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By C. E. Sims

THE carbon-oxygen reaction without doubt is the basic reaction in steelmaking. It is important on several counts: In the first place, carbon is the element that distinguishes steel from iron. It is the principal element controlling properties, and its control is of prime concern. Although the principal objective of the carbon-oxygen reaction is to oxidize excess carbon, the accompanying boil should not be underrated. The mechanical agitation, stirring, and mixing resulting from the boil are so useful in the distribution of heat and in promoting uniformity of composition in the bath that, were it not a natural accompaniment of the carbon-oxygen reaction, it is probable that something would have to be invented to replace it. The open-hearth operation, for example,, with the bath heated from above by radiation, would be impracticable without the carbon boil. The electric-arc furnace is somewhat less dependent on it, but every melter knows how much easier it is to gain temperature with minimum damage to refractories during the boil than with a dead bath. The motor action of the induced current of the induction furnace makes the carbon boil unnecessary but even there a severe oxidation has been found useful in giving greater freedom from porosity in certain steels. The quantitative aspects of the carbon-oxygen reaction have been given considerable attention by a large number of investigators, and the principles of physical chemistry have played an important part in these studies. Physical chemistry is the science of the mechanics and mathematics of chemical reactions. It is possible to study the mechanisms of reactions in a qualitative manner without reference to mathematics and thus obtain valuable concepts as to the manner in which the wheels go around. When it is desired to express quantitative relations in these reactions, however, resort to mathematics is not only convenient but necessary. Mathematics may also be regarded as the shorthand language of physical chemistry. A basic relation whose description requires numerous words may be expressed very simply by a mathematical formula or equation. A good example of this is the equilibrium constant for a chemical reaction. Expressed verbally, it is: When a chemical reaction has reached a condition of equilibrium, the product of the concentration of the reacting substances on one side of the equation, divided by the product of the concentration of the reacting substances on the other side, gives a quotient that is a constant at constant temperature. For the carbon-oxygen reaction C + 0 [=] CO this is expressed simply as [ ] where K (from the German Konstant) is the equilibrium constant for the reaction. Although mathematics is such a necessary and useful tool, it is also a potential pitfall. Mathematics in itself is an abstract science, which is not inhibited by consideration of mechanisms or materials.

Jan 1, 1947

By A. Kaufmann, B. Cullity, G. Bitsianes

T0 determine the bulk of the phase diagram, techniques for melting, thermal analysis, heat treatment, metallography, and X-ray diffraction that have already been described were used.' It proved difficult to get definitive results for most of the alloy system because of the large number of compounds, their high melting points, and their extreme brittle-ness which made metallography difficult. The final phase diagram, essentially as shown in Fig. 1, was issued with considerable trepidation.' The phase relationships at the two ends of the system were defined with satisfactory accuracy. In the central region between U,Si, and USi, there was great uncertainty concerning the melting points and even the composition of the compounds. At the uranium end of the system, it is quite clear that a eutectic exists at about 985 °C and approximately 8 or 9 atomic pct Si. The a-to-8 transformation is not appreciably altered by silicon, but the 8-to-y transformation is raised to about 795°C. There is appreciable solid solubility in y-uranium, as demonstrated by the micrographs of Fig. 2. The occurrence of the E phase was not suspected at first, since the alloys as melted and furnace cooled gave no X-ray diffraction or thermal arrest indication of it. However, suitable metallography revealed a rim around each of the compound particles as shown in Fig. 3. Heat treatment above 600°C revealed that the rim was another phase which formed by peritectoid reaction between uranium and U,Si,. This reaction proceeds slowly and it is difficult to get it to go to completion. Consequently, there is some uncertainty concerning the exact composition of P and the exact peritectoid temperature. On the basis of various metallurgical studies, it was decided that the most probable composition for t was about 23 atomic pct Si. Metallographic examination shows the closest approach to a single phase at this composition. Likewise, density and hardness measurements of heat-treated alloys shown in Figs. 9 and 10 show a change in slope at 23 pct Si. This is revealed most clearly by plotting the difference in hardness or density between chill-cast and heat- treated alloys as shown in Fig. 4. Zachariasen2 was able to index the diffraction lines of P and to determine the arrangement of the atoms in the unit cell. He concluded that the composition must be US. However, it is felt that the metallurgical studies are reliable and that Zachariasen's X-ray work does not furnish positive proof that the P phase exists exactly at the stoichiometric composition U3Si. There are many instances in alloy systems where a phase does not occur at the composition dictated by the molecular structure. It is possible that the chemical analyses used in the present work were subject to some systematic error. This seems unlikely, however, since recent work in several laboratories seems to show excess compound at 25 atomic pct Si.

