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By W. T. Swensen

The Anaconda Company, through its wholly owned subsidiary The Anaconda Company (Canada) I,td., has investigated, optioned and partially developed a large tonnage of iron ore amenable to magnetic concentration. The reserves are located in north central Ontario and occur within a twenty-two mile belt of layered and intricately folded metamorphic rocks, close to the north contact of an igneous complex of granite and pegmatite. There are two main ore deposits. Briarcliffe is a steep to vertically dipping body 100 to 500 feet wide and over a mile long. The Two Mile Lake deposit is flat dipping and confined to an open, asymmetrical syncline; it is approximately a mile wide and 250 to 4.00 feet thick. On its flat easterly plunge, it is saucer-like in shape and is amenable to open-pitting for an east-west distance of several thousand feet. Magnetometer surveys, confirmed by drilling, indicate at least a three mile eastward extension of this deposit. Location and Access: The property is located in the Kowkash Mining District of northwestern Ontario, roughly forty-four miles north of the community of Nakina on the main line of the Canadian National Railroad. (Fig. 1) Access during the exploration period was entirely by airplane from Nakina. (Fig. 2) More recently, Nakina itself was connected to the highway network in the Longlac-Geraldton area. The property is roughly 190 miles by existing and proposed railroad from the Great Lakes waterway system. The Trans-Canada pipeline moving natural gas from western to eastern Canada passes through Geraldton roughly 70 miles south of the property. Topography: The surface features in the area are typical of a sizeable portion of the Precambrian Canadian Shield area. Many lakes, low swampy areas, and glacial moraine-type features are common in this recently glaciated area. The average elevation is between 800 and 900 feet above sea level, and the relief is probably less than 100 feet with the greater portion of the area less than 50 feet. The topographic "highs" are formed either by outcrops that were resistant to glacial erosion or by moraines, eskers and drumlins which were deposited upon the recession of the glaciers. The better mineralized zones, composed chiefly of quartz and magnetite, commonly form ridges resistant to erosion and weathering. Previous Work: Because of the obvious outcrop of the magnetite-rich beds and knowledge gained from early developments within the general region, it is conceivable that the presence of the iron formations has been known for a good many years. The area is included in studies made by L. F. Kindle* in 1929 and 1930 for the Ontario Department *Kindle, L.F., Kowkash-Ogoki Gold Area, Ontario Department of Mines Annual Report, Vol. XL, Part IV, 1931; map 40f

Jan 1, 1961

By Roy Lindsay, Paul O'Hara, Gary Halverson

"The New Britannia Minesite is located in Snow Lake, Manitoba, 420 miles north of Winnipeg (figure 1). The mine previously operated from 1949 to 1958 extracting some 5.39 million tons of ore at a 0.150 opt gold grade. From 1959 to 1986 the property was held by Nor-Acme and Hudson Bay Exploration and Development and in 1987 High River Resources Ltd. Optioned the property, dewatered the mine and conducted a diamond drill program between the 1 780 and 2400 levels. In 1988 two companies, Nor-Acme Mines Ltd. and High River Gold Mines Ltd., negotiated an option agreement with INCO Gold whereby !NCO assumed management control of all site exploration work. During this period, a bulk sample of 10,000 tons was extracted from the 1780 level with no further exploration recorded after its removal. Both Hudson Bay Exploration and Development and INCO Gold conducted feasibility studies on reactivating the property but at a calculated capital cost of Cdn $70 to $80 million found the rate of return on their investment unacceptable.In 1991 !NCO Gold merged its interest with the assets of TVX Gold Inc. and in February 1994 TVX Gold Inc. and High River Gold Mines Ltd. entered into a joint venture partnership to develop the Snow Lake property, naming TVX Gold Inc. the operator. Upon completion of a feasibility study in April 1994 by Bharti Engineering Associates Inc., a decision was made to reopen the Britannia Mine at an established project cost of US $33 million.Project construction commenced in July 1994 with the hoist house excavation. The first concrete for the hoist house level footings was poured on August 4, 1994 and the project was completed on October 1, 1995 at a cost of US $36 million. The first gold pour took place November 4, 1995.This paper not only presents the metallurgical aspects of the operation but also describes the novel approach used to complete the design and construction of the site facilities."

