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By M. Szumny, P. Mertuszka, K. Fuławka

Mining-induced seismicity is one of the adverse side effects of mining with the use of explosives at great depths. Disturbance of the primary stress state by the development of the network of excavations combined with the continuous generation of dynamic loads by the detonation of explosives in mining faces has a negative impact on the level of safety of crew and machines. To ensure the stability of excavations it is necessary to identify in detail the nature of the seismic hazard by means of continuous seismic measurements. Unfortunately, the technologies used so far are characterized by high costs of installation and further maintenance, which clearly limits the possibility of using a large number of stations in a small area. A breakthrough in this matter may be the technology of microelectromechanical systems, which is several times cheaper than standard solutions used in mining seismology. This technology, with the appropriate configuration of devices, can be successfully used to monitor dynamic phenomena generated by mining activities. As part of this study, the assumptions and configurations of a prototype 42-channel accelerometer network using MEMS technology have been presented. The network was installed in the Lubin underground copper mine in Poland in a seismically active area, where multi-face destress blasting are conducted regularly. As a result, 14 tri-axial accelerometers were installed in the immediate vicinity of the active mining front at a distance of about 1,000–4,000 ft (300–1,200 meters) from the closest faces. Highfrequency recordings are collected based on algorithms that trigger the system when the Peak Particle Acceleration set value is exceeded or on the basis of a manual external triggering device connected to the blasting machine. During the measurement period, several high-energy seismic tremors and several dozen of waveforms generated by blasting were recorded. The obtained results are the basis for assessing the effectiveness of the destressing measures and for the analysis of geomechanical risk based on periodic analysis of the velocity of seismic wave propagation

Jan 1, 2024

By G. R. FITT, S. R. B. Cooke, C. W. Davis, V. H. Gottschalk, C. G. Maier, C. E. Wood, R. S. Dean, S. B. THOMAS, John Gross, E. P. Barrett, T. L. Joseph

Lack of funds has prevented publication of much of the metallurgical work of the Bureau of Mines during the past 2 years . The present progress report covers studies in the direct production of iron and steel . The experimental work was carried out in cooperation with the universities of California , Minnesota , and Missouri . Complete reports will be published when funds are available .

May 1, 1934

By Rushikesh Battulwar, Javad Sattarvand, Joseph Seamons, Masoud Zare

In the last decade, new developments took place in the area of indoor positioning (or localization). Since the Global Navigation Satellite System (GNSS) cannot be used in underground mines, other technologies are needed for localization. Positioning and communication options today primarily include Wi-Fi, Bluetooth Low Energy (BLE), Ultra-Wideband (UWB), Radio Frequency Identification Device (RFID), etc. Smartphones and tablets currently have an array of sensors and radios, which can provide valuable information to allow indoor localization via various methods. Where mineworkers could keep smartphones with them, they can be highly effective at enabling localization and navigation. Recent applications of these technologies in underground mines have been thoroughly reviewed and examined for the likelihood of their utility for accurate localization where no other means exist. Some critical challenges and gaps that need to be addressed in future research have been identified.

Sep 5, 2021

By Adolf Mikula

Lead-tin solders are commonly used in electronic packaging due to their unique combination of electrical, chemical, physical, thermal and mechanical properties. Since it is known that lead and lead containing alloys cause great environmental concern and health hazards it is necessary to replace lead in solder materials. Besides the environmental concerns new technologies in electronic packaging require new and improved solders. In most cases the new solders will consist of ternary or quarternary alloy systems, the main component will be tin or indium and the second element could be bismuth, silver, copper and gold and to improve certain properties a third element will be added. For a third element zinc, nickel, antimony and aluminum can be considered. This report will concentrate on solders containing zinc as an environmental safe element.

Jan 1, 2003

By P. Hale

"The trend to drives of more than 10,000 hp on large-capacity ball and autogenous mills for increased operating efficiency has been limited by factors in the conventional drive system. A solution to this problem, using modern developments in static converter technology, is the concept of driving the mill directly without gearing using a low-speed, low-frequency synchronous motor with a cyclo-converter power supply.This paper presents various practical arrangements of mill and low-speed motors giving the specific advantages of each system. The means of controlling inrush currents on starting and of spotting by the use of variable-frequency control are outlined in general form. Several gearless ball mill drives are scheduled for start-up in European cement plants and further orders have been placed."

