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By Barry A. Hillman

The rapid evolution of computer and field sensor technology is now providing the ability to integrate mine and office operations. Digital maps and mine plans as well as CAD and GIS can be transferred to ruggedized field computers for development of real-time mine surveys and real-time GPS machine navigation and monitoring. Surveyors can insure that their surveys are accurate before returning to the office. Engineers and surveyors are also able to upload field computer-based surveys to mine planning software and directly to mine equipment including shovels, drills, and dozers providing the operator of the equipment with a real-time view of their work space. Production information can be transmitted through dispatch and/or centralized mine servers to update mine plans with mining progress and production data. Static mine models then become a dynamic element of operations, providing greater use of information that emphasizes the spatial aspects of the mine by providing real-time maps, productivity charts, and graphs. This information can be disseminated through various mine communication systems to provide operators and management with real-time feedback as well as daily and weekly reports. Integrated systems now being used in extensive trials are reporting productivity increases of 4 -7% or more thereby providing rapid payback to the mine.

Jan 1, 1998

By J. A. Burkhardt

Field measurements and theoretical studies have been made of pressure surges—momentary variations in fluid pressure—produced by movement of pipe in mud-filled boreholes. Pressure measurements were recorded by five pressure gauges located at various positions in the borehole. An important positive pressure peak was found to occur as the casing moved with maximum velocity. Important negative peaks were found as the casing was lifted from the slips and as brakes were applied to stop pipe movement. A rigorously formulated theory has successfully predicted the sequence and magnitudes of these positive and negative surges and has established a basis for understanding how they occur. Both the measurements and theory indicate that the most important pressure surge is usually due to viscous drag of the flowing mud. The theory of viscous-drag pressure surges has been approximated by simplified graphs and calculation procedures to facilitate ready use in field operations. Comparison of measured results with those predicted by the simplified theory shows that the magnitude of this surge can be predicted accurately. INTRODUCTION It is widely recognized that raising or lowering pipe in a fluid-filled borehole produces momentary variations in fluid pressure, commonly called pressure surges. Both negative (or "swabbing") surges and positive (or "fracturing") surges may occur. In 1934, Cannon1 measured the negative surges and showed that they could be large enough to cause flow of formation fluids into the well-bore and, in extreme cases, lead to blowout conditions. Later, Coins2 measured the positive surges associated with lowering pipe. His results and subsequent field operations strikingly demonstrated that pressure surges could be an important factor in some cases of lost returns. In addition, although the evidence is less clear than in the case of blowouts and lost returns, other investigators 3, 4 feel that pressure surges probably play a part in many instances of minor gas cutting, salt-water flow and other hole trouble. The importance of pressure surges in drilling operations led naturally to attempts to explain the physical causes, nature and magnitude of the surges. Cardwell5 was the first to publish a theory which allowed the quantitative prediction of momentary pressure variations. He assumed that the drilling fluid was a 300-cp Newtonian fluid in turbulent flow. Most field muds have a considerably lower viscosity and are generally believed to be Bingham plastic in nature.6 However, card-well's results were useful because they were presented in a form convenient for field use and, in some cases, gave a reasonably accurate predicted value for the maximum pressure surge. Subsequently, Ormsby7 published a more comprehensive theory of pressure surges. He discussed both laminar and turbulent flow and considered the theory of mud-bypass devices for reducing pressure surges. As a consequence of his more rigorous approach, his results were more accurate but more complex and difficult to use. Further, both Ormsby and Cardwell considered only the pressure surge arising from viscous drag of the moving mud. Clark later published idealized graphs of surges and presented equations for predicting their magnitudes. In addition to pressure variations arising from viscous drag, he considered those caused by inertial effects. His theory was in this respect more complete than those of Cardwell and Ormsby, although he did not discuss pressures due to breaking of the gel. Furthermore, his equations, while not exceptionally complicated, were too complex for ready use at a drilling location. One difficulty common to all three theories is that none was tested rigorously by direct comparison with measured pressure surges. Their accuracy, therefore, could, not be demonstrated. Further, the two theories based on most realistic assumptions (Ormsby and Clark) required the solution of one or more rather complex algebraic equations. The research described in this paper was undertaken to supplement that described and to overcome some of the difficulties noted. It seemed obvious that a fully satisfactory study of pressure surges should encompass three main phases. 1. A valid theory useful in all field situations must be developed. This theory must be based upon realistic assumptions, must be formulated rigorously and should lead to clear concepts whereby the nature of pressure surges can be easily understood. 2. The theory, however complex and involved, ultimately must be presented in simplified form for convenient field use. This may involve extensive machine computations and the use of figures and empirical equations. 3. The accuracy of the simplified equations must be established by comparing measured pressure surges with those predicted by the theory. These must agree both in their characteristic nature and in magnitude. 'This means that careful measurements of surges occurring in actual field operations must be made.

