north of the study area. Elsewhere, three samples of altered volcanic tuff taken within the study area contain from 46 to 70 percent zeolite (clinoptilolite). The diatomaceous earth and zeolite sampled are not of sufficient quality to compete with materials presently being marketed. There has been no mineral production from the study area, but a caved adit, about 25 ft long, and six prospect pits were found.

Jan 1, 1987

By Sergio N. Monteiro

Polymeric composites reinforced with natural fibers are increasingly been used in several engineering applications, from automotive parts to building construction elements. In addition to the relatively low cost, the natural fibers are also appraised by their renewable and biodegradable characteristics. Fibers extracted from the crust of coconut fruits, also known as coir fibers have been investigated for a possible use in composite materials. In the present work, the coirfiber/polyester matrix interfacial strength was evaluated by means of pullout tests. The variation of the pullout tensile stress vs. the embedded coir fiber length permitted to determine the critical fiber length and, thus, to calculate the interfacial strength. Observations by SEM complemented the results from pullout tests, indicating that coir fibers have a potential for application aspolymeric composites that could replace conventional materials such as wooden and gypsumpanels.

Jan 1, 2006

By L O’Connor, S C. Dominy

"Geometallurgy is an important addition to any evaluation project or mining operation. As a discipline, it seeks to maximise the net present value (NPV) of an orebody while minimising technical and operational risk. It also aims to promote sustainable development and initiatives by ensuring that all stages of extraction are performed in an optimal manner from a technical, environmental and social perspective. To achieve these goals, development of innovative technologies and approaches along the entire commodity value chain are being established (Glass, 2016). Geometallurgy has been shown to increase operational stakeholder collaboration, creating an environment for knowledge sharing and improved data acquisition and interrogation, with the end result being the integration of such data into mine planning and scheduling. All of these aspects create better business optimisation, utilisation of staff and targeted and realistic key performance indicators.The mining industry faces numerous challenges including, but not limited to:declining ore gradesgeometrically and/or internally more complex depositsdeep-seated deposits, with potentially high in situ stress regimesincreasing quantities of mine waste that needs to be managed appropriatelyhigher energy, water and chemical costsprocessing of more challenging and refractory ores – textural complexitiesstricter environmental/permitting conditions – so-called ‘licence to mine’increasing demand for specialist metals (eg rare earth elements, In, Ge, Te, Rh, Se, Ga and Li)commodity market volatilitya difficult funding environment.Given these challenges, geometallurgy provides the opportunity to control or at least manage some of them.CITATION:Dominy, S C and O’Connor, L, 2016. Geometallurgy – Beyond Conception, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 3–10 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By John J. Sammarco, Alan G. Mayton, Elaine N. Rubinstein

Researchers from the National Institute for Occupational Safety and Health (NIOSH) developed a light-emitting diode (LED) area luminaire called the Saturn and conducted a laboratory study using a Fletcher High Dual-boom Mast Feed (HDDR) roof bolting machine. The Saturn luminaire was designed to (1) enhance floor illumination to enable better detection of trip hazards in the interior spaces of a roof bolter and (2) reduce glare that has typically been an issue of concern on roof bolters. This paper reports on the results of achieving the second objective. The existing roof bolter lighting was the baseline and was compared with three versions of the Saturn luminaire relative to light intensity (100%, 75%, and 50%). Discomfort and disability glare data were obtained from 30 participants that comprised three age groups. Discomfort glare perceptions were obtained using the De Boer rating scale, and disability glare was quantified by using Mars Letter Contrast Sensitivity tests. Discomfort glare was reduced at least 3 levels with all Saturn versions. Also, a predictive model was used to estimate discomfort glare, and the results were similar. Disability glare was the least for the Saturn’s 50% intensity, and all Saturn versions had significantly less disability glare than with the baseline lighting. Veiling luminance was calculated and used as another indicator of disability glare. Veiling luminance was 28 to 42 times greater with the baseline lighting as compared with that of the Saturn lighting. Lastly, visibility levels were calculated. The Saturn versions were 4 to 6.5 times better in terms of visibility level.

