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Reduce the respirable dust exposure of the roof-bolter operator when downwind of the continuous miner, particularly in mines where respirable dust standards are more stringent because of silica in the respirable dust. Dust Sources If roof-bolter dust levels are excessive, the bolter dust collector should first be checked to ensure that it is operating properly. (Technology News No. 219 provides information on how to spot and repair bolter dust collector problems). If the roof-bolter dust collector is operating properly and dust levels are still excessive, then the source is most likely a continuous mining machine operating upwind. In many sections, the roof-bolter operator must work on the return side of the continuous miner during part of the production cycle. In three-entry longwall developments with single split ventilation, this may happen as much as one-third of the time. Factors which pro-mote high quartz dust exposure are:

Jan 1, 1985

By Joe Pease

"The demand for minerals and metals is increasing. Head grades of ore bodies are dropping. Remaining ores are becoming finer grained, more complex, and more logistically challenging. Mineral processing – in particular comminution – already consumes a huge amount of energy. But in 20 years’ time, it will require about six times as much energy as today to meet the world’s mineral demand.Unless we do something different.As minerals professionals, it is our job to find that “something different”. The world is relying on us. Of course, we must look for new breakthrough technologies and techniques. We must find them, and we will find them – most likely in surprising areas.But what if we also already know how to make 30-50% improvements to efficiency? Just by using existing technologies, by applying modern analytical techniques, by custom designing our plants, by applying manufacturing principles, by breaking down our management silos between disciplines.The thing is, industry professionals already know this. Yet – in spite of a lot of intelligent people trying very hard – we just can’t seem to make it happen.This discussion considers why, despite our best efforts, we don’t get the best out of what we already have. Why we are wasting energy and money. Once we understand why, we can set about unlocking that value and improving industry productivity and energy efficiency. We will discuss the role that professionals and volunteer professional organisations like CMP and CEEC can play in catalysing the changes."

Jan 1, 2015

By A. M. Gaudin

Jan 1, 1962

By P. J. Rowsell, M. D. Waller

Paper presented at a meeting on: Artificial intelligence in the minerals sector, held in Nottingham, UK, 20 April 1993. The applications of artificial intelligence systems in the upstream petroleum industry are reviewed. Particular emphasis is placed on current and potential applications in drilling engineering. Several recent advances in drilling technology have led to a large increase in the quality and volume of data available. This combined with the escalating cost, particularly of off-shore operations, is testing the traditional reliance on the skill and judgement of rig operators. AI systems offer enormous scope in enhancing and aiding the performance of these operations

Apr 1, 1994

By William J. Campbell

This report describes a Bureau of Mines study undertaken to determine the applications and limitations of solution techniques as a general method of fluorescent X-ray spectrographic analysis. Systematic errors due to variations in particle size, surface preparation, and sample inhomogeneity are eliminated by the use of solutions. The range of applicability of fluorescent X-ray spectrography is increased in two ways: (1) Samples in the form of wire, filings, turnings, etc., can be analyzed as solutions, and (2) samples submitted as solutions can be analyzed as received 0 The lower limit of detectability varies from 0.14 gram per liter for sulfur, atomic number 16, to 0.0015 gram per liter for strontium, atomic number 38. Most elements have limits of detectability between 0.02 and 0.002 gram per liter.

Jan 1, 1959

Jan 1, 1968

By V. B. Dale

This report is one of a series covering the mineral resources of the Nation. It briefly describes most of the known tungsten deposits in Gila, Yavapai, and Mohave Counties, Ariz. Many of the descriptions are taken from the reports of previous examinations by Bureau of Mines engineers, and from Defense Minerals Exploration Administration files. Where a previous examination had been made, and an inquiry disclosed that little or no work had been done since that time, pertinent information from the report was used in this paper with acknowledgment of the source. However, the majority of the descriptions is from field examinations by the author. In the past 3 years (July 1956-May 1959) only necessary annual assessment work was conducted on nearly all the properties described in this paper. There was no active mining on any of the properties examined.

