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By Garland E. Likins

High-strain dynamic testing of drilled shafts and cast-in-place piles has become routine procedure in many parts of the world today. Field testing is performed by measuring strain and acceleration records under impact of a falling mass. Wave equation analysis is utilized to design the weight, drop height and cushion of the hammer apparatus to assure a successful test. The Pile Driving Analyzer* (PDA) and CAPWAP* methods are used for data acquisition and analysis. Testing results yield information regarding pile static bearing capacity, structural integrity, and pile-soil load transfer and pile load-movement relationships. This paper discusses application of high-strain dynamic testing to cast-in-place shafts with emphasis on aspects unique to this type of pile. Suggestions regarding minimum requirements for good quality tests are offered. Five case histories reported in the literature are summarized and a sample specification is also included.

Jan 1, 1995

In general, the metallurgical industry has so far been slower than the chemical industry to adopt ion exchange materials for industrial processes. The atomic energy industry presents a marked exception to this general situation, and the literature shows a rapidly increasing use of ion exchange techniques for the recovery of atomic energy metals on scales ranging from the ultra micro up to that of the largest mining operations. In many cases, the processes used would be equally applicable to more common metals and it is hoped that this review will be of interest to metallurgists outside the specialised atomic energy field. The review is intended to describe developments of ion exchange processes made during the last three years. Earlier studies have been summarised by Kunin and Preuss (1956) and Roland (1957). In order to restrict the number of references discussed, purely analytical procedures have been omitted and only those processes which have been conducted on a reasonably large scale or which, from their nature, areclearly capable of being upscaled, have been considered. The paper is divided into five main sections concerning respectively:Water treatment and effluent disposal.Metal recovery and purification.New ion exchange materials.New ion exchange equipment.Membrane cells.WATER TREATMENT AND EFFLUENT DISPOSALA high proportion of atomic reactors, and particularly those of American design, are cooled by water which is...

Jan 1, 1961

By J S-L Chan, J C. T Chu

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. In its industrial days, Hong Kong’s mining industry was thriving, benefitting from the mineral occurrences that are related to the regional Mesozoic igneous and hydrothermal activities.Hong Kong was unique in the mining sector as it was so small in landmass but with such a rich variety of commodities discovered. There are records of commercial exploitation of tungsten, iron, lead, silver, beryl, graphite, quartz, feldspar and kaolin in Hong Kong before 1981. Of these, most of them are located in the New Territories.The Lin Ma Hang lead mine was operated in the 19th century by the Portuguese and was abandoned in 1958. The Needle Hill tungsten deposit was discovered in 1935 during construction of the Jubilee Reservoir. The Ma On Shan iron mine, which operated for 70 years between 1906 and 1976, was the largest mine in the history of Hong Kong. The Mui Wo lead-silver mine on Lantau Island can be traced back to the Ming Dynasty 400 years ago. West Brother Island, which extracted graphite from 1952 to 1973, was levelled in the 1990s to make way for the development of the airport at Chek Lap Kok.Nowadays, these mines are disused and abandoned, but this extended abstract reviews the legacy of the mining industry in Hong Kong to understand the impact that it had on techniques, the economy and culture.CITATION:Chu, J C T and Chan, J S-L, 2015. The history of mining in Hong Kong , in Proceedings PACRIM 2015 Congress, pp 109–114 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By J. B. Brodie, C. Pelletier

