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By T. Prof. Ph. D. Egleston

THE importance of having perfectly pure metals has led me to present to the Institute a record of some of the trials that have been made to obtain these metals, and also to show one of the largest specimens of extremely thin metal plate which has ever been made. The malleability of metals varies generally directly with their purity, and hence it is only with very pure metals that thin sheets can be obtained. The competition among different manufacturers has been so great at times as to lead to expensive and apparently useless experiments in obtaining in the first instance very thin sheets, and afterwards very large and thin sheets of metal, apparently with no other purpose than that of being able to say that they had produced the thinnest or the largest thin sheet that had ever been made. These experiments were at first confined exclusively to iron, their object being to show the great dexterity of manipulation, as well as the purity of the metal manufactured. They have since been extended to almost all metals by electrical action, and have gone far beyond the limits of what was possible with purely mechanical means. The processes which have been used are rolling or hammering, electrical deposition in a vacuum, and lastly, electrical deposition on plates, easily soluble in acids. The first and last of these methods have been known and practiced for a very long time, having been used to make thin sheets of almost all the metals. The other is of quite recent application. In the iron manufacture, the strife to produce these thin sheets was commenced in the year 1865, by the Sligo Iron Works writing to a firm in Birmingham, England, on a sheet of iron containing 270 square centimeters, and weighing only 4.469 grams. For some time this was considered to be the thinnest sheet iron that could be made. T. W. Booker & Co., of Cardiff, England, however, produced a few months afterward, a sheet of the same size, weighing only 4.015 grams. This was succeeded by one rolled by Neville and Everitt, of Llannelly, weighing only 3.174 grams. This was followed by one from Hallam, of Swansea, which was 283 square centimeters in size, and weighed but 2.979 grams; and this by one rolled by R. Wil-

Jan 1, 1879

By E. M. Frost

"A new apparatus has been devised for quickly and precisely analyzing natural gas for its helium content. The following outstanding advantages make it far superior to any equipment now available for the purpose.3/4/5/6/1. It enables more rapid determinations to be made.2. It has far greater sensitivity than previous apparatus. 3. It is portable.Fifty or more samples may be analyzed in an 8-hour day with the new apparatus and procedure. A maximum of about 10 samples per day could be analyzed with previous apparatus. In the apparatus described, the volume of pure helium obtained from a sample is determined by measuring the pressures created by that pure helium when it is expanded into a constant calibrated volume. In older methods the pure helium separated from a sample is pumped into a burette and measured at atmospheric pressure. The new apparatus and Procedure used with it reduce the average time for an analysis from about 40 minutes to less than 10 minutes,Samples containing a few thousandths of a percent helium may be analyzed as readily as samples containing 1 percent or more, This was not possible with former apparatus. Duplicate samples containing a few thousandths of a percent helium have been analyzed, results checking to one ten-thousandth of a percent. Attempts to measure a corresponding volume of helium in a burette at atmospheric pressure become futile. The ability to determine very small quantities of helium has become of great importance recently in gas- and oil-field engineering studies such Os the utilization of helium as a tracer gas in following the movement of gases through underground structures.A complete apparatus was recently carried more than a thousand miles in a passenger automobile. It arrived without breakage, was .set up and ready to make an analysis in a few hours. .Former apparatus was not portable. The portability of the present apparatus permits taking the apparatus to the field for more efficient prosecution of field engineering problems. The only services required in the field are electricity, tap water, and a source of liquid air or liquid nitrogen.The principle involved is based upon the fact that large volumes of all the constituents usually found in natural gas, except helium, are adsorbed quantitatively on cocoanut charcoal that has been cooled to the temperatures of liquid air. A volume of sample is measured and transferred to a tube of cocoanut charcoal maintained at the temperature of liquid air. After adsorption of all the constituents other than helium, the charcoal tube is connected to a sensitive pressure-measuring device, and the Percentage helium originally in the sample is calculated from two pressure readings and the volume of the original sample."

Jun 1, 1946

By H. Grothe

El presente texto señala las posibildades técnicas y económicas en la instalación de una refinería de zinc y una fundición de plomo en el Perú. Para ello, se revisan los problemas técnicos que comprende (la materia prima y la elaboración). Respecto a los yacimientos y considerando como norma las extracciones actuales, se asegura la existencia de materias primas para un espacio prolongado de tiempo dentro de un período mínimo de 20 años. Asimismo, la calidad de las menas no sufrirá ninguna variación fundamental en este espacio de tiempo y las plantas de preparación existentes estarán en condiciones de suministrar a la nueva fundición suficientes concentrados, tanto en cantidad como en calidad.

