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By Yehia M. Youssef, Nourhan Moukhtar, M. H. Abdel-Aziz, Ibrahim Hassan

Copper was recovered from copper sulfate solution in a batch-recycled galvanic reactor operated under forced convection with the generation of electrical energy during the cementation process. The divided galvanic cell consisted of parallel copper and zinc plates. The mass transfer rate and the amount of electrical energy generated were found to be directly proportional to the solution flow rate and the initial concentration of metallic ions and inversely proportional to the distance between electrodes. The experimental results were expressed in terms of a dimensionless correlation including all parameters. The wastewater treatment presented herein cell can be utilized to recover many soluble heavy metal ions from solution with high efficiency.

Oct 2, 2020

By Robert S. Schechter

A minitest, consisting of an injection/production well and at least two observation wells designed to detect the arrival of injected fluid leached minerals, and nonideal flow, is considered in this report. The test goals are to determine the susceptibility of the host formation to uranium leaching, kinetic parameters to scale the process, and to facilitate site restoration. This report considers permeability and mineral heterogeneities and other oxidant-competing minerals. To circumvent these nonidealities, which obscure the results, methods of interpretation have been proposed and tested by a computer simulator. In complex cases, clear-cut methods of interpretation were not found; but in every case the design of a test most susceptible to interpretation has been considered. The minitest is operationally simple and can be completed in a short time. With the correct design and interpretation it can return information to evaluate economics, ensure satisfactory leachate performance, scale to larger operations, and to identify restoration problems.

Jan 1, 1983

By D. L. Murr, J. R. Jensen

Testing was conducted on a Minnesota Iron Ore concentrate with Cook Clay as a binder using compressive sheer mixing to enhance the performance of the agglomeration mechanism. The testing was conducted on a bench scale at the Midland Research Center the summer of 2004. Results of the test program will be presented that shows the impact of compressive sheer mixing had on the strength achieve in a green ball.

Jan 1, 2006

By R. Simkus, J. K. Gowans

Polaris Operations, a Cominco Ltd. lead-zinc mine, is located on Little Cornwallis Island, Northwest Territories, at Latitude 75°23' N and Longitude 96°75' w. When the Polaris Mine went into operation in late 1981, it became the world's most northerly base metal mine.The Polaris Concentrator, housed in a unique process barge, is a basic lead-zinc concentrator where flotation is used to produce the lead and zinc concentrates.The paper describes the ""coarse lead"" flotation feature incorporated in the concentrator flowsheet and describes the start-up problems and continuing operation of this circuit.

Jan 1, 1984

By J. Ruben Velasco, Roland B. Mulchay

CANANEA has long been recognized as a remarkable field for geologic study. The copper deposits and rocks of the district have been described by many geologists and engineers, but only the most general correlations have been made between Cananea sedimentary rocks and other known sedimentary sections in the southwestern United States and northern Mexico. The present paper describes the Cananea sediments in greater detail than has been done before and attempts to fit the Cananea sedimentary section more closely into the geologic time table. The lack of well-preserved fossils has made it difficult to date the sediments accurately in geo- logic time, but it is possible to make tentative correlations between the Cananea sediments and the southeastern Arizona sections, based largely upon lithology and general position in the geologic column. It appears that sedimentation at Cananea and Bisbee may have been closely similar during Paleozoic time. Even such generalized correlations, however, may be subject to considerable modification in the future. The present study has led to the recognition of other problems of age and mineralization relationships in the Cananea district. Cananea is located in the north-central part of the state of Sonora, Mexico, at an elevation of 5270 ft. It is about 135 miles northeast of Hermosillo, the state capital, and 25 miles south of the international boundary. By road Cananea is 40 miles from the twin towns of Naco, Ariz., and Naco, Sonora, and about 50 miles from Bisbee, Ariz. It is served by the Nogales-Naco branch of the railroad, F.C. Pacifico, and is connected with Chihuahua and Mexico City by the Aeronaves airline.

