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By Wetzeil N

High ambient temperatures combined with high surface humidity in the north of Australia and, in particular, the northern areas of the Northern Territory can make underground workplaces relatively inhospitable at certain times of the year. . Woodcutters' silver/lead/zinc mine, situated some 80 km south of Darwin, would be the most northerly underground operation of any significance in Australia. As such, during the build up to the wet season, it has a particular problem of ventilating a deep underground mine with already high dry and wet bulb temperatures at the surface. The Mine Management Act and Regulations mention only that workplaces shall be 'in a fit state for a person to work in or occupy'. Woodcutters therefore set in progress a Heat Stress Program to endeavour to set standards which would be more measurable and justifiable. The aim of the program was to compile a record of ambient atmospheric conditions in the working areas such that areas and/or work activities generating high ambient temperatures and humidities could be identified, quantified and qualified. Once the analysis stage of this program was completed, Woodcutters compiled a set of recommendations for the continued monitoring for, and control of, heat stress conditions to ensure that no underground employee was placed at risk from 'heat stress'. These recommendations are discussed in this paper.

Jan 1, 1994

This paper considers the standard of ore reserve assessments required by lenders when presented to support requests for project based loans. The way lenders use this information to structure a suitable financial package shows why ore reserves should be measured by industry set standards. This in turn raises questions concerning the assumptions used to derive mineable reserves from geological reserves. Consideration of the variety of related problems highlights the need for assessments to be defined according to acceptable standards. These should also address the suitability of the methodology to the assumed configuration of the orebody; the degree of variance and relaibility of estimates of grade and tonnage presented; and the estimation of probability that ore will in practice fall within the defined limits. In an increasingly international marketplace it is appropriate to compare Australian industry requirements to those of similar overseas industries, in this case the United States. Lenders would like to see that individuals responsible for the preparation of ore reserve estimates are certified on the basis of their skill and expereince by an industry body such as The AusIMM. The paper discusses how each of the parameters indicated above may impact upon a lender's assessment of the viability of a project. A number of practical examples are presented where inaccuracies or inadequacies in ore reserve information have led to reduced project performance.

Jan 1, 1987

By C. H. Johnson

The Big Jim mine of the United Eastern Mining Co. is at Oatman, Mohave County, Ariz. Oatman is in the foothills on the western side of the Black Mountains, at an elevation of about 3,000 feet. It is on a paved highway about 30 miles west of Kingman, the principal distributing; center for mining supplies in the district, and 25 miles from Topock, en the Colorado River. Both latter towns are stations on the Santa Fe Railroad; Oatman has no roil connection. Mining conditions are typical of western Arizona; water is scarce, no mine timber is available locally, and the winters arc mild and the summers hot. The supply of a killed labor is usually adequate, but in 1933-34 it w not more than sufficient for the restricted operations. Wages have been $4.00 to $4.50 for miners. Electric power was supplied from Kingman and cost about 2.6 cents per kilowatt-hour.

Jan 1, 1935

By T. E. Masoner

The struggle to get the minerals industry seriously interested in high intensity wet magnetic separation* has been difficult. The high capital cost of the equipment, the lack of basic research, the lack of operating information, and the diverse characteristics associated with different minerals and ores have prevented the development and use of HIMS-W on a wide scale. The Climax Molybdenum Company, a Division of American Metal Climax, Inc., located at Climax, Colorado, was among the first companies in the Americas in recent years to support the development of HIMS-W to recover weakly magnetic minerals on a large scale. The Climax Molybdenum Company, one of the world's largest underground mines, processes about 40,000 tons per day of ore, from which about fifty million pounds of molybdenum disulfide are produced each year. By-products include tungsten, iron pyrite, tin, and some monazite.