Mar 1, 1960

By R. Q. Honaker

A significant problem in ultrafine particle classification is the significant amount of submicron particle by-pass to the coarse particle stream. In classifying cyclones, submicron particle by-pass to the underflow stream can be reduced by decreasing water recovery. Past studies have shown that a reduction can be realized when the feed solids concentration is increased or the apex diameter is reduced. However, both adjustments tend to increase the particle size cut point and negatively affect classification efficiency due to the impact on slurry rheology. The addition of a viscosity modifier to the feed stream of a classifying cyclone improved the classification performance and decreased the particle size cut point over a range of feed solids concentrations. The detailed test program investigated the use of the modifier in conjunction with varying apex diameters to identify conditions that minimize ultrafine by-pass. With small apex sizes, roping conditions were readily eliminated by the addition of viscosity modifiers. The addition of the modifier had no deleterious effect on froth flotation performance, which commonly serves as a downstream separation process. The fundamental and practical benefits of viscosity modifiers in classification processes are discussed in this publication.

Jan 1, 2006

By Long Fan, Shimin Liu, Guijie Sang

"Weak shale roof falls have long been the main cause for fatalities in underground coal mines. Moisture-induced swelling is one of the root causes for the degradation of roof shales. In this study, slake durability tests are conducted on shale samples collected from Illinois basin coal mines, and different levels of durability are analyzed according to Gamble slake durability classification. There are two main mechanisms influencing the shape of retained fragments after two cycles of wetting and drying: mechanical abrasion and swelling pressure. A prototype optically based shale swelling apparatus is designed and manufactured for the shale free-swelling measurement. The experimental results suggest that swelling pressure tends to deteriorate shale laminations. Moisture-induced swelling of the No. 6 roof shale from Bear Run Mine was measured under 100% relative humidity condition. The measured swelling strain normal to beddings is ~5 to 7 times greater than the swelling strain parallel to beddings. This suggests that interlayer expansion plays a key role in moisture-induced swelling. Cracks induced by swelling pressure tend to occur along the bedding plane and lead to shale deterioration. INTRODUCTION Background Ground falls have long been the cause for nearly 50% of all fatalities in underground coal mines and continue to be one of the greatest safety hazards in underground spaces. Among the various ground fall hazards, roof failure takes up 23% of total fatalities in underground coal mines, of which 13% are due to skin failure and 10% are due to massive roof falls (Mark, Pappas, and Barczak, 2011). Roof failures associated with weak shales are summarized in previous studies (Molinda and Mark, 2010; Aughenbaugh and Bruzewski, 1973; Bajpayee, Pappas, and Ellenberger, 2014; Murphy, 2016). For mine roof instability and failure, two aspects can explain the failure mechanism of weak roofs. One is the elevated stress concentration in lateral direction due to the mining-induced excavation and its stress redistribution around the mine opening (Song and Stankus, 1997; Fan and Liu, 2017; Hill, 1986). The other mechanism is the passive stress-relief due to the strength weakening induced by the ambient moisture and temperature fluctuations during a period of time. Shale is moisture sensitive and presents a lower durability if it is exposed to a highly humid environment for a long time, thus leading to roof deterioration and instability in underground coal mines (Aughenbaugh and Bruzewski, 1976; Stateham and Radcliffe, 1978; Chugh and Missavage, 1981; Klemetti, Oyler, and Molinda, 2009). It is well known that shale is a clay-bearing sedimentary rock and that clay minerals are water sensitive. The moisture uptake for shale will induce the micro-deformation of a shale matrix, thus the structure and strength of shale is a function of time and intensity of moisture exposure. All mine engineers notice moisture-induced shale deterioration; however, the underlying mechanism(s) are still not fully understood due to the complexity of geophysical-chemical water-shale interactions (Huang, Aughenbaugh, and Rockaway, 1986; Hensen and Smit, 2002; Diaz-Perez, Cortés-Monroy, and Roegiers, 2007). The coal mining industry is still in the process of finding a technically sound, cost-effective technology to prevent this unexpected and unpredictable shale roof failure. Therefore, understanding how the moisture-sensitive shale responses to various ambient moisture and what role exposure duration plays in shale roof failure is key to prevent unexpected roof incidents, which will lay the foundation for the long-term roof support design and ground control management."

