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Application of microprocessors, programmable logic devices, and other computer-oriented hardware and software on-board large surface mining equipment to optimize availability and productivity, stretch machine life, and protect against catastrophic breakdown has been a goal of heavy-equipment manufacturers for several years. Progress in this direction has not been as rapid as many manufacturers anticipated in the mid-1980s, and, on the other side of the coin, mining industry and machine operator acceptance of such products has not always been enthusiastic. However, the trend toward such development seems undeniable. Large surface mining equipment in the future will doubtless carry more, and not fewer, applications of computers and computer-related products. The intensity of development interest and degree of progress in commercializing such on-board computer and computer-related products on surface mining equipment varies considerably among the manufacturers. Summarized here are the on-board computer-oriented products of three heavy-equipment suppliers-P&H Harnishfeger, Marathon LeTourneau, and Haulpak not a comprehensive survey, but, perhaps indicative of the direction such development is taking.

Jan 1, 1990

By George J. Conroy

To provide data as a basis for proposed acceptance standards and procedures covering permanent splices in trailing cables, the Bureau of Mines conducted testing programs on the flexure life in flat types W and G dc trailing cable splices and ground conductors. Primary reliance was placed on laboratory testing, although some cross comparisons were made at manufacturers' plants and mine operations Besides providing data for acceptance standards and procedures, results of the program should promote the general improvement of commercially available splice kits.

Jan 1, 1977

By Jeffery L. Dean

Founded in 1974, the ISEE has grown to more than 3600 members representing 72 countries. The Society and its 35 chapters in the US, Canada and Australia promote research and education, provide forums for the exchange of explosives technology, serve as a repository of explosives information, provide expert help to governments, conduct certificate/training programs, and promote the teaching of the safe and controlled use of explosives.

Jan 1, 1997

By M. W. Robotham, H Wang

removal efficiency is analysed from a stochastic

Apr 1, 1995

By Joseph M. Kuchta

The limits of flammability and minimum autoignition temperature of a fuel are important elements in assessing fire and explosion hazards that may exist when using or handling the fuel. The limits of flammability define the range of compositions of the fuel gas or vapor mixed with an oxidant through which a flame, initiated by an outside energy source such as an electrical spark, can propagate. The minimum autoignition temperature (M.A.I.T.) is the lowest temperature at which the fuel vapors ignite spontaneously in a specified medium; in this case the ignition energy is supplied by the heat content of tae environment. This temperature is also referred to as S.I.T. value by some authors. Because the autoignition of a fuel also depends on the time interval during which the fuel is subjected to heat, ignition delays are significant. Ignition delay is defined here as the total time elapsed between the introduction of the liquid fuel into the oxidizing atmosphere and the appearance of a flame. This time interval includes both the physical and chemical processes leading to ignition. The ignition delay is usually maximum at the M.A.I.T, and decreases as the temperature of the system is increased. The flash point and the fire point are also useful in assessing the fire and explosion hazards of a fuel. The flash point is the lowest temperature at which saturated, flammable fuel vapor-air mixtures are formed at atmospheric pressure and, therefore, it is essentially the lower limit of flammability

Jan 1, 1962

By K. Y. C. Chung

A case study on foundation engineering through organic soils is presented. Located along the west shore of the Hudson River, site soils consist of random brick fill over a thick layer of peat and organic silts or clays. The organic layer is underlain by medium dense to dense sand with varying amounts of silt. Strong artesian pressures were measured in the sand. A pile foundation system was selected to support all structures. To avoid periodic flooding, new fill must be placed on the existing fill. Large total and differential settlements will occur due to consolidation and secondary compression of the organic soils. This settlement will reduce the allowable pile capacity due to the large negative skin friction in the organic layer; and will necessitate long-term maintenance of the final grade elevation. Pile load tests were performed to determine the allowable compression and uplift capacities, long-term capacities and pile driving criteria.

