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By Eric K. Albert, J. Kiusalaas

The paper presents an overview of SPASID (Kiusalaas and Albert, 1983), a new computer program developed under U.S. Bureau of Mines funding for the prediction of surface subsidence caused by under- ground mining operations. The presentation, which is illustrated with two case studies, also re-evaluates the influence function method as a tool of subsidence prediction, arriving at some rather unconventional recommendations. SPASID consists of four modules that communicate through common data bases: (1) Preprocessor. This module prepares and maintains the database for the entire site. The database contains all the information about the site and the mine operation that is necessary for the computation of subsidence. (2) Subsidence Predictor. The influence function method is used to predict the surface displacements that occur in any portion of the site that occur between two given dates. The computations take into account the time lag between extraction and displacement, and the effects of pitching seams and incomplete compaction at the edges of panels. The program contains i not he's influence function and the Green's function of transversely isotropic elasticity theory. (3) System Identification. The purpose of System Identification is to determine the optimal values of the various parameters associated with the influence functions in the Subsidence Module. System Identification requires measurements of subsidence from a site with a sirnilar overburden structure. The values of the subsidence parameters are obtained by minimizing the discrepancy between the measured and computed surface displacements. (4) Postprocessor. The Postprocessor is a graphics facility for displaying the data generated by the other program modules.

Jan 1, 1984

By J. Douglas Gibson

In Canada, the economic climate for mining is still warm, but a noticeable chill set in last November when the Government published a White Paper on tax reform known as the Carter Report. Moreover, this chill could drop to a freeze injurious to the whole Canadian economy if two of the proposals in the Carter Report are adopted. The offending suggestions call for an end to (1) the depletion allowance and (2) the three-year tax holiday for new mines. Both of these tax incentives have played a major role in the postwar development of the Canadian economy and will, if undisturbed, play an even more important role in the future. The fact that they have worked and worked well is evident from the record. Fruits of an Industrial Beanstalk Excluding fuels, the value of Canadian mineral production was just under $3 billion in 1968-almost nine times as much as in 1946. With fuels included, the figure is $4.25 billion, or almost ten times as much as in 1946. Proportionately, this growth far exceeds that of Canada's manufacturers or of her economy as a whole. Table I traces the overall mineral production growth by principal products. Of particular interest here are petroleum, iron ore, natural gas, sulfur and potash, the combined production of which has grown from little or nil to a point where it now accounts for more than 40% of Canada's mineral output.

Jan 1, 1970

By Sam Oaks, David A. Smith

The new Corridor "G" Federal Highway Project in Logan County, West Virginia is the largest mass excavation highway project currently being built in the United States. Seven sections covering 14 miles of four lane highway and two connector roads will require over 30 million cubic yards of excavation. Construction is on a fast track schedule requiring the contractors to complete excavation and pavement placement in a little over 19 months. The two different general contractors have implemented several innovative Blasting and Excavation Programs to complete this project within the tight completion schedule. The paper expands on some of these unique programs that made the project a reality.

Jan 1, 1994

Work on this program was supervised by R. C. Streeter, Project Scientist, R. K. Young, Principal Investigator, and R. A Glenn, Project Director Technicians involved in the conduct of the experimental work were J R. Allender, D. R. Wolber, G. L Maclay, and A. C Rupert The assistance of Project Scientists C. T. Ford in the electrokinetic studies, and R. R. Care in the spectrographic analyses, is also acknowl- edged. The valued advice and guidance during the course of this program from R. D Hill, EPA Project Officer, and Dr. D R. Maneval, Director of Planning and Coal Research for the Department of Environmental Resources, Commonwealth of Pennsylvania, is sincerely appreciated.

Jan 1, 1971

By Mungo Park, C. Baring Horwood

This paper is intended, in the light of recent investigations, to call attention to some of the essential features of good practice in sampling and mine-valuation. Mine-sampling may be divided broadly into two classes: (1) development-sampling and cornputatioll of ore-reserves; and, (2) stope-sampling and estimation of stope-values. Development-Sampling. It is with development-sampling only that this paper deals— the term development being taken to mean the opening-up of a mine by cross-cuts, drives, connections, etc., preparatory to actual extraction of the ore for milling. In development-sampling the work of the sampler and the consequent estima-

Jan 1, 1909

By R. N. Torbin

The degree to which automation, remote control and robotics have been used in the mining industry is far less compared to general industry. Reasons include the adverse working environment, the difficult work operations and the generally lower incentive for capital investments in new mining equipment. The author and his employer has been involved in the development of advanced mining and underground construction equipment. This equipment is designed to he remotely operated, to improve both productivity and worker safety. Many of these machines employ advanced electronics and robotic features. The types of machines that will be discussed include remote shaft lining and placement, remote excavation and mining operations, and automated conveyor systems.

