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By P. Desclaux, A. Gosselin

"In 1999, PFC measurements were carried out at Alcan smelters as part of a large measurement campaign led by the Canadian Aluminium Association. Side worked prebake (SWPB) and horizontal stud Söderberg (HSS) plants in Arvida were the selected sites. CF4 and C2F6 emissions were measured continuously in the exhaust duct and at the roof vents for a week. In parallel, voltages from four designated cells were recorded at a high scan rate. Results were analyzed and correlations between voltage, anode effect duration and PFC emissions were tested. Some fundamental anode effect mechanisms were proposed and validated with the observations. IntroductionFollowing the international agreement reached within the scope of the Kyoto protocol, voluntary partnerships have been established in many countries especially for the aluminum industry. It is well known that the PFCs that are periodically emitted during aluminum production are the major source of fluorocarbon emissions. The latter are part of the greenhouse gases. In the fall of 1999, Alcan announced that it will adopt, promote and regularly renew a long-term greenhouse gas management commitment at all of its facilities within the framework of the so-called TARGET program that was implemented during 2001. The program is intended to produce on-going reductions, which will be reported publicly on an annual basis.Improvements in the understanding of the mechanisms leading to PFC emissions will contribute to targeting the most appropriate reduction actions. PFC measurement campaigns have been driven toward this end. The first measurement campaign was conducted in 1993 in order to get a picture of the emissions and a base line. The last measurement campaign was conducted in 1999 and its main objective was to compare current emissions with those measured in 1993 and to confirm the accuracy of the predictive equations for the calculation of PFC emissions. This campaign has been conducted by the Canadian Aluminium Association and measurements were made in plants using different technologies. Results of this campaign have already been reported by Bouchard et al. (2001)."

Jan 1, 2002

By Frank H. Reed

This report is one of a series written by members of the Solid Fuels Mission to Germany describing wartime developments in the mining , preparation , and utilization of coal . This mission was organized early in 1945 under the auspices of the Technical Industrial Intelligence Committee , which cooperated with a counterpart British committee . The Solid Fuels Mission operated under the direction of a steering committee headed by Dr. C. J. Potter , Deputy Solid Fuels Administrator . The personnel of the mission consisted of H. F. Yancey, in charge , J. W. Buch, Thomas Fraser , L. L. Newman , and L. D. Schmidt of the Bureau of Mines ; H. H. Lowry , Director of the Coal Research Laboratory , Carnegie Institute of Technology; H. J. Rose , Vice - president and Director of Research , Bituminous Coal Research , Inc .; and F. H. Reed , Chief Chemist , Illinois State Geological Survey . Over 50 reports were written by the members of the Solid Fuels Mission . These , together with microfilms of supporting data obtained in the course of the investigations , are on file at the Bureau of Mines , Washington , D. C. , where they are available for public examination . The Office of the Publication Board in the Department of Commerce is prepared to furnish photolith copies , photostats , or microfilm reproduction of all declassified reports . A Bibliography of Scientific and Industrial Reports is issued weekly by the Department of Commerce , Office of the Publication Board , and is sold by the Superintendent of Documents , Government Printing Office , Washington 25 , D. C. , on a subscription basis . An initial payment of $ 10 will provide for approximately 9 months , and subscribers will be notified when additional remittance is necessary . All subscriptions will begin with volume 1 , No. 1 , unless ordered otherwise . The Bibliography, covers all materials and subjects and gives instructions for obtaining the desired items . The reports of the Solid Fuels Mission relate to the following general subjects : Mining methods in the Ruhr district of Germany , with special reference to mechanical cutting and loading equipment , pneumatic packing , and Diesel mine locomotives ; activities of industrial research laboratories supported by the German coal and coke industry ; coal preparation in western Europe ; low- temperature carbonization processes ; metallurgical coke from

