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By Carl Fisher

A microseismic roof fall warning system was field tested in Western and Eastern coal mines in the United States to better define the capabilities and limitations of the microseismic method in predicting roof fall. Microseismic event and energy type data were obtained and documented for twenty-three coal mine roof falls, Field test results indicate that both the microseismic event and energy methods, as applied in this development effort, have a high probability for successful application in a commercially practical roof fall warning system. Based on the results and experience obtained during field testing, a commercial prototype microseismic roof fall warning system was designed and constructed. Although it was the intent of the program to field test the commercial prototype system, delays in equipment fabrication and contract time limitations did not permit field testing.

Jan 1, 1980

The 53 countries that constituted Africa in 1993 accounted for a significant portion of total world output of a number of mineral commodities. For the continent as a whole, world shares of most commodities showed little change from those of 1992 although most output volumes showed a slight decline. There were no significant production increases, but there were significant decreases of cobalt and copper because of political instability in Zaire and production problems in Zambia, of chromite resulting from cutbacks in South Africa and Zimbabwe, and of phosphate rock owing to a lower output by producers in general. (See tables 1 and 2.) Among the most significant mineral commodities produced in Africa, ranked by portion of world production in 1993, were diamond, cobalt, chromite, gold, phosphate rock, manganese ore, uranium and petroleum. Others of importance in world trade were andalusite, antimony, asbestos, bauxite, coal, copper, fluorspar, lithium minerals, platinum-group metals (PGM), titanium minerals (ilmenite and rutile), vanadium, vermiculite, and zircon. Several of these-chromite cobalt, diamond, and manganese-were not produced in the United States.

Jan 1, 1995

Lime and cement manufacturing has a proud history in Otago, with the earliest lime kilns appearing around 1849 at Caversham and Kaikorai in Dunedin . At Dunback or Makareao (to be precise) three well-type kilns were built by the government in 1899. In 1909 these kilns were leased to the then Milburn Lime and Cement Company. They erected a large brick Schmatolla kiln in 1909, elliptical in plan and fired by coal gas. The kiln operated up until 1944 before being left derelict. The quarry which supplied the kiln also supplied the Burnside Cement works from 1929 up until its closure in 1988. The quarry was shifted to the top of the hill in the 1950s.

Jan 1, 1992

By Oliver Hall

This paper sketches the mining at Noranda as it would be sketched to a visiting engineer. It does not follow quite the usual form, but is presented somewhat along the lines of a conversation. TO give the mining at Noranda its proper perspective, it is necessary to sketch the whole picture and outline: 1. History 2. Metallurgical Problems 3. Exploration 4. Mining Methods 5. Mining Details 6. Filling 7. Pillar Extraction 8. Costs HISTORY Noranda is a relatively young enterprise, with much of the personal character of its founders woven into it. The name Noranda is an abbreviation of Northern Canada and the name has been a happy one for an enterprise based on northern resources, tenacity and courage. The discovery credit goes to Ed. H. Horne. This intrepid prospector returned again and again to his sulphide discoveries on the shores of Osisko lake and, in 1922, after ten years of prospecting, succeeded in interesting S. C. Thomson and H. W. Chadbourne in his discoveries. The early exploration by L. K. Fletcher, from 1922 to 1925, for Thomson and Chadbourne, indicated promising, but somewhat perplexing, ore conditions. Mr. E. Hibbert and Mr. H. L. Roscoe rook on the task of preparing the mine for production and building a smelter in 1926, and this difficult task in this isolated area made steady progress and the smelter was blown-in in December, 1927.

Jan 1, 1937

By Peter Moser, Frank Chiapetta, Sacha Diaj, Florian Bauer

Good toe breakage and a flat working bench after blasting are important parameters to achieve a high productivity during material loading and reduce the necessity for secondary blasting. Good toe breakage requires a proper burden – side spacing design and a suitable sub-drilling. With unfavourable jointed rock mass conditions the use of horizontal bottom holes still can be found as common work practice even that this is associated to high risks.