Jan 1, 1958

By E. A. Gulbransen, J. W. Hickman

The physical and chemical structure of the oxide films formed on metals and alloys is of interest in our understanding of their protective properties. According to Pilling and Bedworth,¹ if the specific volume of the oxide is equal to or greater than that of the metal, a compact or continuous structure results; if the volume of the oxide is less, a cellular or porous structure forms. With the cellular type of coating the surface layer of oxide offers no impedance to oxidation; at a given temperature the rate of oxidation is quite constant. On the other hand, the compact type of coating acts as an effective barrier to oxygen and the rate of oxidation will follow a parabolic law. The recent work of Gulbransen2 and of Leontis and Rhines3 on the oxidation of magnesium indicates that it is not necessary for the volume of the oxide to be greater than that of the metal in order that the oxidation may follow a parabolic rate law. One exception to the rule of Pilling and Bedworth¹ is noted by Scheil;4 namely, tungsten. At 500° and 700°C long-time oxidations indicate a linear rate law with time. However, Dunn's6 0xidation measurements from 700°to 1000°C indicate that a parabolic rate law is followed. The oxide is mainly yellow WO a with a thin layer of the blue oxide. Preliminary results on the oxidation of tungsten6 in the temperature range 400° to 500°C indicate that the oxidation does proceed according to a parabolic rate law. Irrespective of the actual rate law that tungsten may obey, it is of interest to compare the results obtained on the oxidation of tungsten in the thin film region with those found when the metal is scaling. A time-temperature study of the oxides formed on both molybdenum and tungsten may indicate whether there exist any peculiarities in the oxide structures of the thin film region compared with those of the scaling region of oxidation. In a recent paper the authors7 presented an investigation of the structures of the oxide films formed on the metals iron, cobalt, nickel, chromium and copper. The results of these studies are presented in graphical form as existence diagrams of the oxides on a time-temperature scale. The existence diagrams of the oxides occurring on some of the metals are simple and show few chemical transitions, but there are many cases in which the physical state of the oxide surface changes as a function of time and temperature, as evidenced by the appearance or disappearance of orientation effects and sharpness of patterns. In general an increase in temperature results in an increase in

Jan 1, 1947

By Earl Oliver

This paper is based on the formula that the petroleum industry is sick—find the cause, eliminate it, and the industry will get well. There is perhaps no difference of opinion that the cause is overproduction, actual or potential. But that, again, is a result rather than a cause. The problem is to study the influences that serve to keep production and consumption out of balance. Production control is a popular theme and a natural one at this time when the whole world is unstable; but production control in its popular sense means little more than the application of emergency measures while danger threatens. Economists differ as to the effectiveness of these, most of which are designed to alleviate and not to cure, but we assume there are none who question the wisdom of promoting conditions under which economic forces are permitted to operate freely in bringing about stable conditions. The petroleum industry suffers from two classes of economic ills that serve to promote overproduction; namely, those which are common to all industries and those which are peculiar to this industry. It is of the latter I wish to speak. Strange to say, government is responsible in large part for this latter class of ills that affect the petroleum industry and we are coming to recognize that only through the assistance of government can they be corrected. Instability of the petroleunl industry, in so far as human agency was involved, had its inception in 1875 when a Pennsylvania jurist, called upon to make a decision for which there was no precedent and fancying he noted some resemblance between the so-called fugitive nature of oil and gas and that of wild game, made mention of that resemblance. Other courts being impressed by the analogy enlarged upon it, and gradually fixed upon oil and gas a legal status in certain important respects similar to that of wild game. Although later the courts abandoned this analogy, certain practices that developed out of that early concept have continued to this day and are largely responsible for the industry's present plight. Thus, instead of ownership in place that is characteristic of private property generally, the law of capture was applied to oil and gas. Now, the rapid and wasteful depletion of game