Jun 1, 1948

By A Guillen, J-P ChilFs

Most 3D geological modelling tools were designed for the needs of the oil industry or detailed mine planning and are not suited to the variety of situations encountered in other application domains. Moreover, the usual modelling tools are not able to quantify the uncertainty of the geometric models generated. The potential field method was designed to build 3D geological models from data available in geology and mineral exploration, namely the geological map and a digital terrain model (DTM), structural data, borehole data and interpretations of the geologist. This method considers a geological interface as a particular isosurface of a scalar field defined in the 3D space, called a potential field. The interpolation of that field, based on cokriging, provides surfaces that honour all the data. The 3D model and its parts are always consistent with the observations. New developments allow the covariance of the potential field to be identified from the structural data. This makes it possible to associate sensible cokriging standard deviations to the potential field estimates and to express the uncertainty of the geometric model. It also, for the first time, gives a statistically optimal, geologically sound way of interpolating geology, other than directly joining the dots as you do with CAD. Practical implementation issues for producing 3D geological models are presented: how to handle faults, how to honour borehole ends, how to take relationships between several interfaces into account, how to model thin beds over many kilometres, how to optimise lithological properties and how to integrate gravimetric and magnetic data. We describe all geology surfaces and volumes using implicit functions. These are then rendered onto the required sections, plans, etc. The estimation of orebody grades and tonnes, using an unbiased and optimal geostatistical technique, makes use of the stratigraphically bound 3D geology model. An application to the geological modelling of the Hamersley iron ore district, Australia, is briefly presented.

Jan 1, 2009

By Peter Shuttleworth, Chris Fesq, Eddie Woods

Precast concrete segmental linings for tunnels have traditionally been designed with conventional steel bar reinforcement. In many cases, this has been satisfactory in service, but in others, major problems have occurred with the durability of the linings. Commonly this has resulted from corrosion of the reinforcement, mainly from chloridesin ground water, causing spalling of the concrete and leading to very expensive and disruptive repair programs. This paper discusses the relative merits of designing tunnel linings with steel fiber reinforcement to provide long-term durability, improved impact resistance and toughness for greater load capacity across joints, enhanced robustness during transportation and erection, plus improved fire resistance with the addition of polypropylene fibers. Guidance is also given in the selection of the correct fiber type, mix design and testing methods to establish the optimum dosage required and production techniques to ensure even distribution and compaction.

Jan 1, 2005

This report on the Venezuelan coal industry is the seventh in a series of studies on coal exporting countries requested by the House Appropriations Committee, The committee asked that the basic differences in mining costs for U.S, and foreign mines be identified, especially those costs incurred in complying with health, safety, and environmental regulations.1 Basic costs in extracting raw coal are analyzed in this report for surface operations, This report also provides a limited analysis of the relative market competitiveness of selected Venezuelan and U,S. steam coal mines in three electric utility markets: New England and the east coast of Florida in the United States, and western Europe. Although some Venezuelan coal has coking characteristics, all coal-producing regions of Venezuela sell coal in steam markets.

Jan 1, 1994

By Brendan Demich, Joseph McGuire, Emily J. Haas

Near misses recorded and reported by workers can provide awarenessto the potential causes of injury and prompt safety management initiatives. Although most companies require near-miss reporting, it is unclear what the value of these reports are, if any, and how they influence subsequent actions or controls to reduce on-the-job risks. Researchers at the National Institute for Occupational Safety and Health (NIOSH) conducted a case study with an aggregates company in which near-miss reports were analyzed at each of their locations over an entire quarter during the summer of 2018. Within that quarter, workers recorded 249 near misses. Of those, 167 were valid near misses that occurred at work. Researchers coded the reports using a qualitative 5 × 5 risk matrix. Of the 167 near misses, 19% were deemed low risk, 25% moderate risk, 30% high risk, and 26% critical risk. Several patterns in the near-miss incidents were documented, including classification of incidents and common corrective actions referenced (i.e., elimination/substitution, engineering control or redesign, work process/procedures, and personal protective equipment). The analysis provides insight into ways that risk communication and management programs can be improved to reengage workers and their situational awareness on the job.