Jan 1, 2017

By Laxman M. Amaratunga

Laboratocy flarmnability tests were perfonned on dust samples from Fraser Mine in a 1.2 L Lindenburg horizontal tube furnace to detennine the percentage of sulphur oxidized during ignition. The explosion pot ential of sulphide dusts depends on their degree of spontaneous oxidat ion, which was measured by the quantitative analysis of so2 gas released during ignition. Test results indicated that dusts with low sulphur content could exhibit a higher degree of oxidation than a sample with high sulphur content. txlst characterisation using image analysis techniques suggests that the structure and the texture of dust are important factors influencing the explosibility of sulphide dust at ignition temperatures. Therefore for safe mine operations% sulphur content cannot be considered as a reliable single index that could be used to predict the potential of a sulphide dust explosion. Physical, chemical and mineralogical characterisation of dust plays an important role in the detennination of suitable indices for the prediction and prevention of sulphide ore dust explosions.

May 11, 1988

By Paul Billingsley

Introduction. THE Georgetown mining district is located in Deerlodge county, Mont., about 20 miles west of Anaconda. It lies along the divide between the headwaters of Warm Springs creek, draining eastward, and Flint creek, flowing west and north through the Philipsburg valley. The actual divide is formed by Cable mountain, a narrow ridge running north and south, terminating to the south in low hills overlooking Georgetown lake, and to the north in a high, rugged plateau that falls off to the west to the wide valley of Flint creek. Oil the eastern, or Warm Springs, slope of Cable mountain is the Cable mine, with the Hidden Lake mine a few miles north. On the western slope is the Southern Cross group, with smaller mines, the Twilight, Cincinnati, Red Lion, and Big Bill, at intervals to the northward. The Georgetown mines lie in the hills south of Cable mountain; the Philipsburg mines, of which the Granite Mountain, Bimetallic, Hope, and Trout are the chief, form a separate group to the north, overlooking Flint Creek valley and Philipsburg. (See Fig. 1.1) The region ranges in elevation from 5,000 to 9,000 ft. It is, with the exception of the lower valleys, well timbered with small fir and pine, although Cable mountain and the higher summits to the northward rise slightly above timber line. The main valleys have the smooth contours of glaciation, and their mouths are frequently choked with morainal deposits.

Jan 9, 1913

By J. Keith Seidler, David R. Lentz, Douglas C. Hall, Nicholas Susak

Abstract - The Ta-Nb-Zr-REE-rich McKeel Lake alkali granite pegmatite-aplite dike swarm is hosted within the late Silurian multiphase alkali granite intrusion (Welsford) near Browns Flats in southwestern New Brunswick. A steep easterly dipping series of pegmatite-aplite dikes trending 170º can be traced 150 m along strike; they are up to 40 cm wide, closely spaced (10-20 cm apart), and interconnected by narrow branching dikelets that generally trend perpendicular to the overall strike direction. The Welsford intrusion has mantle A-type affinities characterized by enrichment of Zr, Ta, Nb, Th, and rare earth elements (REE). Two separate sets of dikes have been identified: (1) an unmineralized fine-grained porphyry, which occurs at depth and seems to be the youngest intrusive phase; and (2) a mineralized pegmatite-aplite dike swarm (419 ± 20 Ma) that crops out at surface. The mineralized pegmatite-aplite dikes likely represent a late magmatic, highly fractionated phase of the Welsford intrusion. XRF and INAA data indicate that the Welsford intrusions and related pegmatite-aplite dikes show elevated levels of Ta (74-220 ppm), Nb (750-3,040 ppm), Zr (1,450-36,000 ppm), Y (540-3,070 ppm), Th (170-870 ppm), U (60-250 ppm), Ce (430-1,950 ppm) and Yb (110-290 ppm). Electron microprobe analysis of two samples identified Ta-Nb- and REE-rich phases: euxenite, fergusonite, aeschynite, (Y)-aeschynite, and a REE carbonate.