Jan 1, 1968

By D. S. Scovira, T. Gustavsson

Exiting WW2 (mid-1940s), the potential of nitrates (ammonium nitrate, calcium nitrate, sodium nitrate) and hydrogen peroxide for application as a commercial explosives for mining, construction, and other industrial purposes both became known. The technology stream advanced the development and uptake of nitrate based explosives to the point that they are the current global standard for blasting. Today, environmental issues are shaping the strategic agenda across various industries. Most global mineral resource, construction houses, and explosive manufacturers have publicly announced ESG carbon reduction commitments in support of COP26 Net Zero 2050. The mid-2010s saw a renewed interest in hydrogen peroxide explosives to eliminate NOx fume. Carbon reduction initiatives in the early 2020s provided additional impetus to investigate hydrogen peroxide based explosives for industrial use. Hypex Bio has recently pioneered the formulation, manufacture, and end-use delivery of a Hydrogen Peroxide Emulsion (HPE) on an industrial scale. The HPE is composed primarily of hydrogen peroxide (H2O2) plus a lesser amount of fuel and emulsifier phase. The base HPE is produced in a low energy intensity modular plant using industry proven mixing techniques. The base HPE is a white, highly viscous emulsion that is similar in consistency to base nitrate emulsions. To enable end blasting use, a mobile charging unit gases the base HPE to a detonable density. The HPE is compatible with current priming and initiation systems. Hydrogen peroxide explosives offer a significant reduction in total carbon emission as compared to nitrate based explosives. The production of ammonium nitrate (AN) emulsion is energy-intensive and not carbon neutral. Based on the EU Average and for the oxidizer phase only, 1 kg [2.2 lb] of AN emulsion emits 2.3 kg [5.1 lb] of CO2 as compared to the production of hydrogen peroxide emulsion that results in 0.23 kg [0.5 lb] of CO2. This is a difference of 90%. HPE contains no nitrates and does not generate post blast nitrous oxides (NOx). HPE generates no aqueous nitrate or ammonia pollution and is a solution to meeting increasingly regulated mine site water discharge limits. Hypex Bio recently conducted a successful underground HPE evaluation with a major mining company in Sweden. HPE blast designs were the same as those done with nitrate based emulsions. Rock breakage, advance, muck displacement, and excavator performance were equivalent. Ventilation and re-entry times were reduced. The mining company has expressed further interest in assessing HPE and is demonstrating industrial leadership by exploring this transformative explosive technology

Jan 1, 2024

Due to complex mineralogical and chemical interactions of the value and gangue mineral phases present in uranium-containing lateritic ores, deleterious pulp gelation which impacts on value metal recovery sometimes occur during atmospheric leaching. In this study, the leaching behavior and particle interactions of selected oxide (hematite, quartz) and clay minerals (muscovite, chlorite), which constitute predominant host gangue phases of typical lateritic uranium ores are investigated to provide basic, mechanistic understanding of temporal pulp gelation phenomenon. Isothermal, batch leaching with H2SO4 was carried out on concentrated dispersions (30 ? 57 wt.%) of single minerals at pH 1 and 25 or 70 °C and their concomitant solution, speciation and rheology (shear yield stress, viscosity) were characterized. It is clearly shown that despite the high oxide content of lateritic ores, the pulp chemistry and rheology is largely affected by the incongruent leaching behavior of more reactive, acid-consuming aluminosilicate clays. Furthermore, time- and temperature-dependent alumino-silicate species polycondensation interfacial reactions are shown to be responsible for the enhanced particle interactions, reflecting strong pulp rheology in agitation and pumping. If not properly mitigated, high pulp shear yield stress and viscosity have a striking impact on processability and hence, value metal recovery.

Sep 1, 2012

By M. Tangstad, J. D. Steenkamp

In April 2013 a 48 MVA submerged arc furnace producing silicomanganese was excavated in South Africa. Since the high shell temperatures recorded in the tap-hole area resulted in the furnace being switched out for relining, the tap-hole area was excavated systematically. A refractory wear profile of the tap-hole area with affected hearth and sidewall refractory was obtained in elevation. The carbon ramming paste in front of, above, andbelow the tap-hole was worn, as was the SiC with which the tap-hole was built. A clay mushroom formed but was detached from the refractories. Thermodynamic and mass-transfer calculations were conducted to quantify the potential for wear by chemical reaction between refractory and slag and refractory and metal in the tap-hole area. It was found that chemical reaction between refractory and slag or metal could offer only a partial explanation for the wear observed; erosion is expected to contribute significantly to wear.

