Search Documents

By D. A. Stokes

"In October of 1980, Fording's 15 000-ton capacity clean coal silo was put into operation. The silo was unique in that it was designed to allow the mass flow of material, coupled with a sophisticated computer-controlled dynamic loadout/weighing system.On May 1, 1982, an explosion, attributed to a methane buildup, devastated the top of the silo. .As a contingent plan to minimize the effect of the production loss the conveyance to the silo top was reconstructed and the silo' was back in operation by mid-June 1982, although the silo top was left open to prevent further methane buildup. As dust emissions occurred during loading ofthe silo, an extensive study was undertaken to establish dust control for the silo, while at the same time providing methane detection and control.The study, conducted for Fording by the Cambrian Engineering Group of Calgary, involved an extensive search and investigation of existing coal silos. The study concluded that there IS no universally accepted method of controlling methane emissions in coal silos.The study also produced a unique conceptual design for handling methane, while at the same time, protecting the environment . Fording's Clean Coal SiloThe silo, located at Fording Coal's Fording River metallurgical coal operation, is utilized for the storage and load out of cleaned thermally-dried metallurgical coal.The silo was constructed in 1979 and 1980 to reduce unit train loadout times and to facilitate the handling of “special shipments"" of coal. The silo went into operation in October 1980, under manual control and utilized computerized, automated loading by February 198I.The silo is 21 m in diameter and 76 m high, with a nominal capacity of IS 000 live tonnes. The coal storage portion of the silo is 21 m in diameter and 48 m high, utilizing 2 steep-angled hopper outlets allowing mass flow of the stored coal during train loading. Each hopper has a control gate and a discharge chute, one chute for bulk loading, the other for trim loading of coal into the rail cars."

Jan 1, 1986

This paper gives a general description of mining operations at the Mount Morgan Open Cut. Certain features such as blast hole diamond drilling, which may be of particular interest, have been described in detail. The paper is covered by the following headings:-1. History2. Ore Reserves and Production Data3. Mining Methodsa. Design and Layout of the Open Cut.b. Overburden and Ore Breaking.c. Loading and Transport of Ore and Overburden.d. Transport of Men and Supplies.e. Survey and Assay.f. Drainage.4. Power and Compressed Air5. Mining Equipmenta. Shovels.b. Mine Transport.c. Dozer Tractors.d. Drill Shop.6. CostsHISTORYIn order to appreciate fully the design of the present Open Cut at Mount Morgan, a brief outline of the Mine's history and past mining methods is necessary. In 1882 the Mount Morgan Syndicate began to mine this large gold-copper orebody by small hill-top quarries...

Jan 1, 1952

By Juan Languasco de Habich

El presente texto señala la situación actual de la pequeña minería, así como las ventajas, decreto ley 18880, garantía, reservas, requisitos, características del financiamiento, crédito minero, rol de tasa, modalidades del crédito minero, y las fuentes de financiamiento para la pequeña y mediana minería.

Sep 1, 1979

By César Augusto Martín Hilser Vicuña

El "Punto de fluencia” es el contenido de humedad crítico a partir del cual un mineral concentrado sufre “liquefacción”, es decir, libera la humedad como agua libre al ser sometido a las sacudidas propias de una travesía por mar. En esta perspectiva, el presente texto correlaciona la influencia que tiene el proceso de producción de los concentrados en el punto de fluencia a través de los siguientes factores: granulometría, efecto de los reactivos de flotación y la mineralogía. De forma que al conocer los factores que influyen notablemente en el valor de la humedad límite de transporte, se evita los riesgos de que la carga sufra licuefacción durante su transporte por mar.

Sep 14, 2009

By Jon Holder, Brann Johnson

Pore-fluid/rock chemical interactions on both short and long time scales can produce significant pore structure and mineralic changes that can markedly alter transport properties, such as fluid permeability. The introduction of the chemical factor requires modification of experimental systems and methodologies developed for measurements in which chemical effects are minimal. Particular attention must be given to temperature effects, fluid chemistry, fluid/rock reactions and kinetics, fluid flow rate, and fluid/experimental-system reactions. The ability to obtain very low, steady flow rates at constant fluid pressure is important for study of some fluid/rock systems. Minimization of metal corrosion is of paramount importance and requires choice of proper metals, such as titanium, and certain Ti-alloys and Ni-alloys. In this paper, we briefly discuss the relevant chemical factors affecting system and experimental design. The primary focus, however, is on the characteristics of highly corrosion resistant metals, thermal and chemical resistant jacketing materials, and the attributes and limitations of various flow-rate and back-pressure control systems and flow-rate measurement systems.