"The vulnerability of Canadian and U.S. companies, their directors, officers and employees to onerous penalties associated with violations of environmental statutes and common law actions has provided the impetus for the increasing use of environmental audits. This trend is developing in direct proponion to the cost and difficulty of obtaining liability insurance. Companies operating in British Columbia should be cognizant of developing legislative and enforcement trends and their implications for individual and corporate responsibility. Canadian mining companies doing business in the U.S. should be particularly aware of the environmental exposure which may be assumed with property acquisition or by operations which produce or use any of an ever-increasing list of regulated substances.The environmental audit is now a key component of prudent business planning which will identify noncompliances and environmental liabilities, outline defensive strategies, and assist in a legal defence should charges be laid. This paper will discuss the purpose and mechanics of an environmental audit with emphasis on those features which will maximize protection against statutory and common law actions.IntroductionThe environmental audit is but one weapon in a comprehensive defensive strategy for corporate and individual survival in an increasingly litigious world. The principles of the environmental audit have been formulated as a logical response by management to an ever-growing list of environmental vulnerabilities, which often have the potential to result in plant shutdowns, prosecutions or fmancial liability of major proportions. Accordingly, the audit may play a critical role in maintaining profitability as well as assisting in the defence of a company and its employees against actions taken by regulatory agencies and citi7.cns under statute and common law. Should convictions result from these actions, the penalties are likely to be ameliorated by the demonstration of due diligence through management policy supporting the audit procedure.An awareness of environmental sensitivities, strict adherence to licensing requirements, and planning for environmental emergencies are now generally considered to be as important to profitable performance as operating costs, metal prices, and labour peace. Why is this so? The increased priority given to environmental matters is partly a result of changing attitudes amongst the mining profession, but perhaps more importantly, it is also a direct consequence of the proliferation of ever more stringent environmental legislation, the targeting of management for responsibility and the draconian penalties imposed for violations of such legislation. Contributing to this trend are recent court decisions involving disputes of an environmental nature in which the standard of care required for a successful defence now requires almost super-human diligence in environmental management. The principle of ""strict liability"" (in which negligence or permit violation does not have to be shown) is also being increasingly applied in the resolution of civil actions."

Jan 1, 1988

By Eugene Guccione

The US mining industry today is fighting for its existence. We are plagued by the shortage of materials, of equipment, of fuels, of capital, of manpower. If we solve those shortages, we are then frustrated in our attempts to open a new mine or, perish the thought, a new smelter. If we manage to make a profit, demagogues will accuse us of stealing from consumers; and, if we do not make a profit and have to shut down, the same demagogues will accuse us of creating unemployment. Meanwhile, in every aspect of our business - from research, exploration and development, to production, marketing and selling - we are hindered in every way by the bipartisan mismanagement and crippling controls of a government bureaucracy gone amok. We are fighting a war on every front. Some of you realize that ours is a war of ideas. In order to win, our industry must make its ideas heard. But to be heard, we must have something to say - which means: we must know our case logically and consistently, all the way down to essential principles. A principle is a primary truth applicable to a great number of instances. A principle is like a road map: it shows you all the possible alternatives for getting from where you are to where you want to go. Although practically everybody recognizes the usefulness of a map and the need to consult it to find the best way' to get from one city to another, most people are not as careful in charting the course of their life, or the course of their industry, or the course of their nation. And so they act blindly, at random, by the whim of the moment, and get nowhere fast.

Jan 1, 1975

By Mario A. Terceros H., K. Rainer Massarsch

"ABSTRACTThe Expander Body (EB) technology has been used successfully to increase the pile toe capacity of bored piles in loose to medium dense soil. An important advantage of the EB system is the ability to monitor the EB expansion process, which provides important information regarding soil strength and soil stiffness. This information, obtained for each installed pile, can be used to determine the actual shape and pile toe area. The expansion pressure can be used to design the pile base capacity.The Expander Body system has been recently improved by incorporating the possibility of post-grouting of the soil below the expanded pile toe. This improvement measure provides additional strength and stiffness to the pile toe and reduces pile settlement.The shaft bearing capacity of bored piles can be increased by using a soil displacement auger, which avoids soil decompression and increases lateral soil stress. This paper describes the principle of the EB system. During the past 20 years, a large number of EB piles have been installed in Bolivia and elsewhere, providing a sound database. Results from field loading tests are presented. A comprehensive study of test piles with and without EB base has been carried out which demonstrates the improvement effects that can be achieved by the EB pile system and the combination with the displacement auger pile method. A design concept for the EB pile system with the full displacement auger pile is presented. A high degree of quality control can be achieved by monitoring the entire pile installation process, including the displacement pile and the Expander Body.1. IntroductionIn many regions of South America, soil deposits consist often of predominantly loose to medium dense sands and silts, often with high groundwater table. In the Santa Cruz area in central Bolivia, such soils are frequently quaternary sediments, deposited by the river Piray. The city of Santa Cruz is located at the right bank of the river.The most common deep foundation method during the last 30 years has been cast in situ piles, augered and concreted under support of bentonite slurry. The design of such piles has been based on SPT results. However, SPT is often performed without quality control and the reliability of geotechnical data is therefore often poor. Traditional methods of pile installation with simple well drilling equipment of insufficient capacity are frequently used. Such methods lack basic requirements of quality control. Such piles have usually low toe resistance and work mainly by shaft resistance . Although the construction process and materials are cheap, the final product has variable and limited capacity. However, the most serious deficiency is that actually achieved pile capacity and pile settlement can be erratic and difficult to predict, leading to uncertainties with regard to actual foundation performance."

