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By K. G. Thorne, M. J. McLeod, D. Hoy

"Throughout the Paleozoic, a variety of gold depositional environments were created in the New Brunswick segment of the northern Appalachians because of the complexity of arc and continental plate collisions and subsequent erosion of the orogen. In southwestern New Brunswick, recent exploration and research has focused on deposits and occurrences that can be broadly classified as intrusion-related, generated by late- to post-orogenic felsic to intermediate plutonic rocks emplaced during the Early to Middle Devonian. This work has led to the establishment of models for gold mineralization and guidelines for exploration in this area, which might also be applicable elsewhere in the southern part of the province and, perhaps, throughout the northern Appalachians. The deposits in the vicinity of Clarence Stream in southwestern New Brunswick exemplify this deposit type, and highlight the emergence of a possible major gold district in the region. Durant le Paléozoïque, une grande variété d’environnements aurifères ont été créés dans le segment néo-brunswickois des Appalaches du nord en raison de la complexité des collisions entre arcs et plaques continentales ainsi que durant l’érosion subséquente de l’orogène. Dans le sud-ouest du Nouveau Brunswick, les travaux d’exploration et de recherche récents se sont tournés vers les gisements et les indices appartenant à la classe des gîtes associés aux intrusions, générés par des roches plutoniques felsiques à intermédiaires tardi- à post-orogéniques mises en place au Dévonien précoce à moyen. Ces travaux ont permis d’établir des modèles de mise en place pour la minéralisation aurifère ainsi que des guides d’exploration pour ce secteur, lesquels pourraient aussi être appliqués ailleurs dans le sud de la province et, possiblement, dans l’ensemble des Appalaches du nord. Les gîtes aux environs de Clarence Stream dans le sud-ouest du Nouveau Brunswick sont un exemple de ce type de gisement, mettant en valeur ce qui pourrait devenir un district aurifère majeur dans la région."

Jan 1, 2008

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 Andreas Hucke

For the roadway design in the German hard coal mining industry, an advanced combined planning system has been applied during the past 20 years. The German mining industry is working with single entry roadways system. After first longwall passage the roadways will be stabilised with side wall building material packages. Later this roadway will be used again for the second retreating longwall. The intention of the implementation of several different design methods for the planning of the roadways is to enhance the reliability of the results. On one hand the planning system uses numerical simulation and physical modelling in addition to analytical and empirical methods. On the other hand in-situ monitoring and analysis during the roadway development will be used to verify and calibrate the numerical and physical models. Especially before the implementation of new support elements in underground, this system is suitable and reasonable because the new support elements will be tested in the physical and numerical simulation prior to cost intensive underground tests. The interaction between the numerical and physical modelling in comparison with underground monitoring and analysis during development and the later use of roadways will be shown with some examples. The first example shows a rock bolted rectangular roadway which will be mined at both sides of the roadway. Different support and roadway building material package systems are investigated under various stress conditions. The results are utilised to optimise the roadway support and the roadway side package systems. The influence of different points in time of the installation of several support elements in a combined arch and bolted roadway is shown as another example. Two different types of support systems are compared within the physical models. These models are used as a base for ongoing numerical analysis and simulation to find out the ideal point of time to assemble the different support elements. The last example handles the influence of slickensides in the roof of arch shaped roadway on their stability. Different slickenside positions and densities are investigated and classified.

Jan 1, 2006

By E. Concha

The concept of an Automated Continuous Explosive Excavation system (ACEE) for the underground mining applications of development drifting and room and pillar mining has been evaluated in comparison with conventional drill, blast and muck operations. The role and possible extent of application as this method was identified. The evaluation examined each element of existing and of proposed ACEE design concepts in a defined mine environment. Step by step procedures were developed to quantify the evaluation process where this appeared feasible. One conclusion drawn was that a system approach to ACEE design is not only feasible but attainable within the state of the art. Several preliminary design concepts were formulated and examined in order to determine what further research or development might be needed to realize them.

Jan 1, 1982

By John C. Machisak

This publication, for the calendar year 1959, contains statistical data on injuries and employment pertinent to metal mines, ore-dressing plants, and primary nonferrous smelters, refineries, and reduction plants. The Bureau of ,Mines is authorized to request data on injuries and employment in the metal-mining industry, and the information, voluntarily submitted by the operators, contributes immeasurably to the promotion of safety in the metal- mining industry. Every effort has been made to make the annual canvass as complete as possible. The data presented are classified according to the hind of ore mined and includes information on copper, iron, lead-zinc, gold-silver lode, placer, uranium- vanadium, and miscellaneous metals. A breakdown of miscellaneous metals by commodity is shown in tables 17 and 18.