Jan 1, 1986

By T. L. Loucks, E. T. Guerrero

Pressure drop characteristics in a system composed of two adjacent concentric regions of different permeability were studied. The differential equations for continuity of mass flow in the two regions were solved using the Laplace transformation and the necessary boundary conditions to give the pressure distribution in the composite reservoir, the resulting equation for pressure drop at the inner boundary was evaluated for a variety of composite reservoirs and compared with the results for a uniform reservoir. From this study it was found that under certain conditions the permeability in both zones, as well as the size of the inner zone, can be determined from the pressure drop curve. INTRODUCTION The theory for the pressure distribution and pressure build-up behavior of a well producing a single, slightly compressible fluid from infinite and finite homogeneous reservoirs was presented by Hornerl and Miller, Dyes and Hutchinson.2 Extensions on this original work to provide improved and extended interpretations and better agreement between theory and observed results have been made by Matthews, et a1,3 van Everdingen,4 Gladfelter, et al5 Stegemeierand Matthews,6 Hurst and Guerrero,7 and Perrine.8 More recently Lefkovits, et al,9 studied pressure build-up behavior in bounded reservoirs composed of stratified layers. Houpeurtl0 has suggested various approaches to the general problem of variable permeability and porosity but presented no analytic solutions for particular permeability variations. Albert, Jaisson and Marionll studied the finite composite reservoir and presented numerical solutions to the unsteady-state case and an analytical solution valid only for large times. They also studied the so-called pseudo-steady state for several examples of radial permeability variations. Very similar examples have been treated in the unsteady state with application to pressure build-up by Loucks in an unpublished manuscript. More recently Hurst12 has presented the complete point-sink solution (valid for all times) for the infinite composite reservoir. He applied these solutions to interference between oil fields along with an even more elegant application of his explicit solution to the material-balance equation including water influx. Mortada 13 approaches the same application by avoiding the point-source limitation but gives the solution for the aquifer region which is valid only for large times. Hopkinson, Natanson and Temple14 have treated both the finite and infinite composite reservoir obtaining the pressure distribution for the inner zone valid for large times. This paper presents a theoretical study of the pressure distribution in an infinite composite reservoir composed of two adjacent concentric regions of different permeability. The object was to determine the manner in which pressure drop at the inner boundary of a composite reservoir depends upon time, the permeability of each zone and the size of the inner zone. Expressions for the pressure distribution in both zones are developed which take into account the radius of the sink and are valid for small times as well as large times. It was felt that an understanding of the pressure drop behavior in various composite reservoirs would be of assistance in the interpretation of some pressure build-up curves which do not behave according to the theory derived for uniform systems. Often the region surrounding the wellbore is either more permeable or less permeable than the reservoir because of the various drilling and completion practices. The effects of reduced permeability due to drilling-fluid invasion and of increased permeability due to fracturing or acidizing need to be more carefully defined. Therefore, an equation for the pressure drop in a composite reservoir was developed, and the effects of both the permeability in each zone and the size of the inner zone were studied. STATEMENT AND SOLUTION OF PROBLEM BOUNDARY CONDITIONS AND ASSUMPTIONS The physical system studied was a composite

By J. W. Miller

An investigation was begun by the Bureau of Mines in 1948 to determine the preparation characteristics of American coals. Results of the investigation were planned to be reported on a county basis and from the data developed to determine: 1. Which coals either as mined or after beneficiation by conventional preparation are chemically suitable under present standards for producing metallurgical coke. 2. Which coals require special and more intensive treatment in preparation than is now practiced. 3. Which coals cannot be considered potential sources of metallurgical coke, regardless of preparation by present-day methods. This report is one in this county series that describes the preparation characteristics of the coals of Lee County, Va.