Jan 1, 2009

By J. H. Soulé

"The Copper King copper-gold-silver deposit was discovered about 1880. Various individuals and companies have been interested in the deposit and considerable work has been done, although production, if any, has been small. The deposit is located in the western part of Laramie County Wyo., and is favorably nituated with respect to rail and truck transportation and high-tension power facilities.Mild summers and cold winters characterize the climate. Precipitation averages between 16 and 17 inches annually, with considerable snowfall in the winter. Permanent streams are small and most available water in being stored for use by Cheyenne, Wyo. Range grasses comprise the bulk of the vegetation, with small treed and shrubs common in the most rugged areas.The deposits lie upon land owned by Wyoming, now leased by a group of Wyoming and Colorado businessman constituting the Copper King Mining Co.Primary copper-gold mineralization seems largely confined to an equigranular, relatively fine grained gneiss that is part of a pre-Cambrian complex of metamorphic rocks ranging from schists to pegmatites. The copper minerals are oxidized to a depth of from 100 to 150 feet, with the occasional occurrence of secondary minerals at greater depths. The copper minerals chalcopyrite, malachite, chalcocite, bornite, cuprite(?), and some native copper were observed in Le deposit.In addition to the 4,030 feet of diamond-core drilling in 11 holes done on the deposit by private companies, the Bureau of Mines drilled 3 holes for a total of 2,630 feet. The sample results of this drilling plus available data from previous drilling and sampling are appended to this report."

Jun 1, 1955

By M. L. Chapman

When originally accepting the assignment, the Client had described the property as vacant land. A prior appraisal was later discovered and revealed that the property included a mineral rights appraisal. Further research disclosed an old dispute with a court ruling based on testimony by AIMA-certified experts. The present appraisal was therefore based on data from findings of the court with a fresh look at discount rate, absorption period, and residual land value. Fortuitously, the property subsequently sold on the market, while meeting all criteria for Fair Market Value. This provided insight into a market-based discount rate. Also, the absorption period could be adjusted in accordance with the current market conditions. The residual land value was minimal (based on comparable sales and projecting trends in market) as the property was affected by a flood zone and the surrounding development was sparse. PROPERTY HISTORY: A GREAT INVESTMENT Briefly, the subject property is located in the floodplain region of the San Jacinto River, a short river in southeastern Texas that flows into Galveston Bay, filled with sand and gravel. This location is on the north side of Houston, north of Beltway 8 on the east side of I-59.

Jan 1, 2012

By C. Strachan

This paper presents an evaluation of tailings dam incidents from the 1994 USCOLD Tailings Dam Committee report. Comparisons are also made with water storage dam incidents from USCOLD reports and recent tailings dam incidents. The evaluation results show that tailings dam incidents are due to a number of factors including overtopping, static and seismic instability, seepage and internal erosion, and foundation conditions, and that no particular type of tailings dam or operational condition is more susceptible to incidents. In addition, the results confirm that tailings dams should be located, designed, operated, and reclaimed with a thorough knowledge of site conditions, mill operation, site monitoring, and tailings characteristics.

Jan 1, 1999

[Ferro Alloys Producers Association The South Africa Institute of Mining and Metallurgy www.saimm.co.za Mintek www.mintek.co.za Eskom www.eskom.co.za ]

Jan 1, 2004

By J. F. Shao, G. Duveau, W. Z. Chen, O. Ozanam

In this paper, we present a sensitivity study for the numerical modelling of hydromechanical coupling around a shaft in partially saturated claystone. Two representative constitutive models have been used: an elastoplastic damage model (IDEPLML) and an elastic perfect plastic model based on the Hoek and Brown failure criterion (H&B). A series of comparative studies have been performed with respect to main parameters involved in coupling process (mechanical, hydraulic and hydric properties). The emphasis is put on the evaluation of induced plastic, damaged and failed zone due to excavation and drying process. Dans ce papier, nous présentons une étude numérique paramétrique du comportement hydromécanique couplé d’une argilite partiellement saturé, lors du creusement et de la maintenance d’un puit L’étude paramétrique porte à la fois sur le type de modèle et sur les principaux paramètres (mécaniques hydrauliques et hydriques) intervenant dans le couplage. L’accent est principalement porté sur l’évaluation des zones plastifiées autour de l’ouvrage lors de la désaturation. In unserem Beitrag geht es um eine digitale parametrische Untersuchung über das hydromechanische Verhalten eines teilweise durchtränkten Tons beim Abteufen und dem Betrieb von Schächten. Die parametrische Analyse konzentriert sich auf den Modelltypus und auf die wesentlichen bei der Verbindung wirksamen Parameter, d.h. die mechanischen, hydraulischen und hydrologischen. Der Schwerpunkt liegt auf der Bewährung der plastifizierten Bereiche des Bauwerkes während der Austrocknung.

Jan 1, 2003

By Anthony Leddin, Gillian Dooley

This paper is concerned with mineral policy in Ireland and how it might be improved to encourage more exploration and investment in mining in the country. The approach is to first outline the main desirable characteristics of a comprehensive national mineral policy document. This aspirational document is then used to assess the current regulatory, legislative and fiscal frameworks for mining in Ireland. The analysis also contains a brief account of the history, structure and characteristics of the mining industry in Ireland. The main focus of the paper is to identify those aspects of the existing framework that erode Ireland’s attractiveness to mineral investment and to suggest policy improvements.