Jan 1, 1996

By Wendy L. Mathieson

The Bonneville Power Administration (BPA) will build about 500 miles of new 500-kV transmission lines in the next 5 years. Many new lattice towers will be built in remote locations or in environmentally sensitive areas. Therefore, micropile foundations were designed that could be installed in remote areas, in variable subsurface conditions, and in a manner that would reduce excavation volumes and potential erosion concerns. Typical lattice tower foundation axial loads range between 75 and 1,500 kips (300 to 6,700 kilonewtons [kN]) per leg, with uplift loads being slightly less than compressive loads. Lateral loads range from 5 to 320 kips (20 to 1,400 kN) per leg. Full-scale axial and lateral load tests were conducted in geologically representative soil units during the micropile design for the 9-mile-long (14-kilometer [km]), Kangley-Echo Lake transmission line that extends through a protected watershed east of Seattle, Washington. Micropile foundations for single and double circuit suspension and dead end towers were designed using these load test data.

Jan 1, 2004

By T. B. Armstrong

"The developing world energy crisis and spiraling fuel costs have created a new public awareness and general acceptance of the need for energy conservation.Plants will have different objectives for an energy conservation program but there appears to be a common approach on how to save electrical energy.Data for a 180tph Rod Mill powered by a 750 hp motor will be used to demonstrate the relationship of energy input and production levels and to seek an optimum operating condition.Energy Conservation:Plants that have examined ways of dealing with the energy situations have concluded that energy conservation has important benefits for industry, including reduced costs, fewer production slowdowns inthe event of fuel shortages and a continued competitive position.There have been some ""startling"" conservation achievements attained through such simple plant maintenance and operating practices as reducing unnecessary lighting in buildings and yards, turning off' equipment not needed at night or over week-ends, through planning maintenance and production schedules to minimize energy use and through improving quality control to eliminate waste.Significant reducti.ons in energy use have been achieved by some rather simple but vigorous maintenance and plant engineering efforts directed at finding and fixing energy ""leaks"" rather than technological advances or major rework or redesign of facilities and equipment.An Energy Conservation Program often must overcome such obstacles as historic operating practices and emp1-oyee indifference, i.e. the ris.ing costs of fuel should result in re-examination of so1ne basic attitudes to energy conservation. Some measures, rejected in the past largely on the grounds of capj.tal. expenditure, now make economic sense in the light of future escalating energy costs."

Jan 1, 1978

By D Craw, K A. Hunter

Deposits of the metalloids arsenic and antimony occur in quartz veins of mesothermal hydrothermalsystems in the South Island as arsenopyrite (AsFeS) and stibnite (Sb2S3). Arsenopyrite and stibnite occur in natural exposures in gold-mining areas, and additional arsenopyrite and stibnite have been exposed to the atmosphere by mining activity. At present the drinking water limits for dissolved As and Sb are 10 ppb and 3 ppb respectively. Sampling and analysis techniques are critical to determination of metalloid concentrations at these low levels. Endeavour Inlet in the Marlborough Sounds is an historic mining area (late 19th Century) with elevated As and Sb in waters emanating from mineralised rocks. Waters running out of abandoned adits have concentrations of As and/or Sb up to ppm levels. Natural waters have high Sb and low As, and the As levels increase markedly where anthropogenic activity has exposed rock. Changes in Sb/As ratio could potentially be used to quantify the anthropogenic component of metalloid mobility on mine sites on the 100-year time scale.