By C. C. Clark, P. W. Patton, B. M. Stewart

Handling materials in underground mines continues to be a major safety problem. To help reduce materials-handling injuries, researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health are investigating those materials-handling tasks in underground mines that appear to generate a high number of injuries. Data from the Mine Safety and Health Administration for the years 1989-1999 were studied to find out if there were any trends in materials-handling accidents and if so, to determine what tasks were involved and the sources of injuries. Several underground coal and metal mines were visited to document innovative materials-handling technologies. Considerations for safety training and mechanization needs for continued reduction in materials-handling injuries are described.

Jan 1, 2002

By S. H. Lorain

This paper briefly describes the principal commercial and near-commercial deposits of gold-bearing gravel and the important placer-mining operations in Lemhi County, Idaho. It is on of a series on western mining districts being published by the Bureau of Mines. This paper is based on a field survey of the placer-mining districts of Lemhi County in the summer of 1938. Available information concerning gold-bearing gravels was obtained from prospectors and claim owners; operators supplied the data on mining operations. No attempt was made actually to test the gravels. The principal object of the examination was to indicate placer areas worthy of further investigation by prospective operators.

Jan 1, 1939

By Raymond J. Pichette

"Aeromagnetic data can be useful in helping to delineate structures and rock types in gold exploration. Magnetic anomalies associated with Archean volcanic belts in northeastern Ontario can be quickly and effectively analyzed in profile form with the use of model curves. The model curves help to locate contacts between strata. They also help to estimate the magnetite content of the rocks and their depth beneath overburden.An aeromagnetic map of part of Catharine Township, Ontario has been analyzed with the aid of model curves. Several magnetic rock types, potential fault zones and areas of relatively thick overburden were delineated.IntroductionIn any exploration program, a good understanding of the stratigraphy, rock types and structure enhances the possibility of success. For example, environments which host gold deposits in the Abitibi Volcanic Belt may be characterized as follows (Jensen, 1980; Pyke, 1980):(I) They have major faults, especially as tectonic boundaries between volcanic piles which include mafic and ultramafic rocks and clastic sedimentary rocks or gneisses.(2) They have subvolcanic felsic intrusions.(3) They have extensive carbonitization, with or without carbonate and sulphide-facies iron formation.In all cases, delineation of structure and rock type should be a major objective in exploration. The analysis of magnetic data can be a useful tool in this task. This paper is presented with the purpose of describing the application of the magnetic method to gold exploration in Archean volcanic terrains.Magnetic AnalysisTotal-intensity magnetic contour maps can be used to discriminate rock units according to differences in magnetization. However, because of smoothing of texture resulting from the compilation procedure and the fact that survey lines are widely spaced, contours should not be directly used for quantitative analysis. A much more definitive means of magnetic analysis is provided by the use of the original profile or chart recordings. Model curves provide a basis for analyzing these profiles both accurately and rapidly."

