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By Alexander N. Winchell

"Location. The iron formation of the Gogebic district (including the Penokee) comprises a narrow belt south of the western part of Lake Superior extending from Michigan for a considerable distance into Wisconsin. From the mouth of the Montreal River (about twenty-five miles west of Ashland) the iron formation is only about twelve miles distant, but it is about twenty miles south of Ashland. Beginning on the east at a point about eight miles east of Wakefield, Mich., it extends through Sunday Lake, Bessemer and Ironwood in Michigan, and thence south of west through Hurley, Wis., and only a short distance south of Mellen, Wis. About eight miles westward from Mellen, the formation disappears, but six miles further west it is known to reappear and continue thence for about eight miles. The total length of the range is about sixty miles, two-thirds of this distance being in the State of Wisconsin; but nearly all of the ore has been obtained from the eastern third of the district, which is in the State of Michigan.History. This iron range was first noted in 1848 by Dr. Randall, assistant geologist to Dr. David Dale Owen, while following the fourth principal meridian northward. It was also reported by Charles Whittlesey in an account of a survey made in 1849, and published by Owen in 1852. Analyses of the iron ore are given with the following account. ""The bed of magnetic iron ore south of Lac des Anglais is of extraordinary thickness,25 to 60 feet. * * In the wild and deep ravines where the Bad River breaks through the range, there is a cliff of slaty ore * * * probably three hundred feet thick. * * * I estimate more than one-half of this face to be ore, and in places the beds are from ten to twelve feet in thickness, with very little inter-mixture of quartz * * * . The position of the best exposures of ore which I saw is such as to require from eighteen to twenty eight miles of transportation to reach the lake."""

Jan 1, 1920

By L. Evrard, M. Van Camp, J. Y. Yen, R. G. Reddy, D. Mantha

Viscosities of two industrial lead blast furnace slags have been experimentally determined as functions of composition and temperature. A Brookfield viscometer with alumina rods and crucibles were used. Experiments were carried out between 1200 and 1573 K in an argon atmosphere with up to 5% addition of FeO, MgO, and SiO2 to the slags. Results showed that 1) the viscosities of two slags decreased with increase in temperature; 2) addition of FeO decreased the slag viscosities; and 3) addition of MgO and SiO2 increased the slag viscosities. Use of the above slag compositions with the addition of FeO is recommended for successful lead smelter operation.

Jan 1, 2005

By J. J. Poveromo

"Iron ore for alternate iron processes concerns alternate iron products designed for use in EAF (electric arc furnace) steelmaking processes. These alternate iron products include both DRI (direct reduced iron), HBI (hot briquetted iron) and merchant pig iron. Merchant pig iron can be produced in conventional blast furnaces, mini blast furnaces (including charcoal BF's) or novel processes such as RHF/SAF (rotary hearth furnace/submerged arc furnace) such as Iron Dynamics or RHF such as Mesabi Nugget. These novel processes are coal based and can use iron ore concentrates or recycled steel plant oxides. The blast furnace processes can use conventional feed materials: pellets, sinter, lump ore and coke. However, DRI and HBI processes are predominantly pellet based but require DR grade pellets that are low enough in acidic gangue (SiO2 and Al2O3) to avoid additional expense in the EAF process This paper will focus on the quality and availability of DR grade pellets for NAFTA DRI/HBI plants but also concentrates for fines based processes and feed materials for merchant pig iron production. INTRODUCTION This paper will outline alternative (to the blast furnace) competitive ironmaking processes and process routes. Within each section the types of iron ore to be utilized will be discussed. Before discussing some of the details of these processes, it may be appropriate to review some definitions and commonly used terms within this industry. DefinitionsDirect Reduction: Reduce iron oxide to metallic iron without melting. Unreduced ore compounds remain as undesirable oxides • Direct Reduced Iron: Iron oxide feedstock exits in same form as entered (pellets in, pellets out; lumps in, lumps out) • Hot Briquetted Iron: DRI that has been hot (1200°F, 650°C) briquetted to a high density pillow shaped briquette • Hot Metal: Molten iron in liquid form, above 2500°F, 1370°C • Pig Iron: Solid product of the iron blast furnace • Residuals: Undesirable elements such as copper, nickel, chromium, tin, sulfur, molybdenum and phosphorus • Gangue: Rock minerals in the iron ore such as silica (SiO2), alumina (A2O3), calcia (CaO), magnesia (MgO). These remain in the oxide form in DR processes. • Reduction: Fe2O3 + 3 CO = 2 Fe + 3CO2 2 Fe2O3 + 3 H2 = 2 Fe + 3H2O (Fe2O3 > Fe3O4 > FeO > Fe)"

