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By James Carroll, Lance Heyer

This paper describes the shaft design and construction for a 72-inch microtunnel under 14 active railroad tracks in Avondale, Louisiana. Initial shaft design for a deeper tunnel alignment considered secant piles with a jet grout plug. Final design for a shallower tunnel alignment included contractor input with support consisting of braced sheet piles with a jet grout plug. The authors further elaborate on jet grout implementation in very soft organic clay soils and the practical limitations of jet grouting. This paper emphasizes how all project participants worked together to utilize value engineering and alternative delivery on a unique tunneling project with a focus on temporary shaft support.

Jun 23, 2024

By Dorricott M. G

This paper reviews the present status of mining engineering education in Australia, outlines the main objectives of current programs, and looks at some of the difficulties that need to be overcome to maintain and improve current standards.A case is made for greater co-ordination and co-operation between the institutions themselves, and between industry and the professional bodies to ensure the highest standards are achieved in the most efficient way.

Jan 1, 1992

By J. S. Limb

Actual issues which arose during the discovery process or subsequent court testimony are presented. While most of these issues relate to the author’s specialty of mineral appraisal some are more general in nature and could be of interest to those who may be involved in current or future court testimony. Several important areas to be reviewed and agreed upon with the client and their legal counsel are discussed. General observations on litigation, the discovery process, testimony and some repercussion’s are also given.

Jan 1, 2001

By Nicolle Krusberski

Potential errors in XRF analysis are discussed and investigated with specific reference to the analysis of ilmenite samples. A selection of ilmenite samples was chosen and prepared using two XRF preparation techniques: pressed powder pellet and unroasted fusion bead. The merits of the two methods have been discussed in this paper for ilmenite analysis by XRF. Recommendations have been made regarding the use of pressed powder pellets especially with regard to the mineralogical effects that were evidenced during this investigation. The fusion bead technique was found to be far more accurate and able to meet short turnaround requirements provided the calibration methodology used is specific to the grade of samples analyzed.

Jan 1, 2014

By Drupad B. Desai, C. C. Ku

INTRODUCTION The Laurens Street section of the Northwest Line of the Baltimore Region Rapid Transit System, located along Pennsylvania Avenue between Pitcher Street and North Avenue is situated in material which cannot be definitely categorized as soil or rock. However, in the area of residual soils in which these tunnels were constructed, considerable attention was required to determine the character of the ground so that the designers and the constructors could properly evaluate the behavior of the ground and plan their respective efforts accordingly. The Laurens Street sections structures consist of twin rock tunnels, station structure, traction power substation, vent shafts at both ends of the station, the midline vent shaft, and the twin mixed-face tunnels. This paper concentrates on the mixed-face tunnels which extend from Station 99+67.03 (O.B.) to Station 102+49.00 (O.B.) at the southern end of the section. Since the completion of the design of this project, the Laurens Street section has been renamed the Upton Station. (See Figures 1 and 2). SUBSURFACE INVESTIGATIONS At early stages, three preliminary studies were performed by the General Soils Consultant (Ref. 1, 2, & 3). The purpose of the first study was to ascertain the generalized geological and subsurface conditions which might be encountered in the region. No borings were performed for this study. A limited number of test borings were performed for the second study, which included subsurface data for the Northwest and South Lines of the Transit System. Three borings were

