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By Jerry Wang, Greg Bold, Mahmood Khwaja, Rebecca Caldon, William Simcoe

Phase III and Phase IV of the Beaver Creek Clean River Project, Albany, NY, includes microtunnel construction of 2,320 feet of 48-inch/36-inch internal diameter (ID) conveyance pipe and a 525 foot long 9.5-ft horseshoe shape roadheader excavated tunnel. Notable challenges were encountered during the construction including mixed face tunnel conditions, undocumented existing fill ground conditions that resulted in settlement during shaft construction, and unstable tunnel face conditions. This paper discusses several of the key challenges encountered during construction and selected solutions to construction sequencing and methodology to successfully complete Phase III and Phase IV of the Beaver Creek Clean River Project.

Dec 1, 2022

By Rahul Bhaduri

Mercury levels in Twin Creeks Vista pit ore (previously Chimney Creek, North pit ore) increased substantially since plant start-up in November 1987. Consequently, modifications were necessary to minimize industrial hygiene hazards and potential operational problems. The original plant design included mercury control measures. With progressive increases in mercury levels, the issue had to be re-addressed. Modifications to operational practice, industrial hygiene and management philosophy will be discussed. Additionally, a detailed examination of the mercury vapor suppression system currently employed at Twin Creeks will be presented.

Jan 1, 1994

By George H. K. Schenck

It seems appropriate to review the history of mechanization of our underground coal mines at this time when many favorable flags are flying for this industry. It is a reasonable hope that such a review may stimulate thinking as to the directions that new technological developments are apt to take and in which members of the Society of Mining Engineers are destined to play important roles. Discussion of the relative importance of the various changes that have taken place since the advent of electric power provides the starting point. It is in the economic factors utilized that we find conditions which permit more efficient utilization of the capital committed to the industry. Concepts rather than specific items are emphasized in the following discussion because once the value of a concept, such as mechanical conveyors, is established, it then spawns many variations which are not significantly different. The shift from animate to inanimate energy has been the most important change in the modern industrial scene, including coal mining. Although introduced into coal mines for some purposes early in the period of general electrification, the coal industry adopted mechanical power relatively slowly, and 1944 was the first year in which a majority of deep-mined coal was mechanically loaded.

Jan 1, 1968

By William P. Lorenz

The paper describes a uranium by-product recovery plant operating within a copper leach, solvent extraction, and electrowinning circuit. The operation is unique because it is integrated into the main process stream of the copper circuit The plant processes 1408 m3/h of copper solutions containing about 10 mg/L of uranium. An Eluex type process was selected due to its compatibility with the copper leach plant. The paper includes an overview of the copper circuit

Jan 1, 1983

By S. Chander

The advantages and disadvantages of various techniques available for controlling reagents in the mineral flotation systems are discussed. Special interest is placed on potentiometric and voltammetric sensors for monitoring flotation pulps. Different approaches to increase the sensitivity of detection and to facilitate in-stream monitoring of solution species are also discussed. The potentiometric sensors are simple to use but are limited by the availability of an electrode reversible to the species to be monitored. In some cases the response signal could be unreliable due to the presence of interfering species. In comparison, voltammetric sensors require a higher degree of instrumentation which, however, provides an opportunity to decrease interferences and increase levels of detection.

Jan 1, 1993

By J. D. Miller

Flotation chemists have long sought to unravel the mechanisms of carboxylate collector adsorption by semi-soluble salt minerals. In particular, the adsorption density of adsorbed carboxylates, adsorption kinetics, speciation (chemisorbed, physisorbed), orientation, and conformation are of interest. Given the importance of these phenomena in establishing the hydrophobic state at a mineral surface, in-situ surface spectroscopy studies certainly are justified. Such measurements traditionally have been difficult to perform. However, beginning in the late 1980s, a Fourier transform infrared (FTIR) spectroscopic technique was developed that has allowed for the acquisition of a wealth of detailed information concerning carboxyiate adsorption in semi-soluble salt flotation systems. The technique, internal rejection spectroscopy using single-crystal internal reflection elements, is reviewed, as it applies to semi-soluble salt flotation systems.

Jan 1, 1999

By T. Ko, K. N. Han, C. S. Park, N. S. Kim, C. Yoon, H. Yoon

Quantitative analysis of Platinum Group Metals from ore samples and industrial materials using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS), Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), Atomic Absorption Spectrometer(AAS), and X-ray Fluorescence (XRF) techniques was conducted and the performance of various techniques was compared. The effects of different matrices in the sample materials were compared and discussed for each analytical technique. The ICP-AES technique exhibited better accuracy than AAS but showed limitations in its application due to strong spectral interference in the presence of common matrix elements such as iron. The ICP-MS showed the lowest detection limit and less spectral interferences than the previous two techniques. The XRF technique was also applied to examine the total amount of PGM from industrial materials. Results from each analytical method on various sources were presented and discussed.

