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By Oliver Bowles

Sandstone, a widely distributed siliceous sedimentary rock, is the third most popular building stone in the United States. It is formed by the breaking down of preexisting rocks by weathering, subsequent segregation of the detrital quartz grains into discrete deposits by the sorting action of water or wind, and finally cementation of the quartz sand into a coherent rock. The homogeneity and resistance to weathering of the resultant sandstone make it suitable for exterior construction. Its excellent wearing properties explain its popularity for flagging and stair treads. However, quarrying and dressing methods and costs are adversely affected by the abrasiveness and hardness of sandstone especially as compared to limestone.

Jan 1, 1963

By Edwin F. Shorey, Richard F. Coon, Steven B. Fradkin

Crosstown Interceptor Phase IA is the first deep tunnel element of the Milwaukee Inline Project. The tunnel contract includes 6,492 meters (m) of 9.1-m-diameter tunnel, two access shafts, and partial lining for structural purposes. The work also includes grouting to be performed as directed by the engineer to provide groundwater infiltration control in lined and unlined reaches of the tunnel. This paper summarizes infiltration observations, progress of the grouting work, and its potential application to the remainder of the Milwaukee project.

Jan 1, 1987

This paper presents a resume of the likely profitable mining areas in New Zealand. It covers the main 'minerals' û gold, coal, oil and gas, ironsands, silica sands, clays, lump silica, perlite, sulphur and limestone. The potential mining projects are depicted on a map of New Zealand together with the associated works involved in hydro-electric and geothermal power development requirement for industries such as aluminium, nickel ferro-silicon or silicon carbide production. The political need for mining development to relieve unemployment and reverse emigration is stressed. A case is made for exploration and development assistance by government in labour re-training, energy supply and transportation, if the tremendous losses through lack of use of human and industrial resources are to be rapidly reduced. These losses are currently estimated at $10 000 000 000 per year. The need for protection of the sanctity of contract and security of tenure of all mining operations is touched on briefly as is the need for a reasonably balanced view on conservation. However, as both of these are more properly covered in papers on the legal and environmental aspects of the mining climate, they are presented here only as they affect the economy of the mining operation. Finally, there is a brief comment on the mining climate in New Zealand relative to Australia and South Pacific mining operations.

Jan 1, 1990

By Anthony B. Szwilski, Dalip Sarin, Richard D. Begley

This paper will present the results of an analysis of several abandoned coal mine projects and includes field data for over a dozen different reclamation projects recently completed in the state of West Virginia. The analysis was performed with the objective of summarizing and or classification of the environmental consequences with reference to the characteristics of the mining facilities (surface, underground, etc.). The analysis also addressed the itemized cost of remediation with respect to procedures, environmental concerns and time. The results of the analysis are that each abandoned coal mine site in West Virginia have/had many unique features and in most cases include a combination of environmental concerns that complicate comparisons. The study also revealed that the abandoned mine land program for mines abandoned prior to 1977, that is being financed by a tax on the production of coal, has produced many benefits for the state of West Virginia. This grant program administered by the Office of Surface Mining, has resulted in a high quality methodology of remediation that has been successful for many years in greatly minimizing and/or eliminating environmental concerns from abandoned coal mines.

Feb 24, 1997

By M. Beus, S. Inverson, B. Stewart

Abstract Recent ore pass failures have underlined the need for improved designs, standards, structural mon¬itoring methods and better hang-up prevention and removal tech¬niques. Researchers at the Spokane Research Laboratory of the Na¬tional Institute for Occupational Safety and Health (NIOSH) are investigating methods to improve safety during the transport of ore in ore passes. Design criteria and hang-up prevention and remedia¬tion strategies involve studies of the effects of static and dynamic ore and waste-rock loads on chutes, walls, gates and support structures. Particle flow analysis methods were used to simulate the response of various ore pass designs to a wide range of ore loading condi¬tions. A full-scale mockup of ac¬tual ore pass and chute assemblies was duplicated and tested for load response. Data from a particle flow code and the mock-ups were com¬pared Loads on an active ore pass chute were measured.

Rock engineering has now been practised as a discipline for about50 years, and many sophisticated methods of analysis for use in rock engineering design have been developed. However, analysis is only a tool for use in engineering design, and rock masses are often so complex that realistic modelling of them, even with sophisticated methods of analysis, is impossible. At the other end of the scale, rock mass classification methods have been developed to quantify the rock mass. These ?numbers? are now widely used for assessment of stability of underground and surface excavations in rock, for the determination of rock support requirements, and for the estimation of rock mass strength and deformation properties. In considering these areas, the two concepts?design, and prediction of behaviour?will be dealt with. The discussion will be introduced by a consideration of the characteristics of the rock mass, which will highlight the variability in its properties and hence the uncertainty in the behavioural parameters. Examples of real projects will be used to illustrate the discussion.

