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By K. Muralidharan, P. R. Rao, M. Momayez, K. A. Runge

The evolution of trapped geothermal heat in hot underground mine along with emission of toxic gases and dust during mine activity makes the mine environment unfavorable is hazardous to worker’s health. This imposes significant demand on cooling and ventilation systems. As a result, substantial costs are incurred while implementing environmental regulation processes to dissipate the heat and provide comfortable working conditions. Thus, as an alternative, the development of cost effective materials to act as efficient thermal insulators is on the rise. Thermal conductivity is an important property that is a direct measure of a material’s ability to facilitate/deter heat flow. In addition to their superior chemical resistance, adequate mechanical strength, abrasion and fire retardant as well as environmental benefits in comparison to existing building materials such as ordinary Portland cement, aluminosilicate based geopolymers are now gaining widespread interest as promising thermally insulating and sustainable materials. This paper begins with an overview of geopolymers, transitioning into a discussion of recent developments in the field of geopolymer development as a thermally insulating material broadly classified into: filled geopolymers and porous geopolymers resulting in structures with enhanced ability to impede heat flow.

May 9, 2020

By W. P. Sykes

ThiS investigation was undertaken primarily to establish the relations existing between temperature and mechanical properties in molybdenum, nickel, and an aluminum-copper alloy. Mlolybdenutn (m.p. 2500" C.) was chosen because it is partly similar to tungsten and partly similar to the common ductile metals. Also it is known to furnish, by proper treatment, a desirable material to use in studying relation of grain size and physical properties. The molybdenum used was of the quality that is drawn into wire 0.003 in. in diameter for use as filament supports in incandescent lamps; Chemical analysis shows less than 0.1 per cent. of impurities. Nickel belongs to the same class as iron. Its melting point is 1450" C. and an allotropic change at about 370" C. results in a loss of magnetism above that temperature. This feature made nickel doubly valuable for the purposes of these tests. The nickel used was obtained from the Driver-Harris Co. as 0.090 in. (2.3-mm.) wire, annealed; analysis showed 99.8 per cent. nickel and 0.150 per ccnt. iron. Aluminum is one of the low melting-point metals. Some tensile tests at clevated temperatures have been reported by Bengough but the possibility of learning more with the low temperature and sensitive apparatus available rccommendcd this metal. The samples marked A1 arc an aluminum-copper alloy that contains 3 per cent. copper, 0.42 per cent. iron, and 0.21 per cent. silicon. The presence of the copper somewhat coniplicates the analysis of the results; but the action of copper in aluminum has been studied so that its influence might have been foretold, in part at least. The material and analyses were furnished by the Aluminum Castings Co. The nickel wire, which was deformed at 400" C., was drawn under a bath of molten lead and through a die, which also was immersed in the bath. A thermocouple was suspended in the molten metal to indicate the temperature. Hot oil was uscd as the heating bath for drawing the

Jan 1, 1921

By T Berryman, C Adams, L Griesel, C Buxton

The Kalgoorlie Consolidated Gold Mines (KCGM) schedule model is used for short- to medium-term planning and scheduling at the Fimiston Open Pit Mine (the Superpit). The model bridges the gap between grade control models, which are generated one to seven days prior to mining, and the annual Resource and Reserve model update that is used for budget and life-of-mine plans. The schedule model uses close-spaced grade control data (up to 20 000 m drilled each month) as well as resource definition drilling to estimate production volumes three to six months ahead of current mining. From this, a rolling 12 week mining and processing schedule is generated on a monthly basis. As the KCGM operation is mill and sulfur constrained, the schedule model needs to be an accurate predictor of ounces as well as tonnes, gold and sulfur grades. The process must also be time efficient in order to meet monthly planning and reporting deadlines. Due to the large amount of new data generated each month, model updates using conventional interpretation and estimation techniques have proven to be impractical and too time consuming. This paper will examine the evolution of the Superpit schedule model process over time, recent improvements and the effect of different model outcomes on short- and medium-term mine planning.CITATION:Griesel, L, Buxton, C, Adams, C and Berryman, T, 2014. The superpit schedule model – A time-efficient data-driven estimation for short- and medium-term planning, in Proceedings Ninth International Mining Geology Conference 2014 , pp 397–410 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By F. R. Hutto Jr., F. L. Kady Jr., L. E. Weymouth

