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By Robert M. Baker

This document details the method whereby Allen Corporation of America gathered and analyzed data and developed an annotated bibliography of metal and nonmetal mine fire reports (1950-1979). The primary objective of this program was to develop the annotated bibliography which included MSHA accident reports and periodicals. Two additional objectives were to gather data on non-reportable fires and to conduct statistical analyses on the data to delineate trends. Data was acquired from three major areas: periodicals, MSHA fire reports, and mine safety directors. Data was separated into reportable fires (at least ½ - hour duration or injury), non-reportable fires, and opinion data. The data was then analyzed by time trends, state, ore, ignition source, burning substance, location, equipment, detection, duration, injuries, fatalities, and successful extinguishing agent. The authors make a number of recommendations: (1) improved stationary electrical equipment design and fire protection, (2) improved design of mobile equipment to separate combustibles from ignition sources, (3) improved maintenance, (4) improved housekeeping, and (5) improved training. The document is divided into two volumes and an appendix. Volume I contains data acquisition procedures, data analysis procedures, and conclusions and recommendations. Volume II contains a chronological list of mine fires and fifteen indexes to assist the reader in locating fire incident report of interest. The Appendix contains the annotated bibliography of over 300 metal and nonmetal mine fire reports and journal articles and a list of non-reportable fires.

Jan 1, 1980

By Robert M. Semple, Harvey W. Parker

INTRODUCTION Two promising innovative tunnel support systems are being developed by the Civil Engineering Department of the University of Illinois. One of these is a lining which can be placed by a slipform located immediately behind and contiguous with a tunneling machine. Recent advancements in construction materials appear to provide the breakthrough required to make such a system feasible and practical. The lining material which permits this construction scheme is wire fiber reinforced concrete made with high, very early strength regulated-set cement. Parts I and II of this paper relate to this slipformed liner. Part I discusses the material and equipment required to install the liner. The "Extruded Liner System" (ELS) has been devised to place the lining. This ELS concept is briefly described and a tentative development program is outlined. In Part II, the physical properties and practical construction aspects of the liner material are discussed and a program for structural testing of 10-ft diameter prototype tunnel supports is presented. Part III contains descriptions of improvements to conventional steel-rib tunnel supports. It is shown that square tubular box sections are structurally superior to wide flange sections for complex loading conditions often encountered in rock tunnels. Analytical studies and tests on connections have been performed to evaluate their structural behavior. These are presented along with a program for comparative large-scale tests on horseshoe-shaped frames with a 10-foot span. This research is being conducted by the Department of Civil

Jan 1, 1997

By Alvin Schallis

Of all the uses for dolomite that depend on its magnesia content, perhaps the most important is its use in basic refractories. The quantities of dolomite (including both that used as crude and that calcined before use) sold or used for refractory purposes by producers in the United States for 1920-41, inclusive, are shown in figure 1. As can be seen from the chart, the utilization of dolomite as a basic refractory is far from new; it was, in fact, the first basic refractory used extensively in open-hearth steel furnaces. After large deposits of magnesite were opened in Austria-Hungary, the use of dolomite in the open hearth declined somewhat, only to be actively revived during the World War of 1914 to 1918, when supplies from Austria were shut off. The use of dolomite as a refractory in the steel industry again declined slightly for a brief period after the Armistice, but subsequently its use has tended steadily to increase, latest statistics indicating that more dead-burned dolomite is used per ton of open-hearth steel now than during the World War of 1914 to 1918. Despite fluctuations in consumption, dolomite has continued to be by far the most widely used basic refractory material. The following table, showing the quantities of basic refractories consumed in the manufacture of steel, the principal outlet, indicates the relative importance of dolomite. The chief reason for the widespread use of dolomite as a basic refractory is its relatively low cost. Its abundance and the proximity of the deposits to the steel industry (see fig. 2) afford every incentive to enhance the desirable physical properties of dolomite refractories and to ameliorate certain of their less desirable characteristics. The present emergency, with its huge demands upon the steel industry, has lent further impetus to the work of improving dolomite refractories.