Jan 1, 2014

By H. E. Powell

Basic data were recorded on the decompositions that take place during thermal decomposition of siderite (FeC03). Both the naturally occurring and a synthetically prepared mineral were studied by differential thermal, thermo-gravimetric, X-ray-diffraction, and chemical (including gas) analyses. Thermal decomposition was studied in the media of dry air, moist air, dry carbon dioxide, dry helium, and dry carbon monoxide and at atmospheric and at reduced pressures. Results showed the thermal decomposition of FeC03 to be an extremely complex process, dependent on environmental factors and side reactions that cannot now be completely controlled. Therefore, full understanding of the reaction involved must depend on additional research with advanced evaluation techniques.

Jan 1, 1965

By W. Greuer

The objective of this paper is to demonstrate how site-specific slope stability analysis can be performed entirely from the desktop with satellite images, Geographic Information Systems (GIS), and slope stability software packages. This type of analysis would effectively eliminate or restrict the need for expensive field testing of geotechnical properties of a hillside, pit wall, berm, or embankment, and would be particularly useful for slope failure mitigation at remote or otherwise inaccessible locations.

Jul 17, 2000

By Kewal K. Kohli, Thomas Z. Jones

This paper presents a simplified computerized method for the prediction of maximum subsidence and the subsidence profile for the Appalachian Coal Basin using the Hyperbolic Function Profile Method. Several case histories are cited to demonstrate the appropriateness of the predictive method. In addition, sample runs and a detailed listing of the computer program is provided. Other popular subsidence prediction methods are discussed and compared with the Hyperbolic Function Profile Method.

Jan 1, 1986

By B. R. Klahold

Each year hundreds of mineral specimens and numerous inquiries regarding tests and analyses of minerals and related inorganic substances are received by the Bureau of Mines. In response to this demand, in years past Information Circulars were published containing a list of laboratories. This paper is a revised version of Information Circular 7523, The listing has been changed from a regional basis to one of States arranged alphabetically and grouped by cities, again alphabetically, with Alaska and Canada listed at the end. All the services given at these laboratories are listed on one page for convenience and brevity. This list is compiled as a public service, and none of the laboratories listed herein are recommended over any other nor can the Bureau of Mines vouch for their results.

Jan 1, 1954

THIS tunnel, which is an adit 7000 ft. long, was undertaken by the Mount Lyell Mining and Railway Company Limited to connect its treatment works with the North Lyell mine at depth, with a view to effecting economies in transport and drainage. The work was carried out at high pressure throughout from both ends, and although the ground in the mine end was intensely hard, good progress was made, and driving was completed in less than fifteen months.The Mount Lyell mining field is situated in the west of Tasmania, about 20 miles inland, the only means of access being the Mount Lyell Mining and Railway Company's 3 ft. 6 in. gauge railway which connects with the Government railway system of the State at Strahan, on Macquarie Harbour. The region is mountainous, and presents many difficulties to the road and railway engineer. The West Coast range running north and south in a succession of bold prominences, which rise up to 4000 ft. above sea-level, forms the backbone of the district, and on its foothills the Mount Lyell mines are situated. The railway terminus at Queenstown...

