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By Roger T. Laine

"The Carswell structure, located in the western part of the Athabasca Basin, northern Saskatchewan, has been extensively explored since 1967. This exploration has been successful and lead to the discovery, in 1970, of the D sandstone-hosted unconformity related deposit. By the end of 1984, five additional basement-hosted unconformity related deposits had been delineated: the OP and N discovered in 1970, the Claude in 1971, the Dominique-Peter in 1981, and the Dominique-Janine in 1984. The D deposit has been mined out; the Claude open-pit has already produced more than 500 tonnes of uranium, the development of the Dominique-Peter underground mine (first phase) has been completed, and production from the latter started in 1985.All six deposits are located in the southern part of the Aphebian metamorphic core, 18 km in diameter, which has intruded at least 1250 metres of Helikian Athabasca Group sediments during a cryptoexplosion event at 480 Ma, unrelated to the emplacement of uranium mineralization. The metamorphic rocks, affected by the Hudsonian Orogeny, are divided in two lithostratrigraphic units: the Peter River gneiss, aluminous gneiss series, and the Earl River complex, mixed quartzofeldspathic and mafic gneiss series. A well developed regolith profile is recognizable in the south along the contact with the sandstone and inside the metamorphic core sometimes associated with conformable sandstone beds.Basement and sandstone-hosted uranium deposits show many similarities:-linkage to unconformity;-mineralogy and geochronology with a first phase mineralization characterized by a polymetallic sulphide-uraninite-brannerite assemblage dated at 1150 to 1050 Ma, a second phase characterized by a simple sulphide-uraninite assemblage dated at 890 to 820 Ma, and a third phase characterized by a pitchblende-hematite dated at 380 Ma; and,-linkage to early Hudsonian structures with remobilization of these structures during intense hydrothermal alteration resulting in Mg chlorite-illite halos."

Jan 1, 1986

By David Ellis

The next generation of Reusable Launch Vehicle (RLV) will utilize regeneratively cooled combustion chamber liners in the engines. The current design calls for using a new Cu-8 at. % Cr-4 at. % Nb (Cu-8 Cr-4 Nb) alloy for the liners. Work is ongoing to characterize the thermophysical and mechanical properties of the alloy from - 253 to 800°C, the temperature range to which the alloy will be subjected during service. The alloy has been commercially produced in quantity for NASA. The powder size has been characterized and the microstructure examined. The powder was extruded into bar using a commercial extrusion press. In addition, samples have been hot isostatically pressed (HIPed) at NASA Glenn Research Center. Both processing methods produced fully consolidated material. Transmission electron microscopy (TEM) revealed highly faulted Cr2Nb and some elemental precipitates. Cryogenic tensile testing showed the extruded specimens had significantly higher strengths than NARloy-Z (Cu-3 wt % Ag-0.5 wt % Zr) even after being subjected to a simulated braze cycle. The Young's moduli (Cu-8 Cr-4 Nb) were lower than NARloy-Z. The lower moduli is highly beneficial for reducing thermally induced stresses in rocket engine combustion chamber liners and similar applications.

Jan 1, 1999

By Jeffrey M. Listak

The Respiratory Hazards Control Branch of NIOSH routinely conducts laboratory and mine-site evaluations of dust control technologies. Gravimetric and instantaneous dust sampling instruments are used in these evaluations to measure and document dust levels to determine worker exposure. The Thermo personal DataRam (pDR) is an instantaneous sampler that uses light-scattering technology to provide relative measures of airborne respirable dust. The pDR can be used in active and passive modes to measure respirable dust levels. Tests were conducted to evaluate the sampling performance of active and passive pDR operation relative to each other and. against a gravimetric sampler (the accepted standard for respirable dust measurement). The purpose of the test was to determine if the pDR can be used effectively in the passive mode in higher velocity airflows (up to 5.1 m/s (1000 fpm)). Studies of the pDRs in both modes of operation were conducted in a controlled laboratory environment and in field situations. Dust measurements using pDR units in both modes of operation were recorded in ve¬locities ranging from 1.0 to 5.1 m/s (200 to 1000 fpm). Tests were conducted in ambi¬ent air and in air with the addition of moisture. Results show that, although the units measure different concentrations in their respective modes of operation as compared to a gravimetric sample, the relative readings can be corrected to yield accurate dust measurements.

Jan 1, 2007

The American Museum of Safety has installed a large collection of exhibits at 18 West 24th St., New York City, and extends a cordial invitation to the members of the Institute to visit this exhibition. The Museum is open daily from 9 am. until 5 p.m., and special arrangements will be made for the admission of a large party in the evening. The exhibition covers all phases of industrial and general safety, and also the important questions of sanitation and hygiene.