By Tom Plouf, Deepak Malhotra

INTRODUCTION The U. S. mining industry experienced a severe recession in the early 1980's. This resulted in the realization that the domestic mining industry had to compete on a global basis and only the strong or the low-cost producers would survive. The economic viability of a mining company not only depended on maximizing mineral recovery but also on its ability to do so at minimum cost. Companies had to become more productive not only by cutting costs, but also by developing and/or evaluating new technologies in existing or new plants. Several innovative concepts, including in-pit crushing and conveying, fine crushing, improved classification equipment, flotation, column flotation, pressure filtration, etc., have been developed in recent years. This paper addresses the impact of new flotation concepts and equipment on mill design. MILL DESIGN PHILOSOPHY Modern mill design, especially for large capacity plants, has its foundation in minimizing capital and operating costs. Capital costs can be minimized by minimizing the various components of the capital cost: infrastructure, equipment, instrumentation, structural, initial spare parts costs, etc. All these costs are minimized by simplifying the mill design and/or process flowsheet. The simplified process flowsheet, where applicable, consists of a single stage primary crusher followed by a semiautogeneous - ball mill grinding circuit to produce feed for a flotation circuit. Multiple flotation circuits have been eliminated in most cases. These concepts minimize the cost and encourage the use of large capacity equipment while maintaining optimum metallurgical recovery. The philosophy of mill modernization/modification is generally driven by the desire to increase the mill capacity within the limits of the existing mill building. This need is facilitated by using large size flotation equipment and eliminating multiple parallel flotation circuits in order to minimize capital and operating costs. Conventional flotation machine development has paralleled this mill design philosophy. FLOTATION CELL DESIGN Since froth flotation has been the most widely used separation process for over half a century, one would expect that it would be possible to design and select flotation machines for specific applications based on scientific principles. But this has not been the case. Best judgment, experience and personal prejudice have played a key role in equipment selection. These factors, along with the difficulty of evaluating new concepts in commercial plants, has slowed progress in implementation and commercialization of innovative ideas and/or equipment. Conventional Flotation There have been no major technological advances in conventional flotation cell design in recent years. A recent flotation cell survey indicates that 'larger flotation cells are still the order of the day.”(1) A comprehensive review of design of flotation machines indicate that they have been mechanically redesigned and are generally simpler and easier to maintain and less expensive to manufacture. (2,3) The approximate chronological development of conventional cells from the 25 cubic foot cells to the 3000 cubic foot cells, which were recently installed at the Copperton concentrator of Utah Copper, is given in Table 1. Larger flotation cells are the obvious choice for new plants or plants looking for expansion because of the following reasons: • They have lower capital cost per unit volume • Installation costs are generally lower because fewer units require less space • Maintenance costs are lower because of fewer mechanisms • Power requirements (HP/ton dry feed) are generally lower • with increased flotation cell size as illustrated in Table 2 [Table 1. Conventional Flotation Cell Size Development Year Individual Cubic Cell Size, Feet 1925 25 1935 50 1960 100 1965 300 1970 500 1975 1,000 1980 1,500 1985 3,000]

Jan 1, 1989

By Johann-Paul Stemplinger

For lubrication of open gear drives applied in rotary furnaces, often gear greases are used as well as for lubrication of gear boxes in difficult sealing conditions. The selection of the gear grease influences strongly the wear behavior. Investigations with flow greases NLGI 00 were made in a back-to-back test rig determining the weight loss due to wear acc. to the standardised procedure ISO 14635 part 3. Different influences like base oil viscosity, thickener type and additional solid lubricant type were analysed. Only the type and amount of solid lubricant shows a significant influence on the weight loss due to wear. Finally, a linear wear coefficient clT according to the calculation method of the wear amount according to Plewe is derived and can be used to transfer the test results to any gears in practice.

Jul 31, 2018

By E. Godfrey

The average man one meets on the street thinks of an explosive as a medium of death and destruction, something unstable which should be given a wide berth, because he knows little or nothing about its use or its stability. Briefly, explosives are compounds that develop very large quantities of heat and gas in an extremely short time and in a small space, thereby exerting enormous pressure upon surrounding bodies, and by the rapid expansion of this highly heated gas are able to perform a considerable amount of useful work. The amount of heat generated and the volume of gas produced by the decomposition of an explosive determines the amount of mechanical work it can do, and the time occupied by its change from solid or liquid condition to gaseous condition determines its shattering effect. Explosives manufactured by reputable people are not extremely dangerous, on the other hand they are quite safe if handled in a proper manner. Furthermore, before an explosive can be placed on the Canadian market a sample must be submitted to the Explosives Division of the Mines Department, who may condemn or permit its manufacture, according to their findings regarding its safety in handling and its stability during storage.

