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By David Logan, Sigurdur Finnsson

This project, which is intended to provide effective sewerage services to the Blue Mountains community, is located in the Blue Mountains National Park, about 60 km west of Sydney, Australia. The sewerage scheme consists of about 40 km of tunnels, out of which approximately 22 km have been completed. This paper describes the last major tunnelling operation on this project, the Hazelbrook to Katoomba tunnels. These tunnels, which mainly traverse the Hawkesbury Sandstone formation, are being excavated by a new 3.4 meter diameter Jarva Mk12C TBM. The mucking system consists of a continuous conveyor, which has allowed for some very impressive advance rates. The paper will consist of three main sections; the general geological conditions expected along the tunnel will be described in the first section. The second section will discuss the design and main features of the TBM, back-up system and continuous conveyor. The third section of the paper will describe the operational aspects and various performance data of the machine.

Jan 1, 1995

By Julian Boldy

The discovery of the Delbridge massive sulfide deposit in the Noranda district of Quebec resulted from an appreciation of the significance of a mercury leakage haloas a lithochemical pathfinder to blind ore, coupled to its location relative to a geologically inferred ore-bearing horizon within complex volcanic stratigraphy. Systematic sampling of microfractures present in outcrops delineated a diagnostic anomaly, drawing attention to an area considered prospective for buried ore. The massive sulfide deposit was subsequently found to be blind and topped at the 107-m (350-ft) level. This case history is presented in the context of its time and was the first volcanogenic ore deposit to be discovered utilizing mercury as a pathfinder in the Canadian Precambrian. The case history also illustrates that the practical application of an innovative technique coupled to a new geological interpretation can result in success, even on a property that was centrally located in a mining district and had undergone intensive exploration efforts over a 38-year period.

Jan 1, 1991

By R. Benito, J. Lopez, H. Gamarra

This article describes three practical applications of the Hill of Value (HoV) methodology within different stages of strategic planning for open-pit mining operations and projects. In the pursuit of optimal mine planning, this study establishes a comprehensive case study during the (i)design phase, by refining key parameters for efficient decisionmaking. (ii)production planning, where the HoV is used to define achievable production rates, enhancing operational effectiveness through a nuanced consideration of mining and processing capacities. (iii)Additionally, the study introduces a conceptual framework for orchestrating the optimal sequence of multiple pits during the planning phase, with a focus on maximizing project value.

Feb 1, 2024

By Jeffrey J. Schwoebel, Jianliang Li, Daniel J. Brunner

A United Nations (UN) administered degasification technology transfer project, funded by the Global Environmental Fund (GEF) is underway at the Shihao Mine of the Songzao Coal Mining Ad- ministration in the province of Sichuan, Peoples Republic of China. This mine exploits multiple seams at depths ranging from 300 to 600 m below surface. In-seam boreholes and frequently spaced in-mine vertical boreholes, developed from underlying galleries constructed specifically for this purpose, currently degasify the seams in advance of mining at the Shihao Mine. Because of ventilation system constraints and the in-situ gas con- tent, longwall mining of the coals at this mine could not proceed without some form of pre-mining degasification. This paper presents a simulation based degasification plan of long, in-seam horizontal boreholes for the Shihao Mine. Simulations with a coalbed reservoir program assessed time dependent degasification characteristics of both vertical and in-seam horizontal boreholes. The simulations used input data from reservoir and desorption tests conducted at the mine site. The results produced system design nomograms to assist mine engineers in defining the appropriate borehole spacing necessary to degasify the seam in the time available for pre-mining drainage. The predicted effectiveness of the current vertical degasification scheme was compared with that for a horizontal borehole program and served as the basis for the recommended in-seam borehole configuration for the project at the Shihao Mine. The horizontal borehole degasification program requires substantially less gallery and borehole development than the present vertical degasification scheme.

Jan 1, 1997

By Th. Petropulos

The Zn-Ag-Pb mineralization zone near Molai (Greece) was explored by more, than 60 drillholes. Promising results led to the decision of additional drillholes in order to confirm the expected spatial extension of the deposit. A multiobjective approach is described which optimizes the location of a set of 5 additional drillholes. The decision is based on estimation errors for grade, thickness and depth of the main ore bearing layer, with respect to cut-off values for grade and thickness. The linear combination of these variables defines a favorability index which is used for mapping optimal drillhole locations. The map shows several clusters of favorable cells. A declustrering algorithm is used to select a representative cell for drilling in each cluster.