Jan 1, 1981

By Bryan Morris

Quebrada Blanca (QB) is a copper project located in the semi-arid Andean highlands of northern Chile. The operation is situated 170 km ( 105 miles) southeast of the port of Iquique and 30 km (18 miles) west of the border with Bolivia, at an altitude of about 4300 m (14,000 ft) (Fig. 1). The QB ore body is a secondarily enriched porphyry copper deposit containing reserves of 85 Mt (93 million st) grading 1.3% copper. Underlying the enriched zone is a significant primary ore zone containing several hundred million tons grading about 0.5% copper. In the late 1970s and early 1980s Falconbridge and its affiliates spent $20- $30 million exploring the deposit and conducting feasibility studies. Falconbridge, however, decided not to develop the property. It was returned to its owners, Empresa National de Mineria (ENAMI), a Chilean state mining corporation. In 1988, ENAMI announced its intention to privatize the property through public bidding. Cominco Resources, then 61% owned by Cominco Ltd., examined the property and the extensive data base developed by Falconbridge. In conjunction with its parent company, Cominco Resources submitted a proposal to ENAMI to construct an open- pit mine, with heap leaching and solvent extraction/electrowinning (SX-EW) processing facilities. The plan would use patented heap leaching technology developed by Sociedad MineraPudahuel (SMP), a privately owned Chilean mining company. At that time, a $150-million project that would produce about 45 kt/a (50,000 stpy) of cathode copper was envisaged.

Jan 1, 1993

By Patrick M. Y. Waye

As mines utilise more automation in mining operations to improve efficiency and safety, a corresponding increasing demand is placed on the transport of information. Some of the recent technological advances in underground telecommunications are described for various data, voice and video applications. In particular, two new innovative underground communication systems are described, one with high speed data at 30 Mbps and the other for mine wide evacuation and safety applications. The high speed data system incorporates stateof- the-art data networking technologies and the existing leaky cable narrow band radio channels. The new system provides over the same basic infrastructure the high speed data network at 30 Mbps TCP/IP Ethernet with 100 Base-T interconnection, plus 32 narrow band radio channels. The second system is a system for mine wide evacuation with "through the earth" communication infrastructure. Emergency situation can be communicated to and from all the miners within seconds through a central control location. The technology involved does not require leaky cable or any other similar transmission media installation. Many applications are possible, including warning miners of emergency situations, mine rescue operation to communicate with trapped miners, regular reporting from miners working alone.

May 1, 2001

By Richard Krentz

Two separate on-line analyzers are operated at the Corefco metals refinery. The first application is an on-line refractometer which measures the ammonium sulphate concentration in the primary feed slurry tank. The second application is a multi-stream X-Ray fluorescence analyzer which measures the metals and sulphur concentrations in eight key refinery streams. Specific applications of the on-line analyzers with advanced control systems for improved process control will be discussed.

Jan 1, 2003

Lean Iron Ore Beneficiation in India

Sep 13, 2010

By Ronald J. Vance

One of the key elements of change in the mining industry has been the ever-increasing integration and coordination of previously highly segregated business disciplines, the extent to which the marketing and finance functions have evolved and merged within the mining industry. If one listens to the language of mine product marketers today, one hears terms like contango, backwardation, forwards, options, min/max, synthetics, swaptions, caps, collars, FRA's, spot deferreds, double bottom, head and shoulders. The list is endless and a glossary may be out-of-date even before the ink is dry. No longer can a marketer of mine products get through the day and, more importantly, keep his or her job merely by reciting statistics on supply, demand, prices and the jargon of quotational periods, delivery and payment terms. Walk into the office of any marketing department today, and computer terminals spewing on-line market prices and instantaneous news retrieval command the attention of all who enter. Traditionally, mining companies, particularly those in North America, took a passive view toward marketing their products and an even more passive view toward management of price risk. The typical, albeit simplified, gold producer of the 1970s and early 1980s spent all of its energy exploring, delineating, developing and producing a product that was placed by the mine gate. Like magic, anonymous buyers took it away and left piles of dollars in its place. No fuss, no muss and nothing to get in the way of more exploring, delineating, producing etc. The typical copper producer, meanwhile, was slightly more creative. Copper producers still spent most of their energy exploring, producing etc., but they at least acknowledged the identity of their customers. Many even went so far as to fabricate finished mine products into shapes and sizes that their ultimate customer needed. Wire, cable, sheet and extrusions were all in forms ready to be purchased by power companies, motor manufacturers and telephone companies. But, while production and costs steadily increased, research and development into new expanding markets was funded by little more than lip service. Competitors and competitive products steadily eroded market share and realized prices. The now-famous Business Week magazine cover that proclaimed "The Death of Mining" was an imminent reality.