Jan 1, 2010

By M. Shapiro, L. A. le Grange, B. Henning

A paper was presented by Bateman Minerals and Metals at INFACONX (2004) describing a simplified Computational Fluid Dynamics (CFD) Model for predicting the temperature and velocity distributions in all the fluid zones of a single electrode DC Furnace simultaneously with the temperature distributions in the refractory lining of the vessel. The boundary conditions imposed on the model consisted of the arc current, external surface film coefficients and ambient temperatures. The temperature and velocity distributions in the free-board, slag and metal were solved simultaneously by coupling across the interfaces between the fluids and transportation phenomena developing in the plasma arc. A simplified model was used to describe the ex-change of energy by radiation between the arc and surfaces enclosing the freeboard region. The strengths of this model were reported as being the ability to: ?Solve the different zones and transportation phenomena simultaneously without the need to transfer partial numerical results between different numerical analysis applications. ?Solve velocity and temperature distributions without assumptions regarding internal film coefficients and additional internal temperature boundary conditions. One of the disadvantages of the model was that the energy absorbed by the process was not modelled, resulting in vessel performance predictions under heat loss conditions only. Whilst this allowed potential problem areas such as localized refractory heating to be identified, the model was only capable of predicting how these could be improved by varying the overall geometry and materials of construction. This paper presents improvements in the application software and user defined subroutines of the model as follows: ?Incorporation of surface to gas, gas to gas and gas to surface radiation models to improve the accuracy of radiative heat transfer mechanisms within the freeboard. ?Incorporation of a process energy absorption model based on a theoretical temperature dependant enthalpy curve which incorporates melting, smelting and superheating in selected areas of the bath. This enables the effect of feed distribution and power to feed ratio changes to be estimated. The effects of a commercial arc at full power on the freeboard and slag can now be simulated with increased accuracy.

Jan 1, 2007

South Africa has joined the league of other major Western World countries by officially adopting its own code for public reporting of Mineral Resources and Mineral Reserves. The recently published South African Code for Reporting of Mineral Resources and Mineral Reserves (SAMREC Code or Code) (SAIMM 2000) is presented here in its local and global context. The main aspects of the Code are listed and elaborated upon. The Code has been written with the participation of the major South African stakeholders in the field including Government institutions, the legal confraternity and the mining industry. Relevant foreign organisations, such as the Australasian Joint Ore Reserves Committee (JORC) and the United Nations contributed to its compilation, and supported it. The Code thus enjoys endorsement both locally and, to a large extent, overseas. The Code is modelled on, and is 90 per cent compliant with, the Australasian Code for Reporting of Mineral Resources and Ore Reserves (JORC Code) (AusIMM, 1999). The paper also elaborates on the duties and responsibilities of Competent Persons signing off resource and reserve reports and on the new listing requirements of the Johannesburg Securities Exchange (JSE), formerly the Johannesburg Stock Exchange, which has officially adopted the Code.

Jan 1, 2002

By Peter B. Lilly

Thank you, Syd, for the kind introduction and for inviting me to give the Keynote Address at this very prestigious gathering of some of the finest intellect and talent in the domestic and international coal industry. CONSOL Energy has been a part of this conference for its entire 24-year existence. We have presented 27 papers over that time. CONSOL employees have also been members of the planning committee for the conference, and we have been pleased to support the event both financially and with many participants. So I am honored to be here with all of you this morning, especially during such a positive period for coal. You can just feel the enthusiasm in this room for our industry, and for this conference. I can tell you, there?s also a lot of enthusiasm and excitement in CONSOL Energy?s boardroom. And our enthusiasm is mirrored on Wall Street. But there remains an ironic twist to all of this attention. Even when times are good, the coal industry seems to go largely unnoticed by the mainstream. Outside of West Virginia and other coal-producing regions, the industry still seems to lack influence and support, at least here in America. As an example, last month, an ABC News crew visited our Blacksville 2 Mine, near here, to do a feature story on increased employment in the coal industry.

Jan 1, 2006

By D. P. Lindroth

The thermal diffusivity above 298 K, up to 400 K and at pressures from ambient down to 10-10 torr was measured for the following six igneous rock types: tholeiitic basalt, obsidian, rhyolite, granodiorite, gabbro, and dunite. The thermal diffusivity data were obtained by the laser flash method. Extreme values range from a low of 5.3X10-3 cmF/sec for rhyolite at 383 K and 2X10-7 torr to a high of 13.4x10-3 crrf/sec for dunite at 298 K and 760 torr. Data are also included on a commercial fused silica, which was used as a standard.

Jan 1, 1974

By David Chapman, Glen Frank

Due to the transport mechanics of the depositional environment, glacial soils display a very wide range of grain sizes and behavior. Several nonstandard drilling, sampling, and analytical techniques are therefore required to characterize the subsurface. The paper summarizes the geotechnical investigation for the design of a large project in glacial geology, which will include both large and small diameter pressure balance tunneling. The paper focuses on the challenges presented by the glacial environment and the techniques required to identify and characterize it for design and contract document preparation.

Jan 1, 2001

Study on Reasonable Mineral Processing Flow Sheet of Yunfu Low-Grade Pyrite Ores Low-grade ores in Yunfu Pyrite Mining Area were investigated, in order to find an economical, reasonable and environment-friendly mineral processing technology, which is of low consumption and high efficiency in pyrite recovering, which can ensure that the quality of pyrite concentrate product is eligible for sale and the sulfur content of the discharged tailings meets the national emission standards. A flow sheet with a classification, a jigging for coarse-grain minerals and a spiral chute separation for fine-grained minerals was adopted, and the sulfur grade and recovery of the pyrite concentrate is 35.50 per cent and 86.70 per cent respectively, while the grade of tailings is only 6.70 per cent.

