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By R. T. Rudd

The impact of slimes-dam formation on water quality and pollution by R. T. RUDD*, B.Sc., AMI (S.A.) CE (Visitor) This paper discusses the mechanics of pollution by slimes dams in the gold- and fluorspar-mining industry, as well as that caused by coal dumps and slurry dams. The effect of coal mining on two typical rivers in Natal is shown and the implications discussed. The implications and trends of sulphates pollution on the Rand Water Barrage in the Vaal River are discussed. The spread of pollutants (sulphates and fluorides) from the Reef and elsewhere, and the impact on urban use and agriculture downstream of the barrage, are illustrated. Conclusions and future policy are outlined.

Jan 12, 1973

By H. M. Roche

IN the first section of- this article, published- Feb. 4, the author reviewed the his¬tory of iron ore mining in New Jersey, listed the reserves and possible markets of this ore, and discussed the role of Lake Superior and foreign ores in domestic steel production. This concluding section of the article emphasizes the metal¬lurgical value, future markets and mining coats of Jersey ores. Mr. Roche's thesis is that industry can profit both metallurgically and econom¬ically through a greater use of Jersey ores --that these orebodies are as yet prac¬tically unexploited, and con¬stitute a valuable national re¬serve fully worthy of careful consideration by Mid-West¬ern steel makers.

Jan 1, 1937

By J. W. Spretnak, V. Kandarpa

Stress -induced ordering of carbon atoms is studied in a series of Fe-Mn-C alloys. A prominent peak is found in the vicinity of 280°C at frequencies of the order of 1.0 cps, with an associated activation energy of 37 kcal per mole. The height of the peak is linearly rekzted to the concentration of carbon in solution. The distortion of octahedral holes by manganese atoms appears to be predominant over carbon-carbon pair interactions. RELAXATION by stress-induced ordering of point defects is expected whenever the introduction of these point defects produces distortions which have a lower symmetry than that of the lattice. Under zero stress, the isolated point defects occupy the crystallographic-ally equivalent positions in the lattice, as these represent states of equal energy. However, if the defect sites are asymmetric, application of an uniaxial stress will split the energy states, and a redistribution of the defects among various states will take place. This is the case of the internal friction peak called the Snoek peak,1 resulting from isolated interstitials in bcc metals. The interstitial sites in this case have tetragonal symmetry. In the case of fcc and hcp lattices, such an effect is not expected from isolated point defects because of the symmetrical nature of the interstitial sites. However, internal friction peaks arising from interstitial diffusion have been reported both in hcp2,3 and fcc4-8 lattices. These peaks are often explained on the basis of stress-induced ordering of interstitial solutes, caused by the deviation of interstitial sites from their cubic symmetry through the presence of nearby defects. In the case of fcc lattices, evidence for interactions of both the substitutional-interstitial4,6,13 and interstitial-interstitial types5'798'14 have been presented by various investigators. The purpose of the present investigation was to study the internal friction peak attributed to the diffusion of interstitial carbon atoms in high purity austenitic manganese steels and to account for the peak in the light of the existing models. MATERIALS The Fe-Mn-C alloys used in the present investigation were made in two different ways, designated as Type I and Type 11. Type I alloys were made from high purity Fe-Mn alloys obtained in the form of 0.04- in.-diam wires from Materials Research Corporation, Orangeburg, N.Y. These alloys were carburized to different levels using gas mixtures of H2 and CH4 at 1000°C. Type I1 alloys were made in this laboratory starting with zone refined iron, spectrographically pure manganese, and spectrographically pure carbon. They were melted in an argon arc melting furnace and drawn into 0.04-in.-diam wires. All the wires were annealed at about 900°C for 3 hr prior to the internal friction experiments. After the measurements of internal friction, the phases in the samples were identified by X-ray diffraction and the carbon determined by the combustion method. EXPERIMENTAL PROCEDURE In the present work, a classical Ke-type pendulum was used. The details of the equipment were described previously by D. T. Peters.9 Dry helium at 40 torr was used in all the experiments. The internal friction, measured as the logarithmic decrement of the torsion amplitude of vibration was determined as a function of temperature, from ambient to about 500°C. The background internal friction was assumed to have the form of the exponential of the inverse temperature and was subtracted from the raw data. The height of the peak was measured at the position of the maximum in the plot of the internal friction versus temperature. The activation energies of the peaks were measured by the peak shift method. The internal friction values for an alloy were obtained as a function of temperature at different frequencies of vibration. The position of the peak changes with frequency, the higher the frequency the higher the peak temperature. The activation energy of the process associated with the peak is obtained using the formula