Jan 1, 1929

By S. Suwansawat, D. J. Maconochie, C. C. Chang

This paper describes the overall delivery of the tunneling for the Mass Rapid Transit Authority of Thailand’s Chaloem Ratchamongkhon Line in Bangkok and the constraints provided by the alignment. Eight earth pressure balance tunnel boring machines were employed under two major civil works contracts to drive approximately33 kilometers of tunnel in soft saturated ground beneath the crowded streets of Bangkok. Responsibility within the contract for building damage provided an inherent control for ground movement arising form tunneling when the right of way was narrower than the influence zone. These limits affect the earth pressure balance requirements and permissible ground loss. The methods adopted to limit ground movements and deal with the various obstacles to tunneling influenced the design and operation of the machines. The challenges provided by the need to tunnel through numerous lines of piled foundations of canal bridges and overpasses crossing the alignment are described.

Jan 1, 2001

By D Craw, D Wilson, D Chappell

Gold is extracted by cyanidation of a sulphide-rich concentrate at Macraes mine, and after cyanidation, the concentrate is discharged to tailings impoundments. The concentrate tailings were discharged to a dedicated concentrate impoundment from 1989 to 1993, afterwhich they were blended with the flotation tailings. Since mid-1998, concentrate tailings have been redirected to the dedicated concentrate impoundment. The concentrate tailings contain up to 1 ppm gold, and will be reprocessed in the future. However, it is a regulatory requirement that a contingency plan be in place to rehabilitate the concentrate tailings should the mine operation cease for any reason. Initial predictions suggested that the sulphide-rich tailings would oxidise and acidify, creating a potential long term environmental problem. Investigations of the state of the tailings after 4 years show that these predictions were overly conservative. Only minor oxidation has occurred in the upper 2 metres of the tailings where the pH has locally dropped from 10 (discharge condition) to between 7 and 8. Below 2 metres, the tailings are essentially unchanged from their deposition state. The low rate of change in the tailings is due to their very low permeability which in turn is a consequence of the fine grain size (ca. 15 ¦m). Dewatering is extremely slow, and incursion of oxygenated water is negligible. Calculations suggest that water movement over 30 m will take at least 100 years and possibly 1000 years. The contingency plan is to capitalise on the very low permeability and keep the tailings from drying with a semipermeable cap. A layer of limestone will be added to the top of the tailings, beneath the cap, to enhance alkalinity of any percolating water. If acidification does occur, contrary to expectations, any acid produced will be neutralised by underlying calcite-bearing schist, schist in the concentrate impoundment wall, and the flotation tailings immediately downstream. In addition, dilution by alkaline ground and surface waters would further ameliorate any acidic discharge.

Jan 1, 1998

By K. Awuah-Offei

An aggregate plant may have difficulty balancing product stockpile inventories if hot mix asphalt (HMA) design engineers do not account for aggregate inventory during mix design. Yet HMA design engineers do not, often, take this into consideration during asphalt mix design. This is due to the lack of tools that enable the lab technician or engineer to optimize the mix for good performance while helping the aggregate plant manage its stockpile inventory levels and reducing the aggregate cost. This work presents a linear programming model of the asphalt mix design problem that helps aggregate plants manage their inventory levels while meeting HMA customer demands. The algorithm is implemented in MATLAB as an Asphalt Mix Design Optimization (AMIDO) program. The program is successfully validated with real-life data. The results show that AMIDO can be used to successfully produce any mix design while reducing the cost of aggregates by using the cheapest stockpile materials. The application of AMIDO will increase aggregate plant profitability when serving HMA customers and could potentially be modified for concrete aggregate customers too.

Jan 1, 2009

By D. R. Spears

As part of its mission to develop technology to assure a continuing supply of minerals, the US Bureau of Mines has investigated the flocculation of a Stillwater, MT, chromite ore. The ore was flocculated at different solids contents and at different stirring speeds to determine the importance and effect of hydrodynamic factors. In acidic and basic pH, the chromite ore was flocculated with high molecular weight polyacrylamides differing in the degree of hydrolysis. Polyacrylamides were found to bind to chromite ore particles through hydrogen bonding. The anionicity of the polymer and the pH affected the degree of polymer-particle interaction, which in turn affected polymer conformation at the surface. A polymer conformation with many loops and tails was used to explain high flocculation efficiency. It was found that such a conformation could compensate for poor hydrodynamic conditions.