Jan 1, 2005

By H. M. Thorne

The oil-shale deposits of the Puertollano basin in the Spanish province of Ciudad Real appear to have been give little consideration in discussions of oil-shale resources throughout the world. A small, integrated oil-shale operation has been conducted at Puertollano since about 1922 by a French company, Sociedad Mimora y Metalurgica de Penarroya, hereinafter referred to as "Penarroya", but only within recent years have the potentialities of the Spanish oil-shale deposits been recognized. Empresa Nacional "Calvo Sotelo" do Combustibles y Lubricantes, hereinafter designated as "Calvo Sotelo," which was created in 1942 by the National Industrial Institute of Spain to produce liquid fuels from oil shales, has made marked progress in the design and construction of a complete oil-shale plant at Puertollano. Penarroya is mainly a coal-mining company, and the oil-shale operations were on a small scale of approximately 220 tons a day in October 1947. It is an integrated operation comprising oil-shale mining and retorting and shale-oil refining. Motor gasoline, Diesel fuel oil, light burner fuel oil, lubricants, paraffin wax, cresols, and ammonium sulfate are manufactured.

Jan 1, 1950

By F. R. Archibald

SINCE the opening of the Beattie mine, in 1933, the concentrate produced by flotation has been considered refractory. As the gold extraction by cyanidation was poor, the concentrate, during the first four and a half years of operation, was shipped to a smelter for further treatment. After the installation of the cyanide plant, in 1934, seventy per cent of the gold in the concentrate was recovered before shipment to the smelter. In 1937, a roasting plant was built so that treatment might be complete at the mine. Much experimental work had been done by a number of investigators prior to the installation of the roasters, but none of them had seriously attempted to identify the causes of, or the elements responsible for, the refractory behaviour of the concentrate. Intensive investigation in this direction commenced in the Beattie lab-oratory in July, 1938, has led not only to the identification of several causes contributory to the refractory behaviour, but also to revisions in procedure and principles with respect to roasting Beattie concentrate in particular and arsenical concentrates in general. The accuracy of the identification of these causes and the soundness of the principles is borne out by interpretation of roasting plant records, by improvements and simplification since applied. to plant operation, and also by laboratory and test-plant results on arsenical concentrate produced by another mine. It is the purpose here to present an account and interpretation of the laboratory investigation, together with a correlation of laboratory and plant results. Incomplete extraction of the gold by cyanidation after roasting is due primarily to the nature of the material roasted, and secondarily to the manner in which it has been roasted. There is a possibility that better extraction may be obtained by improvements in both particulars.

Jan 1, 1939

By A. Villanueva

The effect of High Pressure Grinding Rolls (HPGR), as a preceding stage to a conventional ball mill circuit at PT Freeport Indonesia?s C1/C2 concentrators, has been studied in terms of downstream grinding efficiency and circuit performance. When milling the product from the HPGR, mill capacity increased by 21% for the same product grind size, when compared to processing similar ore from a conventional crushing circuit. This achievement is a result of several reasons, among them: reduction in feed size (F80), fines generation beyond the proportional reduction in F80, reduction in ore hardness induced by HPGR comminution mechanism, optimization of the recycle system of the HPGR and ball string optimization in the ball mill circuit given the new feed to the mill.

Jan 1, 2012

The U.S. economy continued to expand during 1986, although at the slowest pace since 1982 when the current business expansion began. Real gross national product (GNP) grew about 2.6%, slightly below 1985 growth but significantly below that of 1984. The continuing expansion was fueled predominantly by rising personal consumption expenditures as well as growing government purchases of goods and services. Fixed investment, although positive, failed to grow at the rate of the overall economy. The trade deficit, which increased more than 30% over the record 1985 level, continued to depress economic growth despite significant declines in the price of petroleum and the value of the dollar. On a more positive note, domestic employment continued to grow--increasing over 2 million from the 1985 level--and inflation and interest rates declined. The unemployment rate dropped slightly to 7.0%. Of direct importance to the minerals-producing industries, expenditures for consumer and producer durables as well as investment in residential construction each grew faster than the overall economy, but investment in nonresidential structures fell more than 10% from the 1985 level. The low level of real capital spending declined about 3% in 1986, following strong gains in 1985 and in 1984. Capital expenditures for new plant and equipment bottomed out in the second quarter and expanded in the third and fourth quarters. The decline in the first half of the year was partially attributed to uncertainty arising from the then-proposed tax bill. Also, there was little impetus for corporations to invest in new capacity since factories were operating at less than 80% of capacity during most of the year, in part because of continued competition from imports.

