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By Peter O. Wilkinson

Ascot Racecourse in the UK is a major international venue for horseracing. The racecourse is being redeveloped to provide entirely new public facilities. The development includes the construction of a new grandstand. A site investigation was earned out comprising mainly cone penetration testing. The site is underlain by the Bagshot Formation, comprising predominately cohesionless deposits of medium dense becoming dense, silty fine to medium sand, containing occasional layers of clay. Shallow foundations would present uncertainty regarding total and differential movement; hence a piled foundation solution was chosen using a continuous flight auger (CFA) piling system. The possibility that piles may found either directly on or within the influence of cohesive material suggested uncertainty regarding toe resistance. In order to measure shaft friction, an instrumented preliminary test pile was undertaken. The results were compared to published correlations of cone and shaft resistance. This approach resulted in a net saving in terms of pile length which resulted in optimum value engineering and hence a cost saving to the client.

Jan 1, 2006

Mineralogical analysis of a nickeliferous laterite from the Rockhampton region shows that the nickel is largely associated with the manganese wad and opaline silica. The laterite also contains an appreciable chromite content (about 12 per cent Cr2O,) although this tends to be poorly liberated.Leaching with hydrochloric or sulphuric acid, at atmospheric pressure at the boiling point is non-selective with respect to iron dissolution.The degree of dissolution increases as the acid concentration and retention time are increased; cobalt dissolution requires less aggressive conditions than does the dissolution of an equivalent amount of nickel.Leaching with sulphuric acid at elevated temperatures and pressures leads to a minimum amount of iron dissolution, is rapid, and requires a reduced acid addition rate. Nickel and cobalt recovery from the clarified leachate would be simplified because of the leach selectivity.Pressure leaching appears to be the most practical route for treating the Rockhampton laterite. The economics of processing would be made more attractive by the recovery of a chromium concentrate from the leach residue. This would typically contain about 45 per cent Cr2O, and could be used as a source of chromium chemicals.

Jan 1, 1986

By None None

Use this month wisely — go online and take advantage of your new member benefit. As an SME member, you can read and download for free all of the full-text papers of the Mining, Metallurgy & Exploration (MME) journal, including the 22 papers in the launch Special Issue on Mineral and Metallurgical Processing in Honor of Professor Emeritus Douglas W. Fuerstenau as well as the archived articles of Minerals & Metallurgical Processing (MMP), all the way back to Vol. 1, No. 1. Just follow the instructions on this page.

By Hou Shitao

With the development of Wuhan's city planning in China, new buildings of moderate and high store have been increasing day by day. Precast concrete piles or cast-in-site piles were used in the major foundations of the buildings. In process of their design and construction geotechnical engineers are concerned very much about practical bearing capacity and construction quality of pile foundations. In order to grasp accurately the cases static loading or vibration test is used generally to judge them. At present, the major questions in existence are that although a load is applied directly on pile and measured datums are reliable for static loading test, it must take a lot of work and longer time and engineering cost is higher. A vibration test has the advantages of which checking up of pile quality can be performed rapidly, the test is simple and convenient, and scope measured wide. But bigger error exists generally in measured datums. Therefore, it is nesessary to make vibration test on piles more perfect for pile foundation engineering. It is stated in paper that adapted technique of vibration test on piles is quite right in developmental direction sense for pile foundation. There are a great variety of vibration test methods on piles. A few of methods which often are adapted in practice can not meet the need of different practical engineering. It is also an important question whether the instruments of vibration test and relevant computer softewares make a response accurately for practical case. Different sequence of operation and technical requirements comes into being some influence directly on the test results. Meanwhile, different combination of soil stratigraphy, soil texture, groundwater and pile could cause different error of test datum. It is necessary to analyse and judge objectively the results of vibration test. Therefore, on the basis of developing and perfecting further the technique of vibration test, the applied technique of vibration test should be standardized so that better test results can be obtained.