The behavior of particulate non-metallic materials in moving contact with smooth surfaces is of interest and concern to manufacturers and users of abrasives, of fillers, and of pigments alike. The theoretical aspects of the subject have been treated to considerable extent in the literature, and correlatic,ns are available that attempt to relate various methods of hardness determination." 2 The particle size and friability are characteristics of the abrasive that are not related to the smooth surface. The hardness, on the other hand, may be visualized as relative to that of the smooth surface. In a study of abrasive action, the role that hardness, per se, plays is a complicated one. For it is necessary to compare the "hardness" of the abrasive, usually a non-metallic, with that of the smooth surface, generally a metal. Hardness of non-metallics is defined as resistance to scratch and is almost universally described with respect to the Mohs scale.3 Minerals have been rated by Mohs numerically from the softest (talc = 1) to the hardest (diamond = 10). By definition, a mineral has a designated hardness when it is scratched by the standard that is numerically just above it on the scale; and conversely, when it scratches the standard that is just below it. Hardness of metals. however.. implies resistance to indentation, a property that has been measured by a number of methods. In fact, the indentation hardnesses of the standard minerals on the hlohs scale have been determined by the Rockwell tester. Reproduced below are two versions of this correlation. 'A conversion chart, prepared by Wilson Mechanical Instruments Division of American Chain and Cable Co., merely gives the conversion from Rockwell to Knoop hardness. The relation between Knoop indentation hardness and Mohs scale has been reported by G. S. Smith — A New Scale of Hardness, The Engineer, Aug. 26. 1949. G. F. Kinney in Engineerin Properties and Aplications of Plastics reports the Rockwell hardness of the minerals directly in the Mohs scale. The question immediately arises as to whether this relation is valid when applied in reverse; namely,

Jan 1, 1961

By Michael V. Markel

This report summarizes work performed under USBM Contract No. J0100047 revealing the performance characteristics of a composite-type resilient screen deck. The ability of the composite to perform or compete with steel in noise attenuation and longevity was of interest. Tests were conducted at the River King Preparation Plant of Peabody Coal Company. This facility was chosen because it provided parallel process flow and met standard coal cleaning requirements. Comparisons could be made between the adjacent resilient and steel screen decks under similar operating conditions. Noise reductions of 1-6 dBA were realized in the near field. Although the test period did not determine resilient screen life, indications are favorable for their longevity.

Jan 1, 1981

By Hon-Yim Ko

The properties of coal from the Pittsburgh seam, procured from the Bruceton and Federal No. 2 Mines were found to be similar. Strength and stiffness properties of Beehive Mine coal were determined and the material found to be isotropic. Mechanical, index and geologic properties of roof and floor coal measure rocks from Beehive mines were measured and correlated. Analytic formulations are given for coal creep under uniaxial loading, while triaxial creep is being investigated. Results of testing of coal model structures are compared with predictions from using several material models.

Jan 1, 1976

By Warren D. Longwill

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Jan 1, 1981

Jan 1, 1902

By Uwe Hess

For the Danish landworks for the coming fixed link between Denmark and Sweden across the Øresund the focus has been on the environmental aspects of the construction and operation of the facilities. This paper describes how the environmental objectives pertaining to the project have influenced the design and construction of one of the major elements of the Danish landworks, i.e. the tunnel in Sydhavnsgade and under Sydhavn Station. The chosen construction methods for the construction pit bracing and the groundwater lowering will be described along with the observed effects on the environment as shown by simulated or measured values for noise impact, settlements, pumped groundwater and extension of the drawdown cone.

Jan 1, 1996

By W. H. MacLean, P. J. MacGeehan, A. J. Bonenfant

"The Norita deposit is an Archean volcanogenic-exhalative Fe-Zn- Cu sulphide accumulation of the distal type, consisting of six overlapping stratiform massive sulphide lenses, interbedded with exhalative cherts and thin pillow basalt flows, which formed down-topographic-slope from a mineralized hydrothermal discharge zone in the Norita rhyolite. The sulphide lenses are of two main types: channel-fill deposits such as the Main Zone and Main Zone West, composed of intricately layered pyrite-sphalerite-chert, which formed by the dynamic down-slope transport and re-deposition of sulphide exhaled from the vent zone; and stratiform lenses such as the Cu-rich A-Zone and A-Zone West, which formed even farther down-slope, in basinal depressions flanking the dome. Although rotated into a vertical position by folding, the sulphide lenses are otherwise essentially undeformed and contain a wide range of preserved primary sedimentary structures.Of prime importance in exploration has been the recognition that the formation of the distal sulphide lenses was controlled by submarine paleotopography, and that it is possible to approximate the sea-floor paleotopography using variations in the thickness and strike extent of the interbedded volcanic rocks. This has proved to be a major and successful exploration tool in the search for further sulphide mineralization in the mine, and offers prospects for use elsewhere in the district."

