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By L. B. Pankratz

Heat content measurements were conducted for GaPo.996 and InPo.986 over the temperature range from 298° to 1,100° K, and for In2S2.897 over the range from 298° to 1,200° K. Both the actual experimental data and values adjusted to conform with the stoichiometric compositions (GaP, InP, and In2S3) were reported. Entropy increments above 298.15° K were calculated for the stoichiometric compounds, and heat content and heat capacity equations were derived.

Jan 1, 1965

Commercially interesting deposits of zeolite rich tuffs and amorphous silica have been discovered recently in the Taupo Volcanic Zone (TVZ), North Island, New Zealand. This paper reviews them and comments on the potential for further discoveries. Potential markets for these unusual industrial minerals are discussed.

Jan 1, 1997

By J. Asfahani

"The Schlumberger configuration used in geoelectrical sounding is slightly adapted here to obtain reliable data for both shallow and deep penetration depths from the same survey. In this configuration, two kinds of current electrode half-spacings are used: the first enables construction of vertical electrical resistivity sounding (VES) curves for shallow depths (<50 m), and the second for depths =250 m. For a given VES location, two field curves are measured and interpreted using two standard approaches. Practical characteristics of such a modified configuration are illustrated with two field applications in Syria. The first aims to characterize the structure of Quaternary and recent deposits in the Al-Ghab depression region, and the second deals with exploration for phosphatic sedimentary units in the Al-Sharquieh mine. La configuration de Schlumberger normalement employée dans les levés géoélectriques a été légèrement modifiée afin d’obtenir des données fiables à faible et forte profondeur durant le même levé. Dans cette nouvelle configuration, deux types de demi-espacements des électrodes sont utilisés : le premier permet le développement de courbes de sondage de résistivité électrique verticales (REV) pour les faibles profondeurs (<50 m), et le second atteint des profondeurs =250 m. Pour une localité REV donnée, deux courbes de champs sont donc mesurées et interprétées grâce à deux approches standardisées. Les caractéristiques pratiques de cette configuration modifiée sont illustrées par deus exemples d’application en Syrie. Le premier vise la caractérisation de la structure des dépôts Quaternaires et récents de la région de la dépression d’Al-Ghab, et le second traite de l’exploration pour des unités phosphatiques sédimentaires à la mine Al-Sharquieh."

Jan 1, 2009

By J. J. Baz-Dresch

"The Cannon Mine, a joint venture between Asamera Minerals (the operator) and Breakwater Resources, is located in the centre of Washington state at the eastern base of the Cascade Mountains. The mine complex is located three blocks south of the city limits of Wenatchee, part of an urban area with a total population of 47 000. The closest residence is 350 feet from the mine portal.The B-Neath zone is a narrow, high-grade, downward extension of the southern tail of the mine&apos;s main ore body, the B-North zone. It also underlies the northernmost portion of the B-West zone (Fig . I) . The ore is usually reasonably competent but completely surrounded by very weak rock consisting of shear zone and unsilicified sandstones and siltstones.The zone has maximum dimensions of 420 ft in thickness, 500 ft in length , and 200 ft in width . The economic reserves extend from the 70-ft elevation (elevation above sea level) to the 630-ft elevation and consist of about 1.3 million tons of geologic reserves (proven and probable) at an average grade of 0.33 ounces per ton.Acquisition and ExplorationInitial DiscoveryThe initial discovery of the B-Neath zone was made by Tenneco Minerals during July through September, 1984. Their 22-hole surface drilling program consisted of 18 200 ft of drilling. Tenneco Minerals had acquired the 91/2 acre lease from United Mining Corporation.Asamera Minerals subsequently purchased Tenneco&apos;s lease in July, 1985; Tenneco retained a royalty position which was later purchased by Echo Bay Mining.Follow-up drilling by Asamera Minerals consisted of both surface and underground drilling. Eight surface holes (7200 ft) were drilled commencing in December, 1985. Following evaluation of the geologic data, an access drift was driven on strike along the top of the ore zone on the 500 level. Diamond drilling from this platform consisted of 17 200 ft in 79 holes."