Jan 1, 1993

By Eugene Guccione

Evidence that the United States is gradually converting to the metric system of measurement can be perceived today even by housewives in a supermarket. The question is no longer whether but when the country will have completed the conversion. To the extent that any bickering about metrication still exists, the debate now centers on such issues as finding agreement on details of implementation, and whether federal legislation should speed up the metric-conversion process or allow it to proceed along its present evolutionary and voluntary course. Apparently, the voluntary or "make-haste-slowly" approach is gaining widespread support. According to The Research Institute of America, Inc., if and when federal legislation is enacted it will likely include the following national ground rules: (1) A National Metric Conversion Board will develop and submit to the President and Congress a comprehensive plan to achieve a coordinated, minimum-cost changeover. (2) The change- over will be completed 8 to 10 years after the board's plan goes into effect, and by that time the US will be predominantly, though not exclusively, metric. (3) Costs will "lie where they fall"; subsidies, special tax concessions, and antitrust exemptions will not be authorized by the legislation. (4) The changeover will be voluntary because of the recognition that while some firms can "go metric" in a matter of weeks, others may require 15 years or more, and a few might never convert. (5) In determining whether or not to convert, on an individual company basis, adherence will be to the "rule of reason-that is, ". . . do not convert unless the engineering, economic, or other benefits outweigh any metric-related disadvantages. No one is talking about rip- ping up our railroad tracks or rewiring our homes just to conform to the practice of metric nations in Europe." (6) Government is to be part of the solution, not part of the problem; in effect, says The Research Institute of America, the leverage of federal procurement will not be exerted to force-feed the metric changeover but will be coordinated with the sector-by-sector conversion of the economy.*

Jan 12, 1975

By K. Sinding, R. Poulin

"Recent land-use decisions in British Colwnbia, and the publication of a report on compensation for expropriations of resource interests, have highlighted the nature of land use policies. Landuse decisions, such as the creation of large new parks, raise three principal issues which have implications for how land-use policy is conducted and how it impacts on the mining industry. The first is the identity of the parties advocating different land-use policies and their motives for doing so, the second is the changing nature of benefits derived from land, and the third is the change of property-rights regime which is devised to accommodate the (changing) benefits from using land and natural resources, as well as the interests of the different parties involved.Involved Parties and BenefitsThe process of establishing or modifying property rights depends on the interest groups involved. Three distinct categories, each with distinct incentives which can influence the process, must be distinguished: private claimants, politicians and bureaucrats (Libecap, 1989).The first groups claim rents and management powers through asset ownership. They may be incumbent owners seeking enforcement of the status quo, new claimants seeking redistribution of assets, or third parties who depend on the distribution of assets (e.g. lenders, labour suppliers and contractors). Some infonnal property arrangements can be negotiated within the group whereas others requires action in the political arena through lobbying politicians for (re)allocation of property rights and influencing bureaucrats for favourable administrative decisions. The second category is politicians, who direct the powers of the state to change or enforce property rights. Both incwnbents and office-seekers fall in this category and their actions and opinions are shaped by their constituencies and financial backers. However, not all causes can be championed and trade-offs have to be made, resulting in decisions that maximize political benefits. The third category of parties in the process is the bureaucrats. The power to manage has been delegated by politicians but bureaucrats also have opportunities and incentives to further their own interests. These can include maintaining or expanding jurisdictional turf or increasing operating budgets (Libecap, 1989)"

Jan 1, 1994

By M. P. Filion, K. Ferguson, L. L. Sirois

Acidic drainage is the largest single environmental problem facing the Canadian mining industry today. Technologies to prevent acidic drainage from occurring in wasterock piles and tailings sites, and on the walls of open pits and underground mines, need to be developed and demonstrated. There are two groups in Canada which have accepted this challenge: the national Mine Environment Neutral Drainage (MEND) program and the British Columbia Acid Mine Drainage (BCAMD) Task Force. This paper summarizes the activities of these two organizations.