Jan 1, 1963

INTRODUCTION ò World coal production, Exporters and Importers òNew Zealand Exports, Markets and Products ò Types of Markets and Price Setting ò Bench Mark Prices and Exchange Rate ò Transport ò International Marketing - Key Factors ò Coal New Zealand , the Challenges

Jan 1, 1996

By R. E. Lindstrom, D. J. Bauer

Studies were conducted to assess the potential of naphthenic acid as a fractional extractant for rare- earth mixtures and yttrium in sulfate solution . Naphthenic acid was an effective extractant , and separation factors were favorable in the presence of aqueous phase chelating agents . Addition of EDTA to the naphthenic acid extraction system resulted in average separation factors of 2.2 between adjacent yttrium- group elements , whereas DTPA resulted in average separation factors of 3.5 between adjacent cerium- group elements . EDTA was of value in separating yttrium from the rare- earth elements . Thorium and uranium were preferentially extracted over the trivalent rare- earth elements by naphthenic acid .

Jan 1, 1964

The compilation of the sampling nomogram is an essential tool in the optimization of a sampling protocol and allows the operator to track the change in relative variance of the sampling error (the Fundamental sampling error) during steps of comminution and mass reduction in the process of recovery of the aliquot for analysis. The data required for the compilation of the nomogram are centred on the sampling constant K and the exponent, alpha (a) of the nominal fragment size. Five methods for establishing K have been identified, but two of them, the duplicate sampling analysis method and the heterogeneity test method purport to provide such constant. The step by step procedure for each of these two methods was examined using broken ores from three mines, Mponeng mine, Kloof mine, and Lily mine. Two of these mines (Mponeng and Kloof) are typical Witwatersrand-type gold mines, and the third is an Archaean-type shear related gold deposit situated in the Barberton Greenstone belt. The results suggest that the factor K derived using the heterogeneity test is very accurate, but applies only to a single size fraction in the spectrum of comminuted materials. The calculation of gold grain sizes using this method appear to be too small and do not conform with the results from detailed mineralogical studies. The factors K and alpha derived using the duplicate series analysis are appropriate for use across a wide spectrum of comminution sizes and also provide realistic gold grain sizes, comparable with the equivalent circular diameter of gold grains identified in mineralogical studies of the ores.

Jan 1, 2010

By Thomas S. Jones

This report discusses processing and use of the principal forms of manganese. The focus is on trends in the United States in the 20th century and specifics of domestic manganese material flows as of about 1990. To protect proprietary data, quantitative assessments are limited to the iron and steel industry, which accounts for about 90% of consumption. Nonmetallurgical uses are considered qualitatively. Approximate disposition of a U.S. cumulative consumption during 1901-90 of an estimated 69 million st of manganese is estimated to be iron and steel slag, 69%; nonmetallurgical uses of a dissipative na¬ture, 10%; iron and steel scrap, 9%; National Defense Stockpile, 3%; unidentified and/or including items in service, 10%. In slag from iron blast furnaces and steelmaking, manganese is present as a minor, relatively im¬mobile component, which so far has been uneconomical to recover. Construction and road building are main applications for these slags. Steel slag contains the greater amount of manganese. Studies by others of global manganese fluxes and the effect of human activities on them also are discussed. One source concludes that the main effect of human activities, via deforestation and agricultural activities, has been to increase the rate of transport of manganese to the oceans.

Jan 1, 1994

By John C. Machisak

This publication, for the calendar year 1959, contains statistical data on injuries and employment pertinent to metal mines, ore-dressing plants, and primary nonferrous smelters, refineries, and reduction plants. The Bureau of Mines is authorized to request data on injuries and employment in the metal-mining industry, and the information, voluntarily submitted by the operators, contributes immeasurably to the promotion of safety in the metal-mining industry. Every effort has been made to make the annual canvass as complete as possible. The data presented are classified according to the hind of ore mined and includes information on copper, iron, lead-zinc, gold-silver lode, placer, uranium- vanadium, and miscellaneous metals. A breakdown of miscellaneous metals by commodity is shown in tables 17 and 18.

Jan 1, 1963

By D Connelly

High purity alumina (HPA) is a processed, premium non-metallurgical alumina product characterised by its purity level ie 99.99 per cent (4N) or 99.999 per cent (5N). The market price, application, and performance of HPA varies widely according to its degree of purity. High purity alumina is a form of aluminium oxide (Al2O3) with growing use in LED lighting and coating on the ceramic cathode separator sheets in lithium ion batteries. This paper describes a study on producing high purity alumina from feldspar to produce HPA and potash for use as a fertiliser. The project was positive for a number of reasons. High potassium extraction (>99 per cent) was achieved in the alkali leach using sodium hydroxide as the leaching agent and full dissolution of the alkali leach residue was achieved using hydrochloric and sulfuric acid. The potential to produce a high purity alumina product via a complex but promising emerging process was assessed. The potential to extract potassium as potassium sulfate to add value to the project was also demonstrated with the test work.