Jan 1, 1991

By Thomas L. Ochs

The stripping of iron-laden solvent with hydrochloric acid in the iron-removal step of the clay-hydrochloric acid process for the extraction of alumina from calcined kaolinitic clay results in a loaded ferric chloride stripping liquor. Treatment of this stripping liquor at boiling with calcined kaolin to form insoluble Fe203(s) and a dilute A1C13 solution was undertaken by the Bureau of Mines to characterize process problems and to aid in sizing of solids-liquid separation equipment. Variables identified as important in the chemical reaction were calcined kaolin particle size, ratio of calcined kaolin to FeC13, and reaction time. These parameters were tested for significance and their interactions investigated. Fine calcined kaolin (-65 mesh) at a greater than 1:1 mole ratio of contained acid-soluble A1203 to Fe203 equivalent of the FeC13 in the stripping liquor required less reaction time than coarser (-16 mesh) material. Solids-liquid separation of the reacted slurries by both settling and filtration requires flocculation.

Jan 1, 2011

By James J. Scott

Dynamic rock anchors are interior fixtures developed by the author which promise to be a revolutionary development in the field of ground control. The fixtures are designed to be placed in the ground with modern roof bolting equipment, such as the type used in the American coal mining industry. They are composed of a plastic form- able anchor tube which serves to fasten a buttress deformed rod which is thrust and turned into the plastic and in turn clamps the roof plate to the rock surface. Plastic tubes 10 to 16 inches in length provide sufficient anchorage to exceed the yield strength of steel rods 5/8, 3/4 or' 7/8 inches in diameter. This paper presents field testing and early work done on the device over the last seven years. Results of pull tests, creep tests, laboratory testing in concrete, and field testing under natural rock conditions demonstrate the uniqueness and effectiveness of this new support system. A second development which uses the dynamic rock anchor in conjunction with a resin cartridge to provide a stiffer anchorage system is also discussed. These products will be manufactured and marketed by Ingerso-11-Rand Co. under the trademark of DYNA-ROK and DYNA-ROK PLUS anchors.

Jan 1, 1989

By Art Cooper

Granulation systems are customarily viewed as problem areas in metallurgical operations. The inherent risk of explosion when combining a high temperature melt with water creates a safety hazard. Separation of the granulated material from the quenching medium generally involves equipment that can have significant maintenance and operating costs. Granulation systems' reliability and availability can negatively affect the plant production. Against this background, granulation systems have been treated by design firms and producers as an add-on and a necessary evil. The technology is becoming better understood and solutions to common problems are being found. This paper will discuss typical problems in common systems, and some of the improvements that have been made, with particular reference to non-ferrous applications.

Jan 1, 2006

By John B. Sabey, Vernon R. Degner

The industrial coal processing trend toward greater fines production, due to mining techniques and customer requirements for reduced ash and sulphur content in the fine coal product, is the basis for ongoing efforts to improve the performance of the flotation machine. WCO has successfully adapted the principles of the beds Column to a full size machine prototype. Recent plant evaluation tests confirmed the initial promise of this concept by achieving a considerably lower ash product while maintaining the combustible recovery level of conventional flotation machinery. The paper will include a review of the fundamental principles of the beds Column concept, together with a summary of the WEMCO R&D Program from concept evaluation and laboratory testing, through pilot, to full size machine tests. The performance of the WEMCO/Leeds flotation column will be compared to conventional flotation concepts using a flotation "kinetics" approach, which quantifies the floatable and non-floatable specie recovery performance using the Klimpel model as the basis for analysis. The variety of distinct features unique to this concept include a series of barrier rods which are used to advantage, often together with countercurrent reflux water flow, to achieve a significant improvement in product grade. The hydrodynamics associated with the mechanics of "gangue stripping" from the rising "air bubble-floatable specie" matrix will be briefly reviewed.