Jan 1, 1970

By N. Anacleto, S. Ganguly

Reduction of Groote Eylandt (Australia) and Wessels (South Africa) manganese ores using CH4-H2-Ar gas mixture was investigated in a fixed bed laboratory reactor in the temperature range 1000?1200oC. The extent and kinetics of manganese ore reduction as a function of gas composition and temperature were determined by on-line off-gas analysis using mass-spectrometer and dew point sensor. Morphology of ores and its change in the course of reduction was examined by optical and scanning electron microscopy. Phases of raw materials and reduced samples were analysed by XRD and EPMA. Manganese oxides were reduced to carbide Mn7C3. High extent and rate of reduction by methane-containing gas in comparison with carbothermal reduction were attributed to high carbon activity in the reducing gas, which was in the range 15 - 50 (relative to graphite). The reduction rate of Wessels manganese ore increased with increasing temperature. Reduction rate and extent of Groote Eylandt manganese ore achieved maximum at 1050oC. The decrease in rate and extent of reduction of Groote Eylandt ore at higher temperatures, particularly at 1150-1200oC, was due to sintering and formation of semi-liquid silicate slag. The optimum conditions for the reduction of manganese ores were established as follows: a) temperature: 1150-1200oC for Wessels and 1050-1100oC for Groote Eylandt ores, b) methane concentration: 10-15 vol%, c) hydrogen concentration: above 30 vol%, (d) size: 1-3 mm. An addition of lime (10-15 wt% CaO) to the Groote Eylandt manganese ore increased melting temperature of slag and significantly increased the rate and extent of reduction at elevated temperatures.

Jan 1, 2004

Project developent proceeds by increasingly detailed studies addressing overall project returns through an analysis of the substance, risks and costs associated with the following elements: ò Reserves ò Mining ò Processing ò Infrastructure ò Environmental Impact ò Product Market Computer-based expertise has a potential to ò Capture perishable expertise, making this available for shared access and so reducing the cost of human experience ò Consolidate know-how for optimising process operations, bringing consistency of judgement and advice to decision- making by making the rules, facts and preferences explicit ò Allow assignment of the basis and authority of decisions, so experts can pass routine expertise down the line, freeing their time to generate more. ò Force a review of expertise when creating the knowledge base.

Jan 1, 1989

By Eugie Kabwe

The effective employment of a pretensioned bolt within support structures requires an appropriate installation tension as a result of sufficient bolt head/nut preload. In this paper, a load indicator washer (LIW) able to withstand an assigned static loading as well as provide an appropriate pretension is presented. The different LIW breadths are numerically analyzed with ABAQUS finite-element code to estimate deformation when a designated 60 kN preload is applied. The numerical simulation employs the bilinear isotropic hardening constitutive law governed by the von Mises yield criterion. The simulation also considers the nominal temperature of the nut-LIW-rock bolt connection. Therefore, long-term relaxation effect on bolt pretension as a result of stress relaxation is neglected. The compressive force required to achieve the LIW predetermined deformation is the bolt pretension. It is drawn from the simulation results that LIWs with thicknesses of 1.5, 2.0, 3.0, 3.5 and 4.0 mm are completely flattened when subjected to 28, 42.5, 65, 76 and 88 kN preloads, respectively.