Jan 1, 1942

By G R. Mould

The paper presents a general background to the subsidence research program being undertaken by the Department of Mineral Resources and Development in New South Wales. The results of the studies undertaken over the last ten years are summarised. The differences between these results and those obtained by the National Coal Board are discussed. The results of a study carried out on the effect of total extraction beneath a freeway in the southern coalfields are discussed in some detail. The procedures developed for the construction of a 500 mm diameter natural gas pipeline crossing a number of collieries in the northern coalfields are also outlined. The future direction of the Department's subsidence research program is discussed.

Jan 1, 1980

By B. Haimson

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

Jan 1, 2003

By D. E. Calisaya, É. Poulin, A. Desbiens, R. del Villar, A. Riquelme

"A 15 cm diameter by 732 cm height, fully automated pilot column was installed in the Agnico-Eagle’s Laronde concentrator (Québec), for evaluating the performance of newly developed sensors and advanced process control algorithms. For eventual comparison purposes, the pilot column is continuously fed with the same slurry feeding the copper-circuit third cleaner column. It is equipped with electrical conductivity-based sensors for estimating the three variables used in the multi-variable control algorithm under evaluation: froth depth, fraction of wash water underneath the interface and gas hold-up. Froth depth is regulated using a PI controller while a predictive controller is formulated as the minimization of the tracking errors of gas hold-up and bias rate, keeping several operating constraints between their practical upper and lower limits. In particular, an unreachable high set point of gas hold-up can be selected in order to maximize the bubble surface area available for particle collection, while maintaining bias rate above a minimum value required for froth cleaning. The proposed strategy may indirectly help optimizing flotation column operation by using these secondary variables, without the implementation of a real-time optimization layer.INTRODUCTION Flotation columns have already been used for more than 30 years, mainly in cleaning stages, as a result of their froth washing capabilities. Despite their widespread usage, the measurement of some pertaining variables and their use for automatic control is rather scarce. Among the most important variables directly related to the process metallurgy (concentrate grade and recovery), froth depth (hf) is the only one normally monitored and controlled. Even though commercial sensors are available, gas hold-up (eg), a variable directly related to concentrate recovery, is seldom measured and never controlled. Another important variable, bias rate (Jb) responsible for concentrate cleaning, is simply not measured at all, as there is no commercial sensor available. Therefore, besides froth depth, continuous monitoring of process variables is limited to flow rates (gas, feed, tailings, wash water), i.e. to manipulated variables. Some new available sensors have been industrially tested, e.g. the Sonar-TracTM for eg (O'Keefe, Viega & Fernald, 2007) and the McGill hold-up sensor (Tavera & Escudero, 2002). Others, for bias rate and frother concentration, have been successfully validated at laboratory scale by Laval’s LOOP researchers (Maldonado, Desbiens, del Villar & Chirinos, 2008b; Maldonado, Desbiens, del Villar & Aguilera, 2010a). Some devices have been extensively used for monitoring bubble size and space distri-bution, e.g. McGill bubble viewer (Gomez & Finch, 2007) and others."

