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By D. W. Holliday

The major deposits of anhydrite and secondary gypsum in Jamaica occur discontinuously at a single horizon within the Lower Eocene succession of southeast Jamaica. They are not intruded from other horizons of different age, as has previously been supposed. The gypsum and anhydrite occur in a regressive sequence at the junction between marine (Richmond Formation, Halberstadt Volcanics, Halberstadt Limestone) and overlying non-marine (Wagwater Formation) sediments. They are thought to have been formed in an arid supratidal (sabkha) environment. A variety of 'nodular' structures occurs in the gypsum and anhydrite which can be related to early diagenetic processes and compaction effects. All gradations exist between single isolated anhydrite nodules and structureless anhydrite due to closer packing and coalescence of nodules. The structures and textures in the anhydrite are thought to be consistent with penecontemporaneous formation from gypsum crystals rarely more than 2 cm in diameter. Single anhydrite nodules are not usually larger than 2 cm; nodules of greater size are compound, due to the coalescence of several smaller nodules. Some large compound nodules may have developed from single sand crystals or rosettes. Compaction of anhydrite appears to have been largely mechanical, but some rocks have an aligned fabric, suggesting later flowage

Dec 1, 1971

By Ken Schei, Martin Reed, Samuel Bowser, John Wright

From October 18 through October 21, 2001, United States Antarctic Program blasters opened ten access holes for research divers in 11-ft. thick sea ice at Explorers Cove, McMurdo Sound, Antarctica. During this project, a blasting seismograph with a hydrophone accessory was used to monitor the underwater shock waves associated with the blasting technique. Shock wave values averaged 42.3 psi for initial (cratering) shots and 5.9 for subsequent clearing shots, indicating that the ice absorbs most of the shock wave. The results also provide data for refining safety protocols for divers and for the protection of marine biota.

Jan 1, 2003

By W. G. Pariseau

A U.S. Bureau of Mines case study of pillar recovery in high-grade ore near the Ross shaft at, the Homestake Mine, Lead, SD, has demonstrated the usefulness of the finite-clement method for the evaluation of shaft pillar mining plans and shaft stability. This report, one of three in a series describing the Ross shaft pillar case study, focuses on the premining stability analysis. The two-dimensional computer program UTAH2 was used in advance of pillar mining; results suggested that the shaft would remain stable. Subsequent reports describe parts 2 and 3 of the study. In part 2, borehole extensometers and other instruments were installed to provide data for model verification and shaft monitoring. Results of the recalibrated two-dimensional model confirmed the premining stability evaluation. However, after mining began, great concern developed because of the appearance of cracks and other signs of ground movement over considerable distances from the area of active pillar miping. In part 3, an intense three-dimensional modeling effort using UTAH3 was initiated. The results again showed that the shaft would remain safe. Three-dimensional analyses of alternative pillar mining scenarios indicated that more of the shaft pillar ore reserve could be recovered than previously thought.

Jan 1, 2010

By P. C. Thakur

Methane has been a hazard since the beginning of coal mining and has influenced, more or less, every aspect of coal mine design. It is receiving increased attention lately because the rate of methane emission in coal mines is increasing as increasing demand for coal leads to exploitation of deeper seams and the use of higher productivity equipment. Consequently, the government and private industries have directed a great deal of effort towards understanding and solving the problem of methane emission in coal mines. In the United States, Consolidation Coal Company has pioneered research in this area since the early 1950's.1 Currently this work is being expanded by Consol through the Mining Research Division of the parent company, Continental Oil (Conoca), to find new techniques for degasification of virgin areas as well as control of methane in gob areas. Basic reservoir properties of coal seams, such as gas content, reservoir pres-sure, diffusivity, porosity and permeability are better understood today largely through the efforts of the U. S. Bureau of Minese2,3,4 It is possible now to identify and model the basic mechanism of gas emission from coal and to forecast steady as well as unsteady state emission of methane in coal mines with some degree of reliability. Combining this knowledge with any ventilation simulator should often identify problem areas in advance and permit adequate methane control measures to be planned.5 Another recent innovation in methane control is the horizontal hole drilling technology. The U. S. Bureau of 1-1ines and the Mining Research Division of Conoco have independently developed techniques for drilling horizontal holes 300 to 600 m deep6 The Bureau's method employs a rotary drill string while Conoco uses a non-rotating string with a down hole drill motor. It is the authors' view that the latter provides more positive control on bore hole deviation both vertically and laterally and appears to be faster, though somewhat more difficult to operate. The rate of methane emission depends on a number of factors which can be broadly classified in two groups. These are (1) the basic reservoir properties of