Jan 1, 1990

By E. P. Youngman

Titanium ranks as one of the more abundant elements, is widely distributed, and occurs in concentrated form in numerous deposits. This substance was discoveres 140 years ago; but despite the efforts of metallurgists and chemists to find a place for it in industry, only within the last 10 or 15 years has the increased use of titanium pigments provided any extensive outlet for titanium ores. Even to-day titanium is confined to a few highly specialized industrial applications. The metal itself is now quoted regularly in trade journale, but scarcely yet can it be said that the production or use of the metal. has progressed very far beyond the laboratory stage. Ferroalloys containing the element were largely used for a time, especially in connection with the manufacture of Bessemer steel rails; but as American rail- ways adopted open-hearth rails in preference to Bessemer rails, the demand for the alloys in the rail manufacture gradually dwindled into insignificance. New outlets for ferrotitanium have been found in the steel industry; and the production of titanium alloys, both in the United States and in Europe, has increased in recent years. By far the largest use of titanium at the present time, however, is in pigments. The manufacture of titanium white began in Norway, but at present the United States is the leading producer. One of the two companies now operating in the United States is also the leading factor in European production. Although titanium occurs, in many minerals, the principal commercial sources are rutile (the natural oxide, Ti02) and ilmenite (iron-titanium oxide, FeO. TiO2). The latter is a coal-black mineral, but it is the one used in the manufacture of the titanium white of commerce, as well as in the manufacture of ferroalloys and arc-lamp electrodes. Rutile, the natural oxide, is not pure white and, being less common in nature, costs more; it is, therefore, reserved for use in the manufacture of titanium chemicals employed in relatively small amounts in dye works and bleacheries and for sundry minor purposes. This paper summarizes the titanium industry, with special reference to its economic aspects. It is offered as a survey of current trade literature and as a digest of material in the files of the bureau and is presented in response to numerous inquiries from prospective producers as to ways and means of exploiting deposits. (At present, much of the ilmenite consumed in this country comes from overseas, principally from British India..). A forthcoming circular, devoted to deposits of titanium-bearing ores, deals with foreign and domestic sources of supply.

Oct 1, 1930

By E. D. Attanasi

Geologic resource assessments describe the location, general characteristics, and estimated volumes of resources, whether in-situ or technically recoverable. Such compilations are only an initial step in economic resource evaluation. Forecasts that assume that resources that exist in nature can be commercially produced as needed ignore economic constraints. This paper identifies, by example, the salient features of a geologic assessment that will assure its usefulness for economic analysis. These features are demonstrated with examples of coal resource assessments and coal bed gas assessments.

Jan 1, 2001

By J. D. Noll

An effective technique to minimize miners? respirable dust and diesel exposure on mobile mining equipment is to place mine operators in enclosed cabs with designed filtration and pressurization systems. Many factors affect the performance of these enclosed cab systems, and one of the most significant factors is the effectiveness of the filtration system. High-efficiency particulate air (HEPA)-type filters are typically used because they are highly efficient at capturing all types and sizes of particles, including those in the submicron range such as diesel particulate matter (DPM). However, in laboratory tests, minimum efficiency reporting value (MERV) 16 filters have proven to be highly efficient for capturing DPM and respirable dust. Also, MERV 16 filters can be less restrictive to cab airflow and less expensive than HEPA filters. To verify their effectiveness in the field, MERV 16 filters were used in the enclosed cab filtration system on a face drill and roof bolting mining machine and tested at an underground limestone mine. Test results showed that DPM and respirable dust concentrations were reduced by more than 90% when the cabs were properly sealed. However, when the cab door was opened periodically throughout the shift, the reduction efficiency of the MERV 16 filters was reduced to 80% on average.

Feb 1, 2014

By A S. Derrington

High-accuracy, solid-state digital reference barometers have proven to be well suited to conducting underground barometric pressure surveys. The only problem is their expense; at least A$4000 each. For this reason, and because barometric pressure surveys are not a routine undertaking, very few mines have been able to justify the purchase of suitable instruments. The author knows of only three Australian metalliferous mines that own them.However, this may soon change given the recent development of low-cost, mass-produced miniature barometric pressure transducers. These transducers were developed to provide an altimeter function in the latest generation of smartphones. The main purpose of the inbuilt altimeter function is to allow the smartphone to be aware of its altitude when the global positioning system satellite signal is lost.This paper describes a prototype barometer that was constructed using one of the most accurate of the latest generation of piezo-resistive smartphone barometric pressure transducers. The prototype instrument was constructed for less than five per cent of the cost of a commercially available digital reference barometer. The prototype was subsequently tested against a reference barometer at the University of Queensland’s Experimental Mine to verify its accuracy and suitability for measuring pressure differences between underground survey stations.It is expected that the instrument’s low cost will pave the way for barometric pressure surveys to become more commonly used in mines. In turn, the resulting improvement in knowledge of major underground pressure losses should allow mine ventilation officers and engineers to optimise their ventilation systems and potentially reduce overall operating costs.An alternative option would be to use a barometer-equipped smartphone as a survey instrument, provided that its inbuilt barometer module is sufficiently accurate.CITATION:Derrington, A S, 2015. Development of a low-cost instrument for barometric pressure surveys, in Proceedings The Australian Mine Ventilation Conference, pp 331–336 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By Gordon M. Miner