Jan 1, 1982

By Cuppam Dasarathy

The incidence of liquid inzmiscibility in binar)) indium alloys has been theoretically analyzed on the basis of the Hildebrand-Alott equation. Bedictions of miscibility or otherwise Imve in general been found to agree with those phase diagrams that are already publislzed in the literature. Out of a total of 27 systems, where either the complete phase diagrams are published or liquid immiscible behavior is reported, the Predictions agree with the experimental data in 25 systems, the exceptions being the Te-In and Ni-In systems. According to the equation, liquid immiscibility is also indicated in the binary alloys of indium with K, Rb, Cs, Na, Sr, Ba, Ti, Zr, V. Nb(Cb), Ta, W, U, Re, Ru, Rh, Os, and Ir. RECENT investigations by the author have shown that indium when alloyed with iron, chromium, and cobalt shows liquid immiscible behavior.1"3 The Fe-In phase diagram shows a wide range of compositions where the liquids are immiscible.4,5 No intermediate phases are present in this system. No precise information is available about the extent of liquid immiscibility in the Co-In system. However, it is certain that there is a range of compositions where the liquids are immiscible and that there are two or three intermediate phases,376 in the system. Liquid immiscibility is also strongly indicated in the Cr-In system and no evidence was obtained in the brief investigation to indicate the presence of intermediate Cr-In phases.2 The present paper deals with a theoretical analysis of binary alloys of indium with certain elements of the periodic table and indicates the systems where liquid immiscibility may be expected. The incidence of liquid immiscibility in binary systems has been theoretically examined by many workers and many excellent papers are available on the subject. In this paper, the alloy systems are examined on the basis of the more recent ideas proposed by Mott.7,8 It has been claimed8 that the Mott parameter predicts the incidence of miscibility or otherwise with reasonable accuracy and consistency. BACKGROUND TO MOTT&apos;S APPROACH Hildebrand applied his immiscibility rule for non-polar liquids to various alloy systems.9 The basis of this rule is that the equation for the excess free energy of formation of a liquid solution is rather similar to the theoretical expression for the energy of mixing of a regular solution. He postulated that when the heat of mixing is sufficiently high, separation into liquid phases will occur and the condition for complete CUPPAM DASARATHY is at the Research Centre, British Steel Corporation, (South Wales Group), Port Talbot, Glamorgan, Great Britain. Manuscript submitted March 12, 1969. IMD miscibility was shown as where VA and VB were the atomic volumes of the components A and B, and ?EV the energy of vaporization of the component. The term (?EVA/VA)1/2 was regarded as a measure of the binding energy of the component A and was called the L&apos;solubility parameter" 8A. On this basis immiscibility occurs when 1/2(VA+VB)(bA-bBf > 2RT [2] Apparently, however, there were several inconsistencies in that according to Eq. [2] several systems known to be miscible in the liquid state were predicted as immiscible. MOTT&apos;S ANALYSIS ~ott&apos;" regards that the reason for the inconsistencies arising out of Hildebrand&apos;s equation was largely due to the electrochemical attraction between the two elements, not being considered. Hence, Eqs. [I] and [2] were modified by taking into account the electro-negativities of the two elements XA and XB, and Mott arrived at an equation for immiscibility, i(VA + VB)(6A - aB)2 - 23,Q60n(XA - XBf > 2RT [3j which can be written as i **&£*&* >&apos;*°™- &apos;• HI T being the melting point of the more refractory component of the system. In Eq. [4], the numerator was called the Hildebrand term, the denominator, the electronegativity term, and their ratio, the Mott number. Mott observed that if the Mott number of a given binary system was greater than the maximum number of Pauling bonds which the two metals could form, then liquid immiscibility could be expected. The maximum number of bonds formed by a given metal was considered to be directly related to the number of bonding electrons available, i.e., to its maximum valency. Since the valencies of the elements considered vary from 1 to 6, Mott assumed that if the ratio of the Hildebrand term to the electronegativity term was >6, then immiscibility could be expected. On the contrary, if the ratio is <1, the metals should be miscible. Further, the alloying behavior is not only influenced by the valencies of the two elements but also by the relative atomic sizes that influence the types of packing and hence the coordination number. Mott considers that on average the maximum number of near neighbors of unlike atoms is 6. Thus, on both valency and size factor considerations, Mott concludes that the maximum number of bonds&apos; possible in any system was 6, this being the upper limit of the Mott number for miscibility. In considering the alloying behavior of systems with Mott numbers between 1 and 6, Mott plotted the num-

