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By Henry Kreisinger, WALTER T. RAY

In its investigation of more efficient methods for utilizing the coals and lignites in the United States, to the end that waste might be avoided, the value of low-grade coals increased, and the life of the nation's fuel resources prolonged, the technologic branch of the United States Geological Survey carried on a study of the factors involved in the manufacture and use of briquets, including the suitability of various coals for briquetting, the cheapest and most satisfactory binders, and the furnace behavior and evaporative efficiency of briquetted fuel. The investigations had their beginning in the work done at the coaltesting plant at the Louisiana Purchase Exposition, St. Louis, Mo., in 1904, and were continued at St. Louis and later at Norfolk, Va. Accounts of various tests and statements of the conclusions to be drawn from them have appeared in a number of bulletins. a In connection with the work at Norfolk, comparative steaming tests were made in stationary, marine, and locomotive boilers with run-ofmine coal and the same coal formed into briquets of two sizes. The tests in a locomotive boiler that are described in detail in this bulletin were undertaken to add cumulative evidence to work done at other places. They were made possible through the courtesy of the Seaboard Air Line Railway Company in supplying both the locomotive and the coal used. During the trials the locomotive stood on a side track in the shop yards of the railway company at Portsmonth, Va. No running tests were made.

Jan 1, 1911

By G. L. Liu

"Deformation Banding ( DB ) in cold rolled mild steel has been experimentally established by microstructure investigation. Deformation banding model includes such deformation mode when it is applied to rolling texture simulation. The cause for the occurrence of deformation banding is the reduction of the total work for plastic deformation through a relaxation of the deformation constraints. In the first DB model, all grains are assumed to band from the first deformation step. Such an unrealistic assumption has been eliminated in the new model by the introduction of a banding criterion based on an energy minimizing approach. The prediction is closer to the measured texture by applying banding criterion and setting critical resolved shear stresses (CRSS) ratio for { 110 } and { 112 } slip modes to 0.85.IntroductionBased on the continuum theory of plastic flow and deformation mechanism of crystallographic dislocation slip, Taylor's FC ( Full Constrain ) theory [1] has been widely used in texture modeling. As the process of cold rolling of sheet materials produces a microstructure consisting of elongated or equiaxed flat grain or cell, the ""lath"" and ""pancake"" relaxed constraints ( RC ) models [2, 3] were introduced as the successful improvements over the classical FC model. It has been also recognized that crystals may split into different orientations during deformation and the term deformation banding is used to describe such deformation processes [4, 5]. Lee et al. [6, 7] pointed out that the success of the RC theory in predicting textures depends on the physical processes of deformation banding. They developed so called Deformation Banding ( DB ) model by considering DB in the longitudinal plane to be accounted for by the RC method and allowing DB in the rolling plane. DB model was applied to simulate the texture development in bee case [8], the predicted bee rolling textures are in reasonable agreement with the measured textures. In the first DB model, however, all grains are assumed to band right upon the first deformation step. A banding criterion was formulated [7] which states that DB will occur if the work used in DB model is less than that in RC model. Such criterion has been incorporated into the original DB model for texture simulation and is referred to as DBC ( Deformation Banding Criterion ) model."

Jan 1, 1998

By M. C. Harris

The past twenty to thirty years have seen unprecedented research activity aimed at understanding the performance of flotation froths. In 1990, Finch and Dobby coined the term froth recovery factor, Rr, to represent the efficiency of the froth in delivering particles from the pulp-froth interface to the concentrate. Originally defined for flotation columns, Rr has also been found useful in modeling mechanical flotation cells, and a number of techniques, based on quite different approaches, have been developed for measuring the froth recovery in industrial flotation cells. None of these techniques is universally successful. This paper reviews the concept of the froth recovery factor, and the basis of each of the techniques that have been proposed to measure Rr, and examines the reasons for this parameter being so difficult to pin down. Advances in Mineral Processing Science and Technology Proceedings of the 48th Annual Conference of Metallurgists of CIM Sudbury, Ontario, Canada Edited by