Jan 1, 1977

By J. Finch, Wei Zhang

In this paper we describe the synthesis of a new homologous series of linear Polyglycol-based frothers that consist of Ethylene Oxide (EO) and hydroxyl as hydrophilic groups and Propylene Oxide (PO) and alkyl chains as hydrophobic groups. The synthesized frothers were of two types: Alkyl-Ethoxy-Propoxylate (abbrev. CnEOlPOm) and Alkyl-Propoxy-Ethoxylate (CnPOmEOl) giving: (a) different number of groups and chain length, and (b) different locations of the groups. The identities were confirmed by proton nuclear magnetic resonance (NMR) spectroscopy and total organic carbon (TOC) analysis. The characterization of the products was carried out in a bubble column. At steady state, bubble size, gas holdup and water overflow rate were measured as a function of frother concentration. The results indicate that increasing number of PO groups led to significant decrease in bubble size, and increase in gas holdup and water overflow rate. Increasing the alkyl chain length, gave similar but less pronounced trends. There was no impact of increasing the number of EO groups on bubble size but there was an in increase in gas holdup and water overflow rate. Changing the location of the PO and EO group had a significant effect on all three parameters.

Jan 1, 2015

By G. Laird, N. B. Gray, N. Lawson

"Photographic, video, laser, hot film and conductivity methods are used in the experimental study of gas-liquid flows. A discussion of their capabilities and limitations are given in this paper illustrating the wide range of phenomena that can be studied. Most of these methods are limited to physical models at room temperature with transparent fluids, although they can be extended for use with opaque and hot fluids. A number of these techniques have been used by the GKW CRC in studies on industrial plants and their usage is increasing although a number of technical difficulties still need to be overcome. An in-depth discussion of the laser doppler anemometry (LDA) and particle image velocimetry (PIV) methods is given with experimental results on the flow field of an air plume in water based on advanced development of the techniques and studies carried out at the GKW CRC. The LDA method provides high resolution data on the velocity profiles, while the PIV method provides an overall view of the complex flow structure occurring at the gas-liquid regions. These two methods complement each other in providing experimental data for validating numerical models and exploring the complexities of multi phase flows.IntroductionThe injection of gases into melts is an important operation in the metallurgical industry. It is used in converters, anode furnaces, blast furnaces, ladles, bath smelters, zinc fumers and many other smelting processes. In many of these processes, the gas is injected into a molten bath resulting in the formation of bubbles that promote reaction, mixing, alloying and heat transfer. The study of gas-liquid systems presents enormous challenges to the researcher due to the complexity of the mathematical and physical modelling which require innovative numerical and experimental skills."

Jan 1, 1996

By Modesto Bargallo

De acuerdo a las descripciones de los cronistas del siglo XVI, la "guaira" era un horno pequeño, portátil, de barro crudo y forma troncocónica o troncopiramidal cuadrada e invertida. En ese sentido, el presente texto señala las crónicas y relatos respecto del uso de dicho horno, así como las posibles localidades de las guairas al Cerro de Potosí y campos vecinos como Cerro de Porco y la región de los Lipes: las tres, en época colonial. Asimismo, Potosí y aledaños fueron el lugar clásico, donde funcionaron simultáneamente hasta unas siete mil guairas en sus mejores tiempos de fundición (antes de 1571) según Capoche, y en 6497 existían asientos de guairas.