Sep 1, 2024

By R. M. Mashishi, T. Malehase, O. J. Okonkwo

The concentrations of selected trace elements (As, Cd, Hg, and Pb in run-of-mine (ROM) coal, discard, and coal product were investigated to assess the efficiency of beneficiation in reducing trace element concentrations and ascertain any implications regarding environmental compliance to regulatory frameworks. Samples were collected from a colliery in Mpumalanga Province twice a month for a period of 24 months. The samples were ashed to approximately 0.21 mm, then digested in a mixture of 70% HNO3 and 40% HF and analysed using inductively coupled plasma-mass spectrometry (ICP-MS). Except for Pb, the mean concentration of all elements decreased from the ROM stage to the coal product stage. The order in which trace elements occurred from the highest to lowest throughout the production chain was Pb>As>Hg>Cd. With the exception of Cd, the mean trace element concentrations in the discard were above the total concentration threshold (TCT) set for landfill disposal. The As, Hg, and Cd concentrations in the product were well below the thresholds for all land uses. However, Pb concentrations in the product coal were above legal limits, which is of concern with regard to environmental compliance and the performance and marketability of the product.

Dec 13, 2023

THE area dealt with in this paper is included within a radius of about 3 miles of the Poimena township. Several thousand tons of tin have been won from this field, and probably £200,000 spent in exploiting it.PREVIOUS LITERATUREThe field has been reported on by Government geologists on four occasions and several ,articles on it have appeared in the mining journals. The work done by Government geologists is summarized below:-"Report on the Blue Tier Tin Mining District and its Tin Deposits", 1886.Speaking of the tin-ore occurrences, this paper states:-"In the primary granite the lodes of tin ore occur, also dykes and belts of more recently obtruded porphyries. The really valuable metalliferous deposits may be classified as follows :-1. Lodes (of which the Lottah mine is typical).2. Dykes- (a) Indurated or hard (as shown by the formations at the Anchor and Cream Creek mines). (b) Soft (eg Hayley's Lease).

Jan 1, 1912

By R. E. Siemens

The Bureau of Mines sought to correlate the variation of structure-sensitive superconducting properties with microstructure in selected Cb-Hf alloys and to compare the experimental results with those predicted by the GLAG theory. Alloys in wire and rod form were evaluated by critical temperature, critical current, magnetization, resistivity measurements, and optical and electron microscopy. In the absence of an external magnetic field, the current carrying capacity of columbium was greatly reduced with addition of up to 85 wt pct Hf, but a large increase in Ic occurred for Cb-90 wt pct Hf. Favorable Ic-H behavior was observed in cold-drawn alloys containing 25 and 57 wt pct Hf. Correspondingly, a maximum in Tc occurred at 10-25 and 90 wt pct Hf. Four- or five-hour heat treatment at 600° C resulted in maximum Ic values and maximum hysteresis in magnetization. Dislocation pileup, polygonization, and fine precipitates, responsible for flux pinning, are listed in order of their effectiveness as pinning sites. Sites having an average separation of 1,500 to 3,000 A and a diameter of 1,000 A or less were most effective in influencing Ic-H and M-H behavior. The resistive critical fields increased smoothly to a maximum of 80 k0e between 60 and 65 wt pct Hf. Highfield, mixed state, reversible paramagnetism was observed in some alloys; however, the GLAG theory was in good agreement with experimental results for the majority of the composition range studied.

Jan 1, 1969

By Virgil Marple

In the summer of 1979 the University of Minnesota Mobile Laboratory (UMML), designed for the analysis of airborne particles and gases was used to study fugitive dust from an open pit coal mine. The analysis consisted of determining the particle size distribution and concentration of dust from various mining operations, such as blasting, draglines, loading, roadways and bottom scrapers. For some operations the particles size distribution and concentrations were determined at varying distrances. Details of the dust concentration within the plumes as the plume passed the UMML were measured with an optical particle counter. For line sources, such as roadways this enabled the calculation of the particle flux at the sampling location. In addition to the standard instruments associated with the UMML, the applicability of some new instruments were investigated. These included a uniform deposit cascade impactor and a flux meter. Finally, a technique in identifying plume origins which utilized elemental X-ray flourescence analysis of filter samples was shown to be effective.