Jan 2, 1917

By Jürgen Kretschmann

The Islamic Republic of Iran is a very important producer of raw materials in the world. The country holds 68 types of minerals, including salt, sand and gravel, chrome, lead, zinc, copper, coal, gold, and iron-ore. With more than 37 billion tons of measured and indicated reserves and 55 billion tons of total mineral resources, Iran is ranked among the 15 major mineral-rich countries. Sangan iron-ore mines (SIOM) is one of the biggest iron ore mining complexes in Iran, located in a remote, but strategically important area near the Afghanistan border. The Iranian government has planned several mining projects in this region for a stepwise development over the next 5 years to satisfy the growing demand of the Iranian steel industry. In cooperation with private companies, these projects shall be realized as sustainable as possible. This paper introduces SIOM and describes socially responsible activities undertaken during the initial development of this mining complex. The effects of these activities will be demonstrated. Unique attributes of the Sangan area have a significant impact on the acceptance of SIOM by regional stakeholders. The government has made several social investments that benefit workers´ families and the community. They are attempts to build social capital for the mining operations and demonstrate a commitment for socially responsible mining to the communities and the local population. They aim to create a balance between the local and regional expectations and requirements and the necessity to secure the corporate profitability at a reasonable and sustainable level. Investment in socially responsible activities is not a choice but a necessity to improve the relations between mining companies and stakeholders in the communities. It is recommended that social investments should be carefully planned and implemented from the early stages of mining activities, and should proceed throughout the life cycle of the mines.

Aug 1, 2013

By M. H. Merriss

In the last few years, there have been developed at the plant of the Nichols Copper Co., Laurel Hill, 'Borough of Queens, New York City, improvements in electrolytic copper refining by the series system that have materially increased the flexibility and economy of that system. The purpose of this paper is to discuss, as of interest to refiners and to those who have copper to refine, as well as to the engineering profession in general, the changes' that have taken place resulting in wider application and increased efficiency of the series system. Copper is electrolytically refined in two ways, which are spoken of as the "multiple system" and the "series system." In both systems, the electrolytic tanks are in series electrically. In the multiple system the electrodes in a single tank are in multiple or in parallel, thus: There are two important adaptations of the series process, one represented by the series electrolytic tank room at the Baltimore Copper, Smelting & Rolling Co., Baltimore, Md., and the other by that of the Nichols Copper Co.'s plant. At Baltimore, the anode is rolled to perfect

Jan 1, 1926

By Wilson J. R

The main mining method employed at Mt Lyell is sub-level open stoping with a typical extraction level interval of 100 m and sub-level intervals of 30 m. Currently, pillar blasts provide the major portion of broken ore and firings are in the order of 200 000 to 300 000 tonnes while future firings of 500 000 to 300 000 tonnes are planned. Improvement of blasting techniques in these mass firings has been necessary for the following reasons. 1. Extremely wet ground conditions have adversely affected ANFO performance and placed extreme pressure on the charging and priming phases. 2. As pillar blasts increase in size the problems of wet ground conditions are accentuated resulting in very slow loading of wet upholes with cartridged gelignite and unreliable charging of the remainder with ANFO. 3 Fragmentation in pillar blasts has suffered because of the above, result- ing in increased secondary breaking costs and difficulty of extraction.

Jan 1, 1977

By Robert Uhley, Tsvi Meidav, L. Scharon

Before National Lead built an industrial plant on its Fredricktown property, some 100 miles south of St. Louis, a 750x500-ft area on the proposed site was investigated by electrical resistivity, seismic refraction, and churn drilling. Data were accumulated to prepare an isopach map of the overburden and to determine soundness of the dolomite bedrock and the depth to bedrock at fixed points. The site was on a gently sloping hillside. Elevations above sea level ranged from 760 ft in the northwest corner to 820 ft along the eastern edge, giving a total relief of 60 ft. There were no major drainage features, but in the northern part of the plant site there was an indicated depression area which later was interpreted as reflecting subsurface conditions in the bedrock. No rock was exposed in the entire plant site area; the surface was characterized by soil and overburden. GEOLOGY Prevailing geology in the area of investigation was relatively simple—Bonneterre dolomite overlain by residuum. The red overburden was that derived from the weathered Bonneterre. Some chert was present, interpreted in the general area as a weathering of both the Bonneterre dolomite and younger sedimentary rocks such as the Potosi dolomite. During the period of actual measurements the residuum varied from moist near surface on the western edge of the proposed site to dry near surface on the eastern edge, and for this reason overburden resistivities ranged from low on the west to high on the east. Seismic velocities were low, since the material was not well packed. The bedrock encountered was dolomite, specifically the Bonneterre of Upper Cambrian age which, according to McQueen,' consists of an upper dark gray member and a lower light gray member. These have been further divided into four zones, in ascending sequence a dark gray, sandy argillaceous dolomite; a dark brown or black, fine-grained dolomite: a light gray, finely crystalline, compact dolomite; and, at the top, a dark brown, finely crystalline, compact dolomite. In the area of investigation the upper two zones were encountered in the drilling tests as constituting the bedrock. The dolomite varies widely in porosity, which is low in the dense, fine-grained layers. In this area, therefore, both electrical resistivities and seismic velocities were high. Fracture zones in the Bonneterre are nearly Geology, and may extend to some depth, causing considerable deep weathering. It was realized that over deep fracturing the apparent resistivities