By Reno Pressacco

Abstract- Agrium Inc. is a world leader in the production, distribution, and marketing of agricultural products and services in both North America and Argentina. The new phosphate mine and mill complex located southwest of Kapuskasing, Ontario, was constructed to replace an offshore supply of phosphate rock, and produces a high-grade phosphate concentrate. The Cargill Township Carbonatite Complex is one of a series of carbonatite complexes in the region that are hosted by the 1.9 Ga aged Kapuskasing Structural Zone. The carbonatites in the mine area have intruded Archean gneissic granodiorite rocks of the Wawa Subprovince, and metasedimentary rocks of the Quetico Subprovince. The Cargill Carbonatite Complex displays a typical concentric zonation pattern from an outer ring of alkalic pyroxenites, through an inner ring of sövite-carbonatite, to a central core of rauhaugite-carbonatite. The initial carbonatite intrusion and subsequent residual orebody have been modified by faulting such that the northwestern third of the complex has been displaced approximately 2.5 km northeast. The phosphate ores are composed principally of residual apatite sands that were formed by the weathering and dissolution of the soluble minerals of the carbonatite protolith. These ores are subdivided by their iron content into high grade (A ores) and lower grade (B1 and B2) ores. They are separated from the primary unweathered carbonatite by a layer of saprolite, whose thickness varies depending upon the composition of the underlying carbonatite. Cretaceous waste materials consisting of well-sorted silica/kaolinite sand and peat deposits are typically found to stratigraphically overlie the ores. A minor amount of the ore feed comes from cemented phosphate ores. All rock types are covered by Pleistocene glacial tills and clays.

Jan 1, 2001

By J. Fletcher Smoak

Consumption of abrasive materials in the United States in 1981 was approximately $340 million, of which 37 % was industrial diamond (natural and synthetic), 39% manufactured abrasives, and 24% natural abrasives. Production and shipments of natural abrasives, excluding emery and industrial diamond, decreased in quantity 9% and 7%, respectively, when compared with that of 1980. Emery showed the largest change in output, decreasing 30% in quantity and 20% in value. Production of nonmetallic .manufactured abrasives material plus shipments of metallic abrasives material decreased 5% in quantity but increased 4% in value. Nonmetallic manufactured abrasives consisted of aluminum oxide (fused) and crude silicon carbide produced in the United States and Canada and accounted for 63% of the value of all manufactured abrasives. Metallic abrasives shipments included chilled and annealed iron shot and grit, steel shot and grit, plus cut wire, aluminum, and stainless steel shot and equaled 37 % of the value of all manufactured abrasives.

Jan 1, 1982

By Dave Deglon

"The Western Cape Mineral Processing Facility (WCMPF) is a collaborative educational initiative between the Departments of Chemical Engineering of the University of Cape Town, the University of Stellenbosch and the Cape Technikon. The primary objective of the WCMPF is to facilitate the education, development and graduation of suitably qualified engineering graduates and diplomates for the mining industry. The WCMPF consists of academics and Technical Officers in the Departments of Chemical Engineering of the three tertiary institutions. The Technical Officers are usually metallurgists, with several years of industrial experience. The main objective of the Technical Officers is to improve the practical education of mineral processing students. In addition, the Technical Officers are responsible for organising an annual mineral processing student field trip for students from all three tertiary educational institutions. In recent years the WCMPF has embarked on a number of additional initiatives aimed at improving the quality of mineral processing education. These include the development of several new pilot plant practicals, an initiative in pyrometallurgy, the introduction of novel ‘end to end’ or ‘integrated’ practicals and the use of mineral processing simulation packages to complement the practical training.The WCMPF has been functioning for well over a decade and, by virtue of this, might be considered a successful collaborative educational initiative. The WCMPF has played a key role in the education of over five hundred mineral processing graduates and diplomates. During this time period, the WCMPF has gained a body of internal knowledge which might be of benefit to other educational institutions, viz."