By Paul K. Sims

The Central City district is one of several adjacent mining areas in the Front Range, Colorado, that contain precious metal-bearing sulfide veins of Laramide (Late Cretaceous and early Tertiary) age. The districts are in the Front Range segment of the Colorado mineral belt, and are characterized by porphyritic igneous rocks of intermediate composition that have intruded Precambrian crystalline rocks in the core of the Front Range. The veins and minor stockworks that constitute the ore deposits in the district were formed largely as fracture fillings. The veins range from simple fissures to complex, branching lodes, and commonly range from less than 0.5 to about 1 m in width. The principal values are in gold and silver. The common metallic minerals are pyrite, sphalerite, chalcopyrite, tennantite, and galena; minor minerals are enargite, pitchblende, and gold tellurides. Quartz, cryptocrystalline silica, carbonates, fluorite, and barite compose the gangue. The ore deposits have a well-defined concentric zonal arrangement. A core of pyrite veins (central zone) is surrounded by a peripheral zone of galena-sphalerite vein with gold and silver. An intermediate zone contains transitional veins that have minerals characteristic of both the central and peripheral zones. The minerals were deposited in three stages during a single period of mineralization: uranium; pyrite; base metals, gold and silver. The wall rocks were altered primarily during pyrite-stage mineralization. Sericite envelopes developed adjacent to fractures, and were succeeded outward by zones of argillized rock. The valuable ore minerals were deposited in ore shoots localized by several types of structural controls, principally vein intersections, the physical nature and structure of the wall rocks, and irregularities along the fractures themselves. During supergene alteration, gold was concentrated in the upper, oxidized parts of the veins, commonly to depths of 50 m. The precious metal-bearing sulfide ore deposits are closely associated in space and time with the Laramide porphyritic igneous rocks and are believed to have been derived from hydrothermal fluids related to the magmatic activity. The ore deposits have mesothermal aspects and apparently formed in the temperature range 200°-320°C.

Jan 1, 2013

By B Chapman, B Gaida, L Drowley

The 372 MW Ulu Jelai Hydroelectric Project is a peaking power scheme located in the Cameron Highlands, Malaysia. The main features of the project include an 84 m high roller compacted concrete dam; two weirs which divert flows from adjacent catchments via transfer tunnels into the main reservoir; an underground power waterway; and an underground power station complex comprising three large caverns with connecting tunnels approximately 240 m below surface level. The project includes approximately 25 km of tunnels excavated in fresh granite rock mass with some distinct shear zones of weaker material. The majority of the tunnels are being excavated using drill and blast, with the two transfer tunnels being excavated with a tunnel boring machine (TBM).This paper focuses on the design and construction of the Telanok underground power station complex and also some aspects of the design for the headrace tunnel. Topics covered include geological site investigations including in situ measurements of rock stresses; development of a geological model and parameters for rock support design; three-dimensional modelling to assess interactions between the caverns to optimise rock support; design of a rock anchored crane beam; construction of the caverns and design of the unlined headrace tunnel taking into account hydraulic jacking and operational pressure fluctuations.CITATION:Drowley, L, Gaida, B and Chapman, B, 2014. Design and construction of large caverns in granite – Ulu Jelai Hydroelectric Project, Malaysia, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 361–368 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By M Rafty, A Markham, S Atkinson, M Heyting