Jan 1, 1992

By R. Dippenaar

The emergence of new steel grades is largely driven by the need to produce high quality steel at a competitive price. The principal aims are to attain ultra-high purity, (especially low interstitial elements) and ultra-cleanliness (by the control of the inclusion content and size). Whereas the steel used to build the Titanic contained 650 ppm sulphur, resulting in MnS stringer-inclusions 25 mm in length, modern quality requirements for arctic pipelines would only allow 10 ppm of sulphur and inclusions in ball-bearing steels must be smaller than 5µm. Most developments are aimed at hot-metal treatment before refining and ladle treatment after decarburisation. Because ferroalloys are added during or after the refining step, it is the secondary (ladle) refining production technologies that are of specific interest to the ferroalloy producer. Through ladle treatment, hydrogen and nitrogen contents are reduced, ultra-low levels of solute impurities are attained and the shapes as well as the composition of inclusions are modified. Steelmakers are concerned about the cost effectiveness of the use of ferroalloys such as consistent product analysis and delivery, improved financing arrangements and technical support. Minimal variation in product sizing is vital because it impacts on handling problems and because particle size determines the rate of particle dissolution. The required ferroalloy product quality depends on the specific use but in general sulphur, phosphorous and nitrogen contents are of concern. Apart from the presence of trace and impurity elements, ferroalloys also contain inclusions. For example, ferromanganese may contain MnO-MnS-SiO2 inclusions while high-carbon ferro-chrome may contain different kinds of Cr-Mn-spinels. The presence of these impurities and inclusions has a significant impact on steel production techniques and cost and hence, on the selection and use of ferroalloys. The interrelationship between ferroalloy quality and steel production technology is plant and product specific and hence, effective communication between ferroalloy suppliers and steel producers is essential.

Jan 1, 2004

By R. F. Selden

The material in this paper is intended simply, to be an inquiry into some of the theoretical aspects of the occurrence of methane and carbon dioxide in coal, with a brief resume of the more recent literature. Several discussions on various phases of the subject have been published, a few of which (4, 20, 25, 88, 90)4/ have more or less extensive bibliographies of tie earlier literature. In large measure the pertinent literature deals with the unusual aspects of the subject, and in consequence it might appear that the normal aspects have not been given due consideration here. The latter information is largely a matter of practical field experience, and since that which is normal to one locality is often abnormal to another no sharp differentiation appears to be necessary or, in fact, possible. No attempt will be made to present a critical discussion of the relations between the presence of gases in coal and pertinent geologic features or mining practice. Although the presence of foreign gases in the ventilating air of many mines is not particularly noticeable, in many others the evolution of methane and perhaps small amounts of carbon dioxide (or sometimes the reverse - large amounts of carbon. dioxide with perhaps sore methane) is quite apparent.

Jan 1, 1934

By R. F. Selder

The material in this paper is intended simply to be an inquiry into some of the theoretical aspects of the occurrence of methane and carbon dioxide in coal, with a brief resume of the more recent literature. Several discussions of various phases of the subject have been published a few of which (4, 20, 25, 88, 90) have more or less extensive bibliographies of the earlier literature. In large measure the pertinent literature deals with the unusual aspects of the subject, and in consequence it might appear that the normal aspects have not been given due consideration here. The latter information is largely a matter of practical field experience, and since that which is normal to one locality is often abnormal to another no sharp differentiation appears to be necessary or, in fact, possible. No attempt will be made to present a critical discussion of the relations between the presence of gases in coal and pertinent geologic features or mining practice. Although the presence of foreign gases in the ventilating air of many mines is not particularly noticeable, in many others the evolution of methane and perhaps small amounts of carbon dioxide (or sometimes the reverse - large amounts of carbon dioxide with perhaps sore methane) is quite apparent. The presence of small quantities of carbon dioxide can be attributed to oxidation of the carbonaceous matter exposed to the air. In the few cases in which this explanation is not sufficient, obviously the carbon dioxide must escape as such from the coal and neighboring strata.