Jan 1, 1970

By Thomas Weyand, Thomas Claridge, Dale Nickels

"This paper addresses the initial results of a project to evaluate the suitability of copper mining tailings as raw material for the production of structural products using PMET’s patented technology. Preliminary testing indicated that high performance structural products were possible using these materials. A demonstration scale project produced approximately 1,500 bricks in various colors. These products fall under under ASTM C- 73 and were found to present properties suitable for severe weather applications. Although the products in this project were of typical brick dimensions, other products are possible, for example concrete block substitutes or pavers. These products from the PMET process are commercially known as Brixx. This paper will provide operational details of the production process, mineralogy and mechanical properties of the products.INTRODUCTIONPMET has developed process technology that can convert various siliceous waste materials into competent structural products. This technology is the subject of US patent # 6,068,803. In general, the process consists of mixing lime, water and the major feed stock, pressing to form a “green” shape, and curing the product in an autoclave for 6 hours with saturated steam at ~200oC. The curing process forms Tobermorite, which acts as a crystalline binder. Freeport-McMoRan approached PMET to see whether mine tailings from the Sierrita mine, containing significant amounts of clay, might be a suitable feed material for the production of structural products. “Brixx” is the commercial term used to describe the resultant structural product formed in the test work. This paper is a preliminary evaluation of a technology that is being considered by Freeport-McMoRan. This report is not an endorsement by Freeport-McMoRan of the process or products, nor is it a commitment to use this technology."

Jan 1, 2008

By GERALD H. HUTTON

SINCE the inception of dredge mining, the attention of engineers and operators has been directed primarily toward mechanical improvements and refinements calculated to, reduce operating costs and to increase recoveries. The result has been to develop an efficient excavating and value-saving machine, which, in some instances, has an actual capacity of 15,000 cu yd. per day. Steel hulls and superstructures minimize the risk of destruction by fire and lengthen the life of the plant. Dredges now restore, to some extent, agricultural possibilities to mined ground. Large buckets, with correspondingly heavy parts, are able to handle heavy wash and massive boulders. Mechanical weaknesses have been strengthened. The use of manganese steel in bucket lines and tumblers permits the application too the bank of a digging force that can be withstood only by solid material, such as rock, cement or frozen ground. Various alloys of steel have been applied to certain duties and experiments in their heat treatment are still progressing. Haulage by tractor or truck is in common use. Discarded and worn steel parts are repaired or rebuilt by the use of the oxy-acetylene flame and the arc-welding machine. Gold and platinum saving is more efficient, although still subject to improvement. Dredging for tin ore is in successful operation. Crews are now highly specialized and experience has developed improved methods of work; particularly in the manipulation of dredges to build levees of tailings and to leave open waterways where desired. To sum up by the distribution of overhead expense over several units, ground under favorable conditions can now be dredge-mined for 5)2 c. per cu: yd., in spite of the increase in cost of supplies, power, and labor during, the past few years. Improvements in prospecting methods, however, have not kept pace with mechanical developments. Standard practices of ; testing ground today produce only wide approximations of values; although they obtain information concerning the character of the deposit and bedrock. It is interesting to note that few important changes in the methods of ten years ago are .to be recorded; the latest comparisons between pros¬pecting results and mined recoveries-have been at such variance as to cause confusion to the operator, and, in a degree, the sacrifice of the confidence of the capitalist. On this account, and because the growing scarcity of dredging ground. demands closer calculations on the part of the engineer, this appeal for collaboration and