Jan 1, 1989

By Adam Levy, Thomas Novak, Sampurna Arya, Joseph Sottile, Kozo Saito

The use of a woven wire-mesh screen as part of a flooded-bed dust-scrubbing system is very popular in the underground coal mining industry. It is used in combination with a demister (mist eliminator) to remove dust from the dust-laden air. A study was conducted to measure the pressure drop across a flooded-bed wire-mesh screen at different airflow rates in onephase (dry) and two-phase (wet) conditions. Two empirical relationships between pressure drop and air velocity were developed for dry and wet conditions, respectively. In both cases, the form of the empirical relationships was found to be similar to relationships given by Sabri Ergun for high velocity non-Darcy single and multi-phase flow through porous media. The experiments were repeated on a reduced-scale model of the wire-mesh screen, and the pressure-velocity relationships obtained from the full-scale prototype experiments were tested. The test results show validation of the full-scale empirical formulas on the small-scale model with an insignificant variation. This paper presents the empirical equations for pressure drop across the wire-mesh screen in dry and wet conditions. Researchers can use these equations as a tool to predict total pressure drops for wire-mesh screens of different scale sizes.

By J. M. Mutmansky

The objective of this study was to produce coal dusts for laboratory research that are similar to mine airborne dusts in chemical, mineral, and physical characteristics. In this investigation, dusts produced in laboratory comminution equipment were compared with continuous-miner-generated dust for similarity in physical characteristics. Mining-generated dust (MGD) and bulk coal samples were first collected from an underground mining operation. The bulk samples were then processed in the laboratory for size reduction in various comminution devices. These laboratory-generated dust (LGD) samples were subjected to size and microscopic analyses. Physical properties of the dust particles were studied on a scanning electron microscope (SEM). A numerical shape coordinate system (SCS) was also developed and applied to 300 particles from each sample. Statistical analysis was then performed on the collected data and characteristics of the MGD and LGD samples were compared.

Jan 1, 1995

By David F. Gibson

This paper presents an outline of several models that have been developed to aid surface mine planners evaluate alternative mining methods and dragline sizes. The models presented belong to a larger group of models that are incorporated in the SEAMPLAN computerized mine and reclamation planning system. SEAMPLAN was developed in the College of Engineering at Montana State University. Initial funding for the development was derived from the USDA Forest Ser- vice and EPA. Enhancements to SEAMPLAN are currently being funded by DOE (Contract DE-AC22-80ET-14173). SEAMPLAN is a comprehensive surface mine and reclamation planning tool that contains a number of major modules: Data Entry and Review, Production Analysis, Reclamation Analysis, and Impact Analysis. The Production Analysis Module contains programs that enable the user to evaluate alternative methods of removing overburden in a surface coal mine and then to assess auxiliary activities required to support the overburden removal operation. A set of these programs addresses the use of draglines for removing overburden. Six basic dragline mining techniques have been modeled. For one-pass dragline operations four methods can be analyzed: (i) simple side cast, (ii) side bench, (iii) extended bench, and (iv) extended bench with side bench. Two methods of two-pass operations are modeled: (i) single dragline, and (ii) tandem draglines.

Jan 1, 1982

By A. Aubut, A. Proulx, O. Tavchandjian

Results obtained from conditional simulations and multiple indicator kriging were compared in the assessment of two different mining methods proposed for the extraction of the down-dip extension of a nickel-sulfide ore body located in the Thompson mining camp, Canada. An enhanced turning band simulation algorithm, supplemented with an unfolding technique, was used. A floating stope optimization process was used to effectively compare tonnage and grade figures. A calibration exercise was also conducted in the upper portion of the ore body. This study demonstrates that conditional simulations provide better spatial models for conceptual mine design and capital budgeting decisions.

Jan 1, 2004

By R. Y. Wan

Newmont Gold has advantageously used the capabilities of mineral oxidizing bacteria to develop a process for the pretreatment of low-grade sulfidic and carbonaceous-sulfidic refractory gold ores. The biooxidation process results in the oxidation of the sulfidic minerals with increased exposure of gold for subsequent gold recovery. The biooxidized carbonaceous-sulfidic ores cannot be heap leached with cyanide because of the preg-robbing characteristics of the carbonaceous matter in the ores. Therefore, an alternative heapleach process using ammonium thiosulfate was developed to extract gold from these preg-robbing bioaxidized ores. The ammonium thiosulfate leach process was successfully applied in both laboratory and pilot plant tests. Satisfactory test results were achieved, encouraging the continuation of process development.