Over recent years there has been a significant increase in the number of miners in the Pilbara region of Western Australia targeting channel iron deposits (CID) located in valleys, intersected by ephemeral creeks and below the groundwater table. The falling iron ore price has triggered a drive to reduce cost and maximise yield. Creek diversions provide an opportunity to maximise the utilisation of orebodies and extend the life-of-mine.Creek diversions that are required during mining operations to access ore and provide flood protection have historically been constructed as uniform engineered channels designed primarily for flow conveyance while minimising earthworks costs; however, the design of diversions becomes more complex when they are required to function in a similar way to the existing creek system during operations and remain stable during more extreme events than would typically occur following mine closure, in accordance with current regulatory guidance. The design specifications for closure are often more rigorous than the operational phase, and could incur significant additional cost to implement retrospectively if not planned and designed upfront.The complexity of diversion design depends on site specific factors such as: the size of the creek to be diverted; hydrology; corridor restrictions; geomorphology; hydrogeology; geology; environmental and heritage values; potential impacts and the risk to operations and environment. The complex interactions of these factors must be well understood and hydraulic modelling undertaken to characterise the existing creek system, demonstrate the diversions, provide adequate flood protection during operations, and can function in a similar way to the existing system following mine closure. This paper presents key design considerations for Pilbara creek diversions, operational and closure requirements, mine planning considerations, risks, cost saving opportunities, and the benefits of an integrated approach to design.CITATION:S Atkinson, A Markham, M Rafty and M Heyting, 2017. ‘Back to the future’ – resilience in historical context and implications for the future, in Proceedings Iron Ore 2017, pp 367–374 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The commercial development of the shallow (2200 ft2 400 ft) Windalia sand reservoir at Barrow Island provided the opportunity to conduct an intensive drilling programme using equipment and techniques designed for optimum performance.During the initial exploratory and reservoir delineation phase, 12 specific Windalia test wells were drilled using drilling equipment with an optimum depth range of 6QOO ft - 8000 ft and a 9 5/8 in by 7 in. casing programme was employed. The average time from commencement of move-in to rig release exclusive of coring for five representative wells was 187 hr during this phase.Development drilling commenced December 1966 with one rig, with the second in operation January 1967.As of January 1 1968, 168 development wells had been completed. The two rigs employed are drive-in units equipped with a telescoping .gelf raising doubles mast.Optimum depth range with 4 1/2 in. drill pipe is 2500-4000 ft. Casing programme is 8 5/8 in. by 5 1/2 in. Efficient performance was achieved immediately. The average time from commencement of move-in to rig release for 15 wells drilled early in the development programme was 99 hr.By application of experience and further modification of techniques, performance was improved to an average time of 72 hr per well for 15 wells recently completed.The major drilling problem on Barrow Island is surface hole drilling due to the very hard surface limestone combined with complete loss of circulation at sea level.In this operation, significant improvements have been effected. During the exploratory phase drilling, 12 1/4 in hole to set 9 5/8 in. casing, average penetration rate was 23 ft/hr. At the commencement of the development programme penetration rate, drilling 10 5/8 in. hole to set 8 5/8 in. casing, was 28 ft/hr for the 15 early wells considered, improving to 55 ft/hr for the 15 recent wells considered.This programme is a team effort and much credit must be given to the enthusiastic co-operation of the two drilling contractors.The current field record is 2 days 4 hr with a 4 1/2 hr move including the drilling of mousehole and rathole.

Jan 1, 1968

By Sheldon P. Wimpfen

Under the Wilderness Act of 1964 and the accompanying House Conference Report, the Geological Survey and Bureau of Mines are charged with the responsibility of making recurring mineral studies of wilderness and wilderness candidate areas in national forests within and proposed for the National Wilderness Preservation System. The Wilderness Act, a major shift from the multiple-use concept of national forests, identified for the first time the value of mineral resource information in decisions for single-use designation of public lands. This concept was further realized when the Secretary of the Interior in May 1974 recommended that mineral studies be made prior to wilderness recommendations for five large Interior-managed game ranges and the Glacier Bay National Monument aggregating 7.8 million acres. Presently, our studies have been completed on 126 wilderness and proposed wilderness areas totaling 15.4 million acres in the national forests. In 1973, 1 year in advance of the act's 10-year review deadline, we completed the 34 primitive areas, originally the only potential additions considered by the 1964 Act.

Jan 1, 1975

By Robert W. Waytulonis

This publication contains 1,000 citations of technical and semi-technical literature treating diesel-powered equipment usage underground both generally and specifically. These citations were gathered by U.S. Bureau of Mines personnel over the period of 1978-1983. The citations concern diesel engines as powerplants for underground mining use; their design, emission characteristics and control, maintenance, usage; and health and safety aspects. All citations have been abstracted and arranged 1n a subject classification system with extensive cross-referencing.