Jan 6, 1954

By A. J. Wainwright

The Coffee Creek lode gold discoveries are located in the White Gold district (Dawson Range), west-central Yukon, 130 km south of Dawson City and 30 km south of the Golden Saddle gold deposit (Figure 1). Extensive structurally-controlled gold mineralization has been discovered during the 2010 and 2011 exploration drilling campaigns, highlighting this part of the Dawson Range as a significant emerging gold district. [ ] In this contribution we review the geological framework and describe the mineralization styles and metal signatures observed to date on the Coffee project. The main Coffee area is underlain by a 15 km by 4 km geochemical footprint, characterized by discrete linear gold-in-soil anomalies that correspond to various mineralized corridors. Of several mineralized areas tested in the past two drill seasons by diamond core and reverse-circulation (RC) drilling, we focus on the Supremo, Double Double, Latte and Kona zones; areas with the most information obtained from drilling thus far (Table 1; Figure 2).

Jan 1, 2012

The upper amphibolite-grade mctasediments of thc rinaroo area, North Queensland, form part of a regional aurcole to the large Tinaroo Batholith and are the stratigraphic equivalents of the Hodgkinson Formation of gencrally low metamorphic grade. There is no evidence of any lithological unconformity.The higher grade metasediments have a more complex deformation history than is typical for thc surrounding region and this may bc due to one or a combination of two factors; an additional strain componcnt associated wilh the intrusion of Ihe Tinaroo Batholith, or a more marked finite strain response to the overall regional stress field within hotter. more ductile rocks.Four deformational events can be characterized within Ihc Tinaroo Area. Close to Ihe Tinaroo Batholith D1 and D2, arc so strongly developed that they disrupl the continuily of Ihe original Iithological layering. In the aureole region, D1 is strongly overprinted and its original fabric intensity is obscured, but both D2 and D3 display a mappable decrease in intensity away from the granite margin. These three deformations occurred during Carboniferous or early Permian time. D4 is later and only patchily developed.The broad, moderate pressure metamorphic aureole surrounding the Tinaroo Batholith is a typical of the CairnsCooktown group of Permo-Carboniferous granitoids. which usually develop narrow, lower pressure contact aureoles. Two periods of metamorphism are distinguishable. The first reached peak temperatures somewhat greater than 520°C, the second temperatures around 620-630° C immediately adjacent to the granite contact.Several cale-silicate lenses containing scattered scheelite mineralization occur within the area. Scheelite appears to have crystallized at the same time as the cale-silicate minerals, its appearance coinciding with the intrusion of the Tinaroo Batholith. Unlike many "skarn-type" scheelite deposits, the scheelite-bearing cale-silicates are Fe-poor, with no positive correlation between total Fe and W.

Jan 1, 1982

By D Fergusson, J D. St George

Highwall stability is a major consideration in optimising opencast mine geometry. It involves assessing the risk of those slope failures that are large enough to have significant cost, safety and/or operational implications. These risks are then balanced against the value of the resource to arrive at an acceptable slope design. Load-deformation models (commonly referred to as ænumericalÆ models) of slopes provide a powerful tool in this decision-making process since they can be verified well before slope failure occurs. This gives the slope designer increased confidence in reviewing designs during excavation, potentially allowing early revision of pit geometry to either increase or decrease safety margins as appropriate. However, these models are not always adopted as they depend heavily on an appropriate choice of constitutive model and material parameters.   A preliminary load-deformation model of a 170m highwall in Solid Energy North (SEN) OperationsÆ Awaroa 4 opencast coal mine in the Rotowaro Coalfield has been prepared. This uses a strain-dependent constitutive model based on laboratory test results, strength parameters developed by SEN and excavation monitoring data. The laboratory testing has included triaxial compression tests on large-diameter fractured samples to characterise the stress-strain response of the closely-jointed soft rock masses that exist in many parts of the mine. Data from the monitoring of a 25m cut made during excavation of a haul road has been used to refine and verify the constitutive model. The resulting highwall model has predicted highwall crest movements corresponding to the excavation of each bench, for comparison with monitored values. Key model outputs are total horizontal movements of about 0.5m near the highwall crest and shear strains of 0.5-0.7% at the locations of potential bedding-parallel shear planes underlying the highwall. Most of the movement is expected to occur as creep rather than as an immediate response to excavation.