Jan 1, 2003

By David Chastka, Isidro Rivera, Shawna Von Stockhausen, Idit Zarchi

The City of Santa Cruz Water Department is replacing the existing Newell Creek Dam inlet/outlet works at Loch Lomond Reservoir in the San Lorenzo Valley. The project will improve the City’s overall operational efficiency, improve system performance, and improve the safety and reliability of storage for the City’s drinking water supply. The project comprises new inlet works* (three new inlets that control and convey flows into and out of the reservoir, and an intake control building), an inlet/outlet tunnel with a 48-inch conduit to convey flows into and out of the reservoir, and a new outlet structure at the toe of the dam. The outlet structure includes a release point for energy dissipation of emergency drawdown flows, a connection to Newell Creek Pipeline, and beneficial releases into Newell Creek. The project also includes a new dam seepage collection and monitoring system and appurtenant structures such as a culvert bridge over the spillway plunge pool to improve access to the new outlet. Notable complex project components include in-water work to connect the new intake shaft pipes to the three new inlets. The project includes one major milestone with a work window regulated by environmental permits that could only be amended/ extended with approvals from those agencies. If not met, the milestone work would have caused significant delays (potentially up to one year) to the project.

Jun 13, 2021

By SUMNER S. SMITH

Mine inspection in Alaska by the Federal mine inspector was somewhat handicapped during 1915,the inspector having to spend a large part of the summer and fall in examining the Matanuska coal field in connection with the designation of the Government reservations and the leasing units in that field. However, in addition to>this work, the mines in southeastern and southwestern Alaska were inspected by both Federal and Territorial inspectors, a considerable number of men near the Federal inspector's officeat Juneau were trained in first aid to the injured and in the use of mine rescue apparatus, the mines of the interior and of Seward Peninsula were inspected by the Territorial inspector, and a suit was brought in the name of the Territorial inspector for the nonreporting of serious accidents under the Territorial inspection law. The work of the Federal inspector was handicapped also by a lack of field assistants. This condition is likely to be serious, as preparations have been made for opening the Matanuska, Bering River, and Nenana coal fields, and a number of permits granting the free use of 10-acre tracts in other fields throughout the Territory have been issued. The need of a comprehensive inspection law and experienced engineers to safeguard the opening of coal mines by operators who are not familiar with coal mining and are using inexperienced help is obvious.

Jan 1, 1917

By WILLARD W. CUTLER

This bulletin reviews, in the light of recent experience, the use of production-decline curves in estimating the future production of oil from wells. It deals with the estimation of the reserves of recoverable oil in properties already producing or in those adjacent to them, takes cognizance of the physical laws governing expulsion of oil from oil sands, and shows how the production-decline curve can be made to utilize these laws in estimating reserves and rates of production. The valuation of oil properties should be based on the total amount of oil recoverable from a property by the methods in use, the rate of recovery, the cost of production, and the selling price. Numerous other curves besides those for reserves and rates of production may be formed from the production-decline curve and will present desired information in a convenient time-saving form. These curves also are described. Methods developed before the production-decline curve method was used are briefly discussed in order that the principles on which estimations of oil reserves are based may be made plain. The construction of curves and tables for estimating future production of individual wells and of average wells in most of the important oil districts of the United States is described and operating problems that may be solved by the use of production-decline curves are discussed. The bulletin does not deal with costs, oil prices, or the methods of evaluating oil properties. Many engineers have amply demonstrated the value of the production- decline curve method by forecasting within reasonable limits the production of many thousands of wells and tracts. The value of similar estimates depends however, on (1) the application of trustworthy methods; (2) the care and judgment of the estimator; and (3) the length and reliability of the records and the accuracy of ofher information used in estimating future production. When adequate records and information are available, experience has shown that It qualified engineer can forecast production far more accurately than has been deemed possible, except where the usual conditions governing the expulsion of oil from a sand have been radically changed by applying compressed air or by flooding with water, or, to a less degree, by using vacuum. In general, the production-decline curve method, though there are limits to its accuracy, is far more trustworthy than any other.