Jan 1, 1981

By Michael Hood

Subsidence profiles above two adjacent panels in Illinois are compared with pro- files predicting subsidence behavior obtained using the (i) National Coal Board (NCB, 1975) method, (ii) the profile function method and (iii) the influence function method. The NCB method predicts the maximum subsidence values at the center of the troughs accurately, but, the overall shapes of these predicted profiles do not match the profiles from the measured data well. Consistent values for the angles of draw were measured but these angles were different in the transverse (average value 43 degrees) and in the longitudinal (average value 17.5 degrees) directions. Time dependent subsidence effects are shown to be small but measurable. These displacements continue at a linear rate for at least a 12 month period. A comparison of measured horizontal distances, interpreted as horizontal strain, and the NCB predictions for strain shows that the peak measured strains are greater by a factor f about four than the predicted strains. The relationship between surface curvature and strain is investigated. Problems associated with calculation of surface curvatures from vertical displacement data are highlighted and a recommendation is made for future studies to consider direct measurement of this parameter. Surface curvatures above a moving face are found to be about three times less than the curvatures at the stationary end of the panel. On the other hand, a hyperbolic tangent profile function is shown to serve as an accurate predictive tool for subsidence behavior in two adjacent longwall panels at Old Ben Number 24 mine in Illinois. This function predicts not only the vertical displacements but also the surface curvatures above both panels. Influence functions are shown to be more problematic, although potentially more flexible, in their application than the profile functions.

Jan 1, 1982

By Staff

Minerals contribute to U.S. gross domestic product (GDP) at several levels - from mining and processing to the manufacturing of finished products. In 2010, the estimated real GDP of the United States increased by 2.8 percent compared with 2009 and the estimated nominal GDP was about $14.6 trillion (Table 1).Trends in various sectors of the domestic economy are often rejected in mineral production and consumption rates. For instance, continued declines in the construction industry during 2010 were rejected in further reductions in the production and consumption of cement, construction sand and gravel, crushed stone and gypsum, which are used almost exclusively in construction. Performances in other sectors were mixed and less easily characterized. Recovery from the economic decline of 2008-2009 became apparent in 2010, as prices for many mineral commodities continued to rise with increasing demand for those materials or the products in which they are found.

Jan 1, 2011

By Robert S. Schechter

A minitest, consisting of an injection/production well and at least two observation wells designed to detect the arrival of injected fluid leached minerals, and nonideal flow, is considered in this report. The test goals are to determine the susceptibility of the host formation to uranium leaching, kinetic parameters to scale the process, and to facilitate site restoration. This report considers permeability and mineral heterogeneities and other oxidant-competing minerals. To circumvent these nonidealities, which obscure the results, methods of interpretation have been proposed and tested by a computer simulator. In complex cases, clear-cut methods of interpretation were not found; but in every case the design of a test most susceptible to interpretation has been considered. The minitest is operationally simple and can be completed in a short time. With the correct design and interpretation it can return information to evaluate economics, ensure satisfactory leachate performance, scale to larger operations, and to identify restoration problems.

Jan 1, 1983

By Max J. Spendlove

The Federal Bureau of Mines has been a leader in resource recovery research since it was founded in 1910. Until the early 19601s, most of the projects were concerned primarily with the task of extending and improving conventional technology oriented to secondary metals and minerals upgrading and processing for marketable products of highest value. By the mid-1960's with the passage of the Solid Waste Disposal Act of 1965, all resource recovery research programs were increased in scope and intensity as an effort to solve the growing number of environmental problems and the rapid depletion of domestic energy and mineral resources. Many new materials were investigated including urban refuse, manufacturing, industrial wastes, and stockyard wastes. The objective was to promote maximum recycling as the most practical answer to problems of waste disposal, pollution control, and the short supply of minerals and energy. The new research projects ranged from the conversion of animal manure and other organics to oil, to the recovery of precious and common metals from demolished aircraft and electronic scrap. This profile includes brief descriptions of many selected research projects that typify, the total spectrum of Bureau of Mines research in the important field of resource recovery.

