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By Leon Lorenzen, Trevor J. Britz, Pierre J. Van Zyl, Ellis R. Els

Enhanced granulation of UASB granules was tested on pilot scale with two different test reactors (about 5 litres capacity each). Sludge from a local sewage works was used, with peach cannery effluent as carbon source. Cyclic motion of the reactor contents, and a daily replenishment of feed material create the necessary stress conditions for enhanced growth. Sizable granules, bigger than 0.5 mm, were produced within 20 days. Of the two reactors tested, the reactor equipped with a horizontal agitation shaft proved more effective.

Jan 1, 2003

By Hillary W. St. Clair

This is an initial progress report on a theoretical study of the iron blast furnace. The purpose is to develop a thermochemical model that will simulate mathematically a real furnace. An analysis is made of the behavior of a hypothetical furnace, operating adiabatically on pure ferric oxide, graphitic carbon, and dry air. Relationships are derived for carbon consumption, gas composition, and reaction temperature for a furnace operating at steady state, and in which the smelting rate is slow enough for the gas and solids to approach thermal and chemical equilibrium. Analyses are made for two contrasting types of gas flow: (1) Nonturbulent flow, having no vertical mixing; and (2) turbulent flow, having perfect mixing during each step of the process. It is shown that some vertical mixing is essential for complete reduction of ferrous oxide and that the extent of vertical mixing is one of the critical factors in the behavior of the furnace, This analysis indicates that the thermochemical relationships in a blast furnace can probably be best simulated by a finite series of gas-solid reactors through which gas and solids flow countercurrently and in which the temperature and composition of gases and solids are assumed to be uniform. Any degree of vertical mixing can be approximated by the proper choice of the number of reactors.

Jan 1, 1963

By K. Häge

"Die Nachhaltigkeit der Braunkohlengewinnung in der öffentlichen Wahrnehmung wird nur weiter erfolgreich kommuniziert werden können, wenn durch konkretes Handeln glaubhaft gezeigt wird, dass die offenen Fragen fair und solide beantwortet werden. Dazu gehören insbesondere die neue innovative technische Lösung sowie das sensible Interessenmanagement. Die Braunkohlenindustrie hat gelernt, dass Offenheit und nicht zuletzt das beständige Bemühen um den Meinungsaustausch mit ihrem Umfeld wichtige Elemente sind. Der in Jahrzehnten erworbene Schatz an Glaubwürdig-keit ist eine Basis, auf der die Braunkohlenindustrie ihre Zukunft gestalten kann. Darüber hinaus sind politische Rahmenvorgaben erforderlich. Das öffentliche Interesse an einer sicheren und preiswerten Energieversorgung unter Einschluss der Braunkohle ist unverzichtbar. In diesem Kon-text kann dann die Braunkohle die an sie gerichteten Fragen der Ökonomie, der Ökologie und der Sozialverträglichkeit auch mit Hilfe von Indikatoren beantworten.ABSTRACTThe discussion of the sustainability of lignite mining can only be continued successfully if the indus-try acts in a practical manner and demonstrates trustworthiness by responding fairly and reliably to open questions. This includes new and innovative technical solutions as well as the sensitive management of interests. The lignite industry has learned that openness and the constant effort to exchange viewpoints within their environment are all essential elements. The credibility that has been gained over the decades is the foundation on which the lignite industry can build its future. Beyond that a framework of political guidelines is necessary. Public interest in a secure and inex-pensive energy supply that also includes lignite is indispensable. In this context, the lignite industry will then be able to answer the questions which are directed at them and concern the economy, ecology, and social tolerability also by indicators."