Jan 1, 1988

By Adams F. C, Ridley K. L

Economic conditions after WorId War II made the recovery of Australian sources of sulphur one of considerable national importance. From 1947 to 1949 an investigation was made of recirculation techniques to produce acid plant grade gas from the Dwight-Lloyd down-draught sintering plant.During 1949 it appeared feasible to produce a gas of suitable 802 concentration and a decision was made to construct a gas purification train and a 150 tons/day contact acid plant. However, a number of difficulties remained in the production of the gases for sulphuric acid manufacture and as a result of research conducted to overcome these troubles the continuous up-draught sintering process was developed.The principal difficulties were:(a:) The down-draught sintering practice, as developed, produced an unusually high metallic lead precipitation in the windboxes. The disposal of this lead interrupted sintering operations and the delivery of gas to the acid plant.(b) The production capacity of the existing sintering plant was fully extended and the adoption of recirculation of gases, in an endeavour to satisfy acid plant requirements, would probably reduce the plant production capacity.(c) The prevailing high temperature of water available for purification train cooling required a higher than...

Jan 1, 1956

By Alexander Garcia

Roof and rib falls are the basic ground control hazards associated with underground roadways during development, stand up and, if applicable, retreat. Falls of ground can happen following the deterioration of supports or rock conditions over time, and particularly as a consequence of continuing rock deformation and/ or failure to install adequate support. Once developed, the risk of a failure is increased due to the effects of time as well as to front abutment stresses through retreat mining. The measurement of strata displacement using monitoring equipment is a form of ground control risk assessment. These monitoring systems are active, or ?live?, in a sense that risk is assessed real-time. However, there are circumstances in which falls of ground can occur without the prior recording of excessive movement. In addition, monitoring equipment is typically placed at set intervals, and strata conditions could vary between these points. Consequently, a visual assessment of other factors contributing to the risk of a fall should be made in order to complete a ground control risk assessment. Such surveys are usually one-off, thus capturing roadway conditions at one particular point in time. Ongoing deterioration is not documented through such one-time surveys, and there is a requirement for real-time or live assessment where a system is in place so that observation data can be updated on an ongoing basis, and a useful summary of prevailing roadway states produced on demand. To address the shortfalls of one-time assessments, a ?live? computerbased quantitative ground control risk assessment process has been developed. It combines visual observations processed in a quantitative manner with existing monitoring data into an interpretable output which indicates zones of roadway where there is an increased risk of a fall of ground from the roof or sides, so that remedial action can be carried out to mitigate that risk. Through improved procedures, it is now possible to generate a ground control risk assessment for each roadway, and one which can be updated frequently. This paper aims to outline and describe the assessment process.

Jan 1, 2012

By Eugene T. Sheridan

The Bureau of Mines annually canvasses the fuel-briquet and packaged-fuel producers in the United States and publishes economic data on these industries, based upon reports submitted voluntarily by producers. This publication lists all producers that reported commercial production to the Bureau for 1960 and presents data on individual plants. The companies named herein represent virtually all producers of processed minerals fuels. A few small plants may not have been canvassed or failed to respond to the survey because some of the smaller plants operate intermittently and the survey is voluntary. All plants that reported commercial production were included; regardless of size. Specifically excluded were plants that manufactured briquets from wood charcoal. Fuel briquets and packaged fuel are manufactured solid fuels, produced by mixing fine-sized mineral fuels with binding materials and compressing into small individual shapes, Briquets are produced in pillow-shaped and cylindrical form, are 2 to 4 inches long, and weigh 2 to 4 ounces. Packaged fuel consists of 3- or 4-inch cubes; 6 or 8 of which are wrapped together in heavy kraft paper to form a package weighing 10 to 15 pounds, Briquets are durable and may be stored and handled as bulk fuel; packaged fuel breaks easily and must be stored indoors to prevent it from deteriorating. Whereas briquets are consumed in many areas as a general residential fuel, packaged fuel is more of a specialty item, used at times to supplement other fuels. Packaged fuel is burned without re-moving the paper and is referred to as the "white glove" fuel.