Jan 1, 2015

By Georgene Renner, Chee Theng, William Gleason

"More than 6,300 people attended SME’s 2016 Annual Conference & Expo in Phoenix, AZ and many of them made the trip to the conference to take part in the excellent technical sessions that are presented on a yearly basis by the Society.Holding true to form, this year’s conference was full of options. In fact, this year there were 121 technical sessions and 751 presentations to chose from. The following is a sample of some of the technical sessions as seen through the eyes of the editors of Mining Engineering and SME technical papers.SME Sections Sharing Success: Changing thePublic Perception of MiningThis session was a workshop on how several local sections were effective in getting the message out to their communities and schools about the value of the extractive minerals industry. Several sections shared their outreach successes, including the Mining in Society merit badge activities by the Minnesota Section by Julie Lucas and SME’s participation in the World Scout Jamboree in Japan by Frank McAllister.Dan Alexander highlighted activities by the Pittsburgh Section, such as preparing minerals kits and pamphlets for elementary school classes and regional science fairs. The West Virginia University Student Chapter used the kits as handouts at their local gem and mineral show. School speakers in full mining gear were especially interesting to the young children.Other speakers were Michael Linn, Paradise Valley Unified School District — Business and School Partnerships; and Greg Kruse, Central Wyoming Section of SME — What makes a successful section?Engineering Competency ModelAmerican Association of Engineering Societies and the U.S. Department of Labor, with a grant from the United Engineering Foundation, developed a guide to the set of skills necessary for success in the engineering community -- Knowledge – Skills – Abilities — needed for all disciplines.Various engineering societies are now writing the Tier 5 occupation-specific requirements. The Competency Committee is charged to write concise and discipline-specific mining engineering, mineral processing engineering, geological engineering, and geophysical engineering by Sept. 30, 2017."

May 1, 2016

By L Eriksson, D Penn, J Appelgren

Atlas Copco, a leading supplier of equipment and services to the mining and construction industries, is consistently pursuing its strategy to offer the most productive and economical solutions by continuously offering new innovative products. These are, in most cases, developed and tested in close cooperation with demanding end users before being officially launched on the international market. The demands for higher productivity and improved overall economy have resulted in systems for automation of the drilling cycle and also tools for integrating the drilling equipment to the production control system used by the customer. In terms of improving the blasted material quality, the company has placed emphasis on accuracy in the drilling process and documenting what has been drilled. By applying state of the art technology to the common automation platform, developed for the surface drilling market, major steps in improving overall drilling productivity and blasting performance have been achieved. This paper will give some examples derived from the latest development of solutions for the companyÆs surface drilling products.CITATION:Appelgren, J, Eriksson, E and Penn, D, 2012. Rotary drilling automation increasing operator productivity and drilling quality, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 13-18 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

By Roland W. Rammler

In recent years, the crude oil reserves of the world have increased at the same rate as the consumption. A Consideration of the global figures suggests that adequate supplies of petroleum will be available during the next decades. On the other hand, it in a fast of economic and political significance that the reserves in the industrialized countries increase much more slowly than in the developing countries. In Western Europe the reserves have even decreased. At the present time, about 70 % of the petroleum reserves of the world are in the Middle East and in Africa in regions in which political arises are prevalent or impending. For the industrialized countries, the discrepancies between the consumption and reserves in various regions of the world are a strong urge to investigate whether oil can be recovered from other sources. The situation will probably not be changed to a large extent by the discovery of oil in the north of Alaska. The main starting materials for the production of synthetic crude oil are coal, oil shale and tar sand. In North America, where the consumption of petroleum increases more rapidly than the reserves, there are enormous deposits of each of the three materials. This fact is another incentive toward the utilization of these unconventional oil reserves, which provide a reliable basis for a supple of energy for a long time to come.

Jan 1, 1970

By Beatriz Pereda, Ana Clara Fonseca da Silva, Tiago Seixas Bittencourt

Reinforcing steel bars are usually specified based on mechanical properties with flexibility in chemical composition and processing. Most developments, in these steels, are normally focused on alloy and process design to reach minimum cost and conformity to specification. Processing routes using quenching and self-tempering (QST) and accelerated cooling are the most common. Microalloying with V and Nb have been used in rebar. When acicular constituents must be avoided, a combination of Nb microalloying with judicious control of cooling is one of the preferred options. Niobium can contribute to improvement in tensile properties through austenitic grain size control during hot working, precipitation hardening due to carbonitrides or clusters, and hardenability increase. In the present work the alloy design and development processes of a Nb microalloyed steel for rebars are presented. The designed steel has fulfilled the required specification and is under regular production. Austenitic grain size refining – when comparing with the “basic composition” normally used was observed, even without any change in the thermomechanical processing cycle. There are indications that precipitation hardening may also occur. Results indicate that Nb is a good alternative as a microalloying element in rebars.