Jan 1, 2002

By M. J. Fairweather, J. R. Egan, W. A. Meekel

Cominco Metals, in cooperation with two Canadian Universities and the Government of Canada, is developing applications for column flotation in the treatment of lead and zinc ores. Plant scale results at Polaris and pilot plant studies of Sullivan, Pine Point and Red Dog ores show column flotation to have significant advantages over conventional mechanical flotation for lead and zinc cleaning. Results from these ongoing studies are discussed in relation to ore texture, mineral recovery, impurity behaviour, scale-up and control.

Jan 1, 1988

By J. C. Ashby

Electric utility response to certain amendments of the Clean Air Act has resulted in a production of several types of alkaline coal combustion byproducts. Alkaline combustion byproducts are gaining increased usage for acid mine drainage mitigation and abatement as research leads to a better understanding of their beneficial applications. Since January of 1997, Mettiki Coal Corporation has been injecting alkaline flue gas desulphurization byproducts from Virginia Electric?s Mt. Storm Unit #3 wet limestone scrubber into abandoned portions of the active Mettiki mine. This paper provides an overview of the key design, transportation, regulatory, and environmental issues faced in the project.

Jan 1, 1999

By Kihong Park, Matthews C. Habjan, Arthur L. Miller

New Mining Safety and Health Administration (MSHA) regulations limit the mass concentration of airborne diesel particulate matter (DPM) or, more specifically, the concentration of elemental carbon (EC), in underground mines. The mine operators are responding by introducing a variety of controls to reduce DPM in the mines, potentially including the evaluation of new maintenance procedures to reduce underground mine vehicle emissions. There is currently a lack of an inexpensive and dependable method to directly measure the DPM concentration emitted from the vehicle tailpipe. To that end, this work demonstrated a simple field portable method for estimating the mass concentration of elemental carbon exiting the tailpipe of a diesel engine using a direct reading photometer. Simultaneous measurements of tailpipe exhaust were made with a Thermo Electron Personal DataRAM 1200 photometer (particulate mass concentration based on light scattering) and by analyzing PM2.5 and PM1.0 samples collected on quartz fiber filters using the National Institute of Occupational Safety and Health (NIOSH) method 5040 (mass concentration of EC via thermal-optical method). Results indicate surprisingly good correlation (R2 ) 0.97) of the two methods when the data are adjusted for relative humidity (RH) and corrected using an empirically generated calibration factor. Although preliminary, it may be possible to implement this method in maintenance shops to monitor emission trends and to compare emissions of various vehicles in a fleet. Such data will be useful for fleet planning to meet new air quality standards.

By P. C. McWilliams

Theoreticians in soil mechanics have been pursuing a probabilistic approach to the factor of safety of an embankment or darn for the past 10 years. The motivation for this work is in contrast to the current practice of deterministically computing a factor of safety and treating it as an absolute with no regard to its inherent statistical variability. Basic to the probabilistic approach is the selection of an appropriate statistical model to represent the histogram or probability density function (PDF) of the factor of safety values, Rather than simply assuming which PDF is appropriate, the Bureau of Mines collected data at two waste disposal embankments for consideration, This report addresses three candidate models, using the techniques of nonlinear curve fitting, and identifies the "best" model. A propagation of error formula for estimating the variability of Fellenius? factor of safety is also discussed.