Jan 1, 2018

By P. Michael

Proponents of geomorphic mine land reclamation have criticized current reclamation practices in the coal fields of steep-sloped Central Appalachia as too narrowly focused on civil engineering principles and neglectful of the functional and aesthetic benefits of reclaiming mine sites in ways that mimic natural landforms and drainage patterns. They observe that current mining and reclamation practices are radically transforming the mountain-and-valley terrain into gigantic flat plateaus and, in doing so, disrupting the beauty and ecology of the natural landscape. Instead of designing and constructing linear or planar surfaces and unvarying slope gradients during the reclamation process, they recommend ?landforming,? i.e. the adoption of curvilinear, compound slope forms that blend well with the surrounding physiography and represent the result of naturally stabilizing geomomorphic processes. The authors feel that the concept of geomorphic mine land reclamation is sound, however, its application to the Central Appalachian coal fields faces significant--albeit not insurmountable--challenges. They include: (1) existing reclamation enforcement regulations that are focused on civil engineering principles and not explicitly supportive of geomorphic methodologies; (2) regulatory agencies? current intent to limit the down-gradient reach of excess spoil fills in order to allay disruption or burial of natural streams; (3) actual or perceived increases in reclamation costs; and (4) the challenge of designing and constructing ?natural? landforms that are mature and stable in an otherwise youthful, erosional landscape.

Jan 1, 2010

By R. J. Hickson

The giant El Abra copper mine project under development in Northern Chile will come on stream in early 1997 at a production rate of 500 million pounds of cathode copper annually. Ownership is 51 % Cyprus Amax and 49% Codelco. Cyprus Amax has construction responsibility. Total project cost is $1050 million. El Abra will incorporate latest operational technology with labor efficient practices to achieve world class productivity levels and low initial cash costs of about US $0.35/lb copper. Development procedures for the almost 800 million ton oxide deposit, as well as the hydrometallurgical processes selected for recovery of the copper values are discussed. Construction costs and pertinent technical data are shown.

Jan 1, 1996

By Q. X. Yun

This paper presents a new approach to optimize the transportation system in open-pit mines. The new approach employs artificial intelligence, fuzzy sets, dynamic programming and CAD technique to determine the transportation system. The determination consists of 4 phases: initial selection, road alignment, final decision .and open-pit drawing.

Jan 1, 1992

By M. Mohammed, S. J. Jung

The prime criteria in the design of underground openings with complicated geological structures is ground control. Stability of underground openings for deep mines is critical because incorrect orientation or geometry of the shaft, stopes and accessways often results in the failure of openings due to high stress conditions. Current design procedures for complicated orientation and geometry of mines are rapidly becoming inadequate. In this study, the finite element method (ANSYS) has been used with optimization criteria to design safer, more stable underground openings.

Jan 1, 1995

By Charles E. Scott

The molybdenum industry has been in a depression since the beginning of the decade. Real molybdenum prices are significantly reduced from 1979-1980 levels when there was a perceived capacity shortage and continued expectations of burgeoning demand. Primary capacity brought on stream since then has been unable to operate profitably and indeed, in light of high inventories and reduced demand, has been largely unnecessary. Structural changes in the molybdenum industry will be needed in the future to weed out superfluous capacity and to expand demand through new product applications.

Jan 1, 1986

By R. K. Davey

Before the introduction of computerized procedures, mineralization modeling (compilation of level maps), ultimate pit studies, ore reserve compilations, and long-range mine planning all were performed manually. In fact, much of the basis for today's computer programs was derived from manual procedures and actual experience of mining engineers and geologists.

Jan 1, 1979

By Robert S. Post

A highly respected coal mining company in West Virginia updated their stacker belt by switching to a new magnetic coupling. The savings they achieved are the subject of this paper. A steep incline and heavy belt loads are powered by a dual drive arrangement. The magnetic couplings were custom designed for complete fluid coupling retrofit and easy installation in the field. Maintenance personnel updated the drives in just a few hours. Over the following several weeks, adjustments were made to the couplings for optimum performance. Cost savings are found in reduced down time, no coupling maintenance, and equipment protection.

Jan 1, 2000

By J. Alvarez, S. Helle, U. Kelm, M. Pincheira

The principal geological and mineralogical characteristics of Chilean porphyry copper deposits are described. Elevated contents of fine grained ore and gangue material may cause copper losses and pose problems or render useless the flotation process. Examples of chalcopyrite and bornite size distributions are given. The state of the art of mineralogical and mineral chemical characterization in Chile is evaluated permitting analyses to lm and nm level by lacking the regular use of direct surface analysis.

Jan 1, 1998

By A. Smithson

It is generally accepted by British mining engineers that coal will continue to be worked by the. advancing or retreating longwall system for the foreseeable future. At the coal face, the emphasis will be on better machine utilization; increased equipment reliability; modular design and more standardization; remote control and monitoring; and a continuing drive to increase productivity and safety. Improvements at the face can be sustained only if there are corresponding improvements in efficiency elsewhere in the mine. Coal handling systems, for example, must be able to accept increased tonnages without creating bottlenecks. As workings move further from the shafts, the time taken to transport men and materials must be kept within reasonable limits. Development drivages must he on schedule to be ready for the planned opening of new faces, and face ends must keep up with faster moving faces.