Jan 1, 2005

By James M. Schopf

Gilbert H. Cady (Senior Geologist, Head of Coal Division Emeritus, Illinois State Geological Survey, Ur-bans)— Those coal mining and preparation engineers and operators who read this article will probably be most concerned with those parts which deal with the applied aspects of coal petrology in the fields of mining and technology. Actually the two categories overlap to such a degree that they are essentially one. The article appears to suggest that there are two points of veiw in the field of applied coal petrology. From one viewpoint the interest is in the attributes of the various macerals (Fig. 4)—vitrinite, exinite, and inertinite—-in terms of utilization (when the coal is burned, coked, gasified, hydrogenated, etc.). From the other point of view, assuming that the macerals do possess individuality in behavior, interest attaches to the possibility that coal of a particular type (maceral composition) can be prepared by discriminating methods of preparation and blending. Most of the 29 items listed for mining and technology can be assigned to one or the other of these two categories. Somewhat the same simplicity that resides in the items of the proximate chemical analysis is desirable for the petrologic analysis. This simplicity appears to be fairly well achieved by the group maceral device provided mineral matter is also included. At present, without fully adequate experimental substantiation, the three types of material represented by the group macerals vitrinite, exinite, and inertinite are regarded as sufficiently different in composition and properties so that the preponderance of any one type gives the coal distinctive properties provided it is not too high in rank. This appears to be increasingly true with coals of decreasing rank from medium volatile bituminous coals downward. The article reflects the great emphasis placed on the technique of descriptive coal petrology in America. Such description has resulted in a good understanding of the nature of the fundamental variability in the physical composition of bituminous coals. Such understanding has been attained very largely by the thin section technique used in coal bed profile analysis introduced by R. Thiessen after the manner suggested by the data assembled in Table 11. In contrast, the group maceral concept of coal analysis in terms of the categories indicated on the left hand side of Fig. 4 is particularly useful for broken coal analysis and applied coal petrology, in which evaluation is largely based on quantitative concepts. It is inadequately emphasized in this article that although the Thiessen procedure is suitable for the purpose of petrologic description in which texture and orientation are of critical importance, it is less well adapted to the technological uses of applied coal petrology. No doubt those persons whose interest may have been aroused in the possibilities of more refined coal preparation by this and other recent contributions to the literature of coal petrology will understand that certain technical aspects of coal petrology, particularly in the field of descriptive petrology, are still a matter of some controversy among the coal petrologists, but they will also appreciate that Schopf has made an important contribution to the field of coal petrology in America by pointing out that such petrology requires consideration of disoriented or broken coal samples and that results are expressed less in descriptive terms than in quantitative values with respect to the four types of material composing coal—-vitrinite, exinite, inertinite, and mineral matter. Unfortunately because so much American coal petrology has been descriptive of the coal in the bed there is a dearth of literature on applied coal petrology. Research and experimental data in this field are greatly needed.

Jan 1, 1959

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 Canada Ernst & Whinney

INTRODUCTION The principal objective of this chapter is to provide guidance in understanding and making effective use of published financial statements of mining companies. Although financial statements only represent a gathering together of information relevant to an enterprise's financial position and results of operations, they increasingly reflect the complexities of the modern day business environment. In the mining industry, a wide variety of accounting practices have evolved to deal with the unique aspects of the business in the absence of authoritative accounting pronouncements from standard-setting bodies. Given such complexities and divergent practices, financial statements of mining companies are not easily understood and cannot be used effectively as a tool in decision-making without a basic knowledge of fundamental accounting concepts, generally accepted accounting principles and their application in the mining industry. As such, this chapter is not restricted to a discussion of the accounting for the unique aspects of the mining industry. These aspects are dealt with at length but the text also includes a discussion of general accounting concepts and practices which have wide application in the mining industry. Frequent references are made in the text to international practices and to specific rules and requirements of individual countries. In this respect, the scope is restricted to four major mining environments, Canada, the UK, the US and Australia, all of which have made significant contributions to the development of generally accepted accounting principles. Acknowledgements This chapter was prepared under the direction of Ian Murray of Ernst & Whinney in Toronto, Canada. Contributions were received from Graham Butt, Mark O'Sullivan and Dominic Robinson, all from Ernst & Whinney in Toronto and Bill Duvall and Tom Schoenbaechler from Ernst & Whinney in Louisville, Kentucky, US. The authors would also like to acknowledge the assistance received from David Ferguson, Don MacLean, David Taylor and Susan Zoutman from Ernst & Whinney, Toronto, from the UK and Australian practices of Ernst & Whinney and from Ernst & Whinney International. FINANCIAL STATEMENTS - ELEMENTS AND CONCEPTS Financial statements were originally a stewardship report to owners to satisfy them that management had given a proper account of the resources with which it had been entrusted. Today, the number of users of financial statements has expanded to include the following groups: - shareholders, present and prospective; - lenders, present and prospective; - financial analysts; - regulatory authorities; - taxing authorities; - labour unions and employees; and - creditors and customers. The expectations of these user groups differ. For example, investors and lenders require information that will indicate the adequacy of their security and the profitability of the enterprise; taxing authorities will be concerned with the concept of income; labour unions and employees will focus on the profitability of the enterprise. Ground Rules for Preparing Financial Statements Responsibility for Financial Statements Financial statements are the representations of management. This may strike the reader as a rather obvious statement. It is important to remember, however, the role of judgment in accounting. Notwithstanding the promulgation of accounting standards in the developed countries, considerable flexibility remains in the selection of accounting practices and methods and in their presentation. Arguably, there is more flexibility in the mining industry as few countries have developed standards to deal with its unique aspects. Accordingly, financial statements are as much a product of management's perspective and philosophy as they are a compliance document.