Jan 1, 1983

By M. Schafer

The 6-m- (20-ft-) diameter cast-in-place tunnel lining for Phase 3 of the Mill Creek Tunnel (MCT3) has been completed. This article summarizes aspects of liner design and ad-dresses the construction approach in placing the liner in areas of tunnel that experienced crown overbreak. Tunnel lining production rates, installation procedures and form buoyancies experienced during concrete placement will also be presented. The Mill Creek Phase 3 tunnel (MCT-3) is expected to be completed this year. It is one of the largest tunneling projects undertaken by the Northeast Ohio Regional Sewer District (NEORSD) to date. The tunnel horizon is situated within the Devonian Chagrin Shale rock formation at an average depth of 85 m (280 ft). The tunnel was excavated using a two-pass method. A full face, fully shielded, Robbins 7.2-m- (23.8-ft-) diameter tunnel boring machine (TBM) was used to excavate approximately 4,500 m (15,000 ft) of tunnel and facilitate installation of initial supports (first pass). The final lining (second pass) consists of 305-mm- (12-in.-) thick cast-in-place reinforced concrete and integral low flow channel. Seven shafts were constructed on the project. The excavation of the tunnel commenced at Shaft 14 and proceeded down grade to Shaft 9, the terminus shaft. Because of the presence of overbreak in the tunnel crown, measures were required to support the form and counteract the effects of buoyancy during concrete placement.

Jan 1, 2008

By D. Jacobson

There are many different machine setup parameters and variables that affect the production of cone crushers in a mineral processing plant. One of these variables is the eccentric speed at which the cone gyrates. In June 2012, pilot tests were conducted on a 200 hp high speed cone crusher to determine the production and operating conditions over a wide spectrum of eccentric speed. Every plant will have variations in the ore characteristics and feed rates throughout the life of the mine, and at times throughout a single shift of operation, which result in non-optimal use of the crushing energy and inconsistent process control. For high speed cone crushers, the crusher will exhibit a different capacity, power required, and discharge size distribution as the speed ranges over the design limits of the machine. This study documents the measured variation in production and energy efficiency both when the crusher was ran at full capacity as well as when the feed to the crusher was not sufficient to run at full capacity. Overall, the results match theory and the capacity and power fluctuated by 25% and 17%, respectively, over the speed range when operated full while there was an overall trend of slightly coarser discharge size distribution as the speed decreased. The results with the fixed feed rate were more telling, as the crushers had 4-14% higher production when making a theoretical minus 12.5 mm product when operating at the optimal speed as compared to the worst speed in the ?typical? speed range for this application. Secondary analysis of the fixed tonnage testing also showed that the power draw was more consistent with lower magnitude spikes at the higher speeds (higher cavity level), as on average the standard deviation of the power draw increased from 7% to 18% and the peak power spikes from 20% to 48% over the speed range tested. The findings lay groundwork for more efficient plant design. Varying the speed of the crusher can be used to tune the crusher speed during commissioning, adapt to changing ore conditions over long periods of time, or be used as a dynamic input into an advanced control system. Each action above would serve to make the crusher(s) more productive and more energy efficient, and would also have mechanical benefits for the machine. Key Words: cone crusher, ore reduction, process control, crushing efficiency

Feb 27, 2013

By E. S. Peters, M. J. van Rensburg, M. Le Roux, Q. P. Campbell

"The demand for energy has continued to rise worldwide in line with population growth. The majority of South Africa’s electricity is supplied by coal-fired power stations. The amount of fine coal (-2 mm) generated at coal processing plants has increased, due mainly to mechanized mining methods. Fine coal retains more water, which lowers its heating value.Drying the coal is costly and it is difficult to achieve the required moisture content. Consequently, coal fines are often discarded. An estimated 8% of the total energy value of mined coal is lost1.Fluidized bed technology is often used to dry coal thermally, but this method is expensive and has an adverse environmental impact. The objective of this study was to investigate the removal of moisture from fine coal (<2 mm) in a fluidized bed operated with dry fluidizing air at moderate temperatures as the drying agent. The effects of different air temperatures and relative humidity levels were investigated in a controlled environment. The study further investigated the influence of coal particle size on moisture removal.The drying rate was found to increase with increasing temperature. The relative humidity of the drying air had a more pronounced effect on the drying rate, even at temperatures as low as 25°C.. It became more challenging to remove moisture as the particle size decreased. The gain in calorific value was greater than the energy required to dry the coal samples, showing that a fluidized bed using moderately warm dry air is an energy-efficient drying technology. The energy efficiency of the fluidized bed compared favourably with other thermal drying methods.Paper written on project work carried out in partial fulfilment of Degree in Chemical Engineering(NWU) - Pursuing Masters in Coal Beneficiation"