Jan 1, 1980

By R. Pothina

The objective of this research was to develop a mathematical model for gyratory crushers to help in the prediction of energy consumption and to analyze dominant parameters that affect this energy consumption. The development of a gyratory crusher model was achieved in the following three main stages: mathematical representation and coding of the crushing process; building an amperage constant model to derive an energy-scaling formula; and modifying the amperage constant model to represent a full-scale model. Due to their significant influence on feed-size distributions, two blasting parameters, i.e., burden and spacing, were considered. The crusher parameters that affect energy consumption were also identified. A case study of an operating dolomite mine was performed. The results indicated that by changing the burden, spacing and crusher closed-side setting, the overall (blasting and crushing) costs could be reduced by 4.7% to 7.9% annually. It can also be concluded that burden and spacing values have a linear positive relationship with the crusher energy consumption, while closed-side setting values have an inverse linear relationship with the energy consumption.

Jan 1, 2007

By R. J. C. MacDonald

"The first recorded discovery of placer gold in Canada was on the Chaudiere River in Quebec's eastern townships in 1832 and the first major production came from placer deposits in British Columbia in 1858 (Verity 1974). Placer deposits were the major source of gold until the late 1890's, although lode deposits were found in Nova Scotia in 1862. In 1896 the Klondike Gold Rush commenced with the discovery of gold by Henderson and Carmack in the Yukon. The peak was reached in 1900 when over one million ounces of gold valued at approximately $22.3 million were recovered. With the exhaustion of the easily accessible deposits, more capital intensive operations were necessary such as those initiated in 1906 by the Yukon Gold Corporation. This giant dredging operation continued to produce until 1966. Today only a few small operations remain.The development of Canadian lode gold mining began in earnest around 1900 when the railroads were opening up the interior and western part of the country. At this time many discoveries occurred, particularly where mineral outcroppings were near surface. Tremendous impetus for exploration and the reopening of former producers followed the elimination of the gold standard by Great Britain around 1931, and more importantly the United States in 1933, with subsequent stabilization of the price of gold at $35 per ounce in 1934. Prior to this the price of gold was basically unchanged since 1717, approximately, $20 per ounce (Verity, 1974; Green, 1973).The depression of the 1930s adversely affected most industries, however for the gold producers it was a very profitable time. Prices of materials and equipment declined and labour was cheap and plentiful. Interest in gold mining was further stimulated in 1936 when a three year tax exemption was declared for all new metal mines. In 1938 a decline in the value of the Canadian dollar relative to the U.S. dollar benefitted the industry. The second world war provided yet again further incentive for gold production and in 1941 Canadian gold production reached a high of approximately 5.4 million ounces. This figure was not surpassed until 1991 when approximately 5.6 million ounces were produced (Natural Resources Canada, 1996 )."

Jan 1, 1998

By A. L. Engel

In recent investigations of chloride Volatilization of gold at the Reno Station, it was found that the addition of small amounts of copper and NaCl to the charge brought about improved volatilization of the gold. The investigations described in this report were concerned with the recovery, in an aqueous medium, of fumes from chloride volatilization of gold. It was attempted to discover a suitable aqueous medium that would permit absorption, solution, or precipitation of all the volatilized gold immediately upon contact with the medium. A simple laboratory apparatus was employed to produce fumes by volatilization. To this furnace was attached an absorption train consisting of a series of chambers containing the aqueous medium, through which the fumes were drawn by suction. A satisfactory synthetic ore that contained metallic, gold in a quartz-matrix was made and utilized, enough. gold being present in a' small amount of material to permit an accurate, metallurgical balance of the volatized values' to be obtained in all the experiments.

Jan 1, 1949

A large body of porphyry-type copper mineralization occurs at Panguna in southern BougainviIle. It is associated with the intrusion of quartz diorite/granodiorite into andesites, particularly with the contact zone. Metasomatism of both intrusives and andesite resulted in the formation of biotite pseudomorphing hornblende and the veining of the resultant biotite diorite and biotitized andesite by quartz-chalcopyrite veins with pink orthoclase and dark biotite selvages, respectively.The orientation of intrusives and veins appears to be controlled by premineralization fault-joint patterns in the intruded andesitic Kieta Volcanics.

Jan 1, 1968

By Martin H. Rogoff

This publication combines a critical review of the literature on the microbiology of coal with an introduction to those areas of microbiology related to studies of coal as a biological material. The attack on coal by microorganisms as yet remains doubtful. Only the low-rank coals contain an indigenous microbial flora, and even these organisms are not peculiar to coal, but are common soil and water forms. No experimental data have as yet been presented, either in the literature or in the present work, which unequivocally demonstrate the oxidation of coal by microorganisms. Reasons for the resistance of coal to such attack, including insolubility, physicochemical structure, steric hindrance of enzyme action, and the presence of antibiotic materials in coal are discussed. Microorganisms do attack large aromatic molecules and the mode of oxidation of aromatic ring systems by bacteria is presented. Well-defined pathways are known for the oxidation of polycyclic compounds with one to three rings, and these paths with their key intermediates are described and related to the possible oxidation of coal.

Jan 1, 1962