Sep 13, 2010

Study on the Interaction Mechanism of Flotation Reagents and Rare-Earths-Bearing Phosphate Ore

Sep 13, 2010

Resources and reserves are critical inputs into the determination of an operating mineÆs financial results and balance sheets, but how well understood is this fact. Do the investors, directors, accountants and geologists/engineers responsible for preparing or relying on relevant aspects of the end results properly understand the inputs and outputs and the associated risks that may be established. The first step is to understand how financial reports are impacted. The most obvious, and best known, impact is in the calculation of depreciation and amortisation charges against long term assets. In addition, however, there is a requirement to regularly determine whether asset book values are impaired û this is nearly always performed globally by the preparation of a discounted cashflow model for a mine which is usually based on a mine life as determined from the resource and reserve statement û the particular driver here is normally the short and long term production plans. A key aspect of the short term production plan is that it would normally not assume that the reserve and resource statement implies consistent grade, stripping ratios, etc. However, outside of the early years of a plan, more generic assumptions of these variables are often made in conjunction with the reserve and resource statement. Depending on the timeframe of the detailed production plans, this can have a large impact on a projectÆs net present value. Other financial balances that may also be impacted include restoration and rehabilitation provisions, retrenchment provisions and deferred or equalisation stripping accounts. The age old question of whether all reserves should be used or whether some or all of the resources should be included for financial reporting purposes has never been adequately resolved. It is our view that there should be no prescriptive answer to this question but judgement of all professionals involved in the process needs to be included. Furthermore, the company needs to be able to support their conclusions with well thought out and appropriate answers. This may not be in line with the approach that certain accounting standard setters may be proposing or taking, and this paper will outline the current status of global requirement and the likely future directions. Whether reserves or resources are utilised, does not change the key requirement that those preparing or using reserve and resource statements need to understand key aspects. For example: geologists/engineers do they know how reserves or resources will be used? have they imparted information on variability of key drivers such as grade or depth or dilution? do they know that major financial/business altering decisions may be made based on the analysis? accountants do they understand where the numbers have been derived from and the assumptions that may have been made in their determination? do they understand the degree of accuracy (or inaccuracy) that may exist particularly with resources)? do they understand the history of resource reconciliations and what it may mean for the future? directors do they understand the processes undertaken by the company to prepare the financial report and the interaction between the geologists/engineers and accountants? do they understand the potential sensitivity of results to the input variables? Financial reporting is extremely reliant on the use of the reserves and resources, however, the geologists/engineers, accountants and directors do not always understand the interactions between themselves which may lead to misleading public reporting. More education and communication between various parties is needed.

Jan 1, 2002

By William C. Cooley

This study Identifies and evaluates deposits of noncoal minerals in the U.S. which are most amenable to be mined underground hydraulically and transported hydraulically. A method was developed to screen and compare mineral deposits including economic comparisons. The most applicable minerals for hydraulic mining by borehole monitor jets from underground entries are soft uranium sandstones In Wyoming in locations where water is available. This method with hydrotransport could improve the safety, health and economy of underground uranium mining. Soft oil-bearing sandstones in California and Texas could be mined and transported by this method more safely than by other underground mining methods. Other weak sandstones may be hydraulically mined economically. Man, minerals are too hard to be mined by monitor jet but are amenable to hydraulic transport and hoisting. Uranium sandstone in New Mexico is of interest because of potentially improved health and safety in transport and lower transport cost, Increases in mine output for potash, in New Mexico and trona in Wyoming can be achieved most economically by adding hydraulic hoisting when existing skip capacity is at its limit. Research is recommended to obtain site-specific data on the feasibility of mining uranium ores by monitor jets.

Jan 1, 1981

By Thomas C. Anderson

Tiedback walls are now recognized and accepted as a good solution for a variety of structural problems: ? Retaining Walls and Bridge Abutments in cut situations ? Landslide stabilization ? Repair/support of existing walls Acceptable techniques have been developed for anchoring in cohesive and granular soils and in any kind of rock. Methods have been developed for adequately protecting tieback tendons against corrosion and for testing every tieback to verify its long-term load-carrying capacity. However, the major problem that the industry faces today is how do we get constructable and economical tiedback walls contracted for and built with minimal claims. This paper will explore the issue of "constructability" through a look at specific problems from actual projects. From a research report from the Construction Industry Institute, Austin, Texas (1986), constructability is defined "as the optimum use of construction knowledge and experience in planning, design, procurement and field/operations to achieve overall project objectives." Maximum benefits occur when people with construction knowledge and experience become involved at the very beginning of the project." The design and installation of tiebacks has been developed primarily by specialty contractors; each contractor has evolved its own methods of performing the work, and consequently, many of the techniques are patented and proprietary. The real question is, how do we make effective use of this knowledge and experience during the design phase of the project?