Jan 1, 1961

By D. J. Parker

The ease of ignition and violence of explosion of Utah coal dusts, together with the large volumes of methane given off in some of the mines of the State, made it imperative to abandon obsolete equipment and obviously hazardous practices for up-to-date equipment and safer methods of mining if reasonable progress wore to be attained in fire and explosion prevention. Although much can still be done to improve safety conditions in Utah coal mines, considerable progress has been made in the past 10 years. The fundamentals of such progress include increased use of permissible electrical equipment in gassy mines, closed lights, rock-dusting, more liberal use of water at the face, butter ventilation, permissible explosives fired electrically both within and without the mine, partial inhibition of blasting while the shift is in the mine, 100-percent first-aid training, increased supervision and inspection, and mass safety meetings.

Jan 1, 1935

By C. Hendricks

This paper is based upon field studies conducted in a western Canadian open pit coal mine. This work has involved the adaptation of microprocessor-based instrumentation to monitor various operating parameters on-board blasthole drills and mining shovels. A review of instrumentation and monitoring methodology will first be presented. Based upon experience from field-based studies, the paper will subsequently focus on the application of monitoring technology within the framework of an integrated Equipment Monitoring System. Such a system will permit the real-time performance evaluation of key equipment involved in surface mille production.

Jan 1, 1991

By T. G. Donnelly

This final report summarizes the prototype development and testing of an air curtain respirotory protective device under Bureau of Mines Contract HO122087. The air curtain respiratory protective device, as part of a miner?s hat, provides protection for the underground mining machine operator against inhalation of dangerous amounts of respirable coal dust. Major components of the air curtain respiratory protective device are: 1) a modified miner hat incorporating an air curtain jet manifold from which the protective air curtain emanates, 2) a motor blower which supplies the air for the air curtain, 3) a filter element to remove the particulate material from the air used for the air curtain, and 4) the hoses and coupling used to duct the filtered air from the motor blower to the modified miner's hat.

Jan 1, 1973

By Sunil Koppalkar, Liming Huang

"Since late 1980s the research group led by late Professor Andre Robert Laplante at McGill University undertook fundamental studies and applied research of the Knelson Concentrator (KC) and developed a sustainable method to correctly estimate gravity recoverable gold (GRG). In the early time a concept of ‘free gold’ was used, it was defined as the gold that could be separated and recovered from gold ore by amalgamation. Due to health and safety hazards, its practical use had declined. Around 1994, a methodology using a 3-in Knelson Concentrator to measure gravity recoverable gold was established at McGill University. Through more than 10 years’ improvement and optimization, this technique had become a standard method to evaluate GRG for gold ores, gold plant streams and platinum group metals. Until 2006, about 200 GRG tests had been carried out at McGill University for the ores from all over the world. Recently, a modified version of GRG test (short test) with the advantages of reduced processing time and lower cost had been developed for the mundane needs of gold industry.INTRODUCTIONGold gravity recovery has evolved significantly over the past twenty-five years, mainly because of the advent of the Knelson Concentrator (Knelson 1988, 1990, 1992, Laplante 2000). Now, a series of Knelson Concentrators for different applications are manufactured and used in gold industry all over the world (Knelson Concentrators 2004).In 1980s the Knelson Concentrator gained acceptance from mining industry as an effective device for the recovery of gold from grinding circuit. Knelson Concentrator became the obvious choice because of its design features: a relatively long processing time without concentrate discharge (compared to some other centrifuges, such as Falcon Concentrator and Chinese Yunxi Centrifuge at that time), large throughput capacity, treating a wide size range of material, yielding a high grade concentrate with small mass that could easily be smelted. As more and more Knelson Concentrators were accepted in gold industry, mineral processing engineers faced with challenges: what are the separation mechanisms of the Knelson Concentrator? How much gold can be extracted for an ore if a Knelson Concentrator is installed? For answering these questions, a laboratory scale Knelson Concentrator was created."