Jan 1, 2005

By Edward E. Johnson

The U.S. economy boomed in 1965, completing its fifth consecutive year of expansion. Although the advance was somewhat irregular, previous records for production, sales, employment, and income were topped. During the first few months of 1965, as the economy recovered from the depressing effects of the automobile strikes of late 1964, increases were unusually large. The gains moderated in early spring, but were stimulated at midyear by sharply rising capital outlays, excise tax cuts, in? creased Social Security payments, and accelerated Viet-Nam defense expenditures. Gross national product (GNP) in cur-rent dollars rose $49.5 billion or 7.8 percent, to a total of S681.2 billion. In constant dollars (effects of price changes eliminated), GNP increased 5.9 percent, a rate considerably higher than the historical postwar annual average growth of 3.5 per-cent. Demand increased in most final markets and was especially strong for business fixed investment and consumption expenditures. With the exception of construction, most of the increases in GNP were real, since prices increased less than 2 percent.

Jan 1, 1966

Mr D. Wilson was born in Vereeniging, where he also completed his schooling, matriculating from General Smuts High School in 1977. Mr K.A. van Gessel was born in 1937. His final studies were conducted at Delft University, where he graduated with an M.Sc. degree in mining engineering. Mr J.G. McCaUum was born in 1938 and matriculated at Jeppe Boys' High School, Johannesburg. Mr H. Scot RusseU started his mining career at Randfontein Estates Gold Mining Co. Witwatersrand, Limited, where he served as temporary Geological Assistant, Sampler, Surveyor, Shift Boss, and Mine Overseer. Mr A.M.P. Henderson was born in 1950, in Kiel, West Germany. Mr J.L. Nel matriculated in 1957. This was folowed by his atainment ofthe folowing degrees: B.Sc. (Chemistry, Physics) in 1961, B.Sc. Hons. (Metalurgy) in 1965, M.Sc. (Metalurgy) in 1967, and MDD (student of the year) in 1981

Jan 1, 1989

By R. W. Smith, D. L. Taylor, K. A. Altman

Recent research has shown that traditional sensitivity, what if and best case/worst case analysis of metallurgical data has the potential to over estimate the value of mining projects. Use of simulations, which rely on the input of statistical information, may provide more realistic predictions of the value of future projects. Actual metallurgical data is used to demonstrate that analyzing the data from a statistical perspective can give insight into completing an optimum amount of metallurgical testing and a mechanism to determine that samples used for the testing are truly representative of the ore that will be processed.

Jan 1, 2000

By H. S. Price, F. N. Kissell, R. C. McCulloch, J. C. Edwards

"The methane em1ss10n from deep coalbeds which are actively mined is a serious problem facing the mining industry today. Pinpointing the source of methane and predicting the emission of this gas from these coalbeds is necessary if preventive techniques are to be effectively used to control methane emission. In general, because most coalbeds have water associated with them, the system to be studied may be either single-phase (methane gas) or two-phase (methane and water). Because coal mine geometry is complex and the fluids have variable properties as functions of pressure and methane concentration, the differential equations describing the flow of methane and water are not amenable to analytic solution, but must be solved numerically using high-speed computers. This paper presents the development of such a complex mathematical model along with some preliminary applications of the model to methane emission from one- and two-dimensional coalbeds with and without water present."

Jan 1, 1973

By W. L. Hollinshead, Alwin Poltinger

GENERAL Tunneling by hand digging is as old as the history of humans. Mechanized tunneling did not begin to replace manual methods until around the beginning of the 19th century(Brunel patent, 1818). It brought with it a higher degree of safety for the workers and a much higher rate of boring. But for any kind of tunneling, an accurate and feasible method of survey must be accomplished during mining. That means, that for each tunnel project the most efficient survey method must be devised. The method to be defined depends on the spatial curve, diameter, speed of tunneling method, purpose of tunnel and contractual accuracy. The final accuracy of a finished tunnel is heavily dependent upon three critical elements: 1. Quality of the above ground survey 2. Tunnel traverse and directional transfer from above ground 3. Guidance for the mining job. Combining The Survey And The Guidance System Since the guidance system (GS) is one of the critical factors in the determination of the tunnel final accuracy, it is necessary to analyze how the directional control and tunnel traverse measurements can be effectively integrated into a GS. Any guidance system, whether manual or high technology, must continually detect and compensate for movement of its theodoliteor laser station standpoint. Movement beyond a preset allowable amount must generate a warning or error message to the user. Additionally, optical refraction can interfere with the results. Refraction will have an effect on any kind of optical GS. Therefore, careful selection of target and standpoint locations can minimize, but not completely eliminate, the influence of refraction. Some GS technologies, such as Gyro-based systems, are immune to the effects of refraction, but have other, methodical errors which will be described later in this paper. GUIDANCE Overview Why is a guidance system necessary? A GS, whether manual or automatic, compares the design direction and slope of a tunnel with the current position of the mining