When I was originally invited to speak to this audience on the subject of the future supply of precious metals I was somewhat apprehensive and suggested that the Program Chairman select someone with more credentials. He declined and the results of our conversation gave me cause to reflect and recall the opportunities I have had over the years and how fortunate I have been to be associated with so many successful companies and knowledgeable people affiliated with the precious metals field. I discovered that since 1935, 1 have worked in or visited most of the gold and silver camps in the United States; have been a leaser of a gold mine in Mohave, California; have both lost and made money in the silver futures market; have worked for two of the greatest precious metals companies in the United States - Homestake Mining Company and Hecla Mining Company, have spent a considerable amount of time in precious metal related discussions with men like Don MacLaughlin, Paul Henshaw, Dick Stoehr, Abe Shoemaker, Bill Love, Phil Lindstrom, Simon Strauss, Herbert and Bunker Hunt and many others. It is those exposures and experiences that I draw onto discuss the subject at hand.

Jan 1, 1980

By David C. Kraft

A major manufacturer and user of machine tools had the need to install a screw press machine at its plant site with the following design load requirements: (1) Vertical Compression Live Load = 2000 kip (8896 kN) and Dead Load = 1000 kip (4448 kN), (2) Rotational Moment = 6600 ft-kip (8950 kN&apos;m). The screw press machine was to be located within an existing manufacturing building. The bottom of the footing base was located 15 ft (4.6 m) below existing floor slab. A geotechnical investigation of the site indicated a 17 ft (5.2 m) thick initial stratum of stiff to very stiff clay underlain by a 14 ft (4.3 m) thick stratum of loose to medium dense sand. Beneath the sand stratum was soft rock described as weathered shale. Obvious concern was raised on the possible effects of the dynamic motion of the screw press and potential resulting settlement within the loose sand stratum. This combination of large loads and dynamic motion resulted in the selection of a helical pile and tieback system to support the concrete foundation. The helical pile foundation system consisted of a group of vertical helical piles installed into the shale rock and a group of inclined helical tiebacks set into the remaining portion of the clay stratum. Four load tests were conducted on the vertical helical piles in order to establish compression load capacity. The results of these load tests as reported herein, led to the addition of a limited number of tubular steel push piles in order to meet the project required Factor of Safety on the design loads. All of the helical piles, push piles and inclined helical tiebacks were successfully installed and the screw press is now installed and operational.

Jan 1, 2003

By T. W. Wlodek

"AbstractIn this paper a new type of durable 'spiral-rolled' drill set is introduced and its performance discussed. Efficient and economical mine drilling-depends to a great extent on durability of the drill-set employed. Premature failure of this element damages the drill bit and is costly when tungsten carbide bits are used.Time of drilling of 'spiral-rolled' drill sets introduced at present in Canada is considerably larger than for the presently used drill steel, but laboratory simulated service tests and practical field tests show that the 'drilling life' of the spiral-rolled drill set is several times that of ordinary drill steel.Some features of differential plastic deformation and differential surface rolling, so called 'spiral-rolling', are given.Relations between the drilling machine drill set and characteristics of the ore are discussed. The effect of shims on conical drill rod attachments, the mechanism of failure of drill steel, .and stresses during mine drilling, are analysed.IntroductionIN MINE DRILLING operations, the main interests are: the drilling machines as a source of working energy, the drill set as the tool transferring the working energy to the cutting edges of the bit, and, finally, the drilling characteristic of the .ore or waste rock.This paper includes a review of the possibilities of metallurgical and mechanical improvements in the drill set, with particular attention to drill steel and the attachments.For economical and efficient mine drilling operations, a durable drill rod, attachment, and drill bit are essential. Premature failure of any of these parts interferes with mining operations and is costly."

Jan 1, 1955

By Thomas Domanski

Any type of deep excavation whether for Bored Piling, Diaphragm Walls or Contiguous Bored Piling Walls depends on forming a stable borehole with a defined cross-section to receive safely the permanent materials. In modern construction the excavation depth can reach well the range of 100 m and above. The diameters of the Piles reach often sizes of 2.5 m and bigger. Top casings in Bored Piles (Diaphragm Wall none) are rather short and stability below the casing, need to be secured by stabilization slurry. The boreholes need to be formed through a variety of different materials and stand open for an extended period. Without a safe stable borehole, it is impossible to produce quality products and work cost-efficient. The understanding and proper usage of a suitable slurry is a key element essential for the delivery of Foundation Elements with high quality and within a reasonable budget. The setting of mechanical and rheological parameters in specifications is necessary and helpful, but probably insufficient to embrace and control such a key element in the practical implementation of foundation construction. The proper selection, design, implementation and supervision of slurries on site requires both from Contractors and Engineers to understand how different slurries do function. Only with this knowledge the right decisions in slurry operations can be made. This talk is directed to give some help to both, Contractor’s and Engineer’s, in understanding how different type of slurries do work. (Which ones should be preferred in what kind of soils.) The better knowledge will help the Contractor to control cost and enhance production. The Engineer will be able to assist in arriving at the appropriate technical choices and include in the specifications.