Jan 1, 1932

By H. E. Mills

THE local auditorium of a little Alabama mining town was crowded with expectant men, women and children, as the bulletin board had announced the addition of visiting entertainers to supplement the local talent and motion pictures which usually made up the program of the regular monthly safety meeting. In the audience, near the stage, sat a group of bright-faced boys in boy scout uniforms, discussing the picture just completed. As the lights flashed on a crash and scream was heard from the outside, a shrill whistle and word of command from the scoutmaster, and five of the scouts ran out of the hall, while the mine super-intendent stepped on the stage and requested everyone to keep their seats. The scouts returned, three of them carrying a limp figure in their arms, while the other two cleared the doorway and aisle of excited spectators. They marched to the stage and, placing the apparently badly-injured boy on the floor, proceeded to give an expert demonstration of first aid to the injured. The scoutmaster then explained to the audience that the whole affair had been arranged for their benefit, and invited the local first-aid men to come up on the stage to examine and criticize the boys' work. This gave an opening for several talks on the value of first-aid training and accident prevention, which is the main object of the monthly meetings. This demonstration was given by the first-aid team of Troop One, and the entertainment was provided by members of Troop One and Twenty-eight of the Bir-mingham Scout Council, organized by the writer for the purpose of promoting interest in the welfare and safety meetings in the mining villages of the State. During the past year they have visited a number of such meet-ings and presented programs similar to the one men-tioned above. However, in order to assure a good attendance, entertainment features must also be pro-vided, and the serious part of the evening program was interspersed with excellent vocal and instrumental mu-sic, dancing and novelty acrobatic acts furnished by the visiting scouts. In addition to the numerous first-aid teams of the Birmingham Council, there are hundreds of scouts scat-tered throughout the mining district whose knowledge of first aid, safety first, life-saving, personal health and public health are a constant source of protection to their community. All of these subjects are covered by merit badge pamphlets and are required of an eagle scout.

Jan 2, 1927

By Lloyd A. Morley, Robert Stefanko

This report was prepared by The Pennsylvania State University, College of Earth and Mineral Sciences, ' Department of Mineral Engineering, University Park, Pennsylvania, under USBM Grant No. GO-133077. The grant was initiated under the Coal Mine Health and Safety Research Program. It was administered under the technical direction of the Pittsburgh Mining and Safety Research Center with Mr. G. J. Conroy acting as the technical project officer. Mr. J. A. Herickes was the grant administrator for the Bureau of Mines. This report is a summary of the work recently completed as part of this grant during the period 19 June, 1973 to 17 June, 1975. This report was submitted by the authors on 18 July, 1974. This technical report has been reviewed and approved.

Jan 1, 1974

By Silvano Morelli, Giovanna Cassani, Renzo Bindi, Antonio Nicola

More than 70 km of main line and service tunnels have been excavated to date for crossing the Apennines between Bologna and Florence. A new design and construction approach, known as Analysis of the Controlled Deformation in Rock and Soils, (ADECO-RS), was adopted to tackle the extreme heterogeneity of the ground and the particular stress-strain conditions. The goal of this system is to obtain constant and predictable full section advance rates, even in very poor geology, with the highest possible level of safety and reliability. The execution of this gigantic project required the mobilization of 21 job-sites, with the concurrent operation of 30 excavation headings. The global production rates confirm the high quality of the design and the high level of industrialization reached during the construction stage, levels not previously obtained in similar conditions, using other approaches such as NATM.