Jan 1, 2012

By B. A. Eaton

The subject of many discussions and technical papers in the last 20 years has been the prediction of the well-bore pressure gradients that are required to induce or extend fractures in subsurface formations. The subject merits this attention because of the frequently recurring problems that arise from an inability to predict fracture pressure gradients. Encountered in several common types of operations in the oil industry are problems associated with the prediction of formation fracture pressure gradients. When wells are being drilled in both new and old fields, lost circulation is often a very troublesome and expensive problem. Complete loss of circulation has been disastrous in some cases. Many times, such disasters could have been avoided if techniques for calculating fracture pressure gradient had been employed in the well plans, and if casing strings had been set, and mud weight plans had been followed accordingly. In areas of abnormally pressured formations, the prediction of fracture gradients during the well-planning stage is extremely important. In fact, it is as important as the prediction of formation pressure gradients, which has received a great deal of attention in recent years. There are several published methods used to determine fracture pressure gradients. However, none of these methods appears to be general enough to be used with much reliability in all areas. In 1957, Hub-bert and Willis published a classical paper that included the development of an equation used to predict the fracture extension pressure gradient in areas of incipient normal fau1ting.l Overburden stress gradient, formation pore pressure gradient and Poisson's ratio of rocks were the independent variables that were shown to control fracture pressure gradient, the dependent variable. In 1967, Matthews and Kelly published another fracture pressure gradient equation that is different from that of Hubbert and Willis in that a variable "matrix stress coefficient" concept was utilized.3 Later the same year, Costley wrote about a similar idea.5 Goldsmith and Wilson used a least-squares curve-fitting technique and field data from the Gulf Coast area to correlate fracture pressure gradient with formation pore pressure gradient and formation depth.' They noted that the fracture pressure gradient increased with increasing depth while the pore pressure gradient remained constant. In each of these cases, the problem for which a solution was sought was to determine the bottom-hole pressure gradient required to initiate or extend a fracture. Results of the previous work show that fracture pressure gradient is a function primarily of overburden stress gradient, pore pressure gradient, and the ratio of horizontal to vertical stress. There is argument for a fourth variable in that in many cases breakdown fracture pressure gradient is greater than the fracture extension pressure gradient. However, if the fracturing fluid is able to penetrate the formation through the pores or existing cracks, there is very little

Jan 1, 1970

By Allen D. Look

Underground fires often prove difficult to control , and a small fire can quickly grow into a large one , endangering life and causing large property damage . Even a small underground fire may produce enough noxious gases to cause suffocation ; therefore , every precaution should be taken to prevent and control such fires . It is ironic that mine fires should be caused when utilizing materials that are in themselves fire - resistant ; yet , cutting and welding of iron and steel are proving to be common causes of underground fires in metal mines . This paper includes 19 examples of underground fires of this nature , and undoubtedly this is only a fraction of the number of similar fires that have occurred in the last few years . This paper will review some metal - mine fires caused by cutting or welding and point out precautions to be taken to prevent other fires from this cause .

Apr 1, 1948

By John Hoffert, Darren Colwell, Greg Tucker, Jeremy Kinch, Greg Rasmussen

"The Kemess Mine, a major producer of gold and copper, is located in north-central British Columbia. Kemess was brought into production in May 1998 by Royal Oak Mines. On February 11, 2000 Northgate Exploration Limited acquired Kemess Mine from receivership. Since acquisition in 2000 Kemess has seen many accomplishments, including the reduction of costs by 40%.One of the largest site capital costs was the construction of the tailings storage facility dam, which when finished will be one of the largest earth filled dam structures of its type. The existing construction design by AMEC called for a kilometer wide rock dam to be built from the 1350 M elevation to the 1504 M elevation at a 5.5:1 slope by hauling over 30 million tonnes of non-acid generating waste rock 7-kilometers from the open pit to the tailings dam, which was highly expensive.Kemess realized an opportunity for cost reduction was possible if the dam could be built from suitable quality tailings sand; however the sand did not meet the neutralizing potential ratio specifications. It was determined that cycloning combined with flotation to reduce pyrite concentration in the sand would produce a non-acid generating product for dam construction. The sand plant design challenges were to remove the sulphides from the tailings to obtain an NPR greater than 2:1 and provide a consistent sand product for the construction with a fines content of less than 15% passing 200 mesh. After a 2-year testing design and construction period, the sand plant was successfully started at the end 2002 resulting in higher than expected sand quality and production rates.This paper describes the plant design phase, commissioning, and operation of the tailings sand plant for construction of the tailing storage facility dam to enable us to meet all the engineering and regulatory requirements. The many challenges faced were successfully met using several innovative designs. The operational, economic, and environmental benefits are detailed."

