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By John A. Johnson

Tests ere conducted at the Mount Weather testing adit of the 57 Bureau of Mines on the effectiveness of spraying water along the outside of the drill steel as compared with standard wet-drilling practice. The spray equipment used in the tests was designed primarily for the control, in quarries, of dust from dry drilling with solid type drill steel. Equipment Spray equipment is made in sizes to fit different drill steel but is alike in design, the only difference being in the diameter of the ring and the number of spray holes. The device is mace of cast steel and has a coating of Stellite on the inside edge that comes in contact with the drill steel. It looks like a garden spray, except that the spray holes point in only one direction.

Jan 1, 1939

In recent decades the awareness of environmental issues by the general public has developed at an accelerat- ing rate. This is the result of a number of factors including more scientific knowledge of environments and of the impacts of modern society upon them, higher levels of education, the opportunity for people to travel more, and the success of the various communication media in bringing in- formation to the communities of the world about such environmental crises or threats as the smogs of Los Angeles and London, the Torrey Canyon and Santa Barbara oilspills, Minamata disease in Japan, the spread of the Crown of Thorns starfish, the disposal of toxic industrial wastes into the Upper Rhine, the discovery of high mercury and zinc contents in marine foods in southern Australian waters, and the proposal to mine limestone at Precipitous Bluff in Tasmania.

Jan 1, 1975

By Qi Wang, Zengzhu Kang, Jianguo Liu, Guanglei Liu

"Due to the increase of automotive vehicles, available parking spaces become a new type of limited resource in central cities of China, especially in those old districts without visionary urban planning. Additional mechanical parking in underground space is an efficient solution to provide parking spaces under the situation where the urban space is constrained. Shichahai district is an old protected zone in Beijing which is close to the Forbidden City and there are many Hutong (alleyway) and Quadrangles (courtyard house). No spaces are available for car parking on the ground and all vehicles are parking in Hutong without order currently. The local government plan to do renovation work for this district and improve the residential environment. Several innovative solutions are studied including parking in deep shafts, parking under existing buildings by under-pinned method, parking under buildings by covered excavation method, parking under roads built together with utility tunnel etc. 5000 difference types underground parking spaces are planned to be constructed in the following three years. Project examples are also introduced in this paper. INTRODUCTIONCar parking resources are very limited in central cities, especially in old districts without planning for increasing automotive vehicle volume. Traffic get worse when cars park on the side of the roads or move slowly to find parking spaces. Investigation shows the normal (parking space/ automotive vehicle volume) ratio is about 1.2 in most big cities such as New York, Tokyo and Hong Kong, while this ratio is only 0.5 in Beijing. One solution is to move cars out of central cities. But there are still huge parking requirements for the citizens living in central cities. Shichahai district is an historic protected zone in Beijing which is close to the Forbidden City and there are many Hutong and Quadrangles (refer to Figure 1 for project location). No spaces are available for car parking on ground and all vehicles are parked in Hutong without order currently. The local government had a plan to do renovation work of this district and improve the residence environment. 5000 different types of underground parking spaces are planned to be constructed in the following three years. One project designed and to be constructed by Zhongyan Technology will be introduced in this paper. Other innovative solutions will be introduced briefly as well."

Jan 1, 2017

By B J. Kennedy, G W. Sengstock

During the last two decades, many advances have been made in open cut coal mining technology as new mines have come on stream and old mines have faced increasingly difficult mining and operational conditions. The need for close control of operating costs has necessitated consideration of modified excavation methods.