Oct 1, 2019

By S. D. F. Rocha1, L. Katsarou, G. P. Demopoulos

"Crystalline scorodite (FeAsO4·2H2O) has been pointed out as the most stable compound to immobilize arsenic for disposal due to its good stability performance according to EPA’s TCLP test. However, in anaerobic conditions, arsenic releasing is increased to undesired levels due to scorodite reductive break down, in eh <100 mV at 5.5< pH <7 which causes contamination of groundwater. In this work, the concept of encapsulation by controlled deposition of mineral coatings immune to pH or redox potential variations is presented. Aluminum and calcium phosphates were evaluated as coatings and the release of arsenic from scorodite previously coated with phosphates was substantially decreased when compared to the VALUES (obtained from crude scorodite, both in oxic and anoxic conditions. INTRODUCTIONThe widely acknowledged hazardous properties of arsenic as a soil and natural water contaminant and its adverse health effects when present in drinking water have led to very strict environmental regulations (Mandal & Suzuki, 2002) aiming at the drastic reduction of the presence of arsenic in the effluents of the mining and metallurgical industries.In Canada, the Metal Mining Effluent Regulations (Government of Canada, 2002) dictate that the maximum monthly mean concentration in tailings for arsenic must be lower than 0.5 mg/L. At the same time the new Environmental Protection Agency’s (EPA) standard for drinking water foresees concentrations of arsenic less than 0.01 mg/L, which means that the leachability limit for the industrial waste is set at 1 mg/L arsenic (EPA, 1994; Le Berre et. al, 2007). One of the preoccupations of the mining and metallurgical industries is directed to the elimination of arsenic presence in all its effluents, especially since arsenic is commonly found in many ores mainly in the form of oxides and sulphides. After processing of arsenic-containing ores and concentrates, arsenic can be present either in solid residues and tailings, liquid effluents or in flue dusts. Several of these forms of arsenic waste materials are soluble and therefore may cause the contamination of ground water, if disposed of without further treatment."

Jan 1, 2012

By Walter D. Holland

LFE Environmental performed an Industrial Hygiene survey of the Paraho Oil Shale Mining and Processing facility in Anvil Points near Rifle, Colorado, on August 6 and 7, 1975. This survey consisted of an investigation of the underground operations for diesel emission contaminants and of the above ground work areas for all inhalation contaminants other than silica dust. Samples were collected to investigate the following contaminants: respirable dust, total dust, NO2, NO, H2SO4, formaldehyde, CO2, S02 and CO. None of the determinations of contaminants in the underground operations indicate air concentrations exceeding their standards. The results for the samples collected above ground indicate only one operation where the employee&apos;s exposure exceeds the standards. It is a welding operation where the standards for total dust and lead are exceeded. Since the survey the employer has installed an exhaust ventilation system which has significantly reduced the welder&apos;s exposure.

Jan 1, 1976

By The Staff, Explosives Research Center

The principal activities of the Bureau of Mines Explosives Research Center from July 1, 1962, to June 30, 1963, are described briefly in part 1. Part 2 gives short abstracts of publications that appeared during fiscal year 1963; in general, the research reported in these publications antedates the report period.

Jun 24, 1964

By A. E. Nagel, J. E. Carpetta, M. G. Zabetakis, T. D. Moore

The method of moving averages was found useful in assessing the nature of methane emission in coal mines. Emission rates were influenced markedly by the presence of abandoned oil and gas wells in the vicinity of the mine. Such wells appeared to increase the flow rate of methane into the mine by a factor of 2 to 30 in an active mine in the Pittsburgh coal seam.

Jan 1, 1972

By Woolf, W. G.

Filtration of hot (60°C) supersaturated zinc sulphate solution (sp gr 1.540) from slimy leach residues at the electrolytic zinc plant of Sullivan Mining Co., Kellogg, Idaho, is de- scribed. Separation of liquids and solids in the finished leach is by Burt filters modified to meet conditions of high-acid, high-density process for electrolytic zinc. Operating characteristics of the Burt filter on this pulp are presented.

Jan 1, 1950

By Y. Miron

&apos;This report presents a U.S. Bureau of Mines study to identify the causes of self-heating events beneath the floor of a deep underground coal mine. Mine samples from both heated and unheated areas were examined by various techniques, including visual, microscopic, thermal, chemical, and instrumental tests. The combined results led to the conclusion that pyrite (FeS2) oxidation was the prime cause of the beatings. However, adiabatic oven tests of selected samples did not indicate the effect of the pyrite on the self-heating process, probably because of the experimental conditions. A fast, simple procedure to assess the concentration of pyrite in the mine samples was developed, g the reactivity of the sample with an aqueous solution of hydrogen peroxide (H2O2).