Jan 1, 1970

By W. Drummond

The cooling of smelter gases by air dilution, adiabatic evaporative cooling and indirect heat exchange is discussed with reference to the process, to the subsequent cleaning of the gas. and to the use of the heat extracted from the gas. The method of reducing the effect of acidic sulphide formation on the corrosive properties of the gas and the dust and the development of surface cleaning mechanisms?are discussed. The development of indirect recuperators using air, water or steam cooling, made possible by the control of surface fouling is traced. The application of the modern Waste Heat Boiler to the new sulphide smelting processes is discussed with respect to the natural and forced circulation concepts. Case histories are presented to illustrate mistakes made with respect to designs produced without recourse to sensitivity analysis and without an appreciation of "worst process? conditions".

Jan 1, 1992

By J. Hadjigeorgiou, T. R. Stacey

This paper introduces the Quantified Value-created Process (QVP), a decision-making process for use in mine design and operation. The implementation of the QVP is founded on a ten-step rock engineering design process and a ten-step strategic planning process. The potential of this approach is demonstrated by examples of value created as a result of good research, design, and planning. The QVP is divided into two parts, namely, a ‘planning the process’ section and an ‘implementing the process’ section, and can be considered to be an extension of the risk approach. All costs, direct and indirect, associated with a significant mining decision (design, operational, investment) must be quantified in advance of committing to that decision, to determine the value that will be created in the short, medium, and long terms. Ethical values, associated with health, safety, the environment, public perception, and social aspects, may be difficult to quantify in economic terms, but must nevertheless also be considered. In contrast with a traditional risk approach, the QVP will identify the upside, and allow executives to make more informed strategic decisions. In this context it is essential to actively engage upper management in the decision process.

Feb 2, 2022

By O. W. Ellis

Introduction During the month of September, 1928 enough money had. been promised by private individuals and corporations to comply with the Research ?Foundation Act 1928 (Chapter 57, 18 George V) of the Province of Ontario. The Ontario Research Foundation (referred to below as O.R.F.) may be said to 1iave come into being at that time. Under the terms of this Act, the Treasurer of the Province was empowered to match dollar for dollar of the sums subscribed by private .corporations and individuals up to a limit of $1,000,000. However, the response to the appeal for this by the Premier of the Province, the Honourable Mr. G. Howard Ferg uson, was so exceptional that the Act was amended in 1929 so as to empower the Treasurer to increase the maximum contribution on the part of the Province to $2,500,000. In March, 1933, the Chairman of the Foundation, Sir Joseph Flaville, Bart., was able to report that, in the interval between the Premier's appeal and December 1st, 1932, private enterprise had paid ?into the treasury of the Foundation $1,670,050, and that the Provincial Treasurer had assumed responsibility for a like sum. The endownment Fund of the Foundation was, therefore. $3,340,100. This sum was ?invested a lm~ s t entirely in Government securities, in securities guar. anteed by the Government, and in 1mmicipal securities. Sir Joseph Flavelle remarked at that time that "The payment of $1,670,050 to the Endowment of the Foundation by private persons and corporations is a somewhat remarkable performance when it is remembered that for three of the five years the business of the country has been suffering from a severe depression". Since that time it has been the consistent policy of O.R.F. to live within the income derived (1) from the investment of its Endowment Fund and (2) from fees collected for services rendered.

Jan 1, 1950

By L Clarkson, D Williams, P Redcliffe, F van der Wal

This research presents a snapshot and insight into the trends, patterns, and common considerations identified in the current standing of real-time tailings dam monitoring practice. Based primarily on information derived from concurrent research by the author (in form of a Catalogue of Real-time Instrumentation and Monitoring Techniques for Tailings Dams), challenges and opportunities when transitioning to a real-time monitoring system are discussed. Learnings and key considerations between different monitoring approaches are explored, including themes of limitations and advantages that were observed consistently through global supplier feedback.