Jan 1, 2009

By Robert McClure, Frederic Leclercq, Ricardo Chavez

With significant vibration control and fragmentation challenges facing them, the CBS quarry (department of the Nord) successfully integrated a technical partner and mine to mill optimisation to deal with a difficult environment. For the last three years, CBS has been conducting a global production monitoring program similar to the mine to mill concept used in the mining industry. This concept consists of optimising the drilling and blasting while monitoring the effects on the downstream chain (vibration control, loading, hauling, crushing, plant output). Blast optimization is ensured by systematic control of the blast geometry (volumes, patterns, bench and face anomalies, drill deviation) and by the use of constant specific energy blasting. Constant specific energy optimises the work of the explosive in a blasting operation and, when combined with a high accuracy programmable electronic blasting system, reduces the impact of blasting on the environment and enhances blast performance. These techniques ensure consistent blasting results and hence improved site productivity. The improvements achieved have been identified thanks to an effective system designed to monitor the key production parameters.

Jan 1, 2007

By R. M. Santmyers

The pigments, whose colors are due primarily to iron exides and iron hydroxides, comprise a variety of yellow, brown, red, and sometimes black paint-coloring agents, both natural and artificially prepared. The natural pigments in this group include ocher, umber, sienna, mineral paints, paint rock, and mortar colors. When the natural color or tinting power--either in the raw state or after treatment--is too weak, these pigments may be "forti- fied" or strengthened. Ocher, umber, and sienna, rhile often described as "iron oxide pigments," are also known as "earthy" rigments. Inasmuch as the iron content of these pigments is, in general, somewhat lower than that of other iron oxide pigments, the ochers, umbers, siennes, and other brown earth pigments are not discussed in the present paper. In addition to a discussion of natural or artificial pigments whose color is due to the presence of iron oxide in some form, this paper contains data on mortar colors, which are medium or low grade pigments used for tinting mortar, cement, and concrete. A great variety of materials are used for theso purposes, including "blue billy" (residue left from roast- ing pyrite), ground slate and shale, and even culm from coal washeries. Dur- ing the past three years, there has been a definite trend among the producers of iron oxide pigments to push the sales of the better grades of colors for tinting mortars. Due to the amount of low-grade coloring matter that is re- quired to impart a strong color to concrete (in soro cases as high as 15 per cent of pigment is necessary) the strength of the cement may be materially impaired. The addition of some 2 per cent of the higher grades of iron oxide to the concrete mix imparts a brighter and stronger colcr, does not weaken the material, and in the end is not as expensive as the low-grade pigments formerly used. Iron oxide pigments occur in nature in various shades and colors, but the red pigments are the most important and account for the larger part of the total red pigments used.3/ The nomenclature of these red pigments is involved and the names given to them are descriptive of the shade rather than of origin, method of produc- tion or chemical composition. In most cases the red pigments under this class may occur naturally or may be produced by heating hydrous iron oxide pigments such as yellow ocher to a sufficiently high temperature to drive off the water of composition. They may also be prepared by fortifying naturally-occurring pigments with stronger natural or synthetic oxides or with coal-tar dyes (e.g. alizarine lake), Most of the mineral reds derive their color from the presence of ferric oxide (Fe2O3), the mineral hematite. This may be present in relatively small percentages, as in the red slates and shales, or it may constitute as much as 90 per cent or more of the material, as in Spanish red. The principal iron oxide pigments used in the manufacture of paint are discussed in the following pages.

May 1, 1932

By Arístides Sotomayor

El presente texto señala la importancia del oro a nivel financiero y minero ya que los inversionistas suelen utilizar este metal para obtener ganancias debido al mínimo riesgo existente en la pérdida de su valor comparado con otras divisas. Así, se estima que en el Perú, existen 480 unidades mineras de oro, de las cuales 28 concentran cerca del 90% de la producción nacional, como la Minera Yanacocha, Minera Barrick, Compañía de Minas Buenaventura, Consorcio Minero Horizonte, Aruntani y Aurífera Retamas. Entre las dos regiones que producen mayor cantidad de oro está: Cajamarca y La Libertad ( 38%) y la tercera región es Arequipa, seguida por Madre de Dios (9%).

May 1, 2016

By P. B. Leavenworth

Development in the Upper Texas Gulf Coast during 1945 resulted in the discovery of 23 new fields; one Miocene, eight Frio, three Cockfield-Yegua and eleven along the Wilcox trend. The Wilcox trend appears to he the most active at this time. Producing depths of the new Wilcox discoveries range from 2050 to 10,050 ft. Drilling along the Frio trend has been, for the greater part, projected to the deeper downdip sands. Eighteen of the new discoveries are classified as oil or condensate and five are gas discoveries.