Jan 1, 1995

By Dunlop GA

Pilot Plant confirmatory testing of the treatment route developed in the Metallurgical Laboratory is an essential factor in the development of complex ore bodies. Objectives should be well defined to permit the efficient planning and cost effective operation of the pilot plant project. The primary objective for the pilot plant should be to confirm the viability of the developed flowsheet on a continuous basis, examining only major variables such as ore types, quantum changes in grind, comparison between bulk and sequential flotation circuits, use of flotation columns, evaluation of autogenous grinding and production of samples of concentrates for market evaluation. Secondary objectives may include the collection of engineering design data and the production of a comprehensive report to Bankable Document standards to provide technical support for capital financing. The complexity of the ore body and the scale of the final operating project together with the pilot plant objectives will determine the extent of the pilot plant operations. The level of expenditure associated with a pilot plant can vary, in total cost and as a percentage of the total development capital investment required to take the prospect from exploration to a producing mine. Factors contributing to expenditure are discussed. Associated with cost considerations is the level of confidence mining company investors can have that their capital investment will return dividends.

Jan 1, 1990

By C. C. Herrick

The vapor pressure of indium has been measured by the torque-effusion technique, as a function of temperature between 1102o and 1422oK. For liquid indium, the vapor pressure (in atmospheres) can be represented by the equation -R In P = 5.782 x104/T - 25.29from 1000o to 1422oK. Extrapolation yields a calculated normal boiling point of 2329°K and a heat of vaporization at 298 oK of 58.09 kcal per mole by the third-law method and of 58.39 kcal per mole by the second-law method. Calculations indicate that the free-energy functions of Hultgren are to be preferred to those of Guruich. BECAUSE of the potential uses of liquid metals, it is important that convenient experimental methods be developed which will lead to a sufficient body of thermodynamic data so that reasonable estimates of properties of liquid metals can be made. Indium is particularly well-suited to investigation, since it remains liquid over a long temperature interval, it alloys readily, suitable containers for it are easily procured, and relatively few investigations of its thermodynamic properties in the region above 1000°K have been made. PREVIOUS RESEARCH The first determination of the vapor pressure of indium was made by Anderson,' using the Knudsen method and silica-lines stainless-steel cells. Kohlmeyer and spandau2 determined the normal boiling point, and a mass-spectroscopic investigation has been made by Lyubimov and Lyubitov.3 (Unfortunately, only an equation representing the data of the latter investigators has been available to us.) Hultgren et al.4 and Gurvich5 have published discordant tables of the free-energy functions for indium. EXPERIMENTAL METHOD The torsion-effusion principle has been described amply in the literature.8,7 With this method, one observes the angular deflection induced by effusion of vapor from a multihole effusion cell which is suspended from a filament producing a small rotational restoring force. The pressure within the effusion cell can be computed from the relation ziaifiai where k is the torsion constant of the filament, 6 is the observed angular deflection, and ai, fi, and qi are the area, force factor, and moment arm of the ith effusion orifice. The force factor f is analogous to the Clausing factor,' and corrects for the reduction in effusive force attributable to the finite geometry of the effusion orifice. Schultz and Searcy' have tabulated the force factors for various tube geometries. EXPERIMENTAL APPARATUS The physical arrangement employed in this study is shown in Fig. 1. The furnace elements are six Globar heat rods with 15-in. hot zones. Temperature is maintained to * 1°K by a Beck mechanism driving two 26-amp Powerstats in parallel. A Pt (Pt, Rh 10 pct) thermocouple serves as the sensing element. Four inner tubes act as vibration isolators; the air pressure required for maximum isolation was determined empirically, and is maintained by a solenoid valve. The tungsten fiber, 9 by 0.002 in., is joined to an 0.008-in. tungsten wire or graphite rod via a machined lightweight chuck.