Jan 1, 1987

By Masahiko Yamaki, Takahiro Yamanashi, Hijiri Hashimoto, Hirochika Hayashi

"In this study, the authors used heat conduction analysis with the aim of quantitatively evaluating whether treating improved ground with cover soil is an effective measure for maintaining strength development in the surface layer of improved ground after constructing cement treated soil for the winter season. This report describes a simple procedure to evaluate covering soil thickness, which is necessary for the strength of the surface of cement treated soil, by using the freeze index and both the water content ratio and dry density.INTRODUCTIONIt was reported that when ground improvement using cement is performed in winter in a snowy cold region (Fig. 1 photo, Fig. 2), the uppermost 1 m of the improved ground (i.e., the cement-treated soil) tends to become prone to solidification failure from exposure to the cold air during curing (Hashimoto et al. 2006). In light of this, our research laboratory conducted unconfined compression tests using curing temperature as a parameter of analysis on improved ground toward understanding the influence of curing temperature (ambient air temperature) on the strength improvement afforded by ground improvement.The authors found that if the curing temperature is maintained at 0°C for the first 28 days after improvement and then at 5°C for the next 337 days after improvement, the improved ground is expected to have 90% of the unconfined compressive strength of improved ground whose temperature was maintained at 20°C for the first 365 days after improvement (Hashimoto et al. 2011)."

Jan 1, 2015

This report summarizes the work performed and results achieved in the period from 18 June 1971 through 18 October 1971 under Phase I (Task 1: Literature and Industry Search; Task 2: Conceptual Design and Evaluation; and Task 3: Concept Selection and Preliminary Design) in substantiation of the drill/impregnation machine concept recommended for detailed design in Phase II. Also included as Task 5 are recommendations for an experimental investigation to be conducted during Phase II. The report is submitted for approval and authorization to proceed to Phase II.

Jan 1, 1972

By Alicia Esther Ares

This study was conducted to investigate the directional solidification of Zn-20%A1 and Zn20% A1-1O%Si-3o/oCu alloys under different conditions of heat transfer at the metal/mould interface. The type of structure obtained in both cases was analyzed and related to the solidification thermal parameters such as cooling rate, growth rate, thermal gradient and recalescence which were determined from the temperature versus time curves. These parameters were correlated with the structure-like length of columnar grains and size of equiaxed grains. The metallographic analyses were done performing quantitative metallography and composition analysis of the different alloying elements along the cast samples by SEM (Scanning Electron Microscopy) and EDXA (Energy Dispersive X-Ray Analysis). Correlations between properties, structures and thermal parameters were found.

Jan 1, 2008

By T Angerer, N H. Maund, S Hagemann, D R. Cowan

Cliffs Natural Resources Pty Ltd - Asia Pacific Iron Ore's (formerly Portman Iron Ore Limited) K deposit (Dowd's Hill), at its Koolyanobbing operation in Western Australia, hosts enriched magnetite mineralisation below the presently mined haematite-goethite ore zone. Two distinct northwest-southeast elongated, highly magnetic anomalous bodies that dip to the north-east appear to be sourced by this deeper mineralisation. Magnetic modelling indicates significant remanent magnetisation with Qratios around 1.5, directed shallow down. The north-west anomaly is overlain by a ridge of uneconomic banded iron formation (BIF) and the present waste dump, whereas the south-east body was partly exposed during ongoing mining of overlying haematite-goethite ore. Sections of the magnetite mineralisation in this south-east anomaly were intersected previously by diamond drill holes. Review of the historic cores identified potential magnetite enrichment, with grades and mineralogy that might be amenable to beneficiation. A first-phase reverse circulation drilling program was designed to further delineate the trend and extent of the two anomalies. The following magnetite mineralisation assemblages are recognised from cores, reverse circulation (RC) drill cuttings and pit mapping of the south-east magnetic body: higher-grade magnetite-haematite ¦ goethite and magnetite ¦ pyrite and lower-grade, recrystallised magnetite-quartz (BIF), magnetite-carbonate, magnetite-talc and minor magnetite-bearing mafic schist. Disseminated specularite is locally present in theassemblages. Talc-schist and massive pyrite occur along the footwall contact. Magnetic susceptibility measured from drill chips within the magnetite-enriched zones reveals an apparent susceptibility values range of 0.2 to 1.3 SI. Preliminary results from Satmagan and Davis tube recovery analysis shows that the magnetite content in these mineralised zones correlate well with existing geophysical data and magnetic susceptibility measurements.