Jan 1, 1997

By Ping Xia, Yaoxin Lu

With productivty increment. it becomes very important to monitor the underground production environment. This paper presents a multi-level computer monitoring and managing system, which was specially developed for the mine. In this system, TF-200, Industrial Standard Buses (STD) and 32 bytes Super micro-computer were integrated into one body as hardware; Data Base was designed by means of software engineering method in the software development; on maitenance of the system, the parameters are managed concentratedly and data are classified to process; therefore, the ystem gets to the advanced level in China. The system is composed of four sub-stations: Signal Transmission. Data Collection, Data Processing and Image Display Sub-system. Signal Transmission Sub-system(STSS) A frequency-division transmission method is used. Data Collect ion Sub-system (DCSS) Industrial Standard Buses (STD) is used. It can change data from STSS into suitable form for DCSS, Calculate average value every minute, decide alarm and transmit data to DPSS. Data Processing Sub-system (DPSS) The host is a S/120. With UNIX Operation System. the data from DCSS can be classified. stored, displayed. printed, by means of real-time and time-division processing. Additionally the functions of the historic data search and data analysis are provide. Image Display Sub-system (IDSS) The real-time and historic data was displayed for curves and diageams on screens. This system has been in operation.

Jan 1, 1991

By V. Roze, R. N. Parkinson, R. Shepherd

The alphaDOSIMETER is a complete, integrated system designed to monitor the immediate worksite of underground miners where the disintegration for radon daughters is a risk to the health of mining personnel. The dosimeter weighing little more than one pound is worn by each miner throughout the entire shift and is powered by the miner's cap lamp battery. After this integration period, the unit is connected to a reading network whereupon the day's data is dumped, calculated and stored. Beginning in July 1980, prototype units were subjected to vigorous underground testing in uranium mines in Canada and the United States and in tin mines in Cornwall, U.K. The testing results are summarized and proposals advanced for a typical mine monitoring system utilizing the alphaDOSIMETER.

Jan 1, 1981

By S. Page, R. Bhaskar

The development is described of a real-time tracer gas sensing system for use in fell-scale laboratory studies of air flow behavior around mining machines. A semiconductor sintered tin-dioxide gas sensor is used for gas analyses. A data acquisition and analyses software specific to the sensor characteristics was also developed as part of the system. The system permits the study of transient behavior and assists in obtaining a better understanding of the movement of air around mining machines and in the study of the effect of potential airflow modification devices on the dust exposure of face personnel. It seeks to replace the current method of using a centralized infrared gas analyzer that polls several sampling points using an array of solenoid valves and gas line purgers. The polling results in a significant time lapse between the first and the last set of readings. The system described in this paper has the advantages of real-time sampling and safe operation.

Jan 1, 1992

By J. M. Stewart

The incidence of heat stroke in the South African gold mining industry is today small (less than 1 in 10 6 shifts worked). Acclimatization and selection procedures have been developed and applied throughout the industry, underground working conditions have, and are being improved, and personnel are to-day made more aware of heat stress and its consequences than ever before. Although these actions have, over the years, brought about a steady reduction in the incidence of heat stroke (see Figure 1) the small incidence of heat stroke which persists indicates that heat stress is still a problem. This realization provides the stimulus for the work presented in this paper, which has as its primary objective the development of reliable heat stress limits for men working in South African gold mines. [ ] In keeping with recent trends3I4 the approach followed in this paper is based on the physical principles of heat transfer. Detailed studies of heat transfer from humans have been undertaken,5-l1 and certain of the results form an important aspect of this Paper -

Jan 1, 1980

By H. Colijn

The ever increasing price of bulk commodities forces buyers and sellers in world markets to take a more careful look at methods for obtain¬ing accurate accounting of commodity trans¬actions in commerce and material utilization in processes. Depending upon the application of a sampling and weighing system or the use intended, inaccuracies can result in an eco¬nomic loss of income or a loss in quality of the process. It inevitably results in a loss of control of ones costs. The accuracy of samp¬ling and weighing systems is today extremely important, as they are recognized to be the key components of the overall management system designed to provide both quantitative and qualitative control. This paper will be confined to the weighing systems only and will deal with various as¬pects of system design, calibration and opera¬tions. Special emphasis will be placed on new developments and requirements in this field.