Jan 1, 1957

By S. W. Chang, James R. Hein, S-R. Lee, A. Zondervan, H. Choi

"Nine Fe-Mn nodules from the extensive nodule field in the east of Campbell Plateau of southwest Pacific Ocean beneath the Deep Western Boundary Current (DWBC) and Antarctic Circumpolar Current (ACC) were analyzed for the 10Be/9Be dating by AMS (Accelerator Mass Spectroscopy) at IGNS, New Zealand.Several types of nodule morphology were identified including distinctive discoidal forms with overgrowths resulting possibly from overcrowding and partial sediment burial. Five principal nodule facies were also recognized by location and occurrence (Fig. 1) (Wright et al., 2005). Fe-Mn nodules show various concentric internal growth textures, such as, cuspates, large parabolic cuspates, pseudo-columnar, columnar, globular, and laminated, which vary even in a nodule with hydrogenetic, early diagenetic, or mixed origin. Each texture shows micro-textural varieties and different mineralogy and/or chemistry. The genesis of each internal texture was indicated by the REE patterns, the mineralogy of Mnoxides, and the Mn/Fe ratios."

Jan 1, 2017

By Dr. O. M Solandt

CANADA is not an old country we are just now planning to celebrate our lOOth Anniversary. Nonetheless, we have already developed some well-established traditions. One of the minor traditions is the standard speech on the need for more research and development in Canadian industry. I am sure that you have all listened to it many times -I certainly have given it more than once. Much as I am tempted to honour this tradition by repetition, I shall only give you a thumbnail sketch of the ancient address for the benefit of any unfortunate visitors who have not heard it before, and also to provide a base for some further ideas that I want to leave with you. Briefly, the traditional story is that, for a variety of historical and environmental reasons that I shall not attempt to describe in detail, research and development in Canada has grown up in a pattern that is ill adapted to foster the expansion of our manufacturing industries. The story continues by saying that research in the universities is of excellent quality but that we are very short of money to meet the expanding needs

Jan 1, 1965

By Adam Moore, Peter Radziszewski, Matt Gallimore

"Stirred mill technology dates back to 1928 where the idea to use “an agitator and spherical grinding media” was presented. In the context of the mining industry, interest in stirred milling technologies has grown over the last 20 years where the typical observation reported inDespite these developments, the tumbling mills are continuing to be used in fine and ultrafine grinding applications. The main reason for this, as communicated at the Canadian Mineral Processors roundtable discussion in 2013, is that the comfort level in understanding stirred milling technologies is not at the level of that of tumbling mills.At CMP 2014, one contribution was made to explore how mill design affects power and energy in a stirred mill. While the 2015 CMP paper explored the application of one scale-up methodology to the Gibraltar case. For the CMP 2016, the aim of this paper is to contribute to increasing the general comfort level with stirred milling technologies by developing a better understanding of the different scale-up methodologies used. This will be accomplished by first completing an overview of the scale-up models found in the literature followed by a review of the different testing and scale-up procedures. This review will be supported by a number of case studies found in the literature. The paper will close with a discussion on some of the challenges that these models and methodologies have and how future research might contribute to overcoming them.IntroductionStirred mill technology dates back to 1928 where the idea to use “an agitator and spherical grinding media” was presented (Stehr, 1988). The year 1948 saw the successful application of Du Pont’s “sand mill” for pigment grinding. Subsequent years have led to the development of different types of stirred mills spanning a number of industries that require fine and ultrafine grinding."

Jan 1, 2016

By S. Shrivastava, R. G. Reddy

Spent potliner is generated in the electrolytic process of reducing alumina to make aluminum metal using molten fluoride electrolytes. Spent potliner (SPL), obtained at the end of the pots life contains a small amount of cyanide and fluoride which present environmental problems. SPL became a listed hazardous waste under RCRA (KO88) in July, 1990. One of the possible uses of spent potliner is as a substitute for Calcium Fluoride (CaF2) as a fluidizer in iron- and steelmaking and in the glass industry. A low viscosity and a low melting point are prime requirements for accomplishing the above. In the present study, viscosity measurements were performed. Effect of various additives, such as sand, limestone, dicalcium silicate dust, and MgO baghouse dust on the viscosity of SPL was studied. The results showed that with the addition of sand and limestone, very high fluidity of SPL melt can be obtained at significantly low temperatures. The results suggest that spent potliner mixed with additives could potentially be used as a substitute fluidizer.