Jan 1, 1926

By T Gartner

This paper describes the design, manufacture and site services associated with the supply of mine hoists for the new mine under construction by Falconbridge Limited in Ontario, Canada. Two new shafts are being sunk, and the hoisting equipment at each shaft can be summarised as follows: Ventilation shaft:4.66 m diameter double-drum second-hand hoist, originally in operation at San Manuel Mine, Arizona, to be used as the shaft sinking hoist. The second-hand hoist presented a challenge in that during its previous life, the hoist had been intensively operated during service at San Manuel Mine, and this paper describes the scope of refurbishment work undertaken, both electrically and mechanically, to ensure future reliable operation, together with the requirement to meet Canadian and Ontario regulations and codes of practice. 3.05 m diameter new single drum auxiliary hoist to be used as a second means of egress. Main shaft:4.57 m diameter new double-drum hoist to be used initially as the shaft sinking hoist, and subsequently to be converted to the equivalent of a single-drum multi-rope hoist for service duties during the production phase; 5.49 m diameter new double-drum hoist to be used for skip hoisting during the production phase; and 3.05 m diameter new single drum auxiliary hoist.The new hoists are all designed to comply with SABS requirements such that hoisting with reduced rope safety factors will be possible in the future. This paper describes the principles involved both mechanically and electrically. Particular attention is paid to the conversion of the main shaft service hoist from a double-drum sinking hoist to a multi-rope hoist.This paper describes the ac electrical powertrains (drives and motors) used that eliminate the need for harmonic filters and reactive power compensation equipment since they exhibit no negative effects on the utility electrical network system. This paper describes the logistical challenges of installing, commissioning and setting to work a series of five hoists in a short time frame.

Jan 1, 2005

By E. G. Bazeley

The paper reviews the scope, timing and financial impact of this significant project, which involves the supply and transportation of nearly 4 million tons per year of bituminous coal and lignite from sources in British Columbia. Alberta and Saskatchewan to Ontario Hydro's generating stations. The critical factors involved in the selection and utilization of these coals are discussed in relation to the three types of coal to be utilized initially. The paper then deals with each of the significant project elements to be undertaken by the various companies involved in the mining and movement of the coal, beginning with production at the mine through rail shipment to Thunder Bay, train-to-ship terminalling, shipment by lake vessel from there to the generating station, and finally blending the bituminous coal with United States coal prior to combustion. The review discusses the key features of the facilities involved in each case and the status and timing of the project elements , which are phased for the start of coal shipment by mid-1978. The paper concludes with some observations on the capability of the project to handle increased tonnage s and the challenges facing the movement in terms of quality , quantity and cost.

Jan 1, 1978

By M Akop, G Phillips, L Elliott

An estimation geologist has many tools in their kit and using the correct one for the job is vital for creating a useful model. Reconciliation is a key step to monitor the performance of a resource model and to ensure the correct tools have been selected and appropriate parameters are set. This paper presents an example of refining the estimation methodology for a Channel Iron Deposit (CID), resulting in an improved model. Rio Tinto Iron Ore (RTIO) CIDs are unique iron ore deposits located in the Pilbara region of Western Australia and contribute a significant volume to the world’s seaborne iron ore market. A problematic feature of these deposits is the irregular dispersion of clay pods that cannot be delineated with confidence within the resolution of the exploration drilling. Resource to grade control reconciliation showed an over-prediction of high-grade material in the resource model. A fresh approach was required to improve grade and tonnage predictions. Historically, clay pods were delineated using traditional wireframing techniques and estimated using ordinary kriging with hard boundaries. The new method utilised indicator kriging to estimate the probability of clay. Probabilities generated from the indicator kriging estimate were used as an additional weighting following the ordinary kriging of grades. Results showed indicator kriging improved global high-grade tonnes reconciliation, however, as expected, it did not improve the spatial prediction of clay. Based on improved reconciliation results indicator kriging has now been adopted as a suitable alternative for analogous CIDs at RTIO. These improvements benefit the mine planning process, but do not replace grade control models.

Mar 22, 2022

By Ruirui Wei, Yanhui Liu, Fangqing Yin, Meilong Hu

In China, Basic Oxygen Furnace (BOF) slag is traditionally used as an aggregate for civil engineering, for road engineering and fertilizer. In order to make full use of BOF slag, the experiments of BOF slag with high temperature roasting has been carried out and the phase transformation is studied. The BOF slag from Chongqing Iron & Steel is roasted in the electric muffle furnace at three different temperature. The influences of the high temperature roasting on change the phase composition of BOF slag was characterized by XRD. The results revealed that SFCA was produced at the high temperature in air atmosphere and melting temperature of slag was lowered. Therefore, if the BOF slag which treated by roasting was utilized in the sintering process, it is advantageous to improve the sintering strength and the formation of the liquid phase and reduce fuel consumption in the sintering production process.

Jan 1, 2015