Jan 1, 1964

The discovery of nickel sulphide deposits at Kambalda in 1966 heralded the development of ò an industry with a capital value of over $1.5 billion producing about 10% of the western world's nickel. ò an unprecedented exploration boom in which over $200 mil- lion was expended in 10 years in the search for nickel deposits. ò a major new class of nickel deposits stimulating exploration for similar deposits overseas. and rapidly propelled a struggling small mining and exploration company to become one of Australia's corporate giants, provid- ing a much-needed stimulus to economic activity in a region suffering from a severe downturn in its principal industry, gold mining. Production of nickel in Western Australia commenced at Kam- balda in 1967 and grew rapidly to a rate of over 30,000 t of con- tained nickel per annum in 1970, 40,000 t in 1973 and 50,000 t in 1975. Early production was aided by a shortage of nickel on the world market due to disruption of supply from the major Canadian producers, resulting in high free market prices for the metal. Since these early years, the industry has experienced a number of cycles of indifferent health due principally to market developments overseas, although the level of production of nickel in Western Australia remained fairly consistent. The two most serious of these, in 1977-8 and 1985-6, forced the closure of a number of mines. Current nickel prices are allowing remaining producers to enjoy a measure of relative prosperity, although there is little general speculation that this will be long-lived. Nickel deposits discovered in the exploration boom were almost exclusively related to ultramafic rocks. Volcanic peridotite (komatiite)-associated deposits, exemplified by the Kambalda ore- bodies, were the targets of initial exploration which was concen- trated on ultramafic sequences near lower stratigraphic contacts with underlying mafic rocks. Subsequently, discoveries made in coarse-grained dunites in interpreted intrusive settings broadened the search parameters.

Jan 1, 1988

By Kuzugundenli OE, Nagaraj DR

Organic complexing agents have received special attention over the past few decades in the search for reagents for improved flotation separation of minerals, especially non-sulphides. The majority of such reagents that have been proposed over the past few decades have remained largely a laboratory curiosity, except perhaps alkyl hydroxamates, because their selection is seldom based on commercial viability. In this regard, the choice of complexing agents such as oximes may be more realistic because of their widespread use in solvent extraction of copper. Our earlier studies have confirmed that they are also effective as collectors for copper oxide minerals, including chrysocolla which is the most difficult copper mineral to beneficiate. The flotation behaviour of chrysocolla for several structurally-related hydroxyoximes were studied as a function of pH and oxime concentration and the role of structural features examined. The structural changes studied included substitutions in both chelating and non-chelating parts of the molecule. The results indicated that, contrary to expectations, many of the structural changes in the basic molecule, salicylaldoxime, do not have a positive effect on collector efficiency. The reduction in collector efficiency is rationalised on the basis of possible steric factors affecting complexation and packing of the collector species on the mineral surface as well as effects due to changes in electron density brought about by substituents. Introduction of alkyl substituents on the oximic carbon of salicylaldoxime yielded the highest collector efficiency.

Jan 1, 1993

Jan 1, 1936

By Natalie A. Sapola, Knox Van Dyke, Jean Rabovsky, Vincent Castranova, William H. Pailes, Melanie McPeek, Deloris J. Judy

"INTRODCJCTJONPlatelet activating factor (PAF) is a glycerophospholipid (1-0-alkyl-2-acctyl-sn-glycerol-3-phosphoryl choline) which has been shown to mediate a broad range of biological activities. 1·3 Its pulmonary actions include contraction of pulmonary tissue,4 secretion of leukotrienes from leukocytcs,5 airway constriction,6 pulmonary edema,7 and enhanced migration of neutrophils into the airspaces of thelungs.8-9PAF can be released from several different cell types, such as, basophils, neutrophils and alveolar macrophages, in response to a variety of particulates or membrane stimulants which include zymosan, calcium ionophore, phorbol esters, chemotactic agents, and endotoxin. 1~1 3 Therefore, PAF may play an important role in the development of pneumoconioses by mediating pulmonary responses of lung cells to a variety of occupational dusts. To investigate this possibility, we determined the effects of P AF on several physiological parameters of neutrophils, alveolar macrophages, and alveolar type Il epithelial cells.METHODSIsolation of CellsNeutrophils were isolated from human blood by dextran settling and centrifugal elutriation.14 Isolated neutrophils (93% pure) were resuspended in HEPES-buffered medium (145 mM NaCl, 5 mM KCI, 10 mM HEPES, 5 mM glucose, and 1 mM CaC12; pH = 7.4). Cell number and volume were determined with an electronic cell counter equipped with a sizing attachment.Rat alveolar macrophages were obtained by pulmonary lavage with ea2+, Mg2+-free Hanks balanced salts solution. 15 Alveolar macrophages (94% pure) were resuspended in HEPES-buffered medium, counted, and sized electronically.Rat alveolar type Il cells were isolated by enzymatic digestion for 35 minutes at 37°C with 40 µ/ml type I elastasc and 0.1 % collagenase and purified by centrifugal elutriation. 16.17 Type Il cells (92 % pure) were resuspended in HEPES-buffered medium for measurement of membrane potential, oxygen consumption, and trypan blue exclusion. Type Il pneumocytcs were resuspended in 0.1 M NaCl plus 0.05 M HEPES (pH = 7.8) to measure cytochrome P450-dependent activities and aggregation. Cell size and number were determined electronically."