Jan 1, 1946

By Patrick Scott, Germán Schmeda, Morgan Mullins, Liam Knudsen, Bradley S. Van Gosen, Carma A. San Juan, Nicholas A. Karl, Jeffrey L. Mauk, Clayton Forbush

The objective of the US Geological Survey’s mineral deposit database project (USMIN) is to develop a comprehensive twentyfirst century geospatial database that is the authoritative source of the most important mines, mineral deposits, and mineral districts of the US. Since May 2017, the project has focused on critical minerals. Data for critical minerals that are produced as products are relatively robust, whereas data for critical minerals that may be recovered as byproducts are commonly of much poorer quality. Similarly, more is known about critical minerals that occur in conventional deposits than where those critical minerals occur in unconventional deposits. For example, rare earth elements occur principally in deposits hosted by alkaline igneous rocks, but there is potential for their production from phosphate rock mining, which is less documented. Lithium (Li) has been recovered from pegmatites and brines, but other Li-bearing deposit types have been delineated that may go into production. Cobalt may be produced as a byproduct or coproduct from a wide range ofmineral deposit types, whereas rheniumis a byproduct of copper ore. Significant opportunities for research exist that could help identify new sources of critical minerals, and may also help increase production and recovery from existing sources.

Feb 8, 2021

By David J. Mack

A survey and critical appraisal of published information about Young's modulus was originally made by the writer because of a complete lack of information about this very important quantity in works on. mechanics, physical metallurgy, physics, and other sciences. It was felt that a comprehensive summary of such information about Young's modulus might be of general interest and may suggest new problems or lines of attack on other problems that involve E. Hence this paper has been prepared even though it is only a review, with no new ideas or experimental data. The references are only those used in assembling the paper. No attempt was made to compile a complete bibliography on the subject of Young's modulus. CalculatioX oP YouNg's Modulus from Theoretical or Empirical CoNsidera-tions Many attempts have been made to compute E from theoretical considerations. The earliest calculations were probably those of Tomlenson (1883) and Souther-land (1891), but Fess'enden4',~ made extensive calculations a few years later and arrived at the relationship: £ = 78.TOw(i)* where V is the atomic volume. In 1923, Peczalski, working from the same standpoint but with more information available on atomic structure, arrived at an identical relationship, which he expressed as: where B is a constant of value about 8 . 107, p is density and mis atomic weight; the atomic volume, of course, being ml p. Portevind4 immediately pointcd out that while the equations of Fessenden and Peczalski were true of the common metals, they gave low values for the refractory metals with high moduli (Fig. I). He showed (Fig. 2) that much better concordance was obtained by means of an empirical equation of the form: F- KT" where K is a constant; T the absolute melting point; V, atomic volume, and a and b constants of value approximately I and 2 respectively. This constant K in the Portevin equation is not necessarily the same for all elements, as shown by Thompson. Other equations for E based upon theoretical considerations have been derived by Honda and Yamada49 and Lasareff.50 The most recent calculations of elastic moduli based upon quantum mechanics are probably those of Fuchs He extended the method of Wigner and Seitz for calculating the lattice energy and compressibility of monovalent metals and computed the elastic constants of lithium, 18