Jul 1, 2021

By Loui Geoffroy, Philippe Gaultier, Martin Piotte, Claude Coache, André Drouin

"Automatic driving at high speed of an underground truck was tested at Brunswick mine in September 1995. Modifications to the truck included: a remote interface to control actuators, front and back video cameras to follow a roof mounted optical guide and proportional hydraulic controls on the steering.The mathematical model of the hydraulic system was adjusted using least square regression. The steering data, used in calculating the regression parameters, were acquired from the moving truck. The automatic steering control used three measured variables: lateral deviation, angular deviation and steering angle. Lateral deviations are obtained using the cameras, which are in continuous view of the guide, while steering angles are acquired from an extensiometer placed at the articulation point of the vehicle. Gain scheduling was used to compensate for vehicle speed and available hydraulic flow. Non-linear characteristics of the modeled hydraulic system were offset using open loop compensation.Speeds up to 23 km/h in forward direction and 13 km/h in reverse were achieved deviaduring continuous testing along one of the mine’s production drifts. Proportional steering was essential in achieving high speeds, as it enabled more precise positioning of the vehicle’s steering direction while reducing the abuses on cylinder and cylinder pins via diminished oscillations about the optical guide at high speeds."

Jan 1, 1997

By L. G. Marshall

This report presents a cross section of the sand and gravel operations in the Minneapolis-St. Paul area. The study covers individual operations, economic problems peculiar to the industry, glacial geology of the area and its effect upon the grades and types of products, and past, present, and future trends of the expanding population and its effect upon the industry.

Jan 1, 1963

By L. G. Marshall

This report presents a cross section of the sand and gravel operations in the Minneapolis-St. Paul area. The study covers individual operations, economic problems peculiar to the industry, glacial geology of the area and its effect upon the grades and types of products, and past, present, and future trends of the expanding population and its effect upon the industry.

Jan 1, 1963

By A. C. Fieldner

This report, the third of a series of annual reports of research and technologic work on coal by the Technologic Branch to be released in this form, covers the fiscal year July 1, 1937, to June 30, 1938. Ever-increasing demands for information on the chemical and physical properties of coals, their proper classification rind adaptability for various uses, their economic evaluation in the complex relationships between the costs of production, distribution, and selling, and their beneficiation and amenability to conversion to more valuable and. new products of commerce have necessitated an appropriate and flexible program. To most these requirements, initiation of new projects and new physical facilities has been made.

Jan 1, 1939

By M Warnken

Major cities are not only the focal point for AustralianÆs work, leisure and homes, they also are the focal point for the flow of resources into the built environment, motor cars and transportation and urban consumables. The steady increases in æstockÆ and waste generation, in line with GDP growth, means that cities will become the mine sites of the future if the inherent value is recovered from these materials at end of life. The urban waste stream can be characterised as containing approximately nine per cent hydrocarbon-based materials; 57 per cent biomass-based material; 28 per cent fully mineralised materials that are inert, five per cent metals and less than one per cent of problematic materials that are potentially hazardous and toxic. In order to convert these wastes into value added inputs into the economy, a number of technological interventions are required. These æurban waste mining techniquesÆ revolve around source separation and material streaming. One issue that needs to be overcome when determining which mining technique to implement, is identifying the option that will deliver optimal value, both from a financial and a sustainability perspective. The difference between embodied energy and calorific value is a case in point. Highest net resource value (HNRV) is a concept that can assist in choosing between different resource recovery options. The assessment can be done at a strategic level, or can be used to work out material specific issues. For example, used tyres can be recovered for their energy content at an approximate cost of $120 per tonne, whereas mechanical processing of used tyres can deliver a net benefit of $192.