Jan 1, 1921

By N. A. D. Parlee, M. M. A. El-Naggar, G. 8. Horsley

The apparatus was of a modified Sieverts type1&apos;2 with a reaction tube designed to function also as the cell component of an oxygen pressure gage. The reaction tube assembly is shown in Fig. 1 and described in Table I. The main body is a 1-in.-OD 15 mol pct calcia-stabilized zirconia tube. The ground-glass joint, g, the male part of which carried a prism for optical pyrometer use, was connected to the remainder of the Sieverts apparatus. The calibration of the cell (at its 1000°K operating temperature) for internal oxygen pressures (PO2in) in the range 0.2 to 10 9 atm was made against internal air pressures measured by mercury manometer and McLeod gage. At very low po2in values down to l<Tn atm the performance was checked by comparing pQ calculated from electromotive force measurement when the apparatus was filled with a) pure CO gas and b) a CO-CO2 mixture of the ratio CO-CO2 = 1:0.398, with Po, values calculated from the equilibrium constants of the following reactions at 1000°K:

Jan 1, 1968

By Dongok Kim

Regardless of the advantages of the Friction Stir Process (FSP), for age-hardened aluminum alloys, the mechanical properties such as hardness in the stir zone decreased after FSP due to the growth or dissolution of strengthening precipitates. Here, as a new technique, FSP was introduced to alloy copper nanopowders in Al7075 T651. Mechanical properties of copper nanopowder- alloyed Al7075 T651 together with micro and nanostructures were compared with those of as-FSPed Al7075 T651 using SEM, TEM, and Vickers hardness testing to understand structure-property relationships. It was observed that Vickers hardness of the stir zone in copper nanopowder alloyed Al7075 T651 increased by 20% compared to that of the heat affected zone, while the as-FSPed samples did not show a noticeable increase in hardness in the same zone. Xray mapping showed traces of copper nanopowder after the process. TEM is being used to verify if there was CuAl2 formed in the copper alloyed sample.

Jan 1, 2006

This briefing was sponsored by the Bureau of Mines to summarize ongoing and recently completed chromium-chromite research and resource assessment activities by the Bureau. Through the series of 18 presentations compiled herein, Bureau personnel covered a wide range of topics including U.S. chromite and chromium trends and usage patterns; foreign and domestic resources; and research activities on mineral characterization and beneficiation, chemical and pryometallurgical processing of chromite and chromium-bearing wastes, new low-chromium alloy and coating substitutes, corrosion- and oxidation-resistant stainless steels, and chromium-containing refractories.

Jan 1, 1986

By W. E. Falck, A. Usubiaga, J. Spangenberg, P. Schepelmann, S. Šolar, D. Wittmer, F. Blanchard

The extraction and processing of mineral resources may be accompanied by environmental impacts. In spite of technological advancements, the enormous increase in production volumes within the last decades has induced sizeable environmental impacts along the life-cycle of products. Beside environmental impacts, social issues associated with mining need to be considered to ensure the social acceptability of mining activities. The project EO-MINERS aims at deploying Earth Observation (EO) tools to inform best practices in mining and to thus assist the global mineral resources industries in their transition to sustainable development. In order to facilitate the handling of complex sets of information requirements from a wide variety of stakeholders, a set of indicators was developed that will inform the process of EO tool and services development. The project strives to enable stakeholders outside the industry to meaningfully participate in decision-finding processes on mining-related issues by developing and providing EO products and services that fit the information requirements. The project has identified a wide range of such information requirements by stakeholders that could be potentially provided by EO tools. The applicability of the EO tools on the local level is tested on three mining sites.