Jan 1, 2004

By Phil Keele

Canadian Natural ??Business Approach Efficiency and Execution ?Drive to be the low cost producer ?Focus on exploitation ?Augment exploitation with strategic acquisitions ?Maintain Discipline and Strength while Delivering on the Defined Plan ?Maintain flexibility and control allocation of capital ?Strive for balance (asset portfolio) ?Maintain financial strength

May 1, 2010

By H W. Wu

The objective of this paper is to examine some modern forms of auxiliary ventilation fabric ducting with streamline design fittings and the efficiency of construction practices. The most dynamic form of auxiliary ventilation is a moveable fan and ducting, which is easy to install and uses light weight fabric. The porous nature of some ducting construction results in leakage and loss of efficiency. Flexible fabric ducting is primarily associated with metalliferous mining and industrial material quarrying. Some applications are found in coal in stone/rock development and with use of dust scrubbers.Forcing auxiliary ventilation systems employing circular fabric ducting have been examined. Leakage of air from ducting is affected by ducting material and construction methodology (such as welded or sewn), quality of installation, number of joints, total length, pressure differences between the inside and outside and diameter. The best ducting system with welded construction can have up to four times less leakage as compared with some systems with sewn construction. It is also evident that the sewn type ducting will deliver less air to working faces and require more fan power, hence higher operating costs to run when connected to the same fan.A case study has also been undertaken to compare predicted operating costs of auxiliary ventilation systems connecting various types of ventilation duct fittings. The study also assesses the technical importance of streamline design with low aerodynamic resistance to reduce the shock losses of the duct fittings. It was found that the system connected with streamline designed fittings is able to provide some power cost savings and deliver more air compared with the system fitted with conventional fitting pieces.Using a ventilation ducting system with a lower leakage and frictional characteristic represents a sound solution to new challenges faced by the industry for increasing demand for better quantities and quality of air delivered to working faces; this is due to higher production schedules and stricter mine health and safety regulations within the Australian mining industry.CITATION:Wu, H W and Gillies, A D S, 2017. A comparison of auxiliary ventilation systems and their predicted operational performances, in Proceedings Australian Mine Vent Conference 2017, pp 207–214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Lance A. Roberts

Expansive soil formations can be found throughout the United States. When subjected to wetting, these formations have the potential to swell and exert large uplift forces on buildings and foundations. Lightly loaded structures, such as single family residences founded in areas of expansive soils, can be significantly damaged due to uplift movement from swelling actions. Designing an economical deep foundation that can resist uplift forces is critical to prevent damage to these structures. The current solutions to control uplift due to swelling soils, such as over-excavation and replacement of the expansive material or the use of drilled shafts can be costly. Piles made from recycled polymer materials could provide a solution. Due to a lower coefficient of friction along the interface of the soil-pile interface compared to traditional pile materials, solid recycled plastic piles can allow expansive soils to move nearly independently from the pile when wetted. This results in a much smaller magnitude of uplift force being transferred to the structure, which minimizes the risk of significant structural damage from excessive movements. This paper presents the results of research conducted on the use of recycled plastic piles in an expansive shale environment. The preliminary phase of the project involved the installation of six recycled plastic piles at a test site on the South Dakota School of Mines and Technology campus. Two of the piles were subjected to a full-scale compression load test in order to determine ultimate capacity. The remaining four piles were subjected to long-term monitoring of uplift movement during the course of the project. A concrete anchor was also installed at the test site for uplift monitoring. Data gathered during the field and laboratory testing was utilized in a non-linear soil-structure interaction model to predict the displacement behavior and internal stresses within a plastic pile and concrete anchor subjected to uplift forces from the swelling shale. While more research is needed to further understand the application for recycled plastic piles, the results from this research indicate that their use is a viable alternative for support of lightly loaded structures in expansive soil environments.