Jan 8, 1981

By W. Keilich

A methodology of subsidence prediction using the Distinct Element code UDEC has been developed as an alternative for subsidence modelling in the Southern Coalfield, New South Wales, Australia. The models have been validated by comparison with empirical results and observed caving behaviour. At this stage, modelling capability is limited to flat lying terrain. It is planned to apply the methodology to areas of high topographical relief to investigate the mechanics of valley closure.

Jan 1, 2006

By X. Wu, M. Karfakis, E. Topuz

The generalized ventilation network problems encompassing both natural and controlled splitting networks, is formulated using a nonlinear nonconvex programming model, which has not yet been solved satisfactorily. This paper presents a methodology which can deal with the problem. The proposed methodology converts the nonlinear problem into a linear problem, by using special ordered sets of variables, and optimizes it by a modified branch and bound technique. The global optimality of the methodology and its applicability to different cases are investigated

Jan 1, 1991

By D. A. Elgillani, N. A. Abdel-Khalek

The role of ZnS04 in activation of sphalerite (ZnS) and deactivation of lead-activated sphalerite has been investigated. Adsorption of metallic ions at the solid-solution interface, electro kinetic results for sphalerite under different chemical conditions, and thermodynamic calculations were used to elucidate the mechanisms involved. It is shown that flotation response of sphalerite in absence of activators is rather weak and that adsorption of ethyl xanthate on the mineral mainly electrostatic in nature. Zinc sulfate is found to activate the mineral but only in a narrow acidic pH range. This is attributed to the increase of zeta potential as well as the possible increase in amount of negatively charged bulk precipitated zinc xanthate. Lead ions activate sphalerite in a wide pH range and the lead activated mineral assumes a flotation behavior similar to that of galena (PbS). However, addition of ZnS04 depresses the lead-activated sphalerite by replacing lead ions at the mineral/solution interface.

Jan 1, 1999

By O. A. Bascur

Based on current sedimentation theory an on-line thickener model was developed and coupled with an extended Kalman Filter to obtain additional information such as the compression zone level and concentration, a corrected underflow concentration, the inventory, and some rheological information. The on-line model was installed and tested for robustness for periods up to three days in an industrial environment giving good results. Emphasis was given to signal processing and selecting the appropriate input variables for filtering. The analysis of the thickener from a phenomenlogical point of view provides for better operation, establishes the limiting operating conditions, and assists in the design of control strategies.

Jan 1, 1986

By R. E. Johnson, L. V. Araújo, B. R. Palmer, L. M. Abrantes, G. W. Warren

The behaviour of chalcopyrite - mineral specimens and a Portuguese concentrate - in 2M chloride solutions prepared from hydrochloric acid and sodium chloride, has been characterized by cyclic voltammetry. The study has shown the influence of the potential and of the presence of impurities in the reaction schemes and their relative extent. The dissolution of chalcopyrite concentrate under potentiostatic control has been investigated and found to confirm the effect of the selected potential on the surface modification/rate of dissolution. An attempt has been made to correlate the information obtained with the response of the concentrate electrode to constant current treatments.

Jan 1, 1993

In order to analyze and quantify distinct environmental properties in the vicinity of sites, the Site-Specific Natural Resources Information System (SARIS) has been developed based on a Geographic Information System (GIS). SARIS is one of the fundamental databases of a collaborative research program aiming at the resource orientated analysis of metallic raw material flows with aluminum and copper serving as exemplary case studies. The spatial database incorporates all present production sites of ore extraction, refining and smelting. Environmental data for each location were derived from global digital survey data covering land cover, soils, morphology, climate, topography and population density. The main application of this database is the characterization of environmental safeguard objects, which may be affected by the activity of concern. This site-specific environmental impact assessment is used to determine the relevance of environmental issues based on the distribution pattern of sites in a global framework. The derived results are used to suggest a tailored indicator approach to measure progress and performance of industrial developments relative to the predetermined site-specific conditions.

Jan 1, 2003

By S. Behl, S. Mathur

It was previously reported that dolomite samples from different locations showed varying flocculation behavior with poly(ethylene oxide) (PEO). In this study, a Florida dolomite sample was examined, and it was determined that palygorskite associated with dolomite was responsible for its flocculation with PEO. A detailed characterization of dolomite samples from different locations was made by electrokinetic, XRD and FT-IR analyses, and the relevance of these characteristics to flocculation with PEO is discussed.

Jan 1, 1996

By L. Piga, P. Cipriani, F. Pochetti

High-temperature roasting of alunite in the presence of K2CO3 gives rise to a reaction that results in up to an 80% recovery of its potassium content as K2SO4 by leaching of the roasted mixture. K2SO4 is also generated from the reaction between the added K2CO3 and the SO3 driven off during roasting of the alunite. This limits the environmental and corrosive problems involved in the thermal treatment of this mineral. A solid residue containing mainly aluminum oxide is also obtained. This could be used as raw material for the production of aluminum, as the use of K2CO3 does not introduce different cations than are in the ore. A statistical study was performed on the factors assumed to affect the recovery of potassium, namely, roasting temperature, K2CO3- alunite stoichiometric ratio and leaching temperature.

Jan 1, 2000