Sep 1, 2022

By Arthur F. Hagner

The titaniferous magnetite deposit at Iron Mountain, Wyoming, is in Precambrian anorthosite. Individual ore bodies are lenses, commonly arranged en echelon, conformable to the platy crystal structure and compositional layering of the anorthosite; a few transect these features at various angles. The ore bodies are on the east flank of the principal anticline in the anorthosite mass. Magnetite and ilmenite, accompanied by spine!, are the ore minerals. The principal gangue minerals are olivine, which was introduced with the ore, and plagioclase, the chief constituent of the anorthosite. The anticlinal region appears to have been a structurally weak zone, and westward-bowing curves of the axis were especially favorable sites for localization of the two largest massive ore bodies. These bodies are synclinal and plunge southeast. The proportion of magnetite-ilmenite to olivine and to anorthosite appears to be related to structural features. Where magnetite-ilmenite is present with olivine, the magnetite-ilmenite is encountered along the most pronounced parts of a fold where anorthite content is highest, whereas olivine is associated principally with more gently folded portions. During granulation and recrystallization of the anorthosite mass, temperature and pressure changes furnished the energy required to release and mobilize iron and other elements that migrated to areas of low pressure, the ore zone. Some iron and magnesium may have combined with silica from partly dissociated plagioclase to form olivine. The ore formed by replacement of anorthosite as indicated by: (1) the marked changes in mineralogy along strike, dip, and plunge of an ore body; (2) the concentration of massive ore in folds and olivine on limbs; ( 3) the halo of low-grade mineralized rock that transects the structure of the anorthosite in the hanging wall; and ( 4) the layering in the large southern ore body, that strikes more easterly than the trend of the body.

Jan 1, 1968

Commodities statistics and other information are available through the following three systems: Internet Access: To acccess the USBM Gopher server on Internet, connect to: gopher.usbm.gov port 70, using gopher client software. Or contact the Systems Administrator for technical questions: Matt Klevemann, 412-892-6499 (klevemmc@miner.usbm.gov) These USBM materials are available on Internet, with more to come in the future: Publications and other research findings, including this bimonthly publications list, newsletters, tech transfer updates, enviromental technology research, health and safety information. USBM software products Media materials and speeches. Mines Data: Computer bulletin board. Log on via modem through 202/501-0373, or call 202/501-0406 for technical assistance. Mines FaxBack: Return fax service. 1. Use the touch-tone handset attached to your fax machine&apos;s telephone jack. (ISDN [digital] telephones cannot be used with fax machines.) 2. Dial 202/219-3644. 3. Listen to the menu options and punch in the number of your selection, using the touch-tone telephone. 4. After completing your selection, press the start button on your fax machine.

Jan 1, 1995

By Jonas Pedro Caumor

As válvulas parcializadoras funcionam distribuindo a vazão de vapor em uma turbina de maneira uniforme e o mais próximo possível de uma atuação linear. Esta vazão depende da área de passagem que por sua vez depende do curso. Para o controle da parcialização de vapor, da potência e rotação, o curso da válvula deve ser mantido ao longo do tempo. Os servomotores que atuam nas válvulas, em sua grande maioria, possuem atuação linear, do tipo simples ação, são compostos de molas e são acionados por pressão hidráulica de óleo. Eles sofrem perdas de linearidade ao longo do tempo e entre as principais causas está a histerese de mola, necessitando assim de ajustes ao longo do tempo. Os ajustes são feitos de forma mecânica e hidráulica, manualmente. A leitura do curso é feita visualmente através de régua graduada, feitos com a turbina parada e sem considerar a atuação do vapor nas válvulas parcializadoras. São propostas modificações feitas no conceito do servomotor, usando um de dupla ação e para que o mesmo faça uma correção eletrônica do curso, a posição da válvula é medida através de um transformador diferencial variável linear (LVDT) Um dos conceitos apresentados é o uso do servomotor de dupla ação. O controle da turbina é feito por um regulador que envia um comando a um conversor eletro-hidráulico que atua no servomotor. Os conceitos apresentados fazem com que esta transformação eletro-hidráulica seja totalmente controlável, mais precisa e constante, mantendo o curso da válvula.