Jan 1, 1946

By M Pepper, C R. Roche, G M. Mudd

"The Australian mining industries approach to life-of-mine planning has improved considerably in recent decades. It now needs to be matched by, and embedded in, mining governance systems that utilise a comprehensive whole-of-mine-life approach within a jurisdictional, industry and regional regime rather than just focusing on specific impacts in isolation. The need for a more comprehensive approach is supported by the many mining legacies, from historic, recent and some operating mine sites around Australia. There are sites that are leaving enduring environmental, community and public health impacts that are yet to be accurately assessed. While a number of these sites in Australia are estimated to be more than 50 000, this is probably an underestimation, with a lack of data and different state-based approaches complicating attempts to quantify mining legacies as a national issue. Qualitative assessments about the extent and nature of mining legacy impacts on nature and communities across Australia are also required if we are to understand and avoid ongoing and future mining legacies.This paper commences with an exploration of mining legacies as an umbrella term for previously mined, abandoned, orphan, derelict or neglected sites. This is followed by a discussion of the current status of mining legacies as an Australia-wide issue, contrasting the Australian response with overseas examples. Common themes from past workshops are explored recognising that mining legacies are a growing public policy issue and identifying key ingredients for a successful response. Supporting this, and based on national data which re-enforces the need for action, is the changing scale and intensity of mining in Australia that, while lowering costs for mine operators, increases the liability that may eventually fall to the state if mine sites are not rehabilitated effectively. Though a national issue, mining is a state and territory responsibility, so the current approach to mining legacies is then examined state-by-state. Given the widespread application and recent changes to bonds and levies in Western Australia (WA) and the Northern Territory (NT) the merits of both are examined with reference to specific case studies. Despite the current division of responsibility and diversity of approaches, however, mining legacies remain a significant and growing problem with a recognised need and repeated call for cooperation and coordination at a national and international level. Future action is addressed in the final section with reference to liability, responsibility, industry reputation, regulation and leadership.CITATION:Pepper, M, Roche, C R and Mudd, G M, 2014. Mining legacies – understanding life-of-mine across time and space, in Proceedings Life-of-Mine 2014 , pp 449–466 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 16, 2014

Q: It is May 1961 at Bill Wrather's Washington house. Bill, think back to your first job after college. Wrather: Perhaps I ought to go back a little bit further than my first job. I entered the University of Chicago with the idea of studying law. My intention was to take a 4-yr liberal arts course and superimpose a law degree on that. But during my undergraduate work I fell under the influence of R. D. Salsbury. He decided I had some talent as a geologist and influenced me to take a geological course. Nevertheless, I did not give up the idea of law. While in school I took a spell of typhoid fever and almost died. The doctor recommended outdoor exercise, so a geological job seemed logical. W. H. Emmons was a graduate student in the University and he interceded with Dr. Hayes of the USGS. I went on the payroll as assistant packer at $60 a month. I had one of the most glorious summers I ever spent in my life. That fall and the following year I took law courses and became thoroughly convinced that I was cut out for a geologist rather than a lawyer. I finished up my law work in 1908 while waiting for a job with Bill Emmons, who was doing a careful study of Goldfield and Tonopah.

Jan 4, 1964

By A. Lucian Walker

SILVER is not only of paramount importance to millions of people as a medium of savings and to other millions as a medium of exchange, but it is also valuable and useful in industry. Mexico continues to be the largest producer of this metal, followed by the United States, Canada, and Peru. The largest consumers are China and India, which normally absorb about two-thirds of the world's mine production, hoarding it as savings. The imports by these countries exert a powerful influence upon the price, yet neither country is on the silver standard. China having abandoned it in 1935 and India in 1893, when the rupee was definitely linked to the pound sterling. Other nations such as Persia, Ethiopia, Mexico, and many of the South American countries either have been on the silver standard or have used silver as their chief circulating medium, and most large nations use it for subsidiary coins, this use accounting for 20 to 30 million ounces annually. The arts and industries have consumed 35 to 40 million ounces each year.

Jan 1, 1937

Jan 1, 1991

By W. W. Adams

Every man-hour of work performed in and about the coal mines of the United States had a 2-percent heavier death load from accidents in 1938 than in 1937. This is an unorthodox way of stating that the death rate per million man-hours of exposure or employment was 2 percent higher in 1938 than in 1937, increasing from 1.74 to 1.78. Thus the average miner had a 2-percent greater chance of being killed in 1938 than he had in 1937. The average quantity of coal resulting from 1 man-hour of work increased 3.6 percent -from 0.615 ton in 1937 to 0.637 ton in 1938. The production of the average ton of coal was accompanied by a slightly smaller loss of life in 1938 than in 1937, the accident rate being 2.793 per million tons in 1938 compared with 2.833 in 1937.

Jan 1, 1941

By Robert E. Barieau

General expressions for evaluating various thermodynamic properties applicable to the van der Waals equation of state have been derived. These formulas were subsequently used to evaluate various thermodynamic functions in the two-phase region. The results indicate that, for a van der Waals fluid, there is a finite discontinuity in the second derivative of the vapor pressure curve, in the second derivative of the chemical potential or Gibbs free energy at the critical point, and in the heat capacity at constant volume measured at the critical density. Numerical values are tabulated and graphs are presented for all functions calculated.