Jan 1, 2007

By A. J. MacKellar

The economic viability of any project is generally assessed on an evaluation of the total capital constructed costs along with operating costs, owner's costs and market conditions. This paper will be directed to the role that Cost Engineering plays in the development of the capital costs and the cost control techniques applied thereto.

Jan 1, 1975

By F. N. Voskoboyev

The suggested new method for control of geomechanical state of undermined rock mass ensures, as a safety measure for the earth surface protection, the decrease of deformations by 2,5 - 10 times in mining the single seam, and by 1,5 - 5 times - in mining bed series, i. e. approximately within the seam ranges as in the application of full packing with various compressive properties or partial extraction of resources over the area with different coefficients of extraction. It should be noted that this new method has the following advantages o\w rhr. conventional methods: a) the decrease of the packing area and packing works volume by 2 - 4 fold including the operating and productive expenses; b) the elimination of mineral losses due to the increase of extraction coefficient up to 100 5%; c) rock utilization from workings drivage by its placing in the mined - out space. Perspective field of application of this method: disconservation of mineral resources in the left protective pillars of various designation.

Jan 1, 1996

Collaboration between education providers is the key to long-term sustainability and improved quality in mining education. The mining industry is now, more than ever, an industry doing business on a global basis. Staff are recruited by global mining companies in many different countries and can find themselves deployed anywhere in the world. The mining engineer of tomorrow must be willing to take on this international challenge, and must be educated to a level where he or she has a comprehensive grounding in technical aspects of mining engineering, but also a well-founded appreciation of management, social, environmental and cultural issues which may be encountered around the world. In order to deliver such an education, academic providers must collaborate at both a national and international level. This paper provides an overview of progress that has been made in Australia through the national joint venture ? Mining Education Australia (MEA). Supported by the mining industry in Australia, through the Minerals Council of Australia (MCA), MEA has now been operational since 2007 and is seeing the development of a range of innovative courses and delivery methods, together with a high level of staff co-operation across the country. MEA has also now commenced some international teaching initiatives which are seen as a catalyst for a far greater degree of international collaboration in the future. Such activity is not only to the benefit of the students who are taught by experts from around the world, but it also ensures that individual university programs remain viable in terms of staffing numbers and financial performance. The paper also presents some statistics on recent upward trends in mining engineering student numbers from around the world, in response to the global shortage of mining engineers.

Jan 1, 2009

BUMPS in No. 2 Mine, Springhill, N. S., furnished the main feature for discussion at the morning meeting* on Ground Movement and Subsidence on Feb. 18. Walter Herd, the author of the paper by which the discussion was introduced, not being well, was unable to be present. The paper was presented by T. L. McCall, who laid stress on the presence of sand- stone as the cause of bumps, on the value of retreating longwall in eliminating such phenomena at the coal face and on the advantage of wide headings with packs on either side, leaving space behind them for any coal that bumps might dislodge. George S. Rice, who presided, referred to his visits to the Nova Scotia mines and said that bumps usually occurred only where the coal was thick and strong and the roof and floor both more than usually hard. If any of the three were weak, bumps were not likely to occur. In the Nova Scotia mine, to which Mr. Herd referred, there was no material for packwalls and for this reason as well as for safety he had been convinced that long- wall retreating with a small percentage of pack walling was the most feasible plan.

Jan 1, 1929

By John Reilly

The author?s paper at RETC 2007, ?Alternative Contracting Methods? addressed strengths and weaknesses of DBB+DB and introduced Construction Manager/General Contractor (Portland model) and Alliancing (Australian model). Considerable interest in these was expressed by several public agencies at that Conference and at the presentation. The author is assisting the Washington State Department of Transportation (WSDOT) and the Toronto Waterfront Revitalization Corporation (TWRC) with possible implementation of Alliancing. WSDOT is evaluating ways to do this and is considering a delivery methodology, under existing Legislation, based on the CMGC Portland model with incentives and disincentives, moving towards Alliancing. This paper will build on the 2007 paper and update implementation considerations.

Jan 1, 2008