Jan 1, 1991

By J. P. Allen, D. A. Rice, H. L. Abercrombie

Cobalt, nickel and manganese can be recovered quickly, cleanly and selectively from cobalt-rich manganese ocean crust by leaching in dilute acid solutions in the presence of hydrogen peroxide. Common selective precipitation methods can then be used to recover these metals from the leach liquor. The leaching reaction produces only oxygen as a byproduct, and the waste residue from leaching was tested and found to be nonhazardous under existing EPA specifications. The leaching process is effective in either fresh water or seawater. This research is a part of the Bureau of Mines program to identify the mineral resources of the Exclusive Economic Zone and devise methods, for recovering their valuable components.

Jan 1, 1992

By Fathi Habashi

Precipitation of a metal from an aqueous solution of its salts by another metal is known as cementation, because the precipitated metal is usually cemented on the added metal. This phenomena was once described by the alchemists as "transmutation," when they dipped a piece of iron in a solution of copper sulfate and the iron was coated with a layer of metallic copper. The process can be predicted in terms of electrode potentials. The metal with the more positive (oxidation) potential, as given in Table 13-1 of the electromotive series, will pass into solution and displace a metal with a less positive potential.

Jan 1, 1970

By Ernest Peters, Fiona M. Doyle

The leaching and bulk decomposition of sulfide minerals is of enormous commercial importance in several areas of the minerals industry. These include: direct leaching of ores or concentrates for the recovery of the contained metal values; decomposition of sulfides to recover associated values such as encapsulated gold; and the potentially hazardous oxidation of sulfides in waste disposal facilities. A significant challenge to successful future developments in these areas is to improve our fundamental understanding of the mechanisms of the chemical, electrochemical, and bacterially-mediated interactions between sulfides and aqueous solutions. The paper summarizes current understanding of these mechanisms, and discusses promising new directions for research.

Jan 1, 1989

By Fumihiko Sumiya, Yukio Kato, Yoshikazu Hirosaki

Secluential blasting is one of the most popular methods in blasting. tiowever, it is well known that an emulsion explosive can be dead-pressed by dynamic pressure generated by the previous detonation. It is difficult to gain the expected blasting performance due to tb.e malfunction of explosive caused by deadpressing and shock desensitization. Such malfunction of an explosive is undesirable for safety blasting operation. Voids in the emulsion explosives will considerably affect the performance of explosives such as sensitivity, detonation velocity (DV), pressure-resistance and so on. To clarify the detonability and the performance of precompressed emulsion explosives, the DV was measured. Three types of microballoon or micro bubble ; two types of glass microballoon(GMB), resin microballoon@MB) and chemical gas bubble ; were used as sensitizers for the sample emulsion expiosives. The underwater explosion test was carried out to load dynamic pressure into the sample explosives. The dynamic pressure was generated by the detonation of a donor explosive, and the DV of the sample explosives as acceptor was measured by ionized gap terminals. The dynamic pressure level and initiation interval for the donor and the acceptor were chosen as experimental factors. The detonability was carefully investigated at short initiation intervals taking into consideration the interaction between same delays caused by the deviation of the ignition time of the electric detonators. From these experiments, the following results were obtained ; A) The DV of precompressed emulsion explosives was low compared with that of uncompressed emulsion explosives in all pressure conditions. B) The decrease of DV in the sample explosives sensitized by GMB s was larger than that of DV in the sample explosives sensitized by RMBs or chemical gas bubbles. C) The recovery of the detonability occurred rapidly in the sample explosives sensitized by RMBs and chemical gas bubbles. However, a long period was needed for the recovery of detonability in the sample explosives sensitized by GME! s. It was concluded that the type of microballoon and micro bubble significantly influenced the detonability of precompressed emulsion explosives.