Jan 1, 1991

By R. Patel, D. R. Taylor, P. M. Varley

In-situ measurements of ground stress were made from surface boreholes, using overcoring and hydrofracturing techniques, to obtain data for the detailed design of the underground works at Pergau. Unexpectedly low stresses were measured and appeared to correlate with apparent hydrofracturing observed during permeability testing. The low values of the minor principal stress had a major impact on design, particularly of the lining for the pressure tunnel and shaft. Additional hydrofracture tests were made underground during construction of the low- and high-pressure headrace tunnels and the pressure shaft, to define the vertical reduction in the minor principal stress with overburden. These data were then used to locate and design the steel and reinforced concrete linings

Jun 19, 1905

By K. Loutet, A. Guenkel, K. Nikolaisen

"The INCO SO2/air process was patented by INCO in 1985. Well over 80 mining operations worldwide are using this process to oxidize cyanides to cyanates in the tailings from gold, silver and copper mining operations. The sulphur dioxide (SO2) for this process can be supplied either as liquid SO2, SO2 gas or as a sulphite-based salt. The majority of SO2/air operations have used sulphite-based salts as the ‘SO2’ equivalent probably due to low capital cost. Liquid SO2 has also been used frequently, but due to concerns with safety and availability, this option is often not preferred. The solid salt sodium meta-bisulphite (SMBS) is commonly employed, but its cost is an order of magnitude higher than that of sulphur. Due to the high cost of SMBS, the increased capital cost for a sulphur-burning SO2 gas plant (green field or retrofit) usually has a pay-back of less than three years. In addition, a SO2 gas plant offers potential for significant heat recovery from the sulphur burning process. In terms of safety, the SO2 gas plant only requires the storage of relatively benign sulphur and the site inventory of SO2 will be limited to the plant gas volume. Therefore, a SO2 gas plant will not trigger the Canadian Environmental Protection Act (CEPA) E2 Regulations or the US Clean Air Act Section 112(r) accident prevention regulations, as may be the case for liquid SO2.Most existing mining operations using ‘SO2’ are gold operations, but in recent years there has been an increased interest in larger sulphur dioxide gas plants for hydrometallurgical facilities that employ leaching of cobalt/manganese minerals or precipitation of manganese/iron (e.g. Tenke Fungurume and El Boleo).This paper focuses on the production of sulphur dioxide gas generated on site and on demand for the use in hydrometallurgical processes. The capital and operational costs of a SO2 gas plant is compared to conventional process alternatives using sulphite-based salts or liquid SO2."

Jan 1, 2016

By Günter Huber, Bruno Mattle, Helmut Westermayr, Daniel Spöndlin, Max John, Nejad Ayaydin

PROJECT DESCRIPTION Alignment The Strenger Tunnel forms part of the S16 four-lane expressway between Landeckand Bludenz. The construction of this important East-West connection started in 1973with the Arlberg Road Tunnel as its key constituent. Beginning in 1992, solutions for the section between Pians and Flirsch were investigated. Efforts to conserve nature and to avoid potential avalanche and landslide areas led to a solution detouring the villages in the Stanz valley. The starting points were predetermind by the intersections at Pians in the East and at Flirsch in the West. As a result of the expected traffic load and the comparatively high gradient of 2.9%, both one-way, two-lane tubes were constructed at once. The north tube is 5.851 m long, the south tube 5.775 m, see Figure 1. Layout of Tunnel Cross-Section The tunnel cross-section was determined by 2 × 3.75 m wide, 4.70 m high roadways, two sidewalks and sufficient space for two fans above the clearance

Jan 1, 2005

By Gungor Tuncer, Ali Kahriman, Abdulkadir Karadogan, Umit Ozer, Ertugrul Kaya, Kagan Ozdemir

The results of bench blasting on quarries, have important influences on the performance of subsequent mining activities such as loading, hauling, crushing, grinding etc., and the total costs of that mine. Drilling and blasting is an important step in mine producing chain and its results such as fragmentation, muckpile shape and looseness, dilution, damage and rock softening effect the efficiency of downstream processes. Within the scope of this study, the three different hydraulic excavators’ working performances have been studied considering the particle size distribution after bench lasting at a quarry in Istanbul Turkey. Five shots have been realized on the quarry and average particle size of muckpile after each shot were assessed by digital image analysis method. Bucket loading times have been measured by stopwatch study after five shots. Excavator bucket loading times were also estimated by bucket loading time estimation formula which was published in ISEE 2007 Conference, Ozdemir et al. 2007. Estimated and measured times have been statistically analyzed and the accuracy rate of formula has been determined for five events.

Jan 1, 2008