Jan 1, 1988

By M. Misra, J. Nanor

The removal and stability of arsenic over a wide pH range (3.0-10.0) from synthetic solutions and industrial waste effluents (including mining waste tailing slurry) can be accomplished with addition of impure lanthanum chloride alone or in conjunction with ferric sulfate. The long term stability of these correspond­ing precipitated compounds is critical from the disposal stand­point. In this paper test results of this new process for arsenic removal and stabilization from the above mentioned systems are presented. Also, precipitated arsenic compounds (lanthanum arsenate, lanthanum-ferric arsenate, ferric-lanthanum arsenate and ferric arsenate) from synthetic solutions have been charac­terized. The characterization technique used was XRD. XRD patterns which shows that the lanthanum arsenate and lan­thanum-ferric arsenate formed in acidic and alkaline pH at room temperature are crystalline. On the contrary, ferric arsenate and ferric-lanthanum arsenate compounds formed under the same conditions as lanthanum arsenate were amorphous.

Jan 1, 1998

By David R. Wayman

This paper summarizes environmental compliance and related issues associated with underground construction and tunneling operations, whether new work or rehabilitation. Underground construction and tunneling operations have (in most cases) both an underground and surface component. Since many of the major tunneling projects occur in urban areas, often is areas inhabited for several decades or centuries, environmental problems may already exist in a project area, though that may not yet have been formally recognized. Large projects often attract more than their fair share of regulator attention. This paper addresses the issues with the greatest potential to be encountered by underground constructors, with the emphasis on minimizing contractor liabilities, both in the short- and long-term. Minimizing contractor liability begins with understanding bid documents, contract provisions and necessary means of protection, and carries through project execution by responsible control of hazardous materials, avoidance of media contamination, proper waste disposition, as well as compliance with other environmental requirements.

Jan 1, 1999

By A. Dan Rovig, C. Kevin McArthur

Technical and managerial innovations in the minerals industry have allowed continuing mining activities in the United States, and elsewhere, as gold orebody quality has diminished or has become more refractory. Of course, world markets, permitting requirements, and political processes also have created a need for innovative practices that contribute to the survival of the mineral industry. The gold industry has been transformed, during the past approximately 40 years, from a predominantly underground mining and milling type of exploitation and extraction to the large-scale, relatively low-grade type of extraction that is common in the United States today. Indeed, with the introduction of gold heap-leaching technology and the development of mines that produce from large, relatively low-grade gold orebodies in the western United States, a "new" industry was born and continues to prosper today. It is worthwhile noting, however, that Dobra (1997) has reported that one of the major trends in the North American gold industry is a movement back toward underground developments.

Jan 1, 1998

By Robert L. Cascio

The mining industry uses a large amount of electric power. Their equipment is subject to extreme environmental conditions and mechanical shock. A significant number of electrical accidents are a result of improperly grounded electrical equipment. Federal regulations require the safety ground bed resistance to be measured once a year or after modifications. Most commercially available instruments used to measure the ground bed resistance require the ground conductor to be disconnected and the power system disconnected for safety reasons. The "fall of potential1' method requires auxiliary ground rods and approximately two hours to complete the test. Although a new instrument was initially thought to measure the ground bed resistance immediately without isolating the ground bed, field tests have shown this method is not accurate. In some cases, a continuous measurement of the ground resistance is desired. A monitor has been developed and is presently being evaluated at several mines. These installations will be discussed.

Jan 1, 1992

By C. E. Jordan

The Bureau of Mines conducted research to measure the improvement provided by fine bubbles on the flotation of fine-sized particles (minus 20-um size) in an effort to improve flotation efficiency in our domestic minerals industry. The turbulent velocity distributions of the fluid within the flotation cell were measured as a function of time and position and used to increase the precision of a fine particle, turbulent flotation model. For the mineral system investigated, improved flotation response was obtained under laboratory conditions by using small bubbles and intense agitation. These results matched the model's predicted response.

Jan 1, 1989