Jan 1, 1999

By W. V. Kotlensky, H. E. Martens

In an earlier communication, Ref. 1, the authors presented the tensile properties and the changes in crystal structure and microstructure for pyrolytic graphite tested at 2750°C. It was suggested that changes in the structure may have an effect on the tensile properties of this material. Accordingly, tensile tests were run on a series of specimens, from one block of pyrolytic graphite, some of which were hot-worked by being strained at 2750°C, others of which were tested in the as-deposited condition. According to the manufacturer, General Electric Co., the polycrystalline material was deposited at 2100°C on a substrate of synthetic graphite by decomposition of a dilute natural gas mixture. The as-deposited material had a density of approximately 2.19 g per cc, and as shown in Fig. 1 had a structure of medium size growth cones which were regenera-tively nucleated. All specimens had a gage section 0.75 in. long by 0.06 in. wide by 0.1 in. thick with the thickness direction perpendicular to the basal planes. The testing method and equipment used have been previously described, Ref. 2 and 3. For both the hot-working and the testing the load was applied parallel to the basal planes; a cross-head speed of 1.5 x l04 in, per sec was used. All heating was done in an atmosphere of bottled helium.

Jan 1, 1962

By C. Gosselin, M. Rheault, M. Benoit, Y. Bouroubi, V. Sarago

The last three decades have seen significant mining development in northern regions of Canada, where the freeze and thaw cycle of permafrost and the corresponding surface subsidence and heave represent a significant challenge to the design and maintenance of infrastructures. Identifying areas at risk is of great assistance to reduce the impact of this issue. Over the past ten years, Synthetic Aperture Radar Interferometry (InSAR) has been widely used to monitor ground surface deformation. With this technique, changes in phase between two SAR acquisitions are used to detect centimeter to millimeter surface displacements over a large area and with high spatial resolution. InSAR can be used as a tool to assist the siting and design of new infrastructure as well as highlighting the risk to existing structures in areas of unstable terrain. This paper presents the results of a project carried out by Effigis, which made use of SAR interferometry in the context of monitoring terrain and infrastructure stability in a northern mining environment that is affected by permafrost seasonal and long term changes. TerraSAR-X images acquired during two periods, August to November 2012 and March to October 2013, were used to measure the deformations and/or movement of ground surface, infrastructure and stockpiles caused by seasonal changes in permafrost extent in and around a mining site located in Nunavik, Quebec. The results showed that spatial and temporal distributions of surface displacements are in accordance with scientific and terrain knowledge. Some displacements were observed in loose soil areas while, as expected, none were detected in bedrock and rock outcrop areas. The areas most affected by active layer changes showed surface subsidence in the thaw settlement period. This study confirms that SAR interferometry has a great potential for operational applications related to risks induced by surface deformation in mining environments. It shows that this technique can be used to produce reliable maps of surface movement and monitor the vertical displacement of important infrastructure.

Jan 1, 2015

By P. Crouse, J. Obermeyer

"INTRODUCTION Site location and history The Holden Mine is a former underground copper mine that was developed and operated by the Howe Sound Mining Company (Howe Sound) from 1938 to 1957. The mine is located in north-central Washington State, U.S., near Lake Chelan in the area shown as Holden Village in Figure 1. Although Rio Tinto never owned or operated the mine, they are managing and funding a several hundred million dollar clean-up to prevent future water and soil contamination and to reclaim the former mine site under the United States Environmental Protection Agency (USEPA) Superfund process. The former mine included an onsite mill and a nearby housing complex for the miners. Howe Sound developed the mine as a series of near-horizontal drifts and tunnels, interspersed with stopes and shafts that connect different mine levels underground. The tunnels that were excavated to develop the mine total nearly 100 km in length.During development of the underground workings, Howe Sound removed more than 230,000 cubic meters (m3) of waste rock from the tunnels and deposited this material in two waste rock piles. Ore was processed from the mine in the onsite mill to produce a copper concentrate that was shipped off site for smelting. Roughly 10 million tonnes of tailings were produced as a by-product of the milling operation, most of which were deposited in three large impoundments (Tailings Piles 1, 2 and 3) directly south of and adjacent to Railroad Creek. Howe Sound closed the mine in 1957. In 1961, the property was transferred to Holden Village, Inc. (Holden Village), a not-for-profit corporation that maintains a year-round community and operates an interdenominational religious retreat in the former miners’ town. With the exception of the patented private land, the remainder of the Site is on National Forest lands and is administered by the U.S. Forest Service. The mine is remote. It is only accessible by boat or float plane from Chelan, Washington, up Lake Chelan to Lucerne, nearly 40 km. Vehicle access from Lucerne to the mine is provided through a 17.5-km-long winding gravel road that climbs 640 meters in elevation. The general site features are shown in Figure 2. Physical setting The Holden Mine is located on the eastern slopes of the Cascade Mountain Range at an elevation between 975 and 1,050 m above mean sea level. Holden Mine was developed adjacent to Railroad Creek, which lies in a glacial U-shaped valley carved into the igneous and metamorphic bedrock with steep-sided slopes (Figure 2)."