Jan 1, 1967

By S. Don Brown

Between 1987 and 1988, the Bureau of Mines studied the mineral resources of the White River National Forest and part of the Arapaho National Forest to appraise the resources present and to determine the types of deposits, and their location, that could be mined economically if sufficient demand and metal prices existed. The study included a comprehensive literature search and a limited amount of field investigation of minerals and mining activity in and near the Forest. Mineral resource information indicates that in the Gore Range the area between Tennessee Pass and Gilman may contain large base-and precious-metal deposits, and could be the focus of exploration activity in the near future. The Breckenridge mining district was found to have a moderate to high likelihood for mineral exploration and possible development of gold. Recent exploration and minor development work has occurred in several other areas: Montezuma, Kokomo-Tenmile, and Upper Blue River districts, and portions of the Sawatch Range. Limestone, marble, sand and gravel, rock for crushed aggregate, and other industrial rocks have been recently mined or Quarried in the Forrest, and will likely be mined or quarried in the near future. Currently coal is being produced at one mine in the Forest, and extensive identified coal resources are located in the Forest. Parts of four known gas fields lie within the Forest west of Glenwood Springs; there is current production at one field.

Jan 1, 1990

By A. U. Seybolt, R. E. Honnemon

THE purpose of this communication is to present activity data of nickel in the Ni-A1 binary system that was obtained for oxidation studies in this system. This data has been calculated from previous aluminum activity data at 1000°C1,2 by two types of Gibbs-Duhem integrations. These results should be of particular current interest to oxidation studies of aluminide coated nickel-base superalloys3 as well as other problems. The aluminum activity of Steiner and Komarek1 is plotted in Fig. 1 as a function of composition in Ni-A1 alloys at 1000°C. The dashed parts of the aluminum curves represent our approximate extrapolations from the directly measured regions. In the terminal solution regions (a and L phases) standard parabolic solution functions of the following form are assumed: where i is the component subscript, Ki is a constant at a fixed temperature, and xi is the atom fraction. The resultant nickel activity curve at 1000° C from the Gibbs-Duhem integration4 of the aluminum data is shown in Fig. 1. The solubility ranges of the phases present in the Ni-A1 binary at 1000°C are also denoted at the bottom of Fig. 1. Corresponding values of the nickel activity, aNi and yNi, are listed in Table I at useful compositional intervals. including phase boundary values. The aNi and yNi data listed in Table I are subject to the uncertainties present in the experimental aluminum activity data1 and to deviations from parabolic solution behavior in the terminal solutions. The errors introduced into aNi and yNi due to the parabolic solution assumption are expected to be relatively small (<20 pct of the values given) in all the phases except the liquid phase. Some deviation from parabolic solution behavior in the liquid phase is indicated

Jan 1, 1970

[JAMES A. BARR Consulting Engineer Mt. Pleasant, Tennessee Washington) D.C. BEHRE DOLBEAR & COMPANY Consulting Mining Engineers and Geologists 11 Broadway New York 4, N. Y. BLANDFORD C. BURGESS Registered Professional Engineer Mining Consultant Monticello, Georgia GLENVILLE A. COLLINS Mining Engineer Uranium examinations Cable "Coins" 210 La Arcada Bldg. Santa Barbara, Calif. COWIN & CO. Mining Engineers and Contractors Consulting Shaft & Slope Sinking Appraisal Mine Development Reports Mine Plant Construction I- 18th St. S. W. B&apos;ham, Ala., Phone 56-5566]

Jan 1, 1952

By AIME AIME

It is with the deepest personal sorrow, and with the regrets of the Steel Company of Canada, that I report to you the death of one of our most valued associates, the late Frank B. McKune, superintendent of the Open-Hearth Department of our company. Many of you will remember Mr. McKune for his long attendance at these meetings, for the intelligent interest he took ill them, as well as for his innovations in steel-production practices.

Jan 1, 1940

By R. J. Colony

MINING geology does not lend itself - very readily to a review embracing "improvements in methods," as perhaps do shop practices or laboratory procedures. The "methods" used in mining geology are simply the application of geology to mining; winning the ore, the handling of material, mechanical appliances, all belong strictly to mining proper, and have no place in a review of geology as applied to mining. A comprehensive review would necessarily cover a .very broad field, which could be subdivided into many -parts. Only a few of these can be discussed here. .Those that have been suggested to the chairman indude :

Jan 1, 1930