Mar 1, 1969

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 N. Damiano, C. Zhou, B. Whisner, M. Reyes

"The industrial Internet of Things (IIoT)—a concept that combines sensor networks and control systems—has been employed in several industries to improve productivity and safety. NIOSH researchers are investigating IIoT applications to identify challenges of and potential solutions for transferability of IIoT from other industries to the mining industry. Specifically, NIOSH has reviewed existing sensors and communications network systems used in U.S. underground coal mines to determine whether they are capable of supporting IIoT systems. The results show that about 40% of the installed post-accident communication systems as of 2014 require minimal or no modification to support IIoT applications. NIOSH researchers also developed an IIoT monitoring and control prototype system based on low-cost microcontroller Wi-Fi boards, to detect a door opening on a refuge alternative, activate fans located inside the Pittsburgh Experimental Mine, and actuate an alarm beacon on the surface. The results of this feasibility study can be used to explore IIoT applications in underground coal mines based on existing communications and tracking infrastructure. INTRODUCTION The nation’s approach to health and safety in mining has historically been reactive in the sense that health and safety regulations and mandates have traditionally been passed as a result of tragic mining accidents. An example of this is the Mine Improvement and New Emergency Response Act (MINER Act) of 2006, which was passed as a result of several mining accidents where tracking of and communications with underground personnel were severely limited. While this reactive approach has led to the development and implementation of highly impactful safety interventions and safety practices, there currently exists a technological revolution that can shift the paradigm toward a proactive approach based on preventative methods: Internet of Things (IoT). IoT is the network of physical objects or ""things"" embedded with electronics, software, sensors, and connectivity to enable that network to achieve greater value and service by exchanging data with the manufacturer, operator, and/or other connected devices [1, 2]. It should be noted that IoT has been defined from various perspectives, and hence numerous definitions exist in the literature. The apparent ambiguity of the IoT definition might be due to the fact that IoT is syntactically composed of two terms: internet and things. The first one pushes towards a network-oriented vision, while the second tends to put the focus on generic objects. The traditional internet can be viewed as an internet of computers —i.e., “things” connected to the internet are computers only. IoT “extends” the internet by allowing other generic things that are commonly found in our daily life, such as refrigerators and cars, to be interconnected via the internet, and thus creates a bridge between the virtual word and the physical world."

Jan 1, 2017

By E. D. Regad, W. E. Wallace, P. S. Mike, C. A. Hill, V. Vallyathan, M. J. Keane

"Respirable-sized quartz, a well-established fibrogenic mineral dust, is compared with kaolin in erythrocyte hemolysis assays aher treatment with saline dispersion of dipalmitoyl phosphatidylcholine, a primary phospholipid component of pulmonary surfactant. Both dusts are rendered inactive after treatment, but the membranolytic activity is partly to fully restored aher treatment with phospholipase Ai. an enzyme normally associated with cellular plasma membranes and lysosomes. Phospholipid-coated dusts were incubated for periods of 2-72 h at a series of applied enzyme concentrations, and the adsorbed lipid species and hemolytic activity were quantitated at each time for both dusts. Surfactant was lost more readily from quartz than from kaolin, with consequent more rapid restoration of mineral surface hemolytic activity for quartz. Interactions of surfactant and mineral surface functional groups responsible for the mineral-specific rate differences, and implications for determining the mineral surface bioavailability of silica and silicate dusts, are discussed. INTRODUCTIONMineral particles depositing in the lung acinus will contact an aqueous coating containing surfactant molecules spread on the air-liquid interface and dispersed within this hypophase; the primary components of that surfactant are diacyl lecithin phospholipids (King and Clements, 1972; King, 1982). Adsorption of this surfactant can suppress the cytotoxicity of mineral dusts (Marks, 1957). Suppression of hemolytic activity, a measure of membranolytic potential and an indicator of bioavailability of the mineral surface, of respirable-sized quartz and kaolin clay dusts with the adsorption of dipalmitoyl glycerophosphorylcholine or dipalmitoyl lecithin (DPL) has been measured (Wallace et al., 1985). Such contact and adsorption of pulmonary surfactant in vivo may provide a first defense system of the lung against respired dusts."