Jul 31, 2018

By Roy E. Williams

1. The major sources of heavy metal ions in wastewaters of the Coeur d&apos;Alene Mining District are effluents from metallurgical processing plants. Effluents from mine operations provide a secondary source for heavy metal ions. Based on data analyzed by the Federal Water Quality Administration, mercury and arsenic are escaping from some mill waste ponds, but they are in the suspended phase. 2. Metallurgical process effluents are combined with mine waste effluents in tailings ponds, consequently, the quality of the tailings pond decant water is highly degraded. The major effect of combining metallurgical process effluents with mill wastes is a drastic change of pH in the tailings pond. This chance may be an increase or a decrease depending on the metallurgical process. The effluent from an electrolytic antimony plant drastically increases the pH in the tailings pond permitting the removal in solution of antimony via the pond decant system. The addition of low pH effluents to the tailings ponds results in a net decrease in pH which makes lead, zinc, cadmium, and copper more soluble, thereby permitting their removal from the pond via the decant system.

Jan 1, 2011

By J. Peterson

A review of blast designs and improved blasting practices at the Ekati??Diamond Mine is presented along with the results of three blast-monitoring experiments. Blast monitoring was undertaken to investigate blast damage mechanisms in the mine&apos;s well jointed rock mass. Rock mass damage caused by production, pre-shear and wall control blasts was measured. Ekati??uses 270mm holes for production blasting, and 165mm holes loaded with a decoupled charge for pre-shearing. The production blasts are loaded with bulk emulsion / ANFO blends. The mine plan involves using 30m double benches. A 30m high pre-shear is drilled and blasted prior to the production blasting that is done with sequential 15m benches. This paper summarizes the monitoring equipment and data gathered to date.

May 1, 2001

By L. Kaufman

Fifteen boride composites were synthesized by hot pressing and evaluated by physical and incendivity testing as non-sparking tool materials. The incendivity tests, conducted at the U. S. Bureau of Mines, Albany Research Center, compared the boride compo-sites with standard cobalt-bonded tungsten carbide material used for coal cutter bits. Two titanium diboride composites and two zirconium diboride composites out-performed cobalt-bonded tungsten carbide in wear resistance and reduced tendency to cause ignitions. However, three of these candidates exhibited undesirable chipping. The remaining candidate, a TiB2-(Ni, Cu) composite, did not chip, nor did it cause ignitions at levels where cobalt-bonded tungsten carbide tools caused ignitions in the incendivity tests. Thus, this material appears to be a logical candidate for further development.

Jan 1, 1973

By Verônica Scarpini Candido

O Alto-Forno é o principal equipamento em uso para a produção do ferro gusa. Para a redução do minério de ferro em gusa são alimentados pelo topo do alto forno a carga composta por minério de ferro, carvão vegetal ou coque e calcário. Durante o processo de redução os gases redutores ascendentes entram em contato com a carga e geram pós no interior do alto forno. Para que esse resíduo não seja lançado diretamente na atmosfera é necessário que haja a recuperação desse material particulado e uma das etapas é a lavagem da poeira do gás de alto-forno que permite a separação dos particulados sólidos na forma de lama, denominada lama de alto-forno. O objetivo do presente trabalho é a caracterização físico e química da lama do alto-forno a carvão vegetal de uma siderúrgica integrada localizada na região sudeste do estado do Pará, e assim fornecer subsídios para estudos que busquem o reaproveitamento desse resíduo através da sinterização para torná-lo um material mais reativo e dar uma destinação ecologicamente correta e de acordo com as normas ambientas. Para isso, foram realizadas, em laboratório, análises como a granulometria, massa específica, difratometria de raios - x e fluorescência de raios - x. Os teores dos óxidos predominantes foram 57,33 % de Fe2O3, 8,14 % de CaO, 5,6 % de SiO2 e 1,37 % de ZnO).

Oct 30, 2017

By G. W. Jones

During the course of an investigation by the Bureau of Mines into the causes, behavior, and control of anthracite-mine fires, it was observed that the carbon monoxide disappeared from a sealed fire area much more rapidly than could be explained on the basis of leakage of gases. Two suggestions were offered for this high rate of disappearance: (1) That the carbon monoxide, was oxidized at temperatures below 150° C. by either the anthracite or its ash (tests on many anthracites have shown that at temperatures above 150° C. carbon monoxide is liberated in the oxidation products when air is passed through it); (2) that the carbon monoxide was oxidized by micro-organisms present in the sealed area.

Jan 1, 1939