Jan 1, 2006

By J. W. Jensen

EXTENSIVE research and development was performed on the manganese-copper vibration-damping alloys to determine the relationship between the properties of the alloys and variations in composition, fabrication, Mid heat treatment. Mn-Cu alloys with unusually high specific damping capacity, 20 to 25 percent at a stress of 5,000 psi, have also the following useful properties: Tensile strength, 90,000 to 110,000 psi; yield strong, 60,000 to psi; elongation, 20 to 25 percent; hardness, 90 Rockwell B; and fatigue limit at, 28,000 to 30,000 psi. Both standard and special methods of testing were employed to obtain data on strength, modulus, hardness, resistivity, dilatation, micro-structure, crystal lattice, and damping capacity. The extensive tabular and graphical data on these properties are presented for alloys containing 50 to 85 percent as quenched d solution) and after various aging treatments. Expansion coefficients for all Mn-Cu solid solutions are graphed and a dilatometer study of contraction during aging is reported. Although high damping capacity is associated with aging to precipitate a-Mn from solid solution, with a cubic-tetragonal transformation and with the occurrence of antiferromagnetic ordering in Mn-Cu alloys, a tenable theory of the damping mechanism has not been reached.

Jan 1, 1965

By Randall M. Wheeler

Using Computer software to analyze and interpret blast vibration effects has never been so practical. Fully digital seismographs and powerful desktop and portable computers have led to the development of fast and easy to use analysis software. This workshop will focus on new Microsoft Windows-based blast vibration analysis programs developed by White Industrial Seismology, Inc. The Windows point and click graphical environment is ideal for developing full-featured and yet intuitive software.

Jan 1, 1994

By James Wm. White

Computer-based mine management systems are being used in many surface mines to assign haul trucks, track equipment and manage information. Advances in digital communications allow these systems to be used in underground operations. Underground mine management systems help maximize production by providing gains in equipment and manpower use, drawpoint equalization in block caving operations, preventive maintenance and safety. Current systems use allocated or "locked" train and load-haul-dump (LHD) dispatching. Allocated dispatching rarely optimizes open pit product' on. But it offers an efficient mode of operation underground and where options are more limited. The primary objectives of underground mine management systems are to maximize production and mini¬mize contention time through allocated train, truck or LHD dispatching, traffic control, equipment monitoring and comprehensive reporting. The main components of an underground mine management system include: ? A central computer (personal computer or worksta¬tion) in a central control center. It sends instructions to train, truck or LHD drivers and allows dispatcher interaction. ? A field computer system (FCS). This consists of a touch-screen graphics console (GC) and mobile hub - on each train, truck or LHD to receive and display instructions from the central computer and accept driver input. ? A data radio network based on leaky feeder (data, voice, video) or microcell radios (data only) and advanced token-ring technology. This passes information between the central computer and the FCSs. ? Radio frequency (RF) tags mounted at boxes, weigh bridges, tips and rim tunnel main haulage ways to locate trains or LHDs (Luke, 1993). Such a management system must be in place before implementing computer-based dispatching (Vagenas, 1991) for production optimization.

Jan 1, 1997

Your thoughts on the current status of the global minerals industries? The global economic, technological, social and political changes of the last two decades of the 20th century resulted in the emergence of a restructured minerals industry. This industry is now based on a new cost-cutting philosophy; utilization of modern technology; productivity gains rather than production tonnages; diversification of mineral markets; and globalization of exploration, mining and processing. Quantity and tons used to be the focus. The emphasis today is on remaining competitive in the marketplace by lowering per-unit production costs as much as possible. What factors and trends will impact the minerals industries in this, the 21st century? A number of parameters will impact minerals operations and shape the future sustainability and growth of the minerals industries. Increased demand for minerals will be accompanied by the demand for technical advancements. We will also see a continued emphasis on health and safety, environmental stewardship, and education and training. Let me elaborate.