Mar 1, 1992

By P .. R. Ammann

A two-stage pyrometallurgical process has been developed for the recovery of copper (and other non-ferrous metals) from copper smelter slags. All types of slags, including highly oxidized, converter-type slags, are cleaned in an electric furnace which employs mechanical mixers to promote magnetite reduction and copper extraction at high rates. In a 10-ton pilot furnace, it has been demonstrated that slags can be cleaned to 0.2-0.3 per cent copper with economically acceptable usage of raw materials and energy; copper is recovered as a high-grade matte. Pilot plant data have been scaled up to a commercial furnace and engineering designs have been made for a furnace to treat 60 tons per hour of slag from a Noranda Reactor and the associated converters. Plans are being formulated for the construction of a prototype slag cleaning furnace.

Jan 1, 1976

By L. R. Fisher

The purpose of this investigation was twofold: (1) To devise a rapid method for determining quantitatively the porphyrin-carboxylic acid content of a particular crude-oil porphyrin aggregate, and (2) to isolate porphyrins in the crystalline state from crude-oil porphyrin aggregates. The first purpose was accomplished by applying adsorption chromatography. In fulfillment of the second aim three different crystalline porphyries were isolated by methods which involved both adsorption chromatography and fractionation of benzene solutions with hydrochloric acid of varying strength. The three porphyrins had etio, rhodo-, and phyllo-type absorption spectra, respectively. INTRODUCTION Many samples of petroleum have, as interesting minor constituents, chemical compounds known as metalloporphyrins. Their presence in crude oil and other bituminous materials was first discovered by Treibs a quarter century ago. Much experimental work has been done on metalloporphyrins because of their importance to the petroleum industry. They have a deleterious effect on refining catalysts. The ash resulting from the burning of heavy fuel oil is very reactive, We to the presence of metallic constituents, particularly vanadium. In oil-fired gas turbines, the ash may build up on the blades, causing imbalance of the rotors and, in addition, severe corrosion. In industrial boilers, the ash residue is responsible for severe damage to boiler tubes and to the refractory brickwork (15).4 Through study of the chemical constitution of the various metalloporphyrins found in petroleum, much can be learned concerning the origin, migration, and history of crude oils.

Jan 1, 1961

By E N. Sparg, O D. A Deuchar, F Needham

Decline shafts are an attractive option to both new and existing mining operations where there is a need to access an inclined orebody deposit via on-reef development so as to generate a return in the shortest possible time. There are many different technologies that are available to transport men, material and rock in incline shafts. This paper focuses on the applicability of two hoisting technologies for decline shafts, namely endless and direct rope systems. The pros and cons of each system are reviewed. A common concern with direct rope haulage systems is the possibility of generating slack rope during deceleration. This paper illustrates the issues involved in designing a system so as to avoid the possibility of slack rope. In conclusion, the key factors relevant to the selection of endless or direct rope haulages for a particular decline application are reviewed. The paper is a joint submission by FFE Minerals-Vecor and Qualter Hall UK.

Jan 1, 2005

By James J. Snodgrass

A new technique was used to obtain detailed sonic logging data in drill holes above the water table at a coal mine site in northeastern New Mexico. The equipment was developed under contract to the Bureau of Mines and the U.S. Department of Energy to indirectly evaluate the in situ structural properties of coal and overburden. The system comprises a hydraulically operated, wall-clamping downhole probe compatible with standard four-conductor logging cable, and a surface control module. Resolution of layering is 0.6 meter (2.0 ft), and a redundancy of data from separate receivers provides accurate timing measurements. Preliminary results in the settled overburden of an excavated long-wall panel indicated a low average velocity zone, extending approximately 18 meters (60 ft) into the immediate roof of the coal seam. Subsequent measurements improved the field and recording procedures to produce high quality waveforms from which both P and S arrivals may be visually interpreted. Over a representative section of interbedded sandstone, siltstone, shale, and coal, Vp and Vs varied considerably even within lithologic units. Compressional wave velocity in the coal seam, Vp = 1,740 m/sec (5,700 ft/sec), was in the range of variability of published data.