Jan 1, 1990

By M. Tangstad, B. Monsen, H. Midtgaard

The increased attention towards reducing emissions of fossil CO2 due to its potential global warming effect has resulted in a focus on renewable resources, as charcoal. Since charcoal is produced from growing wood it does not contribute to global warming. This paper gives a brief review of consequences of and reasons for using charcoal in the silicomanganese (SiMn) production. Results are presented from practical SiMn smelting experiments, on a pilot scale, using charcoal as reduction material and comparing with coke. As slag- and CO2-reactivity are important for furnace performance these features have also been measured.

Jan 1, 2004

By Douglas N. Kendall

There are three definite steps in the making of a mining industry in any country. These are as follows: Step A - Geological Mapping This step covers the basic geological mapping of the country at scales of 1/250, 000 up to l/50, 000. This step eliminates territory and directs the exploration teams to the areas of potential interest. Step B Prospecting This step includes all phases from detailed geology through geophysics and drilling up to the point of proving that an economic ore body exists. Step C - Mine Development This is the expensive step, involving the creation of the mine, including shaft-sinking, ore treatment plant, etc.

Jan 1, 1963

The underground mining of a narrow vein hard rock orebody is a capital and labour intensive method of extraction. Due to the nature of underground mining it is difficult for higher level managers to physically see the efficiencies and inefficiencies of a particular method. Extraction methods and sequencing often need to be altered from the original planned methods as a result of mine developent, providing more in depth information as it progresses. As a result of these issues contract mining of these orebodies is common practice. There are several types of contract structures for the purpose of underground contract mining with many complex permutations of them that reflect the different needs of each individual company and orebody. The different contracts are arranged dependent on the mining companyÆs desire to transfer or, alternatively, embrace risk. This presentation gives a brief overview on these different methods and their various advantages and limitations with regard to small scale and narrow vein underground mining. With respect to these different contracting methods, the presenter reviews the mutual growth benefits of emerging partnering opportunities, specifically with regard to smaller explorers exploring and developing prospective mining tenements. The specific advantages to small explorers include the resource flexibility and speed of project development that private mining contractors can provide. Given the contracting methods that are available, there is potential for small private mining companies to gain minor stakes in major projects and major stakes in medium sized projects by employing innovative contracting solutions to provide mutual benefits to the parties. Some potential scenarios to this effect are suggested in the presentation. This paper is available as a PowerPoint presentation only.

Jan 1, 2006

By R. S. Young

There can be very few members of the Institute who failed to appreciate this extremely interesting and informative paper by Mr Rohrmann of Highveld Steel and Vanadium Corporation. This story of vanadium in South Africa has a very wide appeal to members of our profession: it embraces both ferrous and non-ferrous metallurgy, and both hydrometallurgy and pyrometallurgy. In a comparatively short time, South Africa has become one of the the world's leading producers of vanadium.

Jan 1, 1985

By T. Krauthammer

A combined numerical approach is proposed for the analysis of rock-liner interact ion in tunnels under the effects of severe dynamic loads. The method is based on employing finite element formulations which describe the linear behavior and incorporating it into a finite difference code which can describe the behavior of a jointed rock medium. This method can be applied for the analysis of tunnel systems in rock, and for studying the requirements for adequate support of the tunnel.

Jan 1, 1984

By T. R. A. Davey

It is often important in the study of a process to determine whether the limitations are governed by equilibrium or kinetic considerations. Sometimes it is possible to devise a design of the process or the equipment so that the apparent. limitations set by equilibrium considerations are overcome. In this paper, detailed consideration is given to the lead refining processes of sulfiir-decoppering and of vacuum dezincing to illustrate this, and possible implications for other refining processes are indicated.

Jan 1, 2000

By D. F. Coolbaugh

Asia, the largest and most populous continent, has had little political influence on world affairs until very recently. The picture is rapidly changing. Although the cultures of various Asian countries differ widely, today they are united in their desire to industrialize. This desire is the key for expansion of Asian mineral production. The following discussion deals primarily with the situation in the south and southeast Asian countries -India, Pakistan, Burma, Thailand, Cambodia, Laos, South Vietnam, Malaya, and Indonesia.

Jan 10, 1960