Jan 1, 2006

By G. Deschênes

"In 2013, as the prices of precious metals dropped, investors moved their positions to equity markets for higher returns. As a result, the price of gold dropped further to below US$1200 per ounce, prompting additional substantial outflows from gold investments. In response to lagging gold prices, major gold producers initiated large asset write-downs and cost-cutting programmes. In 2015, this trend continues and gold mining stocks are close to lows not seen since the global financial crisis (GFC) of 2008. In the current economic climate many projects have marginal economics, and the number of projects that have competitive development and production costs is declining. A competitive edge is particularly important with the decreasing grades of orebodies, increasing complexity of the mineralogy, and increasingly demanding environmental constraints. In addition, higher cost producers seek to optimize their process t o reduce operating costs.This paper presents some highlights of three case studies on optimization of gold leaching strategies that improved the economics of brownfield projects. Processing of sulphide-bearing ores was optimized by using the synergy between cyanide, lead nitrate, and oxygen. The outcomes were significant reduction of retention times while maintaining or increasing gold extraction and reducing cyanide addition and effluent treatment costs. A stirred tank reactor experimental programme led to direct implementation of reliable leaching strategies from laboratory scale to production. This approach resulted in savings of $2.2 million to $15.2 million on the three brownfield projects discussed in this paper."

Jan 1, 2016

By GERALD H. HUTTON

SINCE the inception of dredge mining, the attention of engineers and operators has been directed primarily toward mechanical improvements and refinements calculated to, reduce operating costs and to increase recoveries. The result has been to develop an efficient excavating and value-saving machine, which, in some instances, has an actual capacity of 15,000 cu yd. per day. Steel hulls and superstructures minimize the risk of destruction by fire and lengthen the life of the plant. Dredges now restore, to some extent, agricultural possibilities to mined ground. Large buckets, with correspondingly heavy parts, are able to handle heavy wash and massive boulders. Mechanical weaknesses have been strengthened. The use of manganese steel in bucket lines and tumblers permits the application too the bank of a digging force that can be withstood only by solid material, such as rock, cement or frozen ground. Various alloys of steel have been applied to certain duties and experiments in their heat treatment are still progressing. Haulage by tractor or truck is in common use. Discarded and worn steel parts are repaired or rebuilt by the use of the oxy-acetylene flame and the arc-welding machine. Gold and platinum saving is more efficient, although still subject to improvement. Dredging for tin ore is in successful operation. Crews are now highly specialized and experience has developed improved methods of work; particularly in the manipulation of dredges to build levees of tailings and to leave open waterways where desired. To sum up by the distribution of overhead expense over several units, ground under favorable conditions can now be dredge-mined for 5)2 c. per cu: yd., in spite of the increase in cost of supplies, power, and labor during, the past few years. Improvements in prospecting methods, however, have not kept pace with mechanical developments. Standard practices of ; testing ground today produce only wide approximations of values; although they obtain information concerning the character of the deposit and bedrock. It is interesting to note that few important changes in the methods of ten years ago are .to be recorded; the latest comparisons between pros¬pecting results and mined recoveries-have been at such variance as to cause confusion to the operator, and, in a degree, the sacrifice of the confidence of the capitalist. On this account, and because the growing scarcity of dredging ground. demands closer calculations on the part of the engineer, this appeal for collaboration and

Jan 1, 1921

By Frank E. Cash, Max S. Petersen

The use of safe equipment, safeguards, and safe practices in the mining and allied industries should reduce injuries and improve accident experience. The object of this report is to give to the mining industry, especially metal mining, a graphic pictorial description of some of the safeguards, equipment, and practices used and followed in the iron-ore mines of the Lake Superior district. Some of the subject material has been in use or has been established for many years, and some is relatively new. Some of the equipment was purchased commercially, and some was designed by the company employees and constructed in the mine shops. The photographs were taken by the personnel of the Health and Safety Division of the United States Bureau of Mines, primarily for use in the Metal-Mine Accident-Prevention Course of the Bureau of Mines. In general, they are arranged under the following headings or subjects: 1. Accident statistics. 2. Support of ground. 3. Hoisting and haulage. 4. Explosives. 5. Fires, gases, and ventilation.