Jan 1, 1934

Distinguished guests ladies and Gentlemen. As many of you know, before I became a Labour Member of Parliament, I had an unusual career path for a politician, in that I spent quite a few years working in the business community. In other words, I was mainstreamed before I was institutionalised. Given that some of this time was spent working for the then Macraes Mining Company Limited, now Gold and Resource Developments NL, I feel that I may have a perspective on how things are seen, on both sides of the fence. In terms of public perception and esteem I am not sure which career option was the step up and which was the step down. So far what I have found very familiar, is that in both roles there is a gulf between the reality and the perception of that reality - a gulf that is both huge and hard to bridge. I think it is a point worth making here amongst another busy industry cluster, that we can all too easily get so embroiled in the day to day activities, that we lose sight of how this might look to those running on a different treadmill. I can still remember scratching my head at the beginning of some days, as I worked to get new mining projects started that I knew were going to bring real jobs and economic benefit to New Zealand, but ending the day feeling like I may instead have been proposing bringing back both strip mining and slavery. If I learnt one valuable lesson out of that time it was this: .... mining has become so publicly demonised on the road to ecological nirvana, that even attempting a lucid dialogue on mining issues, with some, is incredibly difficult.

Jan 1, 2000

By J. Douglas, W. T. Ford, G. E. Henderson, I. F. Roebuck

An implicit numerical method is presented for simulating the differential and algebraic relations governing one-dimensional three-phase flow in porous media. The method is based upon compositional representation of the hydrocarbon system. Variable physical properties and water-oil capillary forces are included in the formulation; however, the effect of gravity is ignored. The effects of changing composition and mass transfer are considered through the use of known phase behavior concepts and correlations. The differential and algebraic equations and the numeric approximations to these equations are presented, and the computing algorithm is discussed in detail. This method is used to simulate a single-phase, two hydrocarbon-component gas displacement laboratory experiment. The method is also applied in simulating a solution gas drive and a gas injection problem using a reservoir oil represented as a nine-component mixture. For comparative purposes, the latter two problems also are examined with a one-dimensional volumetric model. The results of the simulation of the laboratory experiment demonstrate the relevance of this method to problems wherein the effects of mass transfer significantly enter the displacement process. The comparison of the results of the volumetric and compositional methods applied to a reservoir system illustrates not only the advantages and benefits derived from examining the hydrocarbon system composition, but also the necessity of this approach in application to a general reservoir problem. INTRODUCTION The advent of large memory, high-speed digital computers enabled reservoir engineers and mathematicians to pool their knowledge in the development of sophisticated techniques for the prediction of oil and gas reservoir performance. These techniques have progressed from volumetric and trend analysis calculations to the development of "mathematical models", or reservoir simulators. These latter models, in general, utilize finite difference approximations to the rather complex partial differential equations that mathematically describe the physics and thermodynamics of fluid flow in porous media. Many forms of this "model" type are available today, and much of the recent literature has been devoted to either improving known methods or developing new techniques for use in these prediction methods. The more advanced techniques in use at this time consist of the solution of differential and algebraic relations that describe a reservoir geometry in one, two or three dimensions and that incorporate reservoir hydrocarbon and water fluid systems that obey specified physical laws, having properties that might easily be measured in the laboratory. This type of model utilizes formation volume factors and other volumetric data, expressed directly as functions of pressure, to represent the reservoir fluid system. Experience gained with this type of simulator, commonly known as a "beta-factor model", has indicated that the approach has many outstanding defects, most of them due to the assumption that those properties measured in the laboratory completely describe the behavior of the fluid system throughout the life of the project under study. The effects of varying hydrocarbon composition and mass transfer between the phases of this hydrocarbon system must, by definition, be ignored. These defects, which may often be ignored in

Jan 1, 1970