Jan 1, 2002

By K. Huang

"Solvent extraction (SX) is one of the most effective techniques for the multi-metal separation. However, repetitive pre-treatment of feed-in solutions and/or multi-steps two phase equilibrating in conventional SX processes were always unavoidable due to the poor separation selectivity between those metals with similar physicochemical properties. In this paper, our recent efforts, aimed to develop a “Three Liquid Phase Extraction” (TLPE) strategy for one-step separation and selective enrichment of different metals respectively into three coexisted liquid phases, are reviewed. Various feasible “Three Liquid Phase Systems” (TLPS) are evaluated. The TLPE technique provides a potential possibility for multiphase extraction to separate multi-metals.INTRODUCTIONLiquid-liquid Solvent Extraction (SX) is one of the most effective techniques for metal separation and purification. Traditionally, extraction and separation of multiple valuable metals from the leaching solutions of complex ores, industrial wastes and byproducts have to face such difficulties that multiple target metals with similar physicochemical properties co-exist in the solutions, and therefore their mutual separation selectivities are very poor. In conventional organic-water two phase SX processes, repetitive pre-treatment of feed-in solutions including the adjustment of the solution acidity, removal of impurities and/or multi-step liquid-liquid two phase equilibration were always unavoidable (Wang and Chen, 2001). Only one of the target metals is obtained in each extraction step, therefore the whole separation processes for multi-metal separation are typically very long and costly.Liquid-liquid-liquid three phase extraction is a developing technique for separation of complex systems containing multiple target components (Tan, 2003; Shen, 2006; Yu, 2009). The technique is in fact a three-liquid-phase selectively partitioning of different target components through the control of phase-forming behaviors of extraction system to create a unique separation medium with three co-existed liquid phases. The separation selectivity of “Three-Liquid-Phase System” (TLPS) may derive from its three-layered liquid phases from up to down with different hydrophobic or hydrophilic environment, and therefore each phase has its own specific selectivity for dissolving of an individual component. In a well designed “Three-Liquid-Phase System” (TLPS), multiphase extraction and selective separation of different components respectively into three different liquid phases can be achieved by only one-step of extraction. Owing to its distinct advantages, “Three-Liquid-Phase Extraction” (TLPE) technique has found many potential applications in purification of various organic chemicals (Shen, 2007) and biological activities (Chen, 2002; Tan, 2006; Jiang, 2008), treatment of environmental wastewaters (Shen, 2006; Yu, 2009; Yu, 2010; He, 2012), extraction of valuable components in natural products (Liu, 2010) and separation of multi-metals in complex leaching solutions (Jin, 2009)."

Jan 1, 2012

By J. H. Keeler

The tensile characteristics of Zr-Fe binary alloys containing up to 5 atomic pet Fe are reported for the temperature range —195o to 500°C. A linear relation between stress at constant strain and volume fraction ZrFe2 was found. The coincidence of data from unalloyed zirconium with zero volume fraction ZrFe2 indicated little or no solid solution in IL-zirconium, in agreement with Hayes, Roberson, and O'Brien.' The absolute increase in strength due to particle strengthening, although decreasing with increasing temperature, was a greater percentage at high temperature. ZIRCONIUM is of interest for use in nuclear reactors because of its low neutron absorption, good corrosion resistance, and high melting temperature. The alloying of zirconium with iron has been considered as a means of increasing the mechanical strength of zirconium without seriously increasing the neutron absorption " over that of unalloyed zirconium. The Zr-Fe system has a eutectic at 934°C and 23.7 atomic pet Fe and a eutectoid at 800°C and 4.0 atomic pet Fe. The zirconium-rich end of this system determined by Hayes, Roberson, and O'Brien' is shown in Fig. 1. The intermetallic phase coexisting with a and ß-zirconium has been reported as Zr2Fe3,1 with a,, - 7.04A, and as ZrFe2,2 face-centered-cubic, the phase being of the MgCu, type (C-15). It was more recently agreed to be ZrFe33 and face-centered-cubic. This intermetallic phase is essentially insoluble in a-zirconium, the hexagonal-close-packed modification; and the lack of solubility makes the system particularly interesting metallurgically. The system is strengthened almost exclusively by particles of in-termetallic phase, and there is very little solid solution strengthening to complicate the analysis. The Bureau of Mines, in its survey of zirconium-base alloys,' reported the tensile properties of Zr-Fe alloys made from chloride process zirconium, induction melted in graphite crucibles, and swaged at 850°C in iron sheaths. Additional data on these ZrFe alloys were given by Hayes, Roberson, and O'Brien.' Chubb and Muehlenkamp% have recently reported the strength of Zr-Fe alloys containing up to about 1.25 atomic pet Fe. These alloys were made from crystal bar zirconium, hot worked at 820°C, annealed at 700°C, and tested both at room temperature and at 316°C. Experimental Procedure The materials used in this investigation were high purity zirconium made by the iodide process and electrolytic iron. The composition of the zirconium as obtained by spectrographic analysis and the nominal composition of the iron are given in Table I. Alloy ingots weighing 100 g were made by are-melting under argon in water-cooled copper crucibles in a multihearth furnace."