Jan 1, 1961

Currently in Canada there are 15 major mining companies with a minimum of $1 billion in market capitalization or net private value. This group forms the core of an important sector for Canada. The mining sector had gross revenues of about $35 billion in 1988. This compares to a Canadian GDP of $410 billion in 1988. There are at least three different sub-groups within the mining group, each facing the future with very different prospects for the coming years.

Jan 1, 1989

By J. R. Thoenen

Occurrences of titanium, zircon, and other heavy minerals are widespread in Florida. Deposits concentrated as "heavy sands" by wave and wind action have been mined an or near Atlantic coastal beaches since 1916. An important inland concentration at Trail Ridge; .believed, to have formed along an ancient share line, was disclosed by preliminary investigations (1947) by the Bureau of Mines. This report describes investigations to determine the extent and grade of "heavy-sand" concentrations in other inland stabilized dune areas in the central and northeastern parts of the peninsular region of the State (fig. 1). Portions of the central highlands south of Trail Ridge and terraces and dunes in the coastal lowlands region, east and northeast of the ridge were investigated. Holes were drilled in 10 areas (see table 1 and fig. 2) along State and County roads and on private property. They were spaced 250 to 2,000 feet. apart to obtain a cross-sectional picture of "heavy-sand" content in the dune areas. These sections were generally placed in east-west directions normal to the general trend Of the peninsula to intercept one or more of the ancient shore lines in the various areas (figs. 3 to 13, incl.). A total of 433 drive piped and 333 jet holes were drilled, and 7,293 bulk and core samples were taken. Intermediate holes were placed at closer intervals when field analysis indicated 1 percent or more of heavy minerals present. All of the holes drilled and the analysis of samples that contain 1 percent or more of heavy minerals are listed in table 2. Profiles (figs. 14 to 20, inclusive) show the more favorable concentrations, which are irregular in outline and erratic in mineral content. The highest concentrations averaged 1.0 to more than 2.0 percent heavy-mineral content, but a few individual hole samples exceeded 3.0 percent in grade.

Jan 1, 1949

By Gerald Verbeek, Erick Baziw

Downhole Seismic Testing (DST) is a very popular applied seismology site characterizing tool within geotechnical engineering. A challenging aspect of DST is to characterize the acquired seismic data sets to determine the analysis method that will result in the most accurate interval velocity values. BCE has invested considerable resources into developing Seismic Trace Characterization (STC), which uses various independent parameters of the acquired data at a particular depth. Initial work in this area resulted in the selection of the linearity estimate from the polarization analysis, the cross correlation coefficient of the full waveforms at the particular depth and the preceding depth and a uniquely developed parameter referred to as the signal shape parameter for this characterization. Subsequent analysis in STC identified two other parameters: the Signal-Noise-Ratio (SNR) and the Peak Symmetry Differential (PSD). The paper briefly describes these parameters and then outlines how they can guide the data analysis to derive more accurate results, especially near surface, which is especially important to assess the liquefaction potential in areas prone to earthquakes, such as California. The process will be illustrated with actual data from another area prone to earthquakes, namely New Zealand. 1. INTRODUCTION The near surface characterization of low strain in-situ shear wave velocities (VS) has proven critical for liquefaction assessment. Liquefaction is a phenomenon in which dynamic loading of saturated soil results in the material properties to change suddenly from a solid state to a liquefied state. VS is an important parameter for evaluating liquefaction potential due to fact that it is influenced by many of the variables that influence liquefaction (e.g., void ratio, soil density, confining stress, stress history, and geologic age (Andrus et al., 1997)). Aki and Richards (2002) also outline that the amplitude of ground motion should depend on the density and shear wave velocity of near surface soils and rocks according to the theory of wave propagation. Since the change in density with the increase in depth is relative minor compared to that of the shear wave velocity, the latter is a very useful parameter to represent site conditions (Stewart et al., 1997). Bray (2014) and his colleagues carried out an extensive geotechnical analysis of the catastrophic liquefaction that occurred in Christchurch, New Zealand in 2010 and 2011 and found that near surface rather than deep liquefaction resulted in extensive foundation damage.