Jan 1, 2003

By D. W. Partridge, W. Lamb, A. E. Lamb, S. Bird

Due to the constant need to improve SAG mill performance and efficiency, extensive research into all aspects of SAG mill optimization has been performed. This paper will review the current evolution of SAG mill shell liner design and their performance at the Copperton Concentrator. The effect of these liner design changes will be discussed with respect to: • Liner configurations • Mill operating performance, i.e., throughput, power draw, mill control • Mill mechanical performance, i.e., liner wear profiles, liner life, liner breakage, liner hardness • Foundry manufacturing considerations • Economic evaluation of throughput versus liner life This paper will discuss the results of Kennecott Utah Copper’s (KUC) and ME International’s (MEI) test work, providing an insight into the past, present and potential future opportunities of SAG mill liner design.

Jan 1, 2002

New developments in the non-invasive and real-time measurement of the velocity profile of slurry flow in horizontal pipes will be described. This information can be used to determine the approach and onset of solid deposition on the bottom of the pipe. Having this information in real time can enable operation at lower velocities or higher solids concentration or both while avoiding solids deposition or plugging and their associated operational costs. In addition, advances have been made in the measurement and trending of pipewear on slurry lines. In contrast to manual methods, CiDRA?s system uses a permanently or semi-permanently installed ring of conformable ultrasonic transducers clamped onto the outside of the pipe. These transducers are used to measure the thickness of the pipe under their respective locations. This results in better repeatability, accuracy, and failure prediction, along with reduced labor costs. The benefit is significantly improved pipe wear monitoring in pipelines with abrasive solids. This provides an improvement in the ability to insure safe operation and avoidance of costly operational and environmental damage due to leaks caused by pipe wear.

Jan 1, 2009

The construction of the pipeline was completed in June 1956 and the line placed into operation in December 1956, ie. it has now been in continuous operation for approximately three years under an operating pressure of up to 350 lb. p.s.i.In reviewing the operating experiences of the line we must consider three major factors, which are:(a) The effectiveness to date of the protective methods for prevention of corrosion of the pipeline, ie. the preservation of the asset.(b) The maintenance of the line in regard to interference as to its stability which could be occasioned by erosion of the line, land-slides, accidental interference by the public, or construction authorities, etc.(c) The operating techniques employed.PROTECTIVE METHODS OF THE PIPELINESo to permit a clearer appreciation of the effectiveness of the protection of the! steel pipe against corrosion, I will briefly describe the methods used in the construction of the line.The line, which is 18 in. O.D. by %6 in. thickness steel pipe, is located approximately It miles south of the main Melbourne/Gippsland electrified railway.The steel from which the pipe was manufactured conforms to ASA.A33-1937 with the following modifications.Minimum elongation on a 2 in. test specimen...

Jan 1, 1960

By Edward J. Caldwell

In 1930 the Bureau of Mines published a description3/ f the concentrating process of the Magma Copper Co. as it had been developed to that time and was then employed. The prevent paper revises the description to the end of 1943 and includes a description of the smelting processes. Data from the mild and smelter operations for, 1942 are given in tables 1 to 14, Billing costs are included, but it is not permissible to publish smelter costs.

Jan 1, 1944

The 108th Annual General Meeting of The South African Institute of Mining and Metallurgy was held at The Country Club, Johannesburg, Napier Road, Auckland Park on Thursday, 11 August, 2005. Welcome The President extended a special welcome to the guests and representatives of our sister institutes and other associations, also to recipients of awards, senior members of industry, Honorary Life Fellows, past-presidents, our members and other guests, among them the following: Dr Con Fauconnier, President, Chamber of Mines of South Africa Prof. Jay Barton, President, The Geological Society of South Africa V. Townshend, President, Institute of Certificated Mechanical and Electric Engineering, South Africa M. Livingstone-Blevins, President, Institute of Certificated Mechanical and Electrical Engineers, South Africa Prof. B. Lacquet, President, South African Institute of Electrical Engineers Dr F. Malan, President, South African National Institute of Rock Engineering