Jan 1, 2009

By The Staff, Explosives Research Center

The principal activities of the Bureau of Mines Explosives Research Center from July 1, 1962, to June 30, 1963, are described briefly in part 1. Part 2 gives short abstracts of publications that appeared during fiscal year 1963; in general, the research reported in these publications antedates the report period.

Jun 24, 1964

By M. A. Schellhardt, E. J. Dewees, R. Vincent Smith

"INTRODUCTION Abnormal material requirements of the nation at war impose an intensive demand upon many irreplaceable natural resources. Natural-3as reserves) for example, are being subjected at the present time to extensive depletion by large-scale withdrawals of gas to supply unprecedented demands for fuel and raw materials for the synthesis of strategic products. Fluids produced from many so-called gas-condensate type reservoirs have become an important source of hydrocarbons vital to the war effort.Development of gas-condensate type reservoirs in Arkansas, Louisiana, and Texas in recent years created many problems not common to ordinary gas-producing operations. Early in the development of condensate-type gas fields, general practices were evolved and applied to insure efficient re¬covery of the hydrocarbons existing in the gas phase under initial reservoir pressures and temperatures, put often the practices were predicted mainlyregardingupon generalized theory regarding the behavior of the fluids and were not always the most efficient, because field and laboratory procedure for testing these hydrocarbons had not progressed as rapidly or as far as field development. Specific information regarding the composition and properties of fluids ultimately recoverable from many gas-condensate reservoirs, especially, is lacking."

Oct 1, 1944

By Thomas Brunsing

The program was carried out to develop deep kerfing and core breaking techniques to be incorporated into the design of a field prototype hard rock mining machine. The field machine is designed to mine non-abrasive bedded deposits up to 20,000 psi in uniaxial compressive strength. The mining technique involves cutting approximately 2 ft deep parallel kerfs spaced 2 ft apart in either a horizontal or vertical direction and subsequently breaking out the cores so defined. The prototype machine is intended for demonstration of the technique in a quarry or equivalent field environment. The program was aimed at minimizing the required kerf width, obtaining reliable breaking within that kerf width and determining cutter blade requirements necessary to achieve a mining rate of 20 ft3/min. Full scale breaking experiments and 1/2 scale kerfing experiments were employed to evaluate the system. High strength concrete test specimens were used to simulate the rock being cut and broken. The test results indicate the kerf/break technique can achieve the desired mining rate by utilizing two 7 ft diam blades to cut 2 in. wide by 24 in. deep kerfs. A lateral load applied at the base of the kerf (base shear) was selected at the core breaking technique to be employed by the full-scale prototype machine.

Jan 1, 1983

By Jian Li, Tiejun Chun, Jian Pan, Deqing Zhu, Vinicius Mendes

"A study of the coal-based direct reduction behaviors of composite binder magnetite pellets was carried out in a simulating coal-based grate-rotary kiln process. It is shown that preheated pellets possess much better reducibility than fired oxide pellets: 40 min are required for preheated pellets to reach over 90% metallization degree compared to 100 min for fired oxide pellets. The compressive strength of preheated pellets decreases dramatically at the earlier stage of reduction, climbs quickly after reducing for 30min and achieves a high value at the end of reduction. However, the compressive strength of metallized pellets from reducing of fired pellets is much lower, more cracks and fractures being formed. In the preheated pellets, crystallite of metal iron is coarse. In the oxide pellet, a large number of interconnected crystals of metal iron are formed inside pellets, and pellet structure is very compact.IntroductionDirectly reduced iron is an excellent feed in electric arc furnace (EAF) steelmaking, and possesses low tramp element content and steady component. It is generally preferred in the production of high quality steel [1-3]. Nearly 64.44 million tons of DRI were produced in 2009 over the world, over 80% of which were produced by gas-based processes, the left by coal-based processes. However, the DRI capacity was only 600 thousand tons in China in 2009. The EAF steel production has exceeded 40 million tons annually, and most of EAF operate on hot metal as feed [4]."

Jan 1, 2011