Jan 1, 1982

By H. G. Iverson

Solid state reactions of manganese with silica were investigated in high-temperature tests. Reactions of 0.5 to 4.0 moles manganese (Mn) with 1 mole silica (SiO2) at 1,100° C and of 2.0 Mn:SiO2 mole-ratio mixtures at 1,000° to 1,150° C yielded products consisting of a slag phase and a metallic phase. At 1,100° C, the slag phase from reactions of the low Mn:SiO2 mole-ratio mixtures was composed of SiO2 and rhodonite (MnSiO3), and the slag phase from the high Mn:SiO2 mixtures was composed of MnSiOs and tephroite (Mn2SiO4). The metallic phase from the corresponding low Mn:SiO2 mole-ratio reactants consisted of two manganese silicides, Mn5Si3 and Mn3Si; from the high Mn:SiOg mixtures, it was Mn and the manganese silicide (Mn5Si). For the higher mole ratios of MnSiO2 the manganese content in the metallic phase increased, while the manganese and silica contents of the slag phase remained nearly constant. The slags did not contain free or uncombined manganese oxide (MuO). For the 2.5 to 4.0 Mn:SiO2 mole-ratio mixtures reacted at 1,100° C, the maximum quantities of silica reduced and of the manganese in the slag appeared to become asymptotical at about 41 and 48 percent, respectively. A brominating procedure was developed that was highly selective in removing the metallic constituents from the reaction product, leaving the slag phase as residue. X-ray diffraction patterns were obtained on prepared silicides Mn5Si, Mn3Si, and MnSi.

Jan 1, 1967

A newly developed damage model was used in the study of rock fragmentation mechanisms involved in crater blasting. Simulations show that at the detonation of the explosive charge, a crushed zone around the explosive charge is formed due to compressive failure and then a strong pressure wave is sent out forming a pressurized ring that propagates at the dilatation wave velocity. As the pressurized ring leaves the crushed zone, two tensile stress components perpendicular to the radial stress are developed in response to the action of the radial pressure, causing tensile failure and forming a damage zone around the charge. The formation of this damage zone is quite independent of the depth of the explosive charge provided there is no interference by the reflection from the free face. When the pressurized ring reaches the free face, it is reflected there and causes rock failure on the ground surface that forms another damage zone. Under the simulation conditions, it is revealed that the depth of charge is a factor controlling the relationship between the two damage zones. At a depth smaller than the optimum, the two damage zones coalesce into one and there is excessive rock breakage; otherwise, the two damage zones tend to isolate from each other with the increase in the depth of charge. Calculations of fragmentation indicate that the average fragment size increases and the uniformity of fragments decreases when the depth of charge increases as observed in practical blasting.

Jan 1, 1998

By Robert E. Barieau

General expressions for evaluating practically all the thermodynamic properties of a fluid from a single equation of state are derived. Most of the formulas are expressed in terms of the compressibility factor, with this factor being an explicit function of the temperature and the molal density. Similar expressions are given using reduced variables.