Jan 1, 1983

By H. Guyod

The response of the Guard Electrode sonde (LL3) and the Laterolog (LL7) can be mathematically computed only for cases that do not represent realistic conditions. A resistance network analogue that simulates a number of typical—although idealized—formations was used instead to obtain, for both devices, a large number of resistivity logs and current distribution maps. From these data, charts were prepared for estimating true resistivities under a number of conditions. Some of these charts and current distribution maps are presented. INTRODUCTION Two main benefits are expected from a resistivity log: (1) obtaining geological information for mapping and other purposes, and (2) obtaining petrophysical data, based on true rock resistivity. The geological information can be derived from any resistivity curve having sufficient vertical detail, but true rock resistivities frequently are difficult to determine with desired accuracy because we do not have sufficient interpretation data. This is particularly true for the records given by the Laterolog tools. The object of this paper is to throw some light on the factors affecting the responses of these tools so that better resistivity data can be obtained from Laterologs. LATEROLOGS Laterolog measuring systems are of two types: the LL3 sonde, frequently called "Guard", and the LL7 sonde. Both measure the resistance between a single exploring electrode placed in the borehole and a faraway return electrode whose influence will be assumed here to be negligible. Although the principles of these tools have already been outlined,1-3 it is desirable to review them briefly in this article. LL3 Fig. 1, left side, represents a long cylindrical, vertical current electrode placed in a medium of uniform resistivity. The current leaving the center section of the electrode flows essentially along horizontal lines, delineating a surface having the shape of a biconcave lens. It is the elec- trical resistance offered to this particular group of current lines that is measured by the Guard tool. This is done in practice by having a long cylindrical electrode consisting of three sections physically and electrically separated by thin insulating washers, as shown in the center of the figure, and keeping the three sections at the same potential. It is obvious, for all practical purposes, that the current and potential distributions about this electrode are the same, as if we had a continuous electrode of same dimensions. Because the three sections are electrically separated, the resistance seen by the center section E can be independently measured. This section will be called the exploring electrbde, or E electrode. Its height generally is from a few inches to 1 ft. The outer sections are the guards G, which are several feet long. The combined length of the three sections is from 10 to 12 ft for the tools currently used in the petroleum industry. Let V denote the potential difference between E and the faraway return electrode, and I be the current flowing between these two electrodes. The resistance (Re) seen by the exploring electrode is VII, and the corresponding apparent resistivity is Ra = k(Re),............(1) where k is the tool calibration factor. The previous description establishes that the Guard tool uses that central portion of the sonde from which, in a uniform medium, the current follows essentially horizontal paths. When the formation being logged is fairly uniform, and when its resistivity is of the same order as

Jan 1, 1965

By R. A. Swalin

IN this paper, the results of an investigation concerning the diffusion of three elements, magnesium, silicon, and molybdenum, in nickel are presented. The work represents a continuation of a diffusion program relating to solute diffusion in nickel. The program has the dual aim of obtaining useful diffusion data and of yielding insight into the factors governing solute diffusion in close-packed metals. The first paper of this series has been published earlier? In both investigations, in agreement with recent results from other laboratories, the activation energies for solute diffusion were found to be close but not identical to that of self-diffusion in the pure solvent in question. In order to obtain valid diffusion data, certain experimental pitfalls recognized only in recent years had to be avoided. Chief among these were the necessity for minimizing short-circuiting diffusion paths such as grain boundaries and the necessity for using low solute concentration gradients. In this series of investigations the following precautions were taken in an attempt to minimize such errors. 1) Samples with large grain sizes, 0.5 to 10 mm, were prepared. 2) The diffusion coefficients were measured at relatively high temperatures, since imperfections such as dislocations play a less important role at such temperatures than at lower temperatures. 3) Alloys containing less than 1 atomic pct were chosen for study. Experimental Work Materials—A diffusion couple technique was employed in the experimental investigation. Briefly, this technique consisted of the following. A diffusion couple was fabricated by placing a flat face of a cylindrically shaped alloy disk against a similar face of a pure nickel disk, and a bond was formed at an intermediate temperature under pressure. The diffusion couple thus fabricated was subjected to a diffusion anneal at higher temperatures for a measured period of time and then sectioned perpendicular to the direction of diffusion. After analyzing the sections for solute concentration the diffusion coefficient was determined from a probability, plot of concentration vs distance from the diffusion interface. Vacuum melted Mond nickel was used in the experimental program. The chemical analysis of this nickel is listed in Table I. Alloys used were prepared

Jan 1, 1958

In Situ Bioremediation of a Heavily Polluted Alkaline Soil in a Uranium Deposit

Sep 13, 2010

By Betty L. Gibbs

Using a PC can help an operator analyze data more effectively and respond quickly to changing conditions. The cost of microcomputers is low, and fit into the budget of even small mines. Many software packages are also low cost and general software such as spreadsheet, word processing, and data base management programs can help the small miner organize and evaluate information very quickly. A basic hardware configuration is proposed, including hardware upgrades and general and technical mining software packages. The hardware and software suggested can be used by very small as well as larger operations. PC's can be incorporated into all phases of a mining operation at a minimal cost and capabilities can be expanded as the operation grows.