Jan 1, 2010

By Alex Del Castillo

The mineral processing industry has followed the development of database control systems, and various systems have been installed in existing and new plants. The goal is to improve product quality, raise productivity and lower production costs. Improvements in different units for mineral .processing .have been applied. This has led to increasing information for the operators. To support the operators and for an easy overview of the process, a complete concept for an integrated process-control system is required. This paper describes the plant-wide [process control system for the Collahuasi copper project located in northern Chile. The total investment for the project was $1,700,000,000 and included a port area and two copper processing plants, an oxide plant with a cathode production of 50 tons per year and a sulfide plant with a concentrate production of 330 kilotons per year. The main characteristics of the plant-wide process control system include a 200- kilometer long redundant control network and a 24-kilometer long redundant serial network providing coverage for the entire plant. The plants are located around 4,700 meters above sea level, serial communication lids allow the integration of over 2,700 SCADA data units, and the system handles over 7,500 physical signals plus the SCADA data integration. The main equipment consists of 39 different sized controllers, 16 operator stations, 5 engineering stations, 2 information management systems and 4 X- terminals. The project management, control configuration, factory acceptance test, system integration test, training, commissioning and start-up were carried out in close cooperation with the customer. The result was completely satisfactory for the customer.

Jan 1, 1999

LIST OF MEMBERS AND ASSOCIATES ARRANGED ACCORDING TO STATES AND TOWNS ALABAMA Aldrich, Aldrich, W F Anniston, Noble, A E, Smith, N B Aibacoche, Bradley, D II Bessemer, Fergusson, V Birmingham, Aldrich, T H, Aldrich, T H, Jr, Bowron, J, Bowron, C E, Davis, F H, Dimmick, F D, Hillman, McCarthy, M E , McCormack, McCrery, Ramsay, E, Shook, A M Bridge¬port, Wheeler, S K Ensley, McDonald, S, Shook, J W Fanbanks, Hamil¬ton, A L Helena, Squire, J Huntsville, Moss Lehigh, Toulmin Oxmoor, Green¬amyer, A G Plasma, Gage Rock Run, Garvin Sheffileld, Miller, D I Tuscaloesa, Lodge, J University, McCalley Woodward, Bukofzer, Woodward, A H ALASKA Dawson, Buck Douglas Island, Corbus, J P , Macdonald, J Hames, Le Wald, E A Jualin, Hoggatt, W B Juneau, Denby, Gaifield, Garside, Hamp¬ton, W H Rodman Bay, Phillpots Snettisham, Tisdale Sumdum, Thane Tel¬ler, Hirshberg, M R Treadwell City, Batcheller, J H , Kinzie Valdez, Esterly, G M Yukon, Dawson, Elmer, J M ARIZONA Bisbee, Clark, G C, Coombs, H L , Douglas, W, Hoatson, Parnall, S A, Pelton, R T, Ricketts, L D, Sherman, G F G, Smith, F W, Smith, H A Black Diamond, Bagge Blanchard, Cummins, Murray, J J Casa Grande, Rich¬mond, A B Clifton, Colquhoun, Grabill, Murray, H T , Plater, Smith, J D A, Veitch, Watson, W S Congress, Goodloe Crown King, Alexander, G E Douglas, Cornell, Kraemer, E L, Lee, G B, Rutherford, F Globe, Berray, Hoar, Snell Harrisburg, Smith, F C Jerome, Clark, W A, Thomas, C A Kingman, Treadwell, Wallace, J P Kirkland, Bretherton, G K Kofa, Lamp¬shire, J O , Pomeroy, H G Mayer, Haggott, E A Metca j, Blumenkranz, M , Forbes, D L H Morenca, Clark, C D, Fleming, J B, Honey man, Mills, C E, Wallace, L R Morristown, Stevens, H W Nogales, Glove, H G, Sandoval, A , Sandoval, P Octave, Rose, G W Phoenix, Armstrong, T , Butler, C E, Defty, Lindsay, L Prescott, Blauvelt, H , Bunker, C E, Claypool, W M , Drescher, F M , Fairbank, Nissen Tombstone, Gage, Poindexter, C L , Staunton, Walker, E W Troy, Cutting Tucson, Blake, W P, Burgess, De Lashmutt, I, McCleary, Mann, Prout, J W , Jr ARKANSAS Fayetteville, Purdue Fort Smith, Bache, F , Denman, H Little Rock, Fordyce, Scholz CALIFORNIA Alameda, Arents, King, L Arnador City, Downs, Tregloan Angeles Camp, Dig¬gles, R N , Kenney, C E Antioch, Belshaw Auburn, Coe, I J Ballarat, Thorns Berkeley, Abadie,, Christy, Dozier, Hall, F F , Hersam, Landfield, Lind¬say, L , Mansfield, N T, Morley, W S , Sharwood, W J Bag Oak Flat, Dron Bodae, Hamilton, W R, Hoover, T, Hoover, T J, Jackson, B L , Nutter , E, H Bullion, Power, H T Callahan, Scott, E H Campo Seco, Baird Cartero,