Jan 1, 1924

By Sydney H., Ball

ONE of the important mineral discoveries of the eighteenth century was , that of the Minas Geraes, Brazil; diamond fields. The production of this and of .other diamond discoveries in neighboring states made Brazil the premier producer of diamonds, succeeding India; its 140 years of supremacy finally passed to- South Africa- 60 years ago. Three times have diamonds contributed heavily to Portugal's somewhat checkered financial history; first in the sixteenth and seventeenth- centuries when the diamond trade of India was controlled by its citizens residing in ,Goa, later in the late eighteenth and the first 75 years of the nineteenth century when the Brazilian fields were the world's source of diamonds, and now, when the Angola diamond mines are the principal source of revenue of its colony, Portuguese West Africa. Certain phases in the history of the administration of the Brazilian field are sufficiently curious to warrant description.

Jan 1, 1929

By E. O. RHODES

This report is one of a series written by members of the Solid Fuels Mission to Germany describing wartime developments in the mining, prepara- tion, and utilization of coal. This mission was organized early in 1945 under the auspices of the Technical Industrial Intelligence Committee, which cooperated with a counterpart British Committee. In some instances; engi- neers from other allied countries cooperated. The Solid Fuels Mission operated under the direction of a steering committee headed by Dr. C. J. Potter, Deputy Solid Fuels Administrator. The personnel of the mission consisted of H. F. Yancey, in charge, J. W. Buch, Thomas Fraser, L. L. Newman, and L. D. Schmidt of the Bureau of Minos; H. H. Lowry, Director of the Coal Research Laboratory, Carnegie Institute of Technology; H. J. Rose, Vice-President and Director of Research, Bituminous Coal Research, Inc.; and F. H. Reed, Chief Chemist, Illinois Geological Survey. E. 0. Rhodes, Manager, Development Section, Tar Products Division, Koppers Co., Inc., served on the mission for the Chemical Subcommittee of 1.I.I.C. in Europe. His assignment was the investigation of the coal-tar industry. In this connection he prepared this report on the German Low- Temperature Tar Industry as a companion to his provious report on the German High-Temperature Tar Industry (Bureau of Mines Information Circular 7409). Because of Mr. Rhodes' extensive experience in these fields and the impor- tance of the subject material to the coal producers and those utilizing coal-tar products, both reports are issued by the Bureau of Mines. Over fifty reports were written by the members of the Solid Fuels Mis- elon. These, together with microfilms of supporting data obtained in the course of the investigations, are on file at the Foreign Documents Group, Technical Reports Section, Bureau of Mines, Pittsburgh, Pa., where they are available for examination. Copies of reports available in printed form may be ordered from the Department of Commerce, Office of Technical Services, Washington 25, D. C. Check or money order accompanying order for printed reports should be made payable to the Treasurer of the United States. A Bibliography of Scientific and Industrial Reports, covering all ma- terials and subjects and giving instructions for obtaining the desired items, has been published weekly by the Office of Technical Services. Effective July 1, 1948, the Bibliography of Scientific and Industrial Reports will be prepared monthly instead of weekly and on a more selective basis. issue, which will be the first monthly issue, will be available about July The July month thereafter through June 1949. Annual subscriptions and orders for individual copies starting with the July 1948 issue should be addressed to the Department of Commerce, Office of Technical Servicos, Washington 25, ur, and be accompanied by chock or money order made payable to the Troas- Bibliof the United States. Annual subscriptions for monthly issues of the Bibliography of Scientific and Industrial Roports will be $10. Individual issues will cost $1 per copy. Foreign subscriptions will be $14 per year and $1.50 por copy. tions listed in the Bibliography of Scientific and Industrial Reports should All orders for reports in microfilm or photostatic type of reproduc- ורי