Jan 1, 2011

By Russell G. Warncke

"This report is based primarily on a study of safety conditions and practices followed in the coal mines of Japan. Not all of the coal fields in Japan were studied, but typical mines in the largest producing areas and a fair cross section of coal-mine-safety conditions observed during February to April 1948 are described.Information was obtained through investigations conducted in the mines, discussions with mine-management officials and representatives of labor unions of the various mines visited, and examination of records and statistics from the various offices of the Coal Board of the Ministry of Commerce and Industry and from the Coal Association of Japan. Statistical data covering the same subject, obtained from different sources, varied in many respects and apparently were reported inaccurately, but such discrepancies can be attributed to different methods of reporting and compiling statistics.It is difficult to correlate the high fatal and nonfatal injury rates that prevail in Japanese coal mines with the conditions observed in the mines. Virtually all mines visited were attempting to prevent accidents and explosions, by apparently following known safety precautions for the prevention thereof. Some commendable safety innovations were observed at several mines; they indicated that mine officials are giving thought and consideration to hazardous conditions that affect their particular mines.Naturally, the operating officials and management were anxious to impress the writer with their interest in accident prevention and safety. Operating officials were found to be receptive to safety and wore interested in formulating definite safety programs. Some nines had well-planned and well-organized safety programs, which, if put into effect, would contribute greatly toward reduction of accidents.The approach to safety in Japan is quite different from that in the United States, especially the concept of personal responsibility for accidents and the extent to which the individual should be protected against hazards. Management is responsible for providing and maintaining safe working conditions. Collaboration between management and worker, as understood in the United States, does not exist in Japan.Increase in accidents since the cessation of hostilities is the result of unsettled economic conditions in the coal industry, influx of inexperience workers, and breakdown of discipline among the miners, who have been organized into unions. Those unions are greatly influenced by ""leftist"" tendencies.It was observed that the Japanese mine worker is fatalistic by nature and has little, if any, noticable safety consciousness. The most urgent major requirements to reduce accidents in the coal mines are to train the worker in accident prevention and instruct him regarding the inherent hazards of his occupation.Revision of the mining laws would help to reduce accidents if the companies would comply with such laws and provide safer working places and if the workers would cooperate with management and observe and comply with such laws as are enacted for their protection."

Dec 1, 1949

By E. D. Doney

The Kerr-McGee Coal Corporation&apos;s Galatia Mine&apos;s first longwall mining system was implemented on May 3; 1989. Start-up of the longwall face represnted the successful conclusion of an effort begun nearly four years earlier. This paper-presents a case history of the processes that led to the longwall&apos;s implementation, and the subsequent mining of the first 7,900 foot long panel.

Jan 1, 1990

By M. G. Dellow, D. W. Hendriks

"In early 1988 the decision was made by Noranda Minerals Inc. to install pressure filters at the GECO mill to replace the vacuum disk filters and bunker-C fired rotary kiln dryers. Two filters were installed, one for copper concentrate and one for zinc concentrate. Completion of the project was scheduled for the third quarter of 1989. The filters were made operational in October 1989. Some work remains to be done yet on loadout conveyors for total project completion. Capital expenditures for the project have been approximately $2,700,000 to date. The paper describes the selection criteria for the filter, the installation, startup and associated problems.1. INTRODUCTIONThe filter model chosen for the project was the Verti-Press model VP-50-6(7) (Figures1 ,2 and 3) by Filtra Systems of Farmington Michigan, USA. The decision to purchase the Filtra Systems filter was based on gaining familiarity with a different, mechanically simpler pressure filter than the Larox design and to a lesser extent a necessity for repairs to the the disc filter, rotary kiln dryer system used at the GECO operation for its' copper and zinc concentrates. The fact that it is manufactured in North America was an important consideration. The same basic principles of pressure filtration as the Larox machine are used but the implementation is quite different and somewhat simplified with some interesting innovations. 2 filters were installed to allow direct and immediate comparison of the same machine on both fine and coarse materials. Copper concentrate is reground for cleaning on the flotation circuit while zinc is not. Screen analysis of composited samples of concentrates for 1988 indicated that expected copper concentrate would be approximately 66% minus 400 mesh and zinc 50% minus 400 mesh (Tables 1 & 2).The filter is composed of six horizontal chamber module layered vertically and held together in a frame by 1 O large bolts; torqued down to 4000 ft-lbs. 6 individual belts are used; each with its own drive system. The belts themselves are of a 3 piece design with a filter cloth portion, a support belt and a rubberized intermediate portion. They are held together with steel clipper lacings. A basic description (1) of the filter operation is as follows. ""The horizontal filler chamber is closed by hydraulically pressurizing seals across each end of the filter chamber to 200 psi. The feed pump then pumps slurry into the filter chamber. Suspended solids are retained on the filter belt and the filtered solution drains into a lower drip tray and flows from the filter by gravity. At the end of the filtration or feed cycle, a rubber diaphragm in the filter chamber is pressurized hydraulically to 100 psi pressure. This removes all free liquid from the filter chamber and the filter cake. After the diaphragms are retracted the filter cake is blown with compressed air to remove any residual cake moisture. The seals are then retracted and the belt is advanced to discharge the filter cakes. During the cake discharge the belts are washed with a spray header located at the drive end of the filter. The belt assemblies move one (1) complete revolution during the cake discharge cycle. The cycle automatically repeats until the filter is shut down by the operator."