Jan 1, 1997

By J Morton

The Resource Management Act 1991 represented an innovative and unique piece of planning and environmental legislation when it was introduced. Since the Act was passed into law in 1991 it has been subject to nine amendments, many of which were of the ætinkerÆ variety. These amendments recognise that the Act has not been as successful in providing the æone-stop shopÆ for resource users that the Act was hoped to be. The latest and most significant attempt at changing the Act was the Resource Management Amendment Act 2003. The amendments made by the Amendment Act have proved to be largely unsuccessful in achieving any significant changes to the way resources are managed in New Zealand, and have failed to address many of the concerns which drove the original Resource Management Amendment Bill in 1999. The recent decision to discontinue further investment in Project Aqua has once again placed the Act in the spotlight as a significant hand-brake on major projects. This particular event has led to yet another review to be undertaken this year. The review will focus on five key areas:   1.   achieving the right balance of national and local interests; 2.   improving the design and process for local policy formulation; 3.   improving the consent decision making process; 4.   allocation of natural resources (water, air and geothermal); and 5.   supporting measures for building capacity and promoting best practice and implementation at the local authority level.  It is important for the business community and the mining industry in particular to seize the opportunity that this review provides to make sure that any amendments undertaken as a result of the review achieve the aims listed above. The review needs to be considered in light of the current regime for the management of natural resources in New Zealand. In addition to the Resource Management Act 1991, the Crown Minerals Act 1991 and the Building Act 1991, which form the core resource statutes in New Zealand, there have been other developments affecting the regime. Special legislation over and above the Resource Management Act 1991 has been enacted to protect the Hauraki Gulf and special legislation is currently being considered to protect the Waitakere Ranges in Auckland. In the Hauraki District mining is prohibited in some areas and a plan change mechanism is specified as the appropriate tool to use in the event a mineral resource is to be developed in those areas. The current review is a further opportunity to remedy the inadequacies of the Act.

Jan 1, 2004

Jan 1, 1970

By R. B. Tippin

The heavy liquid separation (HLS) process was investigated by the Bureau of Mines to develop a means of concentrating minerals from natural ores, Various spodumene ores were tested in a 0.4-inch diameter cyclone using pure tetrabromoethane (TBE) as the heavy liquid. Studies were initiated to examine the influence of (1) pulp density (2) feed grade, (3) cyclone pressure, (4) cyclone apex opening size) (5) cyclone vortex finder opening sand (6) mineral particle size on the separation efficiency. Each of these factors was found to affect the heavy liquid separation in some degree; the mineral particle size exhibited the greatest effect and the ore feed grade the least. Conditions necessary to yield an 85 percent spodumene concentrate with an 85 percent recovery were determined to be: 70 psig pressure, 10 percent solids, 0.08-inch apex opening, 0.11-inch vortex finder opening and a minimum amount of minus 200-mesh fines in the feed. Operation of multiple cyclones in series resulted in spodumene concentrates assaying over 90 percent and indicated mineral recoveries exceed-in 90 percent.

Jan 1, 1967

By Margarete Kalin

"Difficulties arise in implementing environmental technologies in the mining sector because important fundamental processes, which lead to the environmental degradation, are ignored. Weathering rates, the role of bacteria in the process and the incomplete application of the matching principle of accounting at the time the mining disturbance take place. Mining is a multi-stakeholder activity and the environmental problems have multivariate dimensions also effecting process.The limiting factors in the contaminant generation process are the transport of oxygen by advection, convection or diffusion in air or water and the associated microbial activity. Weathering products are transported from the mineral surface by atmospheric precipitation to surface and groundwater. This contamination takes place at different rates, requiring a long time to evaluate technological choices.Restoration efforts have to focus on slow reaction rates in the contaminant generating processes. Technology, which does not address the reaction rates and is selected based on inappropriate time scales, will not provide long-term solutions. Natural approaches to reduce acid generation, based on Ecological Engineering principles have required decades of research and field testing, but now show promise in addressing the cause of AMD and ameliorating its effects."

Jan 1, 2005