Jan 1, 2002

By Carl Johnson, D. R. Todd

The Blue Ridge Low Level Outlet (LLO) was a design/build contract to provide a secondary means of discharging water from the Blue Ridge Reservoir. The project involved driving a 3.25 m (11 ft) modified horseshoe tunnel by 293.5 m (963 ft) long utilizing conventional drill and blast methodology. The intake shaft and structure were constructed inside of a sheet pile cofferdam surrounded by a maximum of 20.1 m (66 ft) of water. The shaft was excavated 4.87 m(16 ft) diameter to a depth of 12.8 m (42 ft) below the tremie slab elevation. Steel lining, including a transition from 3.66 m to 2.74 m (12 to 9 ft) diameter and a90 degree elbow were installed in the inlet shaft and then backfilled with concrete. This paper will describe the RFP phase, the design phase, challenges of the underground construction and contractual challenges.

Jan 1, 2005

By Robert H. Merrill

In 1960, the Kennecott Copper Corp. and the U.S. Bureau of Mines entered into a joint research program to determine the changes in stress, strain, and displacement created by changes in slope angles. The field site was the Kimbley Pit, located near Ely, Nevada; the supporting laboratory investigations were made at the Bureau's Denver Mining Research Center. Following a study to determine the rock stresses in the mining district, the strike and dip of geologic defects (fractures) in the rock, and the laboratory-determined strength of the rock, a new slope angle and pit configuration was selected, and instruments were installed to measure changes in stress, strain, displacement, microseismic noise rate, and sonic velocities at several points in the west wall of the pit. Between February and November 1966, the west slope was changed from an average angle of 45° to a new slope angle that started at 45° on the south wall, gradually increased to 57 ½ at the center of the west wall, and to 61° on the north wall. The pit was deepened from about 500 feet to about 550 feet. About 2.55 million tons of waste and ore were removed by stripping and mining.

Jan 1, 1968

By H. W. Sohns

A retort was constructed in which fine particles of shale, entrained in steam or other gaseous media, could be retorted at controlled temperatures and residence times and the effects of retorting variables upon quality and quantity of products could be determined. Studies of the effects of temperature upon products obtained from Green River (Piceance Creek Basin, Colo.) and Chattanooga (Tenn.) oil shales were completed. The feasibility of using the retort to process a shale of extremely high moisture content from Brazil also was investigated. Air was used as the entraining medium in a series of studies in which combustion of some of the products of retorting within the retort tube supplied a major portion of the process heat. In another series, shale oil from a conventional retort was cracked thermally to obtain data for comparison with results of retorting en-trained shale. In still another series the effects of rates of steam flow and solids feed upon rates of heat transfer from the furnace to the process stream were studied. Crushed quartz rather than oil shale was charged to the retort in this series. A study was begun in which raw shale was partly retorted, the products separated, and the partially retorted shale recharged to the retort. The shale was to have been recycled until it was completely retorted in an effort to improve oil yield by recycle retorting; however, the project was terminated before the investigation was completed.

Jan 1, 1959

By Fardy J. J

Abundance data are presented for a comprehensive range of elements in oil shale samples from deposits located in Queensland. The techniques of instrumental neutron activation analysis and spark source mass spectrometry were used to obtain concentration data for up to 50 trace elements in each shale. These techniques were supplemented by other spectrometric methods to obtain data for major, minor and some trace elements. Sixty-four elements were determined quantitatively. This comprehensive characterisation of oil shale samples from the major deposits in Australia provides inorganic abundance data not previously available. It also provides important background information for processing studies and the associated environmental aspects of shale oil production and waste disposal.