Jan 1, 1960

Nebraska has never produced coal in any amounts, nearly all of its mining having been by farmers for their own and local use from very thin seams. Tonnages given in Table 73 are estimates. [ ]

Jan 1, 1942

By J. W. LaComb

High speed cameras were used to view the behavior of underground openings during the passage of ground shock generated by an underground nuclear detonation. Movies from these experiments were shown and a general discussion of the media properties, ground support utilized, and general information gained was presented. A brief discussion of "hardening techniques" developed to protect underground openings from the dynamic effects of a nuclear explosion was included. No manuscript received

Jan 1, 1979

By Y. Y. Emelianov

The results of the test work of four treatment options of three refractory gold-pyrite and gold-arsenic flotation concentrates are presented. These concentrates were obtained during the concentration of primary ores of large gold deposits. It was found that ultrafine grinding of refractory flotation concentrates did not increase the recovery of gold during subsequent cyanidation. The elimination of sulfur and arsenic during oxidative roasting is 99 per cent. 88-93 per cent of gold is recovered by cyanidation from calcines. After biooxidation of the flotation concentrates with a mixture of strains Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans 88-91 per cent of gold is recoverable by direct cyanidation. The recovery of gold from flotation concentrates by pressure oxidation is 88-99 per cent. These results suggest that gold recovery is important but the following strategies would have an impact on a plant performance and would be considered when developing an option to treat refractory ores: capital and operating costs, ore reserves, mine location, infrastructure and qualified staff. Keywords: gold, flotation concentrates, recovery, cyanidation, roasting, biooxidation, pressure oxidation

Sep 1, 2012

By N. Charue

An international prediction event was carried out within the framework of a 30-pile testing program organized in a sandy soil in Belgium (Limelette). That program called upon sev­eral testing methods: static load tests, Statnamic testing, and dynamic testing. This paper provides a summary of received predictions and results obtained from the static pile load tests, which were carried up to failure of the instrumented piles. The comparison between predictions is made using load-settlement curves with reference to the results of the static load tests. The predictions are based on a geotechnical approach using an extensive soil investigation program and a dynamic approach using the dynamic load test data.

Jan 1, 2002

The April General Meeting of the Institute was held in Kelvin House, Johannesburg, on 16th April, 1969, at 4.30 p.m. Mr R. C. J. Goode (president) was in the Chair. There were also present nineteen Members, including Messrs R. J. Adamson, F. P. Bath, J. K. E. Douglas, A. R. C. Fowler, P. Lambooy, D. G. Maxwell and J. A. Nixon, (Council Members), Messrs E. L. Atkinson, I. R. Chaston, J. L. Edwards, J. S. Hall, S. A. Hancox, A. F. Lee, W. K. B. Loftus, H. S. Simpson, A. N. Shand, R. A. Wilson, H. J. Wright and J. E. Van Leeuwen. Nine Associate Members, including Messrs O. Davel, G. Douglas, P. R. Garcia, D. J. Murphy, D. Rankin, G. Schwartz, H. N. Singer, S. Thompson and D. A. Viljoen. One Graduate Mr D. Bosley. Ten Visitors, including Messrs S. Adler, C. E. Alvey, B. J. Botha, K. Chant, L. W. Davis, R. N. Guest, R. V. Keet, E. G. Keown, M. D. Lourie and S. McMurray. Secretary Mr D. C. Visser. Total present: Fourty-one. MINUTES The President requested that confirmation of the minutes of the previous meeting be held over as they would only be appearing in the Journal of the following month. Agreed. MEMBERSHIP The President: "I have much pleasure in announcing that the names of the under-mentioned candidates, having been published in accordance with By-law 5.2.2, Council has elected them to membership of the Institute in the following grades: Members: Kenneth Sinc1air Rae, Ian Robert Malcolm Chaston. Associate Members: Norman Isaac Thomas, Ian Connell Robinson. Graduates: Simon Richard Jeremy Perkins, Bleddyn Reginald Lear, David Williams. Affiliate: Richard Robert Will. Students: Angus David McElwee, Clive Renard Archer, Peter Andrew Locke. MEMBER TRANSFERRED TO A HIGHER GRADE From Graduate to Associate Member: Patrick James Burns. I welcome the newly elected members to the Institute and congratulate the member who has been transferred to a higher grade." (Applause). GENERAL BUSINESS The President reminded members that a buffet supper at a cost of 55c would be available after the meeting. PAPER FOR PRESENTATION The President noted with pleasure that a strong contingent from De Beers and the Finsch Mine were present. He expressed gratitude to Mr Loftus for coming