Jan 1, 2003

The choice between EPB - and Slurry Shields is influenced by the following factors: grain size distribution, cohesiveness, occurence of boulders, occurence of gas, feasibility of soil separation and muck disposal, and settlement properties of the soil. The simple equation cohesive soils = EPB Shields and non cohesive soils = Slurry Shield is very often superimposed by other facts. For example, the occurence of a large amount of boulders in weak cohesive soils, where the application of roller discs is not recommendable, may lead to the use of a Slurry Shield with a rock crusher, thus accepting the disadvantage of a sophisticated separation plant; whereas the occurence of contaminated groundwater or gas may exclude the use of a Slurry Shield. In the following examples the choice of a Slurry Shield or EPBS will be explained and justified with regard of the above factors.

Jan 1, 1995

By V. N. Bryant

"1.0 SYNOPSISThe Colomac property, located 137 miles by air northwest of Yellowknife in Canada's NWT. will recover gold from 10,000 tons per day of open pit ore.The decision to proceed with the project was based on a mineable ore reserve of 16 million tons (including dilution) averaging 0.064 oz/ton. After an in-fill drilling program in the latter half of 1988, Colomac's mineable, proven and probable ore reserves were increased to 28 million tons averaging 0.056 oz/ton of gold.A feasibility study completed by Wright Engineers for Neptune Resources in December 1987 examined the possibility of vat leaching followed by C.l.P. and electrowinning. A second feasibility study completed by Wright in February 1988 demonstrated that a conventional agitated leach circuit using a finer grind justified the higher capital cost of this process. This study was accepted and formed the basis of the project authorization.Preliminary engineering commenced in April 1988 and detailed engineering was started in September of that year with the objective of a mine/mill start-up by early 1990.The short time period available to meet the project deadline was additionally challenging, as site access is either by plane year round, and winter road from early February to late March. Normal lead times for equipment design, specifications, quotations and bid analyses were not possible, if the winter road time-slot was to be met."

Jan 1, 1990

By Sharpin P. C

The countercurrent gas-solid heat transfer during the drying of brown coal briquettes in the pilot carbonization plant at Morwell has been analysed and theoretical gas and solid temperature distributions through the drier have been calculated. Although the calculations rest on several simplifying assumptions, the theoretical temperature distributions compare well with those observed in practical operation. Valuable conclusions are reached as to the effects of changes in drier operating conditions on the rate of drying of the briquettes which controls the strength of the char produced. The analysis shows why a limitation was reached in the improvement of char strength in the pilot plant in 1961 due to the performance of the drier and a prediction is made of a way in which the limitation could be overcome.

Jan 1, 1966

By Robert W. Hunt

In 1888 the writer had the honor of submitting to the Institute a paper on " Steel Rails and Specifications for their Manufacture."* In his judgment the specifications were sufficient for "that day and generation." In that paper I said: '' The first duty falls upon the railroad engineer in designing his section. If that is bad, the steel-maker will be heavily handicapped in trying to furnish a satisfactory rail. I suppose it is hopeless to expect the adoption of standard sections."

Jan 1, 1896

By Patrick R. Taylor

The synthesis of high-purity ultra-fine barium strontium titanate powders (BST: BaO6Sro.4TiO3) has been performed in a non-transferred are D.C. thermal plasma reactor. Slurries of aqueous solutions of dissolved barium and strontium nitrates and solid titanium dioxide powders were used as precursors. Oxygen and argon were used as carrier gases, and pure argon and combinations of argon and nitrogen were used as plasma gases. The plasma torch power was varied, as well as the oxygen flow rate and the total molar concentration of the precursors. A graphite plate was designed to protect the torch electrode and lower the level of impurities in the product. A thermochemical analysis of the Ba(NO3)2-Sr(NO3)2-TiO2-H2O-O2 system was performed to predict the conditions for the formation of BST and the feasibility of the reaction, The powders collected from the different sections of the reactor were characterized using Transmission and Scanning Electron Microscopy, X-Ray Diffraction, and ICP chemical analysis. The powders produced showed high conversion to BST, ultra-fine particle size (< 30 rim) and high purity, which makes this a potential process to produce ceramic materials for electronic devices.