Jan 1, 1987

By John C. Branner

Inquiries are frequently made concerning the chalk- and clay-beds of Arkansas, usually with a view to the manufacture of Portland cement. The chalk-deposits were first described by Professor R. T. Hill in the annual report of the Geological Survey of Arkansas for 1888, vol. ii., pp. 153-162. Since the publication of that report I have visited localities then unknown, and have accumulated considerable additional information concerning these deposits, dl of which is brought together in the present paper. My report upon the clays of the State has never been published; only a few of the more conveniently available deposits are mentioned in the present paper. The Chalk-Deposits. Stratigraphic Position of the Chalk.—The chalk-deposits of Arkansas belong to rocks of Cretaceous age. The Cretaceous rocks are confined to a single definite area in Southwest Arkansas. Beginning on the Ouachita river, a little northeast of Arkadelphia, its southern or upper margin follows a line about five miles southeast of, and approximately parallel to, the St. Louis, Iron Mountain and Southern Railway from Arkadelphia

Jan 1, 1898

Purification of Nickel and Cobalt from Heap Leaching Effluents Using Ion Exchange Resins A comparative study among several chelating resins for purification of a heap leaching effluent from a nickel laterite ore has been finished. Chelating resins with iminodiacetate (IDA) and bis-picolylamine (Bis-PA) functional groups, from different suppliers, have been evaluated for their selectivity and loading capacities for nickel and cobalt over impurities. The two evaluated IDA resins, Amberlite IRC 748 and Monoplus TP 207, showed very similar results for both loading capacity and selectivity. Better performance was obtained at 7 BV/h at a pH of 4. Evaluation of Bis-PA resin showed that XUS 43578 has better performance than TP 220, with a 30 per cent higher loading capacity and superior selectivity for nickel over impurities.

Sep 13, 2010

[ARTICLE I. NAME AND OBJECT Section 1. This Society shall be known as the Society of Petroleum Engineers of the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. Section 2. The object of the Society of Petroleum Engineers shall be to furnish a medium of cooperation among those interested in the petroleum-natural gas industry an to promote the advancement of this branch of mineral technology through meetings to stimulate the preparation, reading, discussion and circulation of papers connected therewith. ARTICLE II. MEMBERS Section 1. Any person who is a member of AIME may become a member of this Society by the specified process. Section 2. Local organizations may be formed by the Society of Petroleum Engineers as subsidiary units, the membership of which shall be subject to and in accordance with the by-laws of the Institute.]

Jan 1, 1961

By D. L. Marchioni

"The detection and quantification of the degree of weathering is an important aspect of coal exploration and mining. Tests for weathering which are suitable for the exploration camp should be fast, simple, and require minimal equipment and operator expertise. In this study, two tests which fulfill these requirements were evaluated using samples of Western Canadian coals. These tests, one based on the pH of a coal slurry and the other on the flotation of coal in a water/diesel oil mixture, do not appear to give consistent results and are not recommended as ideal weathering parameters.IntroductionThe weathering of coal results in a deterioration of those properties which render it suitable for use in industrial processes. Consequently, the detection and quantification of the degree of weathering is an important aspect of exploration and mining. Frequently, decisions related to the depth of the weathered zone must be made at the exploration camp and, therefore, tests for weathering which are fast, and require relatively inexpensive and portable equipment and minimal operator experience, would be very useful. The aim of the study reported here was to evaluate two tests used by U. S. Steel Corp. to detect coal weathering and which satisfy the requirements for use in an exploration camp. The study is a continuation of a more extensive examination of the detection of coal weathering by various methods, reported elsewhere (Marchioni, in press)."

Jan 1, 1981