Jan 1, 1985

By Kenneth M. Maas

The Bureau of Mines inventoried all lands in Alaska to determine the availability of land for oil, gas, and coal leasing. Acreage for onshore oil, gas, and coal basins was digitized as was land ownership data. Regulatory policy concerning oil, gas, and coal leasing for various government agencies and private concerns was determined. Oil and gas basins underlie 79.4 million acres of Alaska's 378 million acre landbase. Federal agencies manage 44 million of these acres. The Bureau of Land Management is the lead agency for most oil and gas leasing on Federal lands. Lands have to be specifically opened for oil and gas leasing to be available. The state of Alaska manages 21.1 million acres underlain by these basins. More than 80 percent of this acreage is available for resource development. Native corporations manage the remaining 14.3 million acres of favorable oil and gas land. Coal basins underlie nearly 51 million acres of Alaska. Of this land, 26.4 million acres are under Federal jurisdiction. The state manages 17.3 million acres of land underlain by coal basins. Nearly 7.3 million acres of favorable coal lands are managed by Native corporations.

Jan 1, 1991

By Malte J. M. Gurgel, Axel Preusse

Recent three-dimensional surveying techniques have opened up new opportunities for the registration and monitoring of underground cavities. There are essentially two main methods available: Laser scanning, which is used both above surface and increasingly underground, and photogrammetry, which is also experiencing a renaissance with techniques like structure from motion through the algorithm-based orientation of high-resolution images. Both methods provide the capability to reconstruct reality by various 3-D products like points clouds and meshed models. However, they differ significantly in the steps of registration and calculation as well as in the resulting evaluation options.

By A. McLean, J. Hou

Waste slag is a major environmental concern within the metallurgical industry. In the steel industry, about 100 kg of slag is produced in making one tonne of liquid steel from iron in addition to that produced during ironmaking. The amount of slag from the steelmaking converter can be significantly reduced when charging hot metal with low phosphorus and sulphur contents. In this context, hot metal pretreatment is known as an effective means of preparing high quality charge material for the converter thus limiting the generation of residual slag during the steelmaking process. In the aluminum industry, about 2-4 tonnes of slag, including red mud from alumina production and dross from aluminum electrolysis and casting, are generated during the production of one tonne of aluminum. In recent years, reuse of waste slag from the aluminum industry is a topic that is receiving increasing attention. In this paper, the possibilities of using waste slag and by-products from the aluminum industry as a refining flux in the steel industry are discussed. Several successful processes to convert waste materials from the aluminum industry to steel refining fluxes are described. Some theoretical aspects of using calcium aluminate based flux for desulphurization are outlined together with results obtained from laboratory experiments on sulphur removal from hot metal. By intelligent use of waste materials, the disposal of solid waste from the metallurgical industries can be reduced.

Jan 1, 2004

By Guohong Yin

Oxidized sulfidic tailings contain significant amounts of accumulated acidity in the form of water-soluble secondary sulfate minerals and thus constitute long-term sources of acid drainage at many metal mining sites. As part of site remediation activities, alkaline amendments are often added to the oxidized tailings to increase the pH and immobilize the metals. This study assessed the advantages and limitations of using lime mud, a byproduct of Kraft pulp mills rich in calcium carbonate (> 90 wt. %), as alkaline amendment. The inorganic and organic constituents of lime mud samples were quantified. Leachable impurities were determined by the TCLP method. The performance of lime mud was compared to that of reagent grade quicklime (CaO) and calcite (CaCO3). Tailings treated with lime mud or calcite have strong buffering capacities and remain at neutral pH conditions (pH ~ 6.7) for long times. In contrast, tailings treated with quicklime have a very low buffering capacity, and their pH decreases with time. Furthermore, lime mud has finer particle sizes and thus a greater specific surface area than most forms of commercially available calcite, which results in enhanced reactivity. Dissolved metal concentrations are similar in tailings slurries treated with lime mud or calcite. This study suggests that lime mud is an environmentally and economically attractive alkaline amendment for oxidized mine tailings.

Nov 1, 2002

Long range expansion plans begun in 1966 by The International Nickel Co. of Canada, producer of over 50% of the free world supply of the white metal, are so mammoth as to give rise to the speculation that something might have to burst at the seams. From an annual level of capital expenditure of $35 to $70 million, the company jumped in 1967 to $145 million in new capital investment and will come close to $200 million in 1968. Inco expects to spend $700 million in the next five years, beginning in 1968, for new mines and surface facilities in Canada. The program involves the opening of nine new mines within the next 3 1/2 years, expansion of producing mines, and construction of new plants and modernization and expansion of established ones to process the increased ore production. Beyond this, the company is committed deeply in developing new sources of nickel abroad. Any one of these new projects, if proven economic, would necessitate expenditures of about $100 million or more. For Inco, the economic strain was relieved without a rupture this spring when Henry S. Wingate, company chairman, reported' at the stockholders annual meeting that $150 million had been raised by the sale of bonds. This marked the first time in 32 years that the company had gone into debt.