Jan 1, 1957

By Oliver C., Ralston

THE following data were obtained during Tan exhaustive research into the possibilities of concentrating United Verde massive sulfide copper-zinc-iron ores by flotation. The composition of these ores approximates the following mineralogical analysis: 3 to 15 per cent chalcopyrite; 3 to 11 per cent marmatite (ferruginous sphalerite) ; 47 to 69 per cent pyrite; and 10 per cent quartz. The remainder is usually schist gangue. The sulfide minerals are finely dis-seminated; chalcopvrite and marmatite begin to be liberated on grinding at about 100 mesh, but complete liberation from gangue (pyrite in this case is considered a gangue mineral) is

Jan 1, 1935

Mr. Address Member is hereby proposed by the undersigned, as a Associate Junior Member of the American Institute of Mining Engineers. Signatures of three Members or Associates. Place of birth Year of birth Education, when, where and how acquired, with degrees, if any. A technical education is not requisite for membership. Dates Please give record of experience on following page with dates; for example, in the form used by "Who's Who In America" and similar publications.

Jan 11, 1917

By R. F. Pilgrim

A digital computer program to mathematically simulate the effect of limited changes in feed rate in the range of 80 to 95 tph on a plant-scale wet grinding circuit has been developed and tested. The circuit studied included an 8-ft-diam X 12-ft rod mill operating in open circuit and feeding two parallel 12-ft-diam x 10-ft pebble mills, each one operating in closed circuit with an 8 X 32-ft rake classifier. The simulation is an empirical one based on two sets of data collected manually from the operating circuit under what was said to be steady-state feed rates of 80 and 95 tph with all other operating variables also at steady state. The procedure is a combination of several published approaches to the modeling of grinding mills and classifiers and it is applicable to a wide range of circuits. The program permits the computing of the size distributions of all feeds and discharges of all grinding units and classifiers in the circuit for a specified feed rate. The data used in this report for demonstrating the program are unsatisfactory since the circuit was not operating under steady-state conditions when it was sampled. Consequently the circuit model parameters could not be accurately estimated. The predictive power would be greatly improved if new data were obtained under true steady-state conditions.

Jan 1, 1973

By John A. Breslin

This publication provides an historical overview of research undertaken by the U.S. federal government over the last 100 years to improve the health and safety of our nation?s miners. Federal research efforts began with the establishment of the U.S. Bureau of Mines (USBM, or the Bureau) in 1910. They have continued over the past century, even after the Bureau?s closure in 1996. It is hoped that this publication will give the reader an appreciation for the work of mining health and safety researchers over the past century, and of the miners served by this research. Although not a comprehensive history, this report highlights the key organizational changes made within the Bureau and the federal government that affected mining safety and health research. Some mention is also made of Bureau research not directly related to mining health and safety. Note that the work classified as safety and health research has varied over the last century. For example, before 1970 the Bureau separated mining research and safety and health research. At that time, mining research included ground control and methane drainage because they had direct implications for mine safety. Explosives research was also reported separately from health and safety, even though permissible explosives research was obviously related to safety. Therefore, where budget figures from the Bureau are mentioned in this report, it is often not possible to separate safety and health research from other types of research. This history is generally chronological, with a few exceptions. Because of their prominence and direct links to Bureau research, most of the Public Health Service mining studies completed before 1970, when NIOSH was established, will be discussed in a single section, even though the work spanned many decades. Likewise, for convenience, the brief histories of the Bureau?s mining research centers are located in one section.