Oct 1, 1948

By R. R. Sayers

That the maintenance of proper air conditions is a most important factor in the control of occupational hazards is shown by the large amount of material presented each year through the technical journal's on the effects on workers of injurious dusts, gases, and variations in temperature and humidity.. SUMMARY OF RECENT LITERATURE ON EFFECTS ON WORKERS OF EXPOSURE TO DUSTS The subject of the control of dust and dust diseases continues to be a matter of serious concern in most of the industrial countries of the world, as indicated by the following summary of reports published in a number of foreign countries as well as in the United States. Australia. The Workmen's Compensation Act of 1920 for New South Wales3 provided for the promulgation of schemes for the compensation of workers dis- abled by silica or other dust. In 1924 the prevalence of silicosis and tuberculosis among Sydney stonemasons, quarrymen, sewer miners and rockchoppers was investigated by a Technical Committee of Inquiry, appointed upon the recommendation of the New South Wales Board of Trade. The findings of this committee were published by the Government in 1925. No scheme was promulgated by the Government and in 1926 the Act was amended limiting its scope to workmen disabled by disease caused by silica-dust. This was promulgated and gazetted on September 16, 1927, and applies to men working in sandstone as stonemasons, quarrymen, rockchoppers, and sewer miners in the County of Cumberland.

Feb 1, 1931

By Norman A. Grant

"Location and Transportation FacilitiesTHE BEAVERLODGE area of North Saskatchewan is on the north side of lake Athabasca, 500 air miles northeast of Edmonton.The main Eldorado operation and townsite are on the north •side of Beaverlodge lake, which is immediately north of lake Athabasca and is separated from it by only a mile long portage at Lodge bay. The once famous town of Goldfields. Saskatchewan, and the Box property of the Consolidated Mining and Smelting Company of Canada, Limited, are located on lake Athabasca nine mines from Beaverlodge townsite.Previously, all Eldorado freight was delivered by barge at the Lodge Bay portage, hauled across the portage, and across Beaverlodge lake by small Northern Transportation Company barges, which involved many handlings.In 1952 the port of 'Bushell' was established at Black bay. This is a particularly snug harbour, well protected from the main body of the lake and with good foundations for docking facilities. A Butler building, 300 ft. by 60 ft., and tank farms provide storage at the port. A •road from Bushell to the main Beaverlodge operation, a distance of twelve miles through rugged terrain, was built by the Saskatchewan Government. The cost was shared by the Saskatchewan Government, the Federal Government, and Eldorado and other mining companies.Along this road are located the properties of several enterprising mining companies and near the midpoint lies the ambitious budding town of Uranium. This road has made portaging unnecessary and palletized freight loaded at Waterways, Alta., is now loaded directly on trucks at Bushell and delivered to the point of consumption."

Jan 1, 1953

By J. L. Thornton

Introduction The importance of coal in our economy is well established, but it may not .be so generally realized how important a part it plays in our daily life. Select a product - any product - and, if it is made in America, bituminous coal has touched it first. Everywhere we will find coal, derivatives of coal, or functions made possible by coal. Apart from the well known major uses of coal for domestic purposes, coking, utilities, railways, and manufacture of steel and cement, there are over 200,000 products derived from coal, from lipstick colours to nylon products and perfumes. An item of interest is the recent action of the Canadian Government in voting $90,000 for development of coal deposits in Yukon Territory to make coal available to the settlers in that area. The value of this move, in case of some emergency, is very evident. Coal in its several stages of formation as peat, lignite, sub-bituminous, bituminous, semi-bituminous, semi-anthracite, and anthracite, has been used for centuries. Coal, as such, was not very well known to the ancients. First reference to "magic stone', or coal, was in 371 BC by Theophrastus, a pupil of Aristotle. This substance was said to burn like wood coal or charcoal and was used by the smiths. The first record we have in modern times was in 852 AD, when sea coal was gathered by the cowled monks of Durham, in Britain, and even at that time a major problem was transportation. Our first record of coal in this continent was near Richmond, Virginia, in 1700. Commercial mining was not under way, however, until 1750. The anthracite fields (presumably in Pennsylvania) were opened in 1793. Even so, there was no extensive mining until about the year 1820. The famous Pocahontas coalfields were opened in 1883. The earliest record of coal mining in Canada is about 1746.

Jan 1, 1950