Jan 1, 2005

By I. A. Mwamba

Titanium aluminide of composition Ti-47.5 at.% Al was prepared by melting titanium and aluminium of commercial purity with additions of precious metals of 0, 0.2, 1, 1.5 and 2 at.% content. The microstructure, hardness and oxidation properties were assessed. It was found that at 47.5 at.% Al, the microstructure of plain TiAl alloys was duplex, consisting of duplex lamellar grains and ? grains. The lamellar grains consisted of alternating lamellae of ? (TiAl) and a2(Ti3Al), with overall aluminium content in the range of 43?47 at.%. The ? grains had a aluminium content above 50 at.%. The addition of precious metals to the TiAl alloy resulted in the formation of a new phase, with a high precious metal content, occurring mostly in the ?phase, without any major change to the microstructure. Increasing the amount of precious metals resulted in an increase of the new phase amount, at the expense of the ? phase. The hardness of the different alloys was around 300HV10. Overall, the research has shown that addition of precious metals to TiAl resulted in a slight increase in hardness and a significant improvement of the oxidation resistance. This shows that alloying TiAl with precious metals, at the addition levels investigated, does not alter the mechanical properties very much, but improves oxidation resistance.

Jan 1, 2012

By N. P. Mahumapelo

This paper is based on a study to determine the potential beneficiation opportunities for marble from Griekwastad in the Northern Cape Province. The marble was characterized mineralogically by X-ray diffraction. Major and trace elements were determined using inductively coupled plasma-optical emission spectroscopy. The sample was crushed, and the crushed material beneficiated by tumbling and polishing. The resulting beads were incorporated into a variety of jewellery and other decorative items. It is concluded that the beneficiation of Griekwastad marble presents a good opportunity for value addition and job creation, provided that an effective marketing strategy for the products can be developed..

Jan 1, 2014

By Michael E. Berndt

Asbestos first became an issue to Minnesota?s iron industry when it was revealed that mineral fibers similar to those in Reserve Mining?s tailings were being found in drinking water for several communities that used Lake Superior as their primary water source. This discovery turned what had largely been an environmental court battle into a case concerning public health. The courts listened to much conflicting and uncertain scientific testimony on the size and distribution of the mineral fibers and on the potential health effects imposed by them. In April 1974, the plant was ordered to shut down by a federal judge but the company quickly appealed the decision. The appeals court granted a stay and ultimately ruled that the plant?s closure could not be justified based on the unknown health effects of the mineral fibers since the consequences of such an action would have immediate and severe social and economic impacts. The plant was allowed to continue operation, but ordered to abate emissions to air around the plant and to switch to a land-based tailings disposal system. Much of the scientific uncertainty and public concern over mineral fibers in Minnesota?s taconite industry remain today. ©2007 Elsevier Inc. All rights reserved. Keywords: Minnesota; Iron ore; Taconite; Asbestos; Amphibole; Reserve Mining; Tailings; Mesabi Iron Range

Jan 1, 2007

By A. B. Hazar-Yoruç

Ferrochromium produced by smelting chromite ores is an important alloying component in the steel industry. Ore, coke and fluxes are mixed and reacted in an arc furnace for a smelting process of ferrochromium. In ad-dition to this process, pre-reduction of chromite ore with carbon is an important industrial process. In all these processes, the mechanism and kinetics of reduction of chromite with carbon play an important role. In this study, the reduction of Turkish chromite ore with carbon was investigated. Chromite and carbon were ground to three different particle size groups. Chromite was mixed with carbon in stoichiometric and excess ratios. The samples were reduced under argon atmosphere at temperatures between 1,200° and 1,350°C. The formed phases and alloy compositions of reduced chromite samples were analyzed by optical microscopy, scanning electron microscope (SEM) with EDAX and X-ray diffraction analysis (XRD). Experimental results showed that the degree of reduction and the reduction rate increased with increasing temperature and decreasing particle size. The highest degree of reduction, 61.4%, was obtained at 1,350°C. The reduction took place in three stages: Stage 1: transformation of Fe3+ to Fe2+ and formation of metallic nuclei, Stage 2: formation of metallic crust around the particles and Stage 3: growth of the metallic crust and coalescence of the metallic phase.