Jan 1, 1967

By F. A. Campbell

This paper reports on mineral facies, ore textures, distribution of iron in sphalerites, and fractionation of sulfur isotopes in the Anvil ore body, Yukon Territory, Canada. Because the detailed structure and stratigraphy, both regional and local, are being studied by the geological staff at the mine and members of the Geological Survey of Canada, these topics will be discussed only briefly. The results of our study of the Anvil ore body have implications on theories of the genesis of ore deposits of this type, and these will be discussed. The Anvil ore body is the largest and most significant of three lead-zinc discoveries in an area of the central Yukon where major lead-zinc deposits were unknown only twenty years ago. The Vangorda deposit consisting of 22 million tons was discovered in 1953, followed in 1954 by the Swim Lakes deposit consisting of 10 million tons. The Anvil deposit, which consists of three ore zones, was discovered in 1964. The total reserve at Anvil mine is 63.5 million tons, with an average grade of 3.4% lead, 5.7% zinc, 0.16% copper and 1.2 ounces of silver per ton. This study is concerned primarily with the number one ore body which is about 2,400 feet long, up to 1,100 feet wide and 300 feet thick.

Jan 1, 1973

By K. Liu

"In the present work, two-step heat treatments with preheating treatments at different temperatures (175, 250 and 330°C) as the first step followed by the peak precipitation treatment (375°C/48h) as the second step have been performed in Al-Mn-Mg 3004 alloys to study their effects on the formation of dispersoids and evolution of elevated-temperature strength and creep resistance. During the two-step heat treatments, the microhardness is gradually increasing with increasing time until to a plateau after 24 hours when first-treated at 250°C and 330°C while there is a minor decrease with time at 175°C. Results show that both the yield strength and creep resistance at 300°C reach the peak values after the two-step treatment of 250°C/24h+375°C/48h. The formation of dispersoids is greatly related to the type and size of pre-existing Mg2Si precipitated during the preheating treatments, in which that coarsened rod-like ß’-Mg2Si strongly promotes the nucleation of dispersoids while finer needle-like ß’’-Mg2Si has less influence. Under optimized two-step heat treatments and modified alloying elements, the yield strength at 300°C can reach as high as 97 MPa with the minimum creep rate of 2.2×10-9 s-1 at 300°C in Al-Mn-Mg 3004 alloys, enabling them as one promising candidate in lightweight aluminum alloys for elevated-temperature applications.INTRODUCTION Due to the rapid demand from weight-sensitive automotive and aerospace industrials for the light alloys, such as aluminum alloy on the elevated-temperature applications, Al-Mn 3xxx alloys has been developed to obtain the good properties at both room temperature (RT) and elevated temperature, in which the dispersoid-strengthening mechanism plays a significant role (Li & Arnberg, 2003; Li, Muggerud, Olsen & Furu, 2012; Liu & Chen, 2015, 2015). In our previous works (Liu & Chen, 2015, 2015; Liu, Ma & Chen, 2017), the yield strength and creep resistance at 300°C of Al-Mn-Mg 3004 alloy were further improved by modifying the alloying elements, such as Fe and Mo, to optimize the characters of dispersoids, including the size, distribution and the dispersoids free zone (DFZ). For instance, Mo was introduced in aluminum alloy to further improve the volume fraction of dispersoids and reduce the area of DFZ, leading to increasing on both the strength and creep resistance at 300°C (Liu, Ma & Chen, 2017). On the other hand, the mechanical properties became worse at higher Fe content due to its consumption more Mn to form Al6(MnFe) intermetallics, resulting in less available soluted Mn for the precipitation of dispersoids (Liu & Chen, 2015). Therefore, optimizing the characters of dispersoids is always the key to improve the elevated-temperature properties of dispersoid-strengthened aluminum alloys for elevated-temperature applications."

Jan 1, 2017

By Alton B. Cook

A material balance equation was derived for calculating (1) the initial oil volume and (2) the relationship of average reservoir pressure to net gas in storage in reservoirs used for natural gas storage operations. The equation is also applicable to secondary-recovery operations where reservoirs are completely repressured and gas cycled. Using this equation minimized two probable sources of appreciable error in conventional material balance calculations: inaccurate measuring of and accounting for produced gas, and differences between true reservoir pressure and average reservoir pressures as derived from bottom-hole pressure measurements. A new procedure is presented for calculating water encroachment. By solving the conventional material balance equation and the derived equation for gas storage simultaneously, the values for initial oil in place and net water encroachment can both be determined.

Jan 1, 1966