Jan 1, 1990

By Y. Béliveau

Emission of perfluorocarbon gases, CF4 and C2F6, produced during anode effects from aluminum electrolytic cells are a significant part of the total equivalent CO2 emitted by aluminum plants. With the current concerns about global warming, the reduction of these PFC gases is a key issue in reducing greenhouse gases for a smelter and achieving GHG emission agreement goals. This paper will present the approach taken by the Alcoa vertical-stud Soderberg plant in Baie-Comeau to reduce GHG emissions generated during anode effects and close emission gaps with other Alcoa Soderberg plants. The approach has been to adapt the existing technology in place at the Baie-Comeau Soderberg plant. PFC emissions were lowered by reducing both the anode effect duration and frequency through different methods. Examples of change include: implementing skimming practices and wider side crust break area for better alumina dissolution in bath, increasing the ratio between reacted and pure alumina, reducing the time to declare anode effects in the potrooms, implementing best work practices and finally educating the workforce on the importance of reducing PFC emissions.

Jan 1, 2007

By P N. Martens

In the course of the development of the Report of the World Commission on Environment and Development (WCED) in the 1980s an expression was introduced in the public discussion on environment and development that influenced the international and national policies of the last 20 years in all areas: sustainable development. The UN decided in 1992 to implement a program with the Agenda 21 which contains the demand for developing indicators for sustainable development. In this context an indicator is understood as a quantitative or qualitative measure that can be measured or described throughout time and which moreover is able to depict the current status and changes. In order to enable for a simple holistic assessment of sustainable development, highly aggregated indicators are required, which integrate the criteria identified as relevant within a framework to be defined. In the presented paper, sustainability indicators for the mining industry are developed that account for the allowances of the sustainable development concept and the Agenda 21. The indicators are quantifiable and traceable through time so that developments can be traced and assessed. Furthermore, the indicators account for the multidimensional aspect of sustainable development. They are designed to allow for the integration of several dimensions in one indicator. The premises that are underlying the development of the indicators are the minimisation of negative impacts on the environment and society while simultaneously considering the maximisation of social and economic factors. Moreover, the participative momentum that is part of the sustainability idea is safeguarded in explicitly integrating the social acceptance of certain measures into the assessment. The indicators presented are based on the logical combination of statements through the use of Boolean algebra. Starting with basic statements for which the logical value is oriented on the sustainability paradigm, complex multidimensional statements can be constructed and assessed.  

Jan 1, 2009

By T. A. Rundle, K. Kim, W. M. McCabe, E. C. Gregory

Overcoring tests were conducted at the Near-Surface Test Facility(NSTF) to assess the suitability of five techniques (U.S. Bureau of Mines borehole deformation gauge (BDG), Commonwealth Scientific and Industrial Research Organization (CSIRO) hollow inclusion stress cell, Luleå triaxial gauge (LuH gauge), and Council for Scientific and Industrial Research (CSIR) doorstopper) for in situ stress determination in a closely jointed basalt. This effort is in support of the Basalt Waste Isolation Project, which is studying the feasibility of locating a nuclear waste repository in the basalts of the Hanford Site in southeastern Washington. This paper presents the results from the overcoring study that formed the basis for selection of two techniques to be used during the further exploration of the basalt formations at depth.