Jan 1, 2018

By P. S. Capper

"Generally speaking, the most intensive efforts at dust control in the mining industry have, in the past, been concerned with underground operations and where uranium ore or high silica material is processed. In the past several years, Stoop Rock has made Intensive efforts to reduce dust levels in it's Iron ore pelletizing complex. There have been no great engineering break-throughs with regard to dust control in such plants, and certainly no new engineering techniques have had to be applied at Steep Rock. This paper deals with how significant improvements in dust levels have been achieved through minor modification to dust collectors and ventilation units, improvements in operating practices, and education of supervisors and hourly personnel.PROCESS DESCRIPTIONSteep Rock Iron Mines is located 120 miles west of Thunder Bay near Atikokan. (fig. 1) Run-of-mine ore is pelletized along with some -1"" concentrate that has been processed in the concentrator (a summer operation only), which utilizes gravity separation to upgrade a mechanical mixture of ore and waste."

Jan 1, 1976

[Andrew Allen Glenwood Springs, Colorado C. S. Allen 211 Utah Oil Building, 10 West Broadway, Salt Lake City 1, Utah Earl W. Allen 257 Rio Grande Street, Salt Lake City, Utah Louis B. Allen 411 Walker Bank Building, Salt Lake City, Utah Thomas Allen State Coal Mine Inspector of Colorado, Argonaut Hotel, Denver, Colorado J. B. Ambler P. O. Box 591, Denver, Colorado Nephi W. Anderson Dragerton, Utah F. F. Argust 270 High Street, Pueblo, Colorado E. K. Arnston : 4601 West 26th Avenue, Denver 12, Colorado Abel Audin Somerset, Colorado Clement Audin, Jr Paonia, Colorado Ralph Andin P. 0. Box 285, Somerset, Colorado ]

Jan 1, 1955

By J. Philip Neal

Feldspar is no example of special mineralization in isolated spots: it can usually be found within a mile or so of almost anywhere. Along with silica sand, it is a major part of our world's total mineral composition. This fact imparts to it an economic status different from a sulfide ore, or potash, or phosphate. While every feldspathic "stringer" does not possess economic potential, the generous distribution does yield a high statistical frequency of good feldspar ore bodies: the adjective "good" being subject to some flexibility of interpretation. The strong chemical bonds of this alkali aluminum silicate give it certain use advantages, but under present technology its individual elements cannot practically be separated to create aluminum, potassium, sodium, silicon - or their oxides. Its present uses rely upon chemical inertness - as in fillers; and on its physical melting characteristics and their effect in glass, enamel, or ceramics.

Jan 1, 1973

By J. H. Schulman, M. H. Buckenham

R. W. Christy (Manager of Sales, Sanitary Engineering Equipment, Link-Belt Co.) and C.D. Rubert (Barrett, Haentjens & Co.) — Messrs. King and Schepman have presented an excellent paper which outlines the general practice in the design of thickener mechanisms. Lifting devices, controls, special applications and underflow pumping arrangements have been reviewed in detail. Pumping arrangements were illustrated which eliminate the need for an expensive tunnel beneath the thickener floor. Most of those illustrated have the common feature of a relatively long underflow suction line extending from the hopper floor to the pump located on the bridge at the periphery of the tank. The authors limit these arrangements to comparatively dilute or thin slurrys. It is implied that dense and coarse concentrates, which are difficult to pump, cannot be handled unless a tunnel is constructed. Fig. 1 shows an underflow pump arrangement which negates the need for a tunnel but which permits the operator to convey a heavy dense slurry. The pump is mounted directly on the fixed hoist platform and the impeller is located at the base of the steel center column. Priming water is not needed. The column

Jan 1, 1963

By Thomas Schwind, Pamela S. Moran

For short tunnels, a reinforced cast-in-place lining is not economical and shotcreteis a logical substitution. In the past, reinforced shotcrete linings have been constructed with lattice girders and welded wire fabric. For the Russia Wharf Tunnel in Boston, MA, the Contractor, with the help of the Dr. G. Sauer Corporation offered the MBTA a VECP to substitute the reinforced cast-in-place concrete lining with a steel fiber reinforced shotcrete lining. The challenge was to adequately model the ductility of the steel fiber reinforced shotcrete and to test the shotcrete prior to and during construction to assure quality control. To our knowledge, this type of numerical simulation has not been used on any other tunnels in the US.