Feb 1, 2010

By Francis S. Kendorski

INTRODUCTION Nuclear waste has been generated since the time of the Curie's and continues to be generated worldwide at an ever-increasing rate as the world will (and should) rely more and more upon fission (and hopefully fusion) for power. Also, the needs for strategic weapons will also generate so-called defense wastes. The largest class of high level nuclear waste (HLW) is spent fuel, the tail end of the nuclear reactor fuel cycle. At present, spent fuel is stored at the reactors producing it or at a few accepting places for away-from-reactor storage. All such storage facilities, as presently constructed, will begin to run out of usable storage space during the next decade or so. Congress enacted and President Reagan signed into law in early 1983 the National Nuclear Waste Policy Act of 1982. This law provides for the permanent isolation of nuclear waste in deep geologic repositories. The Act sets 1998 as the date at which the first repository should be operational. This date is extremely ambitious, and the Department of Energy (DOE), which is charged with the responsibility of constructing and operating repositories, admits that this date will slip by at least a few years. The Act also provides for licensing of repositories by the Nuclear Regulatory Commission (NRC) in a fashion very similar to nuclear power generating reactors. This requirement imposes a very special rigor on the analyses, investigations, designs, construction, and operation of repositories so as to assure the protection of the public and the environment from radioactive contamination. In addition the states and affected Indian Tribes must be consulted, especially concerning siting, and, needless to say, no one wants a HLW repository in their back yard.

Jan 1, 1984

By A. H. Geisler

The correlation of property changes during precipitation with structure has progressed, sometimes rapidly but other times more slowly, since the fundamental discovery of Merica, waltenberg and Scott.1 The predominent factor that hampered the progress has been limitations imposed by the various detection methods. Refiments in x ray diffraction tech-niques and in metallographic methods, which have been extended by the electron microscope, have contributed new information within the last few years. These permit an extension of the theory as proposed by Mehl and Jetter in 1940'2 Now that a sufficient number of alloys has been investigated to establish a general mechanism of the precipitation process, a correlation of the facts into a generally applicable theory of age-hardening is both warranted and desirable. The purpose of the paper is to provide an orderly correlation of the phenomenological facts of precipitation hardening. Speculation 011 mechanism of hardening will be confined to that consistent with existing theories of hardening, Age-hardening accompanies the formation of a new structure, the precipitate, as provided by a11 alloy system ill which solid solubility decreases with decreasing temperature. Upon this premise alone all such systems would be expected to include age-hardenable alloys. Alas, this is not always the case. Few attempts have been made to explain the variable degree of age-hardening among different alloys or to explain the influence of small alloying additions upon the hardening. Dispersion hardening as originally postulated3 is not adequate.* Coherency hardening—the term that will be used to distinguish the properties of a two-phase mixture in the unique and unstable transition state at which the phases are strained into precise atomic registry (continuity or coherency) in planes

Jan 1, 1949

By J. Lyndon Rosenblad

The strength of a jointed-rock mass is not well-understood. It is believed, however, that the behavior of a rock mass is governed by both the intact rock properties and the properties of the discontinuities. Rock research in the past has been concentrated on the determination of intact rock properties. Several studies are presently underway which should provide more insight into the properties of the discontinuities. Few research programs, however, have been undertaken with the intent of studying the composite rock mass behavior where either the intact rock strength or the properties of the discontinuities may control failure. There are three approaches available for studying the behavior of a rock mass, namely, field studies, mathematical models (finite element), and geomechanical models. A geomechanical model has been developed in this study where the strength and failure modes of a model rock mass are studied as a function of intact block geometry, joint orientation, joint properties, and confining pressure. The objective of this study is to gain some insight into the parameters that govern the behavior of a rock mass, which parameters are most important, and when these parameters control. This chapter describes only one phase of the study, the development of equipment for use with the rock-blocks model. The models being tested are approximately 22 x 22 x 6-in. The size varies slightly depending upon the joint orientation used. The equipment developed includes model material molds, reaction frames, loading apparatus, measuring and recording instrumentation, and other accessory equipment pertinent to the operation of a successful study. The usual problems in equipment development, such as uniformity of load application, loading capabilities, and reaction capacities are all

Jan 1, 1970

Mr. Address Member ,is hereby proposed by the undersigned; as a Associate Junior Member of the American Institute of Mining Engineers. Signatures of three Members or Associates. Place of birth Year of birth Education, when, where and how acquired, with degrees, if any. A technical education is not requisite for membership. Dates Please give record of experience on following page with dates; for example, in the form used by "Who's Who In America" and similar publications.

Jan 5, 1917