Feb 1, 1949

By S. K. Kawatra, S. J. Ripke, T. C. Eisele

"An estimated 600,000 tons of bentonite clay are used annually in the U. S. as binder for production of iron ore concentrate pellets. Since this is a significant cost item for the plants, and the addition of bentonite to the pellets contributes undesirable silica into the finished pellets, there is considerable incentive for finding methods to reduce bentonite use. One way to reduce bentonite levels is to selectively use those bentonites that are most effective in this application, so that a lower dosage will still produce a sufficiently strong pellet. Unfortunately, there are no satisfactory methods available for accurately predicting which bentonites are actually most effective, short of using them to actually make pellets. One of the popular methods for attempting to evaluate bentonites is the “Plate Water Absorption” (PWA) test. While some plant operators accept the PWA results as indicating the relative quality of bentonites, others disagree and claim that, over a fairly broad range of values, PWA does not correlate with bentonite performance.Since both Ca+2 and Mg+2 ions are known to reduce the swelling and water absorption capacity of bentonite, it was believed that the presence of these ions in plant recycle water could be changing the bentonite performance. Since the standard PWA test uses only distilled water for its measurements, it could not detect these effects. Experiments were therefore carried out on a number of different bentonites using a modified PWA tests, with plant recycle water replacing the distilled water. These experiments showed little effect of the plant water on the PWA value, and chemical analysis of the water showed that the levels of dissolved salts were quite low.Water and accompanying salts were then extracted from a magnetite concentrate filter cake by rinsing with distilled water. Analysis of this water showed an extremely high level of dissolved salts, particularly salts of calcium and magnesium. When concentrations were compared with the recycle water from the plant filters, it was determined that levels of Ca+2 and Mg+2 retained in the filter cake were over 500 times higher than levels in the recycle water. This extreme elevation of soluble salts in the filter cake is believed to be due to adsorption of these ions into the electrical double layer of the magnetite particles."

Jan 1, 2003

By He De-wen

Based on the principle of life cycle assessment (LCA), municipal solid waste management (MSWM) was analyzed by life cycle inventory method. According to the system expansion and substitution method, the content and frame of life cycle analysis is summarized and applied to municipal solid waste. On the basic of feasibility research of life cycle analysis on MSWM, the paper put forwards complete and concrete ?three changes? measures under life cycle analysis on MSWM. Some aims of MSWM can be achieved under above conditions of LCA on MSWM: to improve the current system efficiency of MSWM; to enhance the serve quality of MSWM, to increase recycle garbage from MSW; to reduce waste amount and reach minimization and innocuity aim of MSWM; to help the departments of MSWM to get over all difficulties to realize their ideal goals.

Jan 1, 2009

By R. V. Ramani

In this report, the application and limitation of the various equipment available for surface coal mining are discussed. The correction factors for adjusting equipment performance arising from machine design, material characteristics, and modes of operation are presented. Engineering design, pit layout and equipment selection are discussed with mathematical derivations. Two computer programs (SMCALC and SMRES) have been written to aid in pit design and equipment selection. The Strip Mine Calculation Program (SMCALC) can be used to select the bucket size and reach of shovels and draglines for various pit widths. It will also calculate the number of drills, loading shovels, trucks and bulldozers needed to achieve a production target. The Surface Mine Reclamation Equipment Selector (SMRES) can be used to select the number of bulldozers, scrapers and front-end loaders needed to achieve the desired production.

Jan 1, 1976

By M S. Stern, R Aguila

To control direct blasting costs many open pit mines dewater and line wet blastholes before loading them with ANFO or Heavy ANFO blends of explosives. The plastic lay-flat tubing used for these liners can be punctured during loading and allow water to partly dissolve and desensitise the explosive column which reduces blasting performance.

Jan 1, 1997

By Eugene (Gene) Bounds

The Mining industry faces many challenges, one of which is the demand to communicate over a variety of media, be it visual, sound, voice, data or any combination. Over the years multiple infrastructures have been put in place to overcome environmental obstacles and address these communication needs. A mine is an aggressive environment for electronic equipment and as such only the best quality equipment can perform under those special conditions of e.g. temperature, dust and humidity. Siemens Canada and its partner LComm will discuss a mining solution using a unique combination of technologies based on fibre optics, standard communication interfaces, passive antenna infrastructure and wireless services. The presentation looks at maximizing the use of infrastructure, reducing costs, addressing difficulty of communications coverage above and below the surface and the capability to future proof the capital investment as new requirements and applications are identified. Discussion will address: Wireless voice, high speed data Data acquisition for process control from sensors Video for remote control and security Miner safety and location Timely receipt of large volumes of information

Apr 1, 2005