Jan 1, 2003

By F. F. Peng, S. S. Peng, V. Z. Sun

A detailed study of ponding phenomenon relative to surface subsidence due to longwall mining was conducted for various surface stream conditions. Based on field monitoring, the stream-ponding process and three forms of stream water are described. Also discussed are the criteria of stream ponding and the influences on the ponding process by two key factors: the angle of stream flow and the change in the stream-bed gradient. A numerical (mathematical) model, which combines trend surface technique that describe the topographical features in the vicinity of a stream and the modified influence function, which represents the profile of the surface subsidence trough (or basin), is constructed to predict the formation characteristics of stream ponding in terms of location, boundary and accumulated water volume of migratory and stationary ponds produced by the stream-ponding process. Three cases are analyzed using the model to predict the interaction of the underground operations and the environmental impact due to stream ponding. The feasibility of various mitigative measures are assessed.

Jan 1, 1997

By H. Barry Holt, Charles A. Bischoff

On November 15, 1990, President Bush signed the Clean Air Act Amendments of 1990. The new legislation is sweeping in its demands for cuts in smog, acid deposition, toxic air pollutants and ozone-depleting chemicals. The Amendments will siqnificantly alter air quality permitting and compliance and are estimted to cost billions of dollars to implement. This article provides an overview and summary of each of the eleven titles of the Amendments. It also addresses how the Amendments will be implemented.

Jan 1, 1991

By Jean-Michel Rendu

The semivariogram is one of the most important tools available to the geostatistician for the analysis of mineral deposits. To be complete, a semivariogram study must include a minimum of three parts which are highly interdependent. These are: calculation of the semivariogram, mathematical modeling, and geologic interpretation. The known factors and conditions which controlled or influenced the distribution of mineralization within the body being studied should be considered in the analysis .of the semivariogram. The presence and characteristics of successive phases of mineralization, the chemical and physical properties of the host rocks and the mineralization should all be considered. This requires close and continued communication between the geologist and the geostatistician prior to and during the semi-variogram study. Geologic stationarity is needed if meaningful semivariogram results are to be obtained. The first step is, therefore, to determine whether the mineralization can be analyzed as a whole or if different geologically homogeneous sections must be defined and evaluated separately. Different methods can be used to calculate an experimental semivariogram from known sample values. The method chosen will depend not only on the anticipated and actual statistical properties of the deposit, but also on its geologic characteristics.

Jan 1, 1982

By R. W. Smith

Though generally rather non-selective in nature long chain collectors nevertheless function in different ways in accordance with their own particular physical characteristics. Altering various parts of their structures such as chain length, type of chain, etc. can therefore substantially alter the adsorptive behavior of the collectors in a set environment. The effect of such structural differences of the collectors on physical parameters such as solubility, critical micelle concentration, acid or base strength, tendency to be expelled from the aqueous phase is discussed, as is also the effect of these parameters on flotation behavior.

Jan 1, 1989

By Willard C. Lacy

Discovery of a mine is a complex affair. No mine is simply found but comes about through the efforts of many. It is difficult to establish "credit" when a mine is found and becomes a viable operation, or "guilt" when a mine is lost, goes bankrupt, or remains undeveloped. The story of the Toquepala and Cuajone developments entails various stages of: (1) discovery and recognition; (2) testing and innovation; (3) political and industrial negotiation and intrigue; and (4) finance, development, and operation. The Toquepala and Cuajone projects introduced innovative drilling techniques, were among the first major porphyry copper deposits to utilize induced polarization (1P)geophysical methods, were among the first deposits to undertake complete feasibility studies on drilled- out ore bodies, and were developed by the first large Western Hemisphere copper mining consortium. Many persons have contributed to the development of these two great deposits. Some of the names have been lost and certain contributions have gone unrecognized. I apologize for these omissions.

Jan 1, 1991

By T. W. Healy, M. S. Moignard

The use of electrokinetic or zeta-potential phenomena in studies of the properties of mineral sulphides has increased greatly over recent years. This review aims to examine and discuss the body of literature on the subject of electrokinetic properties of sulphides in a comprehensive and critical manner. Although the review covers the period from 1925 to 1975, it is only in the past ten years that researchers have been fully aware of the implications and problems of chemical reactions, notably oxidation and precipitation reactions, on the surface properties of sulphide minerals. These papers are discussed in more detail than the earlier publications. A table containing a list of determinations of iso-electric- points and points-of-zero-charge of mineral sulphides, and the methods employed in obtaining these results, is presented.