Jan 10, 1968

By J. Ruzicka

IN creep testing, material is subjected to a constant load, preferably at a constant temperature, and its rate of deformation is measured. The method of loading can be of various types but in this paper only creep testing under tensile load will be considered. The ordinary tensile test is essentially a comparison test in conditions that frequently bear little or no relation to those under which the test material is to be used in service. The purpose of creep tests is to measure the strength of the test material at slow rates of deformation that more nearly approach the rates realized in service. One purpose of this paper is to illustrate that the creep test, in addi-tion to its value as a service test, is superior to the ordinary tensile test as a sensitive tool for the comparison of certain metals in investigative testing. The other purpose is to describe equipment having distinctive features of design that make it especially suitable for such tests. Representative data obtained with this equipment on a group of rolled zinc-base materials are given. These data are compared with those from practical comparison tests of the creep type on weatherstrip fabri-cated from the same group of materials. The comparison illustrates the value of the fast creep test and of the equipment.

Jan 1, 1937

By Georgy Cherkashov

The geological setting, morphology and physical properties of massive sulfide deposits must be taken into account when designing the underwater systems being currently constructed for mining of this type of marine minerals. Based on more than 20 years experience of hydrothermal mineralization studies in the northern equatorial part of the Mid Atlantic Ridge (MAR) we have provided the following conclusions:

Jan 1, 2008

By Cornel E. J. de Ronde

Brothers volcano (34°51.7?S, 179°03.6?E) is a large caldera volcano that forms part of the active Kermadec arc south of 32° S, NE of New Zealand. It is an elongate edifice striking NW-SE that is ~11-13 km long by 7-8 km across. The caldera has a basal diameter of 3-3.5 km and is surrounded by 350-450 m high walls with the floor 1,850 m deep. A volcanic cone of dacite composition rises 350 m from the caldera floor and partially coalesces with the southern caldera wall. Much of the caldera construction and the location of the hydrothermal vent sites are controlled by intersecting basement structures. Three hydrothermal sites have been recognized at Brothers; NW caldera, SE caldera and cone. Multiple hydrothermal plumes were mapped from the bottom of the caldera upwards to a depth of 900 m and originate from two of the sites; one on the NW caldera wall the other atop the cone. Analyses of these plumes show that the two vent sites are chemically distinct. The cone site itself hosts three distinct vent fields (summit, upper flank, NE flank) that in 1999 had plumes (mainly from the summit) containing relatively high concentrations of gas with a shift of -0.27 pH units (proxy for CO2) and H2S concentrations up to 4,250 nM, particulate Cu (PCu) of 3.4 nM, total dissolvable Fe (TDFe) of 4,720 nM, TDMn up to 260 nM and Fe/Mn values between 4.4 and 18.2. However, in 2002 plumes from the summit vent field had noticeably lower concentrations of PCu (0.3 nM), TDFe (175 nM), and Fe/Mn values of 0.8, although similar TDMn (220 nM) and shift in pH (-0.22) suggesting a state of flux for this site. By contrast, plumes originating from the NW caldera site have much less gas with a pH shift of -0.09 units and no detectable H2S, TDFe up to 955 nM, TDMn up to 150 nM, and Fe/Mn values of 6.4, and have not changed their composition over the same three year interval indicating a more chronic hydrothermal system. Plume d3He results show helium is decoupled from more near-surface vent fluid sources although a shift in R/Ra values from 6.1 ± 0.5 in 1999 for the combined vent sites to 7.2 ± 0.1 in 2002 indicates a less radiogenic input of helium over three years, suggestive of a greater magmatic input to the system.