By H. Bai, B. G. Thomas

"A three-dimensional finite difference model has been developed to study the liquid steel-argon bubble two-phase turbulent flow in continuous casting tundish nozzles. Experiments have been performed on a 0.4-scale water model to verify the computational model by comparing its prediction with velocity measurements using PIV (Particle Image Velocimetry) technology. The computational model was developed using CFX and then employed to investigate the effects of various casting process variables. A fast, simple inverse model to quantify relationships between those process variables was developed, based on interpolation of the numerical model results, using Bernoulli's Equation and advanced multivariable curve fitting methods. Predictions using this model compare well with plant measurements. The model has been applied to present trends and observations on the relationship between casting speed, tundish depth, slide gate opening, and argon gas injection rate. The results can also be used to predict .the theoretical steel flow rate through the nozzle, so that clogging conditions can be identified in the plant.IntroductionTundish nozzle geometry is one of the few variables that are both very influential on the casting process and relatively inexpensive to change. Designing an effective nozzle requires quantitative knowledge of the relationship between nozzle geometry and other process variables on the influential characteristics of the flow exiting the nozzle. This relationship depends on the flow pattern within the nozzle components. Most previous modeling studies of flow in the nozzle have focused on single-phase flow [1-4]. Argon injection into nozzle is an efficient and widely employed method to reduce nozzle clogging, even though the real working mechanism(s) are still not fully understood [5]. Argon injection may greatly affect the flow pattern in the nozzle, and subsequently in the mold. Therefore, two-phase flow modeling is needed to improve understanding of fluid flow in the nozzle."

Jan 1, 2000

By Misra VN

The carbon-carbon dioxide reaction is the rate determining step in industrial processes such as the rotary kiln direct reduction process for iron ores. The use of brown coal as a reductant in the rotary kiln process has been shown to result in higher throughputs and lower kiln temperatures. No experimental data has been reported on the effect of coal type or the use of brown coal chars. Methods of carbon-carbon dioxide reacti- vity measurement are discussed. None of the methods have been related to direct reduction practice. No standard test has been developed to assess the reactivity of brown coal chars to carbon dioxide. For routine comparative work the gas analysis method of Okstad and Hoy appears to be the most suitable although some modification to the experimental conditions is required. For detailed kinetic studies direct weighing techniques are to be preferred. The factors affecting the reactivity of brown coal char to carbon dioxide are reviewed. Numerous factors such as the origin of the coal, pretreatment and ,physical and chemical differences have been found to affect the reactivity of brown coal chars but no data has been reported on the effect of coal type on reactivity to carbon dioxide.

Jan 1, 1980

By T. Krauthammer

A combined numerical approach is proposed for the analysis of rock-liner interact ion in tunnels under the effects of severe dynamic loads. The method is based on employing finite element formulations which describe the linear behavior and incorporating it into a finite difference code which can describe the behavior of a jointed rock medium. This method can be applied for the analysis of tunnel systems in rock, and for studying the requirements for adequate support of the tunnel.

Jan 1, 1984

By T. W. H. Parker, S. B. Sadleir

ABSTRACT A comprehensive program of air flush core and reverse circulation drilling, trial mining and beneficiation test work was carried out in 1980-1982 to re-assess the potential of the Mitchell Plateau bauxite deposit. The results generally confirm previous work by Amax Corporation. The bauxite is a medium available alumina and reactive silica deposit which responds well to wet screen beneficiation. High grade pockets have developed locally, with the potential for refractory grade extraction. A major feasibility study of the Mitchell Plateau bauxite deposit was completed in 1983. Due to the unexpected severity of the downturn in the alumina market, development of the project has been deferred.