Jan 1, 2003

By William H. Schiffbauer

One of the safety and health research programs of the former U.S. Bureau of Mines Pittsburgh Research Center was the evaluation of technology that will provide remote-controlled operation of mechanized equipment in underground room-and-pillar mining. The purpose of this effort was to enable workers to be located away from the hazardous and unhealthful coal extraction area (the face). As part of this program, advanced machine navigation and control technologies were developed for underground room-and-pillar and highwall coal mining that can be applied to commercially available mining equipment. These technologies use off-the-shelf components and a flexible control software architecture to minimize the effort required to adapt them to mining equipment. An accurate, reliable navigation system that can provide the mining machine&apos;s heading and location is a critical requirement for a remote-controlled mining system. After investigating several different types of navigation sensors, researchers selected the Honeywell Ring Laser Gyro Inertial Navigation System (INS) as showing the most promise. It was installed on a continuous mining machine at our Mining Equipment Test Facility. Extensive testing at an open pit (OP) site was also performed. This report describes the INS as it was employed on the mining machine in the laboratory, in the field, and OP tests, and provides the accuracy and performance results of the OP and highwalltests.

Jan 11, 1997

By Richard E. Chism

Is my paper on Mexican weights and measures, presented at the Bethlehem meeting, I gave a formula for the reduction of Mexican ounces per carga to American ounces per ton, which may prove misleading. I wish therefore to substitute the following rule: To reduce Mexican ounces per carga of 300 Mexican pounds to Troy ounces per ton of 2000 pounds avoirdupois, multiply the number of ounces per carga by 6.078. Or, to reduce Troy ounces per ton of 2000 pounds avoirdupois to Mexican ounces per carga of 300 Mexican pounds, multiply the number of Troy ounces per ton by 0.165.

Jan 1, 1887

By R. C. Chaturvedi, S. B. Padwal

"Padwal and Chaturvedi have developed the model based on M-K theory, considering Hosford's yield criterion and critical thickness strain criterion"" to predict the sheet metal forming limits under simple (constant) strain ratio paths. This analysis has been extended in this paper to predict the sheet metal forming limits under complex strain paths. The effects of exponent ""a"" in Hosford's yield criterion and strain paths on the forming limits under complex strain paths are studied using this analysis. The predictions of the present analysis are compared, both for simple and complex strain paths, with experimental results of Ishigaki for A.K. steel and also with the predictions of Rao and Chaturvedi's model. The quantitative analysis of the error in predicting the forming limits has also been carried out using a method suggested by the authors earlier.1. INTRODUCTIONThe constant strain ratio condition has been assumed in the theories developed for prediction of forming limit diagrams (FLO). In actual forming operation, this condition is seldom satisfied. Even in the case of simple single stage press formed components, the strain path becomes curved and non-linear. In the case of pressings with complex shapes, or multiple stages of forming, the changes in strain path are more pronounced and even abrupt.Experimental study of the forming limits, under two stage strain paths, by Ishigaki [1], has shown that the forming limits are path dependent. It has been observed that the forming limits lower than that under simple strain paths, may be obtained under certain strain paths (when the first stage strain path is either equibiaxial tension or uniaxial tension, followed by the second stage strain path as plane strain). Rasmussen's work [2J, on the theoretical study of forming limits under curvilinear strains paths, has shown that a large drop in formability can result from very small changes in strain path. Thus if a deformation process gives rise to failures due to plastic instability, the failure is not necessarily due to insufficient formability of the material. In such cases, FLOs based on constant strain ratio path should not be used directly in predicting the success or failure of the forming operation. Thus the knowledge of forming limits under complex strain paths is of great importance to the interpretation of press-shop problems."

Jan 1, 1994

Fluorspar was not mined in the United States during 2004, although a small amount of usable synthetic fluorspar (CaF2) was produced from industrial waste streams. The majority of fluorspar consumed in the United States came from imports or stockpiled material purchased from the National Defense Stockpile (NDS). In addition, consumption is supplemented by use of by-product fluorosilicic acid produced at phosphoric acid plants. In 2004, annual production of fluorosilicic acid was 50kt (55,000 st) or about 88 kt (97,000 st) of 92 percent fluorspar equivalent. In 2004, annual production of fluorosilicic acid was 50kt (55,000 st) or about 88 kt (97,000 st) of 92 percent fluorspar equivalent.