Jan 1, 1983

By W. J. Fene

"The prevalence of accidents in the coal-mining industry has prompted a study of the workmen's compensation laws of the various States and the statistics of accident costs, for the purpose of explaining to operators how the compensation laws are regulated and to show the cost of accidents.The subject of compensation laws and accident costs is by no means new, but the prevalence of coal-mine accidents would indicate that the mine operator in general is not thoroughly conversant with their importance. Unquestionably, compensation laws are a large factor in promoting accident prevention, and it is believed that a greater measure of success would be accomplished in preventing accidents if all mine operators were fully aware of their important bearing on the cost of production.Many operators seem to be indifferent to accident occurrence; possibly they do not real¬ize the seriousness of the accident hazards that exist in their mines, even after the hazards are brought to their attention. There is no question that material financial advantages are to be gained by the prevention of accidents and it would appear that when these advantages are thoroughly understood, operators would be anxious to eliminate, insofar as is feasible, conditions likely to cause accidents.The unsettled state of the mineral industry and the irregular operation of mines during the past several years has probably been an important factor in influencing the apparently indifferent attitude of the operator. The chaotic conditions in the mining industry and especially in coal mining are unquestionably a factor that tends to increase accidents, just as mine idleness increases roof hazards and results in deterioration in mechanical, electrical, and haulage equipment, and promotes disorganization of the personnel. During such times greater efforts should be exerted toward the prevention of accidents because of these increased hazards and of the financial advantages brought about by the various savings to be effected when mine accidents are held to a minimum.This report on accidents in the coal mines of Pennsylvania was made possible largely through the cooperation of William J. Maguire, director, Bureau of Statistics, Pennsylvania Department of Labor and Industry, and Rush N. Hosier, superintendent, Coal Mine Section, Pennsylvania Compensation Rating and Inspection Bureau, who made available their records and extended much assistance and numerous courtesies during this study."

May 1, 1932

By Mark Khinkis, Huajun Yuan, Mark Zak, Yaroslav Chudnovsky, Aleksandr Kozlov

"An afterburner for green petroleum coke calcination in electrothermal fluidized bed was designed, fabricated, installed, and tested on a pilot fluidized bed calcination furnace. The experimental set-up comprised a combustion chamber, in which fine particles and volatiles of the furnace off-gas were fully combusted, and a cooler equipped to calculate the related heat recovery and losses. Off-gas composition was analyzed to evaluate the combustion process. The energy balance confirmed the potential to recover a large part of the heat value of volatiles and fme particles from the GPC. Potential future applications of the results are discussed.IntroductionGreen petroleum coke (GPC) is an oil refining byproduct that can be used directly as solid fuel or as feedstock for the production of calcined petroleum coke [1-2]. GPC contains a high amount of volatiles and sulfur. With coke calcination, the GPC is heated to remove the volatiles and sulfur in the calciner off-gas to produce purified calcined coke, which is used in the production of graphite, electrodes, metal carburizers, and other carbon products. Currently, more than 80% of calcined coke is produced in rotary kilns or rotary hearth furnaces. These technologies provide partial heat utilization of the calcined coke to increase efficiency of the calcination process, but they also share some operating disadvantages [3]. On the other hand, coke calcination in an electrothermal fluidized bed opens up a number of potential benefits for the production enhancement while reducing the capital and operating costs.The increased usage of heavy crude oil in recent years has resulted higher sulfur content in green coke produced from oil refinery process, which requires a significant increase in the calcinations temperature and residence time [ 4]. The calorific value of the process off-gas is quite substantial and can be effectively utilized for combined heat and power (CHP) production to complement the energy demand. Waste heat recovered from the product cooling could also contribute to the overall economics of the calcination process. Preliminary estimates indicated the decrease in energy consumption by 35-50% as well as a proportional decrease in greenhouse gas emissions. So, efficiency improvement of the coke calcinations systems is attracting close attention of the researchers and engineers throughout the world."