Jan 1, 2017

By R. V. Lundquist

Leaching manganese-bearing materials with NaOH to remove caustic-soluble silica has been demonstrated as a method for up- grading manganese. Those materials containing opaline varieties of silica respond most readily. Spent leach liquors are regenerated by treatment with lime to precipitate calcium silicate and to reactivate the NaOH for leaching.

Jan 4, 1953

The stability of mine roofs in permafrost zones is determined mainly by temperature and ice content. The deformation resulting from creep and temperature-dependent physical properties of frozen rock mass is the dominant component of total deformation. Roof bolts can consolidate the roof and control its deformation. In this paper, a finite-element model, for the analysis of the effects of roof bolting in a frozen rock mass is presented. The model includes the variables normally encountered when analyzing the effects of roof bolting in rocks. It also accounts for properties unique to frozen rock mass: creep deformation and the change in Young's modulus with changing temperature. The model shows that, as bolt spacing decreases, there is a trade-off between increased roof stability from increased mechanical support and decreased stability from increased conduction of heat into the frozen roof. This result was expected and shows that, for a given set of rock-mass conditions, including ice content, temperature, particle size, etc., there is an optimum bolt length and bolt density for minimum roof deflection.

Jan 1, 1997

[Executive HERBERT G. MOULTON, Chairman WILLIAM WRAITH, Vice-Chairman ,PAUL D. MERICA W. M. PEIRCE H. Y. WALKER Finance H. T. HAMILTON, Chairman ERLE V. DAVELER HENRY KRUMB Admissions FELIX E. WORMSER, Chairman GEORGE D. BARRON, Vice-Chairman CHESTER A. FULTON PHILIP KRAFT EDWARD MEAGHER Alternates P. B. BUCKY LLOYD C. GIBSON F. T. SISCO]

Jan 1, 1940

By C. E. Baltzer

This paper highlights the electric power situation in Canada, and introduces brief explanation of the salient differences between electrical practice in the United States and Canada. The availability of bask energy in the two countries is touched on, also the hydro versus thermal outlook as applying to Canada. De-v2lopment of thermal-electric power is dealt with in some detail, followed by Canada's thermal-electric power requirements, present and future. The fuel requirements for steam-electric generating plant are assessed on the basis of a survey recently made, and the location and size of the major thermal plant operations are given. Fuel contractual obligations on the part ?of suppliers and consumers are mentioned. Finally, an opinion is expressed in regard to the types of f.uel in ?demand on a regional basis with emphasis on the need for coal in the several areas dealt with.

Jan 1, 1958

By B. M. Larsen, K. Heindlhofer

Jan 1, 1945

By Yoshihiro Kawarabata

INTRODUCTION The shield-driven method in Japan has been adopted widely in soft ground tunneling, namely, subway, water supply, sewer and utility tunnels, and recently this is an indispensable method in urban area. Since this method was started to adopt on a full scale from the beginning of 1960, construction achievements in length were about 830 km for 15 years until 1974 (1). According to the recent informations of the Japan Tunneling Association, the achievement in length under construction as of December, 1977, was about 350 km (2) and the extention of increase in shield-driven method can be guessed (Tab. 1). Tab. 1 - Achievement in Length by Shield-driven Method (As of December, 1977, Unit: m) (---): Achievement by Okumura Corporation [ ]

Jan 1, 1979