Jan 1, 1984

By Z. F. Oszter

This paper discusses the materials handling problems encountered in cement plants in the areas of raw and finished product grinding and cement storage. It illustrates by examples taken from actual installations, how optimum feed rate is maintained in grinding circuits with properly applied bin dischargers (vibrating hoppers, Mexican feed boxes and aerated bin bottoms) for materials with high moisture content and/or difficult handling characteristics. Initial operating problems with the equipment will be discussed and maintenance requirements will be indicated for comparison purposes. In a modern cement plant, properly functioning bins and feeders are as essential as process control, for no process control system, however sophisticated, can perform efficiently if raw materials do not flow into the plant processing facilities at the required time and rate. Most materials used in the manufacture of portland cement - such as silica sand, iron ore fines, crushed limestone, gypsum, clinker or cement itself-have difficult handling characteristics under specific conditions. High moisture content or even dampness due to condensation may create bin hang-ups, arching and ratholing, all of which result in improper functioning of the feeders or proportioning equipment. The occurrence of these problems in existing cement plants spurred a search for the corrective devices discussed in this article. The equipment investigated included bin dischargers in the form of vibrating hoppers for moist raw materials, Mexican feed boxes for clinker and aerated bin bottoms for cement. Operating experience with different types of bin dischargers showed that the actual performance of some did not come up to the expected level under prevailing operating conditions. The aim of this paper is to record the results of this experience and there- by aid designers and/or operators in selecting the most suitable equipment for their requirements. BIN DISCHARGERS (GENERAL) A discharger is a device that causes stored solids to flow out of a hopper without metering the rate of flow as a feeder does. The investigation discussed here encompasses the following types of bin dischargers used in a cement plant: (1) vibrating hoppers (horizontal motion), (2) whirlpool hoppers (horizontal and vertical motion), (3) aerated bin bottoms (air fluidization), and (4) Mexican feed boxes. Most of the bins used in the cement industry are of the plug flow type. Raw materials with difficult handling characteristics such as high moisture content may cause flow problems when fed through small openings (12 x 18 in.), even if two walls of the bin are vertical.' The most appropriate solution to these flow problems would be the installation of separate mass flow bins for the different materials such as silica sand, iron ore fines, crushed limestone and gypsum, with each bin correctly designed from test data obtained by measuring the flow properties of representative samples. However, limited storage capacity and plant space usually preclude this approach. Quantitative design of bins for flow based on measured flow properties of representative samples of the bulk solid to be handled is no longer an "engineering art," thanks to the basic research done on the flow of bulk solids in bins during the last decade.2, Where space limitations exist, however, or where improvements are being sought for equipment already installed, bin dischargers offer a satisfactory solution to flow problems. They can be applied effectively under flat-bottom bins or mounted to existing plug-flow bins with very little modification to these facilities. In both the foregoing cases, plug flow will be maintained, but the flow channel will be considerably increased so that it is larger than the discharger's bin-side diameter, and material flow can be sustained if the discharger is correctly selected. The main purpose of a bin discharger is to draw the bulk solids across the whole area of the bin outlet, to make the opening fully effective. As long as the bin-side opening of the discharger is large enough

Jan 1, 1969

IN the underground department of a mine, we may fairly say that "good management is based upon three elementals: first, sound engineering; second, proper coordination and efficiency of every human unit; third, economy in the purchase and consumption: of supplies.This paper is practically an analysis of the second element; which stands out prominently as the most important in the winning of successful results. The human units are divided into officers and men. The officers intermesh. One man takes responsibility where another throws it down; incessantly new conditions are arising where they may be doubtful of their powers; and always, on account of the three shifts, varying methods of work are coming into conflict. This very often results in disorganization. What is most necessary to guard against this is an esprit de corps, which would influence officers to stifle personal feelings for the general welfare of the department, To secure co-operation and loyalty of the staff, the writer recommends for the mines of the field a system of profit-sharing. Distributed on a salary basis, together with liberal holidays (not less than three weeks in each year) on full pay...

Jan 1, 1912

By Simon Mundike, Muwindwa Lipalile

A scraper based block cave method has been successfully applied to extract the Lower Ore Body at Nchanga since the 1950?s. Since inception, scraper drifts and service ways have been supported using steel arch sets fabricated to a specific design from high strength manganese steel To reduce costs and to improve productivity, trials commenced in 2002 using fibre reinforced shotcrete as an alternative support method. One of the areas; the 2420 8E 1C trial drift was subjected to abutment loading for several months prior to undercutting and cave mining. Shotcrete installed exhibited minor cracking shortly after application but very little deterioration thereafter. Following the success of the trial, the application of fibre reinforced shotcrete was extended to other drifts. This paper describes the application of fibre reinforced shotcrete at Nchanga and outlines design and quality assurance methods employed.

Jan 1, 2005