Jan 1, 2014

By R. Dugdale, F. Habashi

Studies on hand-picked samples of chrysocolla from Arizona showed that heating in an inert atmosphere enhances greatly copper extraction by ammoniacal-ammonium carbonate solutions. Heating in hydrogen improves the extraction of copper even further and maximum extraction by ammoniacal-ammonium carbonate and by sodium cyanide solutions is achieved for samples heated at 350°C. Heating in SO2 atmosphere results in the simultaneous formation of CuSO4 and Cu2O; maximum reaction rate is also achieved at 350°C. At temperatures higher than 350°C, CuCO4 starts to decompose. Chrysocolla heated above 600°C either in argon, H2, or SO2, is rendered less amenable to leaching, supposedly due to the formation of insoluble copper silicates.

Jan 1, 1974

By Ching-Liu Wu, John Hawley, Andrew H. Liu, James Chai

The Hatch Mott MacDonald/Bechtel Joint Venture team is designer and construction manager for the 5.25-mile Tunnel Segment of the overall 16-mile Silicon ValleyRapid Transit Project, which extends the existing Bay Area Rapid Transit (BART) system southward from Fremont to San Jose. The Tunnel Segment includes twin boredtunnels, mined cross passages, and three deep station excavations situated in highlyvariable ground, high ground water table, and a dense urban setting with high-risebuildings adjacent to the largest excavation. This paper will discuss design challengesthat have arisen with the excavations and the proposed solutions.

Jan 1, 2007

By W. L. Ott, C. L. Lewis

"AbstractA technique is described for preparation of palladium sponge and for spectrochemical analysis of the metal in this form. The precision and accuracy of the method are discussed. Analyses are compared with previous spectrochemical analyses of palladium in the black form. Good agreement was found in the two sets •of results and it is concluded that they are more reliable than wet chemical .analyses of the same material.IntroductionFOR SEVERAL YEARS the problem of platinum metal analysis by spectrochemical methods has been under investigation at the Spedtrographic Laboratory, Department of Geological Sciences, Queen's University. The problem, briefly -stated, is as follows: Samples of platinum, palladium,-rhodium, ruthenium, and iridium are received as fine metal powders, called sponge. Direct spectrographic analysis of this material has not been found satisfactory due to its heterogeneity •as regards contaminant metals, which may be present up to a total of one per •cent or more. Further-more, spectrographic standards are difficult to obtain and difficult to prepare accurately by adding weighed portions of contaminant metals to the sponge. The fact that •contaminant metals in original samples are probably alloyed with the major constituent is a further difficulty since complete fusion of these refractory metals proved impractical in the present case as a means of standard preparation. It •has, therefore, been found most satisfactory to dissolve the metals, prepare standards by addition of solutions of contaminant metals, and to reduce both standards and samples to a homogeneous form. A previous paper, by Hawley, Wark, Lewis and Ott (2) dealt with a method for spectrochemical analysis of platinum and palladium in their black form. Since completion of research on the black technique, the possibility of analyzing palladium accurately in its sponge form has• been investigated."

Jan 1, 1953

By J. Baz-Dresch

A custom-designed shotcrete system, consisting of an 8-m3 (10-yd3) transit mixer and a shotcrete spray boom carrier, is used bya 2-man crew to transport and place up to 25 m3 (32 yd3) of steel-fiber reinforced, dry, silica fume shotcrete per II-hour shift. Shotcrete is custom blended by a local supplier and delivered predampened. Mix design and quality control is performed with a computer program that develops and graphs a properly balanced mix based upon the materials sieve analyses.

Jan 1, 1991

By O. Tranbarger

In aging tunnels, wall and roof deterioration can eventually result in defects that must be detected and repaired to maintain safe structural conditions. In investigating tunnel defect conditions, a specialized FM radar system was developed with a programmable VHF and UHF operating sweep range for optimizing the penetration and measurement capabilities. The new FM radar technology was tested in two aging brick-lined tunnels in New York City. Test results showed that FM radar signals could penetrate eight courses of water-saturated brick and that the original steel liner outside the tunnel walls was intact.

Jan 1, 1985