Jan 1, 2015

By John M. Devine

The severe corrosion of equipment that is caused by the presence of hydrogen sulphide in oil and gas has been described in detail by several authors.5 Such corrosion, termed "low-temperature hydrogen sulphide corrosion", presents a somewhat different problem from the "high-temperature hydrogen sulphide corrosion" that is encountered in refinery operation and

Jan 1, 1932

An active list of permissible explosives was published in July, 1931, as part of United States Bureau of Mines Report of Investigations 313, under the title of "Active List of Permissible Explosives and Blasting Devices Approved Prior to June 30, 1931." Changes in that list were authorized in August, September, October, November, and December, 1931, and. January and March, 1932, as published in Reports of Investigations 3l40, 3147, 3l50, 3155, 3158, 3161, and 3163, respectively. By these changes the following explosives were added to the active permissible list: [Austin Red Diamond No. 1, L. F. Gel-Coalite W. L. F. Austin Red-Diamond No. 5, L., F. Gen-Gel No. 2. Black Diamond Nu-Gel No. 1 Genite C-1 Burton 1, L. F. Liberty No. 4 Burton 2, L. F. Liberty No. 5 Burton 10, L. F. Peerless D Burton 12, L. F. Permigel 1, L. F. Burton F, L. F.]

Jan 1, 1932

By Leon Lorenzen, Charlene Gokhale

"In excess of 24 x 106 tons (Eskom, 1997) of coal-derived fly ash is produced annually in South Africa for the production of electric power. A large quantity of this ash is disposed of as a solid waste in landfills, thus posing a serious environmental problem. Due to the shortage of landfill sites, new ways of utilising fly ash are needed. Recently several authors have shown that various combustion fly ashes can be converted into zeolites to obtain industrial products with applicability in environmental management. Geopolymerisation has emerged during the last few years as a possible solution to some waste stabilisation and solidification problems. henolic compounds have been shown to be toxic to soil microorganisms at the parts-per-million level. Indeed several of the organic compounds classified by the U.S. Environmental Protection Agency as priority pollutants, are phenols. Immobilisation of phenols by adsorption on zeolites and encapsulation in a geopolymer appears to be a promising solution to this problem.This paper reports a technique for the production of a low-silica sodium zeolitic material from fly ash (zeolite NaP1), and its application for the stabilisation of phenols by adsorption and subsequent encapsulation in a geopolymer matrix. A commercial zeolite, clinoptilolite was also utilised as an adsorbent. Due to their uniform pore sizes and large surface areas, zeolitic materials are suitable for ion exchange and adsorption of certain organic substances. Adsorption data show that the commercial zeolite, clinoptilolite was an effective adsorbent for organics. Adsorption data showed that between 51.2 ppm and 74.3 ppm of chlorophenol or between 15.4 ppm and 32.5 ppm of phenol could be adsorbed. Physical encapsulation of the coated zeolite loaded with organic within a geopolymeric matrix increased the compressive strength of the matrix from 28.80 kN to 40.79 kN. Leaching data for the various geopolymer matrices with encapsulated and loaded zeolites show no organics being leached from the system at a detection level of 2ppm. According to the SABS these would have been acceptable organic concentrations within a waste water stream."