Jan 1, 2007

By Christopher J. Bise

PRINCIPLES OF MINE PLANNING During the initial planning stages, all mining operations are analyzed and evaluated in a similar fashion. This similarity holds true because the mine-planning procedure can be reduced to a network of interrelated systems that are tied together by a common philosophy of mine planning: namely, that the resource is to be extracted in a manner which is safe, efficient, and profitable. The success of the mining operation cannot be guaranteed unless each of these three requirements is met. Fig. 1 shows a flowchart for the initial planning of any mining operation. Notice that there is a preplanning stage that leads to the planning of four interrelated systems. The preplanning stage includes property exploration, estimation of production and manpower requirements, and the establishment of construction timetables. The four systems, evaluated after the pre-planning stage, are broken down into the following: (1) Excavation and handling system, (2) Strata control system, (3) Operating support system, and (4) Service support system. The Excavation and handling system includes the selection of all the equipment for the removal of the resource from its in-place deposit (e.g., draglines, continuous miners, rock drills, etc.) and for the transportation of the mined material from the face (e.g., belt conveyors, trucks, etc.). The Strata control system incorporates all those considerations which maintain the integrity of the roof, ribs, floor, and overburden both during and after the extraction phase; typical considerations in this area include pillar sizing, artificial support of the immediate roof in mine entries, and subsidence protection. The Operating support system contains the "necessary evils" of mine planning; the system consumes a large percentage of the mining engineer's planning time but does not contribute to the actual extraction of the resource. However, if proper attention is not paid to the various components of the system, such as ventilation, drainage, and power, then the mining operation will not perform to its capabilities. Finally, the Service support system is composed of those operations which keep the mine running efficiently; typical examples of these include maintenance and sup- ply. One important concept that Fig. 1 is designed to emphasize is that the four systems are interrelated; typically, a slight alteration of one can affect the performance of another. If these interrelationships are ignored, the effects on the system can be disastrous. The mine preplanning stage and the four subsequent system evaluations constitute the Analysis portion of the mine planning flowchart. After this portion of the study is completed, the overall projected operation can be evaluated by techniques such as financial analysis. This last step in the study is referred to as the Synthesis of the previously calculated parameters into an overall plan. Much has been written about the overall evaluation of mining properties, but, over the past thirty years, very little has been written about the analysis of mine- planning systems in a coordinated manner. Further, those texts which attempted this topic have failed to give sufficient examples for successful implementation, thus supporting the operating engineers' lament that it is easy to discuss theories but difficult to show applications. This text is intended to bridge this gap. Examples of the various stages of the analysis portion of the mine planning flowchart shown in Fig. 1 will be covered in this text, with the exception of the Service support system, since this system is oriented more toward day-to-day planning than long-term mine planning. INTERNATIONAL STANDARDIZATION The benefits that can be derived from an international standardization of the units used in mining engineering calculations are numerous. The interchange- ability of equipment parts and the ability to analyze and compare performance and design specifications on an equal basis are just two of the goals desired by both manufacturers and mine operators. Unfortunately, conversion to an international standard has not been rapidly achieved by engineers in the United States, due to their training under the English system. The Society of Mining Engineers of AIME has made the commitment for the adoption of the Systeme International d'Unites (SI) in all mining engineering calculations. Since many practicing mining engineers and students in undergraduate programs still find difficulty in relating to SI units, the calculations in this textbook will use the English system, with Table 1 available for conversion into SI units.

Jan 1, 1986

By William S. Sanner

A demonstrated reserve base (DRB) of bituminous coal suitable for cokemaking has been estimated based on the latest published information on U.S. coal reserves. Bureau of Mines analyses of raw coalbed samples were used to classify the coals as low-, medium-, and high-volatile bituminous and grade them as premium, marginal, and latent coking coals. Coal rank was used as the basis for identifying coking coals, and ash and sulfur content were used to determine coking coal grade. The demonstrated reserve base of coking coal for the entire United States is 162.67 billion tons. However, only 18.96 billion tons are premium (metallurgical) grade, and between 80 and 99 percent occurs in the Eastern States. The demonstrated reserve base of marginal-grade coking coal is 31.3 billion tons; more than half the marginal reserve base is in the Eastern States, and most of the medium- and low-volatile marginal coals are in the Eastern States. The Eastern and Midwestern States contain most of the latent-grade DRB of 112.4 billion tons; most (106.6 billion tons) is high-volatile coal, and 98 percent of the medium- and low-volatile latent coals occur in the Eastern States. Based on the worst assumption, which assumes that only premium-grade coals are used for cokemaking, the DRB for high-volatile coal would suffice for 127 years, the medium-volatile coal for 80 years, and the low-volatile coal for 83 years.