Jan 1, 1986

By Frank C. Townsend

Waste disposal schemes using spent shale in embankments require a thorough knowledge of its geotechnical engineering properties for environ-mentally safe disposal. In this context, the objective of this laboratory investigation was to determine the physical properties, geotechnical properties, and composition of spent oil shale retorted by the PARAHO and TOSCO processes. Physical properties consisted of mechanical analyses, Atterberg limits, and specific gravity determinations. Geotechnical engineering properties were determined by compaction, maximum-minimum density, unconfined compression, triaxial compression, permeability, direct shear, Ko, cyclic tri-axial, resonant column, and Los Angeles Abrasion tests. Petrographic, chemical, and scanning electron microscopy analyses were used to determine compositional features. Unprocessed shale is hard and durable and more properly described as a carbonate rock instead of shale. PARAHO is classified as a GP, while TOSCO classifies as an SM. PARAHO requires no moisture for compaction to maximum densities; however, TOSCO does. Retorting causes a loss in durability but creates self-cementing characteristics, which for PARAHO a 3-to 8-fold strength increase was observed, while for TOSCO the increase was 1.5 to 3 folds. The shear strength, compressibility, and dynamic properties of compacted PARAHO are comparable to those for sandy gravels. Compacted PARAHO is semipervious, while compacted TOSCO can be semipervious to impermeable.

Jan 1, 1979

By K. S. Gritton

The implementation of advance control systems brings with it the expectation of improvements in process performance and controllability. Specifically, expectations include a shift in the mean value of the gross measure of process performance, and/or a decrease in process variability. When determining statistically-defensible measures of these benefits care must be taken to preclude process parameters from biasing the determination. Specifically, the effects of ore type, shift personnel, water availability, etc., must all be separated from the effect on performance of the advanced control system. Methods are presented for separating the effects of process control from other process parameters. Examples of the required data analyses are also presented.

Jan 1, 2001

By H. B. Jensen

STUDY of the thermal-solution process was begun by treating crushed oil shale in a small autoclave at temperatures of 700° to 950° F. The effect of temperature, reaction time, type of solvent, and richness of shale upon the amount of organic matter that was removed from the oil shale was thus determined. Following this orientation work a semicontinuous, bench-scale apparatus was built so that heated solvent could be pumped through a bed of shale under elevated pressure, thus removing the converted organic matter from the spent shale. After some operating experience had been gained, a continuous unit was constructed. This permitted treating a slurry of shale oil and pulverized oil shale at about 300 p. s. i. and temperatures of 750° to 850° F. for various retention times. Considerable cracking and polymerization of the shale oil were found to take place during the process. In an attempt to prevent this, a study was made of extraction of the shale in batch-type autoclaves under high partial pressures of hydrogen at total gas pressures of as much as 4,300 p. s. i. at 850° F. The thermal-solution process was found to convert over 90 percent of the organic matter in oil shale to oil and gas. The highest yields of gas and oil obtained without hydrogen pressure were equivalent to 119 weight-percent of those obtained from the same shale by Fischer assay. With a high partial pressure of hydrogen, yields equivalent to 126 weight-percent of Fischer assay were obtained. However, the oil produced by thermal solution has a higher boiling range than that obtained by other retorting methods, particularly so if the thermal-solution process is used without a high partial pressure of hydrogen. Nondistillable oil (all benzene-soluble material that would not distill under 2 mm. Hg absolute pressure without cracking) equivalent to over 100 percent of the organic matter in the shale was obtained without hydrogen pressure in the system. When the process was carried out under hydrogen pressure, the yield of nondistillable oil amounted to 60 to 70 weight-percent of the organic matter. Part of this heavy material is formed partly by polymerization and condensation of the shale-oil solvent used. These reactions, as well as cracking of the solvent to form gas and a carbonaceous deposit on the shale, are unfavorable features of the process.

Jan 1, 1953

By Roxanne Scott

Outline ? Overview of Community Investment in the Mining Sector ? Emerging Good Practice: ?Strategic Integrated Community Investment? ? Assessing Local Context: ? Institutional Assessment ? Partnership Assessment Approaches to Community Investment Isolation: No proactive engagement in community development Ad hoc philanthropy: small infrastructure, sponsorships, donations Strategic philanthropy: Community proposes options for development Company decides what to do and carries it out, e.g. building schools, health posts, roads Strategic integrated community investment: ? Aligned with government/community development goals and priorities ? Communities and government involved in decisions and execution ? Focused on training and capacity building ? Partnerships ? Continuation in absence of company support Measured returns on investment

May 1, 2010