Jan 1, 1910

By M. Moinpour, Y. K. Rao

The catalysed direct reduction of copper sulphide with carbon and lime was investigated in the range 850-1000 degrees C using Cu2S-CaO-C and Cu2S-4CaO-4C reaction mixtures. The effects of the catalytic additives K2CO3, Li2CO3, Na2CO3, NaF, Na2SO3 and the ternary eutectic (K,Li,Na)2CO3 were determined. Potassium carbonate, sodium fluoride and the ternary appear to be the most effective catalysts for the direct reduction process. The rate enhancement of the catalysed carbothermic reduction of copper sulphide in the presence of lime was explained in terms of the catalysis of the Boudouard reaction

Jul 1, 1991

By Dave Stefanuto

Voisey?s Bay Project Components ? Mine/Mill Port In Labrador ? Mini Plant in Mississauga ? Demonstration Plant in Argentia ? Supply Vessel (Umiak1) ? Transshipment Facility (Quebec) ? Concentrate Handling & Transport to Sudbury/Thompson ? Cobalt Refinery Upgrade (Thompson) Project Setting ? The Project is on the traditional lands of the Labrador Inuit and the Labrador Innu ? Canadian courts have held that Aboriginal peoples in Canada possess special rights to traditional Aboriginal lands Those rights can include requiring resource developers to enter into Impacts and Benefits Agreements (IBAs) on traditional lands to set forth how lands can be used and benefits to be received by Aboriginal people

May 1, 2006

By S. P. Sandoval

The U.S. Bureau of Mines investigated the separation of aluminum from copper dump leaching liquors using a supported liquid membrane. Aluminum was selectively transported through porous polypropylene impregnated with di (2-ethylhexyl) phosphoric acid in an aliphatic diluent. The effects of variables, such as solution composition, temperature, and extractant concentration, were measured with a three-level fractional factorial experimental design. Experimental results were used to derive equations for predicting transport rates for aluminum, iron, and copper. The major variables influencing aluminum transport were solution temperature, feed solution pH, aluminum concentration in the feed solution, and extractant concentration. Copper and iron transport rates were almost zero when aluminum transport rates were high. Measured aluminum transport rates under the best conditions of 55° C, pH 3.0, 16 g/L A13+, and 65 pct extractant solution confIrmed the predicted value of 210 f.'g/(cm2.h). Transport rates for iron and copper were less than 5 ug/(cm2.h) under these conditions. Aluminum was recovered from the stripping solutions by sparging with gaseous hydrogen chloride to crystallize aluminum chloride hexahydrate, which was calcined to alumina. Sparging crystallization regenerated the stripping acid for recycle.