Jan 1, 1977

By Fulton B. Flick

The micrography and macrography of aluminum and its alloys present certain difficulties. Many of the difficulties attendant on the micrography have been removed by methods developed during the past few years, notably those of E. H. Dix, Jr.1 The development of grain size in aluminum and its alloys may be equally troublesome, yet comparatively little detailed attention appears to have been given to it. Satisfactory reagents are available for the development of such structurcs in ferrous and most non-ferrous metals, but those applied to aluminum and its alloys, i. e., alcoholic or aqueous solutions of sodium hydroxide or hydrofluoric acid are not entirely satisfactory. Hanson and Arch-butt,2 in speaking of these two reagents, state that "These two reagents give fairly satisfactory results, but they sometimes produce badly tarnished surfaces from which the surface deposit is difficult to remove." It has been our experience that neither of these reagents is to be entirely relied on for developing structures suitable for study or photography. This means that when the etch fails to produce satisfactory results the specimen must be repolished, through the 000-paper at least, and then etched with another reagent. This procedure entails a considerable loss of time, and the final results may not be all that might be desired. However, the reagent to be described, although not a panacea for all etching troubles, has improved results so markedly that it is felt that it & worth offering as a grain-size etch generally applicable to aluminum and aluminum alloys. Czochralski3 in 1915 mentioned the application of a solution of 10 to 20 c. c. concentrated hydrofluoric acid in 100 c. c. absolute alcohol, etching in this reagent being followed by dipping in concentrated hydrochloric acid soliltion.

Jan 1, 1925

By Stella Sigler

This publication contains analyses and related source data for 153 natural gas samples from 16 States. Of the total samples, 149 were collected during calendar year 1993. The remainder were collected earlier, but releases granting permission to publish were not received until 1993. None of the analyses have been previously published in annual reports. All samples were obtained and analyzed as part of U.S. Department of the Interior, U.S. Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. This survey has been conducted since 1917. The analyses published herein were made by mass spectrometer and chromatograph.

Jan 1, 1994

Jan 1, 2004

Cyril w. Knight, Toronto, Ont., Canada (communication to the Secretary*).—Mr. Hore's paper presents an interesting summary of our knowledge of this important mineral field ; and is therefore acceptable as giving information which our Transactions did not already contain, although it presents little or nothing not made known by other writers before 1906, when Mr. Hore began work in the field as a student assistant. Contributions of this kind, however, should be made completely valuable by such references to previous work as will enable the reader to follow to their original sources the theories or conelusions stated by the author. It is quite natural, and even excusable, that a new observer should find novelty in his on observations—especially if he is not acquainted with the work of predecessors in the same field. Moreover, the independent repetition of an observation or conclusion has a distinct value as a confirmation, though it may have none as a discovery. But the publication of it, without reference to its predecessors, may place the author in an unfavorable light as either ignorant of the history of his subject, or willing to claim credit to which he is not entitled. Of the latter fault, I do not accuse Mr. Hore ; but I cannot wholly acquit him of the former. Without disparaging his intelligent work, I must point out that his paper, as it stands, might easily give the impression that he claims originality for many statements which are by no means new, and that he emphasizes unduly his own publications. Thus, his remark (p. 481) "I have described the silver-fields in a general way in my paper " (not yet published), should have been accompanied with reference to some of the numerous papers, already published, which describe these fields. Again, on p. 486, he refers to four papers of his own on the Porcupine gold-area, but neither in the text nor in the appended

Jan 1, 1912

By C. H. Schack

Although viscosity is known to be important in processing and handling finely ground urea, its effect has never been fully quantified. This report describes the methods used and the results obtained in the initial phases of a broad investigation of the influence of viscosity of water suspensions of minerals in flotation, thickening, filtering, and other mineral-dressing unit operations. Several types of vis-cosimeters were tested before reliable and reproducible results could be obtained on mineral suspensions. After the viscosimeter used in the research was calibrated and standardized, tests were made on six pure minerals to study the relationship of pulp density, particle size, crystallinity, and cleavage on viscosity. An orifice-type viscosimeter equipped with a mechanical stirrer gave as good results as other types and was more flexible, faster, and simpler to operate. The orifice-type viscosimeter, when calibrated and standardized with glycerin and water mixtures, proved satisfactory over a wide range of viscosities. The accuracy and reproducibility were reasonably constant between 1 centipoise and 200 centipoises, the anticipated range in common mineral-dressing unit operations.

Jan 1, 1957

By Morris B. J

Soil air samples taken from the top one metre of the soil profile, were measured for C02 and 02 using portable field analysers at a number of sites of known sulphide mineralisation in South Australia. Carbon dioxide anomalies were detected over actively oxidising sulphides during autumn and winter following recent rainfall. Anomalies were not detected where no oxidation was occurring, where seasonal conditions had been very dry, or where the sulphur content of the ore was low (

Jan 1, 1993