Jan 1, 1979

By Vincent Castranova, Jane Y. C. Ma, Joseph K. H. Ma, Chang-geng Mo, Carl J. Malanga

"A group of bisbenzylisoouinoline alkaloids has been shown to exhibit various degrees of effectiveness in preventing silica-induced fibrosis in animal models [1, 2]. The objective the present study was to characterize the binding of several of these alkaloids to phosphatidylcholine vesicles and rat alveolar macrophages using fluorometric and equilibrium dialysis methods, respectively. The lipid binding affinity of these alkaloids was found to depend upon several structural factors including hydrophobic substitutions, chiral configurations, and double oxygen bridge-restricted conformation of the benzylisoquinoline moieties. Tetrandrine, which is a highly effective agent in preventing fibrosis, showed strong binding to both lipid vesicles and alveolar macrophages. In contrast, certain analogues of tetrandrine such as curine and tubocurine, which have little or no effect on silicosis, exhibited only weak binding to lipid vesicles and almost no binding to cells. The moderate binding affinity of fangchinoline to vesicles and cells corresponded to a moderate effectiveness of the compound as an antifibrogenic agent. Methoxyadiantifoline, an alkaloid of unknown antifibrogenic potential, also exhibited high binding affinities for lipid and cells. In conclusion, the results of these studies indicate that alveolar macrophages exhibit large binding capacities for certain members of this class of bisbenzylisoquinoline alkaloids. A positive correlation was observed between binding affinity to alveolar macrophages and the reported antifibrotic potency of these compounds. These data also suggest that the ability of these drugs to interact with alveolar macrophages may be a key step in inhibition of the progression of silica-induced pulmonary disease.INTRODUCTIONInhalation of crystalline silica is associated with the development of silicosis. This fibrotic disease is characterized by the appearance of concentric hyalinized nodular lesions in the lungs with the progressive development of pulmonary dysfunction [3, 4]. Many theories concerning the etiology of silicosis involve silica-induced activation of alveolar macrophages. Evidence indicates that in vitro silica exposures result in the generation of chemiluminescence, and the release of superoxide and hydrogen peroxide from alveolar macrophages [5]. Activation of alveolar macrophages has also been demonstrated after intratracheal instillation or inhalation of silica [5, 6]. Such excess release of reactive products from pulmonary phagocytes has been associated with damage to the lung parenchyma [7, 8]. In addition, silica exposure results in the release of mediators from alveolar macrophages, which enhance proliferation of fibroblasts and collagen synthesis by these pneumocytes [9-12]."

Mar 1, 1992

By Hemingway P, Boag J

Major operating aspects of the Mary Kathleen Uranium Ltd. treatment plant are discussed with partkular reference to those which are peculiar to this operation.Problems associated with the production of a penalty free uranium oxide product are examined and the methods developed to overcome them are described in detail.INTRODUCTIONMary K,athleen Uranium Ltd. is the largest of the Australian uranium producers. The flow-sheet is based on fine grinding, standard sulphuric acid leach, ion exchange concentration, and magnesia precipitation of the final product, with certain modifications introduced as the result of pilot plant investigations at the South Australian Department of Mines Research Laboratories in Adelaide.The plant commenced operations in June, 1958, attained design tonnlige of 1,120 tons per day in September of that year and has since operated continuously with a throughput in excess of 1,000 tons per day. Pilot plant recommendations generally have been followed, and predicted results have been attained. The only exception has been the silica and rare earth content of the product produced during the early months of operation. Considerable modification of the early resin regeneration techniques resulted in the reduction of the silica content of the product to within specification limits. Research work in the ion exchange section has also resulted in the reduction of the rare earth content of the product to below specification levels. All product now being produced is completely within the agreed specification limits of impurities.

Jan 1, 1961

A thermochemical model is developed to study the two-stage smelting reduction process for ironmaking without post-combustion. Steady-state multi-material and heat balance equations are solved simultaneously to study the effect of metallisation, slag basicity, coal rank and heat loss on consumption rates of coal, ore, flux and oxygen and production rate of slag to produce hot metal of a given composition, tapped at a given temperature. The model is applied to the commercial data for a COREX-plant producing a wide range of hot metal compositions, tapped at different temperatures. The computed rates of coal, slag, flux, ore and oxygen were found to be close to the reported ones, but an exact match could not be obtained. It is found that a four per cent change in metallisation brings changes the coal rate by five per cent, flux rate by six per cent, slag rate by eight per cent and oxygen rate by 13 per cent, while a ten per cent change in basicity changes the coal rate by ten per cent, flux rate by 13 per cent and oxygen rate by 22 per cent. Further, it is found that an increase in metallisation decreases the coal rate and export gas. At a given per cent metallisation, the coal rate and the export gas are lowest for anthracite compared to all other types of coal.

Jan 1, 1999