Jan 1, 2005

By Dermot Winters

The Surface Mining Control and Reclamation Act (SMCRA, or the Act) was enacted on August 3, 1977. The Act was written, in part, to put an end to uneven environmental standards and to establish minimum national standards. Certainly, one of the motivating factors for passage of the Act was the success of the Federal Coal Mining Health and Safety Act of 1969 in reducing deaths and injuries in the coal industry nationwide. Section 516 (b) (1) of the Act requires *that subsidence be prevented from causing material damage to the extent technologically and economically feasible except in those instances where the mining technology requires planned subsidence in a predictable and controlled manner. Section 516 (c) of the Act authorizes the regulatory authority to suspend underground mining if there is imminent danger to inhabitants of urbanized areas, cities, towns, and communities. On December 13, 1977, the interim program, which applies a portion of the performance standards of the Act, was promulgated. Then on September 18, 1978, the proposed permanent program was published for public comment. Finally, on March 13, 1979, the final permanent program was promulgated and the States were given a period of time to submit their programs for approval.

Jan 1, 1986

By A. B. Campbell

The mines in the eastern part of the now active region of the Tri-State zinc district of Missouri, Kansas, and Oklahoma have unusually acid water, which during periods of moderate or no rainfall is used in the mills to replace losses from evaporation, seepage-, and tailings disposal. Its use has caused difficulties by corrosion of equipment and by interference with flotation. The growing importance of flotation, which requires good water, and the increasing troubles caused by the corrosion of the milling equipment have prompted the Mississippi Valley Experiment Station of the United States Bureau of Mines, in cooperation With the Missouri School of Mines and Metallurgy, Rolla, Mo., to investigate the action of the waters on flotation and to undertake to develop means of obviating their harmful effects. The work was under the immediate direction of W. T. Schrenk, consulting chemist, United States Bureau of Mines, and professor of chemistry Missouri School of Mines and Metallurgy, and. Will H. Coghill., supervising engineer of the ore dressing section of the United States Bureau of Mines.

Jan 1, 1932

By H. J. Sutherland

This paper reviews the results of the subsidence research prop ram at Sandia National Laboratories. The manuscript highlights the following: the application of empirical methods (profile functions) to the subsidence above longwall panels in the U.S.; the use of the "rubble model" to describe the behavior of broken strata as it distends when it falls to the Mine floor (or top of the rubble pile) and then is subsequently compacted as it is loaded by overlying elements of strata; and, the application of physical modeling techniques (centrifuge simulations) and numerical techniques to study the failure mechanisms in highly structured stratigraphy. The capabilities of the latter two are illustrated ')y comparing their predictions to the results of a field case that has complicated stratigraphy.

Jan 1, 1982

By P. J. Watson

The objective of this study was to prioritize the potential risks nuisance and biologically active dusts and fumes present in metal and nonmetal mines. This was accomplished by ranking numerical values derived from a matrix formula calculation that took into account dose, mine population, and sampling size. Data used in these calculations were obtained from the Mine Inspection Data Analysis System (MIDAS). The dusts determined to have the highest risk potential were quartz respirable particulates, mine dust, cristobalite respirable particulates, welding fume components, and nuisance respirable dust. Other dusts and fumes that were not ranked in this study, due to small sampling population, but which show a potential risk, include asbestos, talc, hydrogen cyanide, organic compound dusts, arsenic, metal dusts, and metal and nonmetal fumes.

Jan 1, 1987

Quantitative seismology is an important tool for investigating mineinduced seismicity and the quantification of the seismic rock mass response. The spatio-temporal interpretation of seismic data within an ever-changing three-dimensional mining environment provides some challenges to the interpretation of the rock mass response. A grid-based approach for the interpretation of spatial variation of the rock mass response provides some benefits compared with approaches based on spatial filters. This paper discusses a grid-based interpretation of seismic data. The basic methods employed in the evaluation of the parameter values through space are discussed and examples of applications to different mine sites given.

Jan 1, 2014