Jan 1, 1990

By Secis R

Northparkes Mines is located 27 km northwest of Parkes in central west New South Wales. The E26 deposit is the largest of all defined to-date in the area, containing over 50 per cent of Northparkes&apos; resources and reserves. The combination of orebody geometry and geotechnical characteristics provide ideal conditions for the block cave method of mining of the first lift of the E26 deposit. Although this method of underground mining has been used for decades in other countries, E26 is the first example of its use in Australia. Copper-gold mineralisation at Northparkes is related to quartz monzonite porphyries that have intruded coeval Ordovician volcanics. Sulphide mineralisation (dominantly bornite and chalcopyrite) occurs principally within quartz veins associated with the porphyry intrusions. Veining and mineralisation occurs within both the porphyries and volcanics. To optimise the recovery of a resource within a block cave mine, a good understanding of the rock mass and ore flow characteristics is essential. These have a significant effect on the fragmentation size and range and on parameters such as the drawzone spacing, height of interaction zone and dilution entry. As ore within a cave column moves and mixes when material is extracted from below and beside it, the total reserve extracted is unique for a particular draw strategy/production history. Until recently, reserve estimates and production schedules were based on the application of a uniform dilution factor to the tabulated resource. However, given the complicated flow and mixing within the cave column, such a simplistic approach can produce erroneous results. Northparkes Mines purchased and sponsored the upgrading of a commercially available software package specifically developed for modelling removal of resource blocks under caving conditions. This Gemcom software package, PC-BC, has been used for mine planning, reserve reporting and production scheduling. Blocks within it resource block model are converted into a mineable reserve taking into account mixing and dilution during depletion of drawcolumns (by horizontal and vertical redistribution of insitu tonnage and metal). As PC-BC gives individual drawpoint reserves, it can be used during the planning stage to determine whether or not a drawpoint is economic. For E26 Lift I an optimal layout containing 130 drawpoints has been developed based on a nominal 14 m x 14 m drawpoint spacing and a 0.8 per cent equivalent copper (eCu) cut-off grade. Annual production schedules for the depletion of material above this layout are based on: I higher tonnage removal from higher grade drawpoints in the early years of production; and 2 drawpoint production rates proportional to the total tonnage of orr remaining in the drawcolumn up to the optimal height of draw tier subsequent years. The reserve is tabulated from the combined annual production schedules over the life of the lift. The pre-mining reserve for Lift I of E26 is 26.6 Mt at 1.43 per cent copper and 0.39 g/t gold, of which approximately 23.4 Mt will be extracted under caving conditions. By scaling down the annual production schedule, weekly drawpoint tonnage calls can be given for short-tern production scheduling.