Jan 1, 2010

Norton Co., the world&apos;s largest producer of abrasives, is enlarging its proppant operation. Proppants are strong chemical particles used to wedge open rock formations in deep oil wells, thereby increasing the well flow rate, sometimes as much as tenfold. Norton" aluminum oxide-based proppant is rapidly displacing less durable materials. The company is building the world&apos;s largest proppant plant in Fort Smith, AR. ALUMINUM--See also REFRACTORIES The price of primary aluminum ingot was increased by several producers in July. Kaiser Aluminum & Chemical Corp., and Revere Copper & Brass Inc. increased the price of primary aluminum to 63.0 cents per pound, effective July I. Reynolds Metal s Co., Anaconda Aluminum Co., Howmet Aluminum Corp., and Marti n Marietta Aluminum Inc. increased the price of 99.5% primary aluminum ingot to 63.0 cents per pound, effective July 5, The Aluminum Company of America increased the price of aluminum ingot to 62.5 cents per pound, effective July 9. The range of prices at the end of the month was 58.5 to 63.0 cents per pound.

Jan 1, 1979

By Vincent A. Scovazzo

During the winter months of late 1985 and early 1986, residents along Dry Fork near Grundy, Virginia (United States) experienced seismic events that they attributed to longwall mining at Island Creek Corporation’s (Island Creek) Virginia Pocahontas Mine No. 3 (VP-3 mine). Island Creek contacted STS D’Appolonia Ltd. (STSDL) on March 7, 1986, to investigate these events. An STSDL representative, Vincent Scovazzo, interviewed residents of Dry Fork on March 10, 1986. It was noted that only people within a residential structure felt the events they described as house shaking, vibrating walls, and ceramics falling from shelves. STSDL representative installed a blast monitor at a residence. Within 2 days, various events were recorded. Some could be attributed to truck and heavy equipment movement. Eight events had no obvious cause but appeared on resident’s written logs as earthquakes caused by mining. STSDL contacted Utah Geophysical, Inc. who had developed a technique to determine the mode of rock failure using the seismic record. Utah Geophysical was engaged to install and monitor a microseismic network, locate the epicenter of the events, and work with STSDL in determining modes of failure. The network was comprised of six geophones located at five stations. Data was recorded for 24 days from May 20 through June 13, 1986. The data was filtered to eliminate events determined to have an origin other than the longwall panels’ overburden and under-burden. The larger events from this filtered data set were selected and analyzed to determine their hypocenter locations, time of occurrence, magnitudes, and failure mode. Processed data was interpreted, tabulated, and plotted by STSDL to provide information relative to the sources of the seismic vibrations and their possible relationship to the mining operation.

Jul 1, 2023

By C. T. Anderson

In July 1947, the U. S. Bureau of Mines, in cooperation with the Air Materiel Command, started an investigation of zirconium alloys with the object of determining the suitability of such alloys for high-temperature applications. This report covers the preliminary study of about 25 zirconium-rich alloy systems with respect to preparation, fabrication, tensile properties, metallographic structures; constitution, and heat resistance. Obviously, each system could not be investigated thoroughly, and this publication can be regarded only as a first approach. The more promising individual alloy systems will be studied in greater detail and reported in subsequent publications. The study of zirconium alloys on such a scale has been made possible by the U.S. Bureau of Mines developments in the past 5 years On producing zirconium metal. This basic process is similar to that developed by Kroll for producing ductile titanium metal and consists essentially of reducing zirconium chloride by means of molten magnesium. The Northwest Electrodevelopment Laboratory at Albany, Oreg., has produced several thousand pounds of ductile metal in this manner and has a pilot plant producing over 300 pounds of metal per week. Alloys were prepared by melting Bureau of Mines zirconium and the best available grade of alloying element in graphite, with suitable provisions for preventing oxidation. The ingots were quartered longitudinally and sheath-swaged at 850° c. to 3/8-inch diameter rod. Two of those rods were send to Wright Field for room-temperature and 1,200° F. tensile properties. The remaining two sections were used for metallographic, hardness, heat-treatment, and heat-resistance studies. The salient features of this investigation are summarized in table 1.

Jan 1, 1950