Jan 1, 1976

By A. T. Visser

The expansion of surface mining has led to the development of very large off-highway trucks capable of hauling payloads in excess of 290 t (320 st). Mine haul roads have historically been designed empirically, relying heavily on local experience; the trend in increasing truck size will thus render the current pavement systems inadequate. Because truck haulage costs can account for 10% to 50% of the total costs incurred by a surface mine, not only would the maintenance costs of existing roads of inadequate design increase, but vehicle operating and maintenance costs would increase prohibitively. Thus, there is a need for improved design technologies encompassing the construction and management techniques of mine haul roads appropriate for the wheel loads of vehicles now in use. This paper presents the different components of a mine haul road design and management system and demonstrates the value of its application through case studies. The system has been applied at several South African surface mines, and distinct benefits have been derived. The improved structural design of a new road resulted in a 29% saving in construction costs and provided better service, while the optimal selection and management of wearing course materials provided better functionality at lower total transportation operating costs.

Jan 1, 2000

By Paul B. Queneau, Barry J. Hansen, D. Erik Spiller

Most lead and zinc secondaries are recycled pyrometallurgically. However, many problems encountered in secondary smelters have been solved by addition of physical concentration and/or hydrometallurgical processing steps, with resulting important environmental benefits. U.S. secondary lead and zinc operations are described, covering conventional smelters, EAF-dust treaters, and zinc sulfate/fertilizer producers, including plant capacities, technologies, and outputs. During the past two decades, remarkable advances have been achieved by recycling spent lead-acid battery components. Interaction between primary and secondary zinc producers, the fertilizer industry, and the zinc chemical industry has substantially decreased waste generation.

Jan 1, 1993

By D. X. Tang, G. Wilson, Y. Luo, S. S. Peng

Knowing the location of voids/fractures in roof rock will be greatly helpful for roof support design. The drilling parameters obtained during normal roof bolt installation cycle provide a fast and economic way for determining void location in roof rock. In this research, feed pressure and rotation torque are found to be good indicators for identifying the voids, based on the results of a series of laboratory experiments. A set of computational rules has been developed to locate voids in mine roof using the measured roof drilling parameters and implemented in MRGIS, a software package developed to allow mine engineers to make use of the large amount of roof drilling parameters for predicting roof geology properties automatically. Anew feature, 2D map+3D figure display, is also added to MRGIS.

Jan 1, 2004

By T. Chandler, R. Buchan, J. H. Blowes, E. G. Haldeman

The regional geological setting and nature of the serpentinized ultramafic rocks are described. It is postulated that lateritization started in Miocene time. Repeated uplifts led to at least four physiographic cycles and to the development of a mature lateritic soil profile. Complete profiles are subdivided from top to bottom as follows: Zone A - chocolate-brown limonite; Zone B - ochre-brown limonite; Zone C - soft serpentine; Zone D - hard serpentine; Zone E - serpentinized peridotite; Zone F - ultramafic rock. Zones A and F rarely attain ore grade. Canga is conspicuously absent. Rocky ore of Zones D and E amounts to 40%, limonite ore of Zone B to 25% of total ore reserves. Nickeliferous serpentine is the major crystalline phase in Zone C. In this zone and deeper, crystalline quartz occurs, particularly in fracture zones where nickeliferous cryptocrystalline quartz is of ten accompanied by garnierite.

Jan 1, 1979

By Scott G. Britton

Up to now, the hands-on approach to construction has been stressed. This chapter reviews the basic tools available for construction design and monitoring of a construction project. It is divided into three discussions, all under the general title of computer aids, since the trend for using these tools-is via the computer. In the context of our discussions, the focus for computer aids will be on the use of evaluation and analysis techniques for coal mine construction applications, including mainframe programs, CPM techniques, as well as mini and microcomputer applications. Although the presentation of material in this chapter may be detailed at times, by no means does it cover the entire field of computer applications for design or project scheduling and monitoring. It is only an attempt to illustrate the possibilities that are available to construction and mine engineers. Interested persons can pursue computer applications for coal mining by reviewing Computer Methods for the 80's. by Alfred Weiss, editor, published by SME-AIME.

Jan 1, 1983

By B. J. Arnold, B. W. Parker

Rosebud Mining Company added a classifying cyclone/spiral concentrator circuit addition to its McVille Preparation Plant, Freeport, PA, in mid-2002. This paper will describe the plant addition, which was implemented fully by plant staff, and review improvements in cleaning plant performance and economics.

Jan 1, 2003

By E. Woodburn, R. Putman, A. L. Mular

Optimization strategies of possible interest to mineral processing are reviewed and typical strategies initiated in processing plants to date are discussed. Both On-Line and Off- Line optimization procedures have been employed by industry, assisted either by operators or by digital computers. In every case, dollar benefits have accrued.

Jan 1, 1976