Jan 1, 1997

THE 125th meeting of the Institute was held in New York, Feb. 20-23, 1922, inclusive, and was the most successful annual meeting of the Institute ever held; there was a larger registration, there were more sessions of importance, and a greater number of sessions, than in any previous year. The total registration was 1331, comprising 351 New York members, 393 visiting members and 587 guests. At the annual business meeting of the Institute, held on Tuesday, Feb. 21, with President Ludlow presiding, there was a much larger attendance than usual. The report of the tellers was read and the following officers were declared elected: Arthur S. Dwight, Director and President-District 0 J. V. W. Reynders, Director and Vice-president-District 0 A. R. Ledoux, Director and Vice-president-District 0 Charles F. Rand. Director-District 0 George D. Barron, Director-District 0 William H. Bassett, Director-District 1 Thomas B. Stearns, Director-District 8 William Kelly, Director-District 5

Jan 3, 1922

By Alan A. Campoli

OD March 20, 1989, a meeting was held at the U.S. Bureau of Mines Pittsburgh Research Center at the request of Senator Pete V. Domenici of New Mexico. The purpose of the meeting was to engender a technical relationship between the National Laboratories and the minerals industry. During the meeting, the Director of the Bureau of Mines, T S Ary, suggested that since the Bureau is the focal point for mining research in the United States, it would be appropriate for the agency to act as the liaison between the National Laboratories and the minerals industry. As the first step in this process, the author was selected to perform a 6-month investigation to better define the proper role of the Bureau in this area. As part of the investigation, the mining and mineral-related technology available at 21 major U.S. Department of Energy (DOE) Research Laboratories was reviewed. It was assumed that the broad range of scientific and technical areas covered DOE research would provide fertile ground for mining-related technologies. It was hoped that the applicability of DOE research to this liaison effort would be indicative of Federal laboratories in general.

Jan 1, 2011

Addressing community concerns in relation to an economic activity, particularly when it causes significant community impacts, is especially important for the development of extractive industry projects. Pipelines comprise an integral part of many hydrocarbon developments, which may cause different effects on local economic development, communities and the environment compared with open cast mines. This paper explores community impacts associated with a case study of the oil pipeline æEastern Siberia-Pacific OceanÆ in the Republic of Sakha (Yakutia), Russia. Based on semi-structured interviews, conducted in 2006 - 2008 in Russia, the paper investigates claims of local communities about potential impacts of the pipeline development of their environments and economic activities as well as community claims for greater involvement in sharing the benefits from this major infrastructure project. A community of Indigenous people, Evenk, is likely to be most profoundly affected by the development due to impacts on their traditional activities such as hunting and reindeer herding. The paper examines in detail the regional economic, social, environmental and Indigenous peoples concerns over the construction of the oil pipeline and investigates actions and methods adopted by community organisations to voice their concerns about the pipeline development. Finally, the paper assesses the process of interaction between the pipeline developers and regional stakeholders.

Jan 1, 2009

By A. J. Farstad

The principle objective of the research effort described herein was to identify as rapidly as possible a practical trapped miner location system. Much effort has been expended in the past on the development of a highly sophisticated seismic location system [1] for trapped miners. Field tests of this system have shown that the location accuracy is limited by a combination of seismic velocity anomalies, timing errors, and in general by the relatively weak nature of the signals received at the surface. It was first felt that similar propagation anomalies would be experienced by electromagnetic systems, but to a greater extent than the seismic. However, preliminary tests performed by Westinghouse on the Operations and Maintenance Program, Contract No. H0210063 in 1971 and 1972, indicated that an electromagnetic solution to the location problem may be more feasible than a seismic solution. Thus a more concentrated effort was launched in 1972 and 1973 to more completely determine the feasibility of electromagnetic location systems for trapped miners. Two different approaches to the location problem were undertaken on this program: (1) A pulsed electromagnetic system was developed by the Special Systems Division of Westinghouse in Baltimore, and (2) a Continuous Wave (CW) System was developed by Westinghouse Georesearch Laboratory (WGL) in Boulder, Colorado. Part I of this report will deal only with the development and results of CW Location System developed by WGL. The CW Location System was field tested at three eastern coal mines and at one western hardrock mine. The maximum overburden depth penetrated during these tests was 990 feet at the Robena No. 4 mine near Waynesburg, Pennsylvania. The earth conductivity at this mine was measured to be 1. 1X102 mhos/m, which combined with the deep overburden make this mine representative of expected worst case conditions for a coal mine EM location exercise.

Jan 1, 1973