Jan 1, 2003

By D. Harrington

The experience of the past 2 years has demonstrated clearly that mine explosions with heavy loss of life can be prevented. The investigations of the Safety Division of the United States Bureau of Mines disclose that during the fiscal year 1934 there were only 28 deaths from mine explosions in the United States, and during the fiscal year 1935 there were 54 deaths, a very favorable reduction when compared with an average death toll of 265 from this cause during the 20-year period prior to 1929. Although the frequency of occurrence of explosions has not decreased greatly during the past 7 years, there has been a marked decrease in severity, indicating that the coal-mining industry is taking more effective precautions to prevent the spread of explosions. A number of large coal-producing States, which in past years have experienced numerous disastrous explosions, have been free from such disasters for continuous periods of as much as 5 years or even longer. A study of several hundred mine explosions occurring in the United States during the past 10 years or more indicates that the factors mainly responsible for these explosions are inadequate or defective ventilation and disregard of the hazards from explosive gas. Both of these factors are subject to control, and if controlled it is safe to say that deaths from explosions would be reduced to a negligible number as relatively few explosions are now initiated by dust.

Jan 1, 1936

By Rudolph Emmel

THE mines operated by the South American Development Co. are located in the Zaruma mining district of southwestern Ecuador. They are near the old mining town of Zaruma, which is the only important city in the canton of the same name. The district is situated in the upper end of a valley lying between two spurs of the Cordillera, one of which may be considered the Coast Range and the other an intermediate range. The mining camp proper, known as Portovelo, and the plant are 2.4 km. south of Zaruma, on the north bank of the Amarillo River, a tributary of the Tumbes River, which flows southwestward through Peru to the Pacific. Portovelo is difficult of access; it is reached from Guayaquil by means of river steamers and muleback. Embarking at Guayaquil, the route is down the Guayas River, across the Jambeli Canal, and up the Santa Rosa River to Santa Rosa, a distance of 177 km. From Santa Rosa, the road or trail follows the Santa Rosa River, then across the summit of the Coast Range into Portovelo, a distance of 74 km.-a two-day trip on muleback. The mining property of the South American Development Co. comprises 297 lode claims and 142 placer claims. The combined lode claims cover an area, roughly rectangular in shape, 9000 m. long from north to south by 4000 m. wide; the northern edge of the rectangle is about 3000 m. north of the central plaza of Zaruma. Mineral lands in Ecuador are held by virtue of an annual tax per claim paid to the central government, no surface rights being included.

Jan 1, 1925

By Charles E. Whieldon

Data on the oilfields in Mahoning, Columbiana, Carroll, Jefferson, and Harrison Counties, Ohio, were collected from scattered sources and compiled to make the information readily available to operators who may be interested in conducting secondary-recovery operations in the area. General geology, oil production, oil-productive acreage, core data, reservoir calculations by townships, and miscellaneous data and reference material are presented.

Jan 1, 1965

By James Y. Oldshue

"Very seldom is it possible when contacting a gas with a slurry to measure the dissolved gas concentration in the slurry, and even were it possible, seldom are equilibrium data available with a suitable Henry’s law constant.In general, by assuming a reasonable value for the dissolved gas concentration in the slurry and a corresponding equilibrium gas partial pressure P*, Kga values can be calculated for the pilot plant and scaled up. Then, with the same P* value at various reaction conditions, a mixer can be designed which is quite satisfactory, having a reasonable design factor for full-scale performance.We will take as an example a slurry of a known solids composition and use a continuous 4 tank system. By assuming a percentage saturation of the dissolved gas in the first tank, the dissolved gas concentration can be obtained in the other three tanks. It usually is possible to measure the off-gas composition in each of the 4 tanks. If the top of the tanks is connected in the form of a multi-compartmented horizontal autoclave, then a modified top off-gas composition in each compartment must be used."

Jan 1, 2003

By Rolf Katzenbach

The principle questions related to the design of deep foundations especially in soft soils are the stability and the cost optimised settlement reduction to prevent possible damages and to minimise the deformations of the adjacent infrastructure. The present develop­ments in the design of deep foundations lead to the design approach of the Combined Pile-Raft Foundation (CPRF) which offers a lot of new possibilities, e.g. the utilisation of the CPRF for horizontal loading or the use of the subsoil as a geothermal storage system.

Jan 1, 2006