Jan 1, 2004

By J, T C. McCuaig, J Hodgkison, T Fouet

Olympic Dam is the eighth largest Cu deposit and the largest U deposit in the world, with approximately 35 million tonnes of contained Cu and 1.2 million tonnes of U. The most recent resource estimate was for 2.95 billion tonnes of mineralised material with average grades of 1.2 per cent Cu, 0.4 kg/t U, 0.5 g/t Au, 2.6 g/t Ag as contained mineral resources. Olympic Dam is expected to produce >200 000 tonnes of Cu and 4200 tonnes of U3O8 from 9.8 million tonnes of ore in 2004, making it the 12th largest Cu producer in the world. One of the impediments to achieving targeted rates of production has been oversize material (>0.9 m) reporting to stope draw points. A major contributor to oversize material may be overbreak along pre-existing structural weaknesses from stope walls and backs during the production life of a stope. Underbreaking to structures can also have a detrimental effect on the performance of a stope. In an effort to understand the influence of structural geology on stope performance, WMC Resources and SRK Consulting partnered during 2003 to refine the current system of structural mapping, and to use historical data to produce a structural interpretation covering a large part of the mining area. The interpretation has been wireframed in DATAMINETM into a three-dimensional structural framework model. To date, there are more than 600 structures of >50 m strike length incorporated into the structural framework model, which covers a study area 1500 m + 600 m + 350 m. A back-analysis exercise to assess the influence of interpreted structures on overbreak and underbreak was completed for laser-surveyed stopes.

Jan 1, 2004

By D. Q. Li

"This paper briefly introduces problems that can occur in the design of rare earth separation processes and that require close attention during engineering design. Important factors must be considered include the following. 1) The separation process is primarily based on two points. One is the raw material composition and the other is the product purity requirements. 2) Optimization of the rare earth separation process requires optimization of the flowsheet configuration and each process parameter. 3) The separation of heavy rare earths is performed under non-equilibrium conditions. 4) The radioactive elements uranium and thorium must be removed from the feed to separation. 5) Process economy and environmental protection must be considered together in the evaluation of any separation technology options. INTRODUCTIONThe importance of rare earth (RE) is well recognized in high-tech applications and sophisticated national defense technologies. RE is the treasure house of the 21st Century new materials. The RE separation processes developed using HEHEHP (P507), P507-alcohol (ROH) and naphthenic acid (NA) have been widely applied in China. These processes have led to industrial production of all of the individual RE with up to 4N (99.99%) or higher purity (Li, Wan, Lin, Xie, Lin, & Wang, 1980; Li, Wang, & Xie, 1985; Li, 1995; Li, Wang, Meng, & Li, 2005). In order to achieve the best economic and environmental benefits, this paper discusses several problems to which attention must be paid in the design of rare earth separation process."

Jan 1, 2016

By J. Botha

There are many underground mining software tools available to plan and schedule the development of underground mines. A shortfall of these tools is the optimization of the underground equipment and strategy in order to maximize the development rate. This paper will illustrate how the SimMine® software was used to maximize underground development at Petra Diamonds' Cullinan Diamond Mine. It will also determine the effect of various development strategies and equipment capacities on the underground development rate and pinpoint potential bottlenecks in the mine development cycle.

Jan 1, 2010

By Jian Li, Pei Liu

In recent years FIB has become a powerful instrument to perform ion beam sectioning and site-specific TEM specimen preparation. However, there are still gaps in understanding FIB-induced artifacts. Gallium ion beam damage and specimen heating during FIB milling can produce unwanted artifacts during FIB work.Calculations ofmaximumspecimentemperature increaseshavemostlybeen based on the assumption that ion beam implantation into substrate of infinite size. This deviates from finite specimen volume in FIB TEM specimen preparation that impedes specimen heat dissipation. In this paper, the authors will demonstrate a few commonly observed FIB artifacts, and discuss the concerns of specimen temperature rise during FIB milling process.

Mar 1, 2017

By C. Pattenden

The viability, self-reliance and resilience of small communities are perennial challenges in regional Australia. Recent developments in Australian mining regions seek to govern the minerals industry in a more holistic way that contributes to sustainable futures for affected communities in different contexts. In some areas of the State of Queensland land use conflicts and the cumulative impacts of multiple projects and activities across time and space have come to the fore. In more isolated regions of Western Australia the dominant issues relate to overstretching people, infrastructure and services in predominantly mining towns. In both cases, there is an ambition for regional towns with a strong extractive industry presence to transition into desirable, liveable and affordable cities with a diversified economy. The paper analyses two strategies - the Pilbara Plan in Western Australia, and the Sustainable Resource Communities Policy in Queensland - to identify how these governance instruments are contributing to sustainable development.

Jan 1, 2011

By Smith G. A

The scope and complexity of the Melbourne Underground Rail Loop Project and the budget restraints on the planning, design and construction of the works necessitated sound manage- ment procedures for control and co-ordination. Project Management Procedures formulated by the Principal Consultant to the Authority, John Connell - Mott, Hay 9 Anderson, Hatch, Jacobs, ensured that the Authority retained overall control of the project at all times.

Jan 1, 1981