Jan 1, 1989

By D. Rendini, R. D. Gutridge

INTRODUCTION Gwinnett County, Georgia, is a part of the rapidly expanding metropolitan Atlanta Georgia area. Located approximately 48 km (30 miles) northeast of Atlanta, Gwinnett County has a current population in excess of 600,000 and is projected to reach a population of 1,200,000 by 2025. As a part of the County’s master plan to supply drinking water for the expanding population and to increase system reliability, the Gwinnett County Public Utilities Department undertook the Shoal Creek Raw Water Intake and Pump Station Project. Figure 1 shows a vicinity map for the project. Prior to construction of the Shoal Creek Raw Water Intake and Pump Station Project the County had a single raw water intake to feed water from Lake Sidney Lanier (Lake Lanier) into a filter plant for processing into potable water. This project together with a newly constructed water filter plant provides Gwinnett County additional capacity and system redundancy to prevent interruptions to the drinking water supply. Lake Lanier is a man made reservoir with over 800 km (500 miles) of shoreline and was constructed by the Army Corps of Engineers in the 1950s for hydro electric power generation, flood control, and navigation benefits for the Chattahoochee River. Over time, Lake Lanier has become an increasingly important source of drinking water for the metropolitan Atlanta area. This paper focuses on the primary underground construction and lake tap components of the project including a 42.7 m (140 ft) deep pump station shaft 24.4 m(80 ft) in finished diameter transitioning to a 6.1 m (20 ft) finished diameter shaft, a3.05 m (10 ft) finished diameter by 19.8 m (65 ft) deep intake shaft constructed in an average of 21.3 m (70 ft) of water, and a 190.5 m (625 ft) by 3.05 m (10 ft) finished diameter modified horseshoe tunnel connecting the two shafts. This raw water intake system, in conjunction with the incorporated pump station with 8 pumps and dual1,829 mm (72 inch) pipelines, provides a system capacity of 1,091,062 m3/day(240 MGD) to two water filter plants and is expandable by the addition of pumps to1,500,210 m3/day (330 MGD). Parsons provided design and construction management services for the project. The $29.6 million contract to construct the project was awarded to W.L. Hailey &Company. Notice to proceed was given August 6, 2001 and substantial completion was achieved on January 20, 2004. Value engineering changes adopted for the project contributed to completing the project at a final cost of $28.8 million.

Jan 1, 2005

By Trevor Saldanha, Nawshad Haque, Will Sikora

This study reported life cycle assessment (LCA) of six copper mines in Australia, Papua New Guinea and Portugal. Inventory data was sourced from published papers, sustainability reports by mining companies, independent technical reports and previous CSIRO studies. Sima Pro software and various databases were used to evaluate life cycle based environmental impacts. The impact indicators were: global warming potential (GWP), acidification potential, water footprint, ecotoxicity potential, ozone depletion potential and human toxicity potential (carcinogenic and non-carcinogenic), abiotic resource depletion potential (minerals and fossil fuels), particulate matter and ionizing radiation. Generally, open pit mines were found to have a GWP of approximately 1.0 t CO2-eq/t Cu concentrate while underground mines had approximately 1.3 to 1.8 t CO2-eq/t Cu concentrate. Environmental impacts varied between mines considerably due to several factors, most notably: ore grade, mining method, flowsheets and ore mineralogy. Energy consumption and sources were significant contributors to most impact categories.

Mar 1, 2018

By Deane Tunaley, Clint Brearley, Steven Kotsonis, Richard Goodridge, Tom Smylie

Explosives are widely used in the Oil & Gas Industry for subsurface mapping via measurement of reflected sound waves as each charge is detonated. To complete a seismic survey, several thousand explosive charges may be deployed into narrow boreholes, often in areas difficult to access or where socio-political factors may increase the risk of unlawful recovery or sabotage of the explosives. Therefore, when misfires occur, the explosives left in the ground often cannot be retrieved or sympathetically detonated safely, in which case they are “abandoned” (in-line with local regulations) potentially posing a safety and security risk.

Jan 1, 2014