Jan 1, 2005

By R G. Barker

This paper reviews the annual status of the New Zealand mining industry (metallic minerals and coal) including key aspects such as mineral production, mineral exploration expenditure, commodity price trends, key industry players, market activity and other significant commercial factors. &nbsp; Strong commodity prices during 2006 have been underpinned by a number of key factors including US dollar weakness and emerging market demand, particularly from countries such as China and India. In real terms commodity prices have recovered significantly since 2002 and are currently at 20-year highs. &nbsp; New Zealand exploration spending on metallic minerals (predominantly gold) is at a 15 year high driven by rising global commodity prices. New Zealand gold production in 2006 was about 340,000 oz and is expected to grow in 2007 as new mines at Frasers and Globe-Progress (Oceania Gold) and Favona (Newmont) come on stream. Gold production broadly lags 10 years behind exploration spending and exploration activity over the last five years remains well below that seen in the early 1980Æs. Expenditure on coal exploration shows a similar trend with strong growth from a low base over the last five years, reaching over $11 M in 2006. Total coal production in 2006 was 5.9 Mt, an increase of 10% on 2005 with imports from Indonesia adding a further $1.1 Mt. &nbsp; Newmont and Oceana Gold are by far the largest public gold mining companies operating in New Zealand, although only Oceana Gold maintains a presence on the local stock exchange. Other metals explorers with New Zealand projects include a range of public-listed Juniors (market capitalisation less than NZ$50m) domiciled largely in New Zealand, Australia and/or Canada. Capital-raising on public markets directed towards New Zealand exploration is estimated at around NZ$12 M for 2006, the bulk of this coming via Glass EarthÆs NZ$10 M IPO on the NZAX in October. &nbsp; The New Zealand Coal sector is dominated by the state-owned enterprise Solid Energy with around 80% market share by production. Other domestic coal competition remains limited, and includes the L&amp;M Group, Pike River Coal, Eastern Corporation, and New Vale (acquired by Solid Energy in 2007). Pricing parity comes mainly from imported coal and global thermal coal prices have remained strong during 2006 at around US$45-55/t, driven by continued expansion in Chinese demand. Coking coal prices have eased 16% since 2005 to around US$98/t in 2007. &nbsp; Although recent increases in exploration spending suggest a renaissance in the New Zealand minerals sector, long-run trends indicate that we have simply rebounded from a low base over the last five years and much work is still to be done to stimulate further growth in the mining industry to maintain minerals production at current levels. Key industry challenges include marketing exploration opportunities to local and overseas investors, building a critical mass of NZX-listed explorers and providing an internationally competitive environment to attract further capital and expertise.

Jan 1, 2007

By A. Bruynesteyn

It is well known that most North American gold deposits are of a hydrothermal origin and therefore they are often associated with sulphide minerals such as pyrite and arsenopyrite. When the precious metals in such ores are held captive inside sulphide crystals, the ores are called refractory because they do not respond to treatment by direct cyanidation. In these cases, it is necessary to recover the contained precious metals using high temperature treatments such as smelting or roasting, or high pressure leaching processes to break down the sulphide crystal matrices and thus liberate the precious metals for subsequent extraction by cyanidation. Sulphidic gold ores containing arsenic and/or antimony are considerably more difficult to treat because, in addition to their refractory nature, the arsenic and antimony content also prohibits treatment by direct cyanidation or amalgamation. These ores must be milled and their sulphidic gold values concentrated by flotation. The resultant concentrates must then be roasted to break down the sulphides before cyanide treatment can be applied.

Jan 1, 1985

The 2003 SME Annual Meeting and Exhibit will take place Feb. 24-26 in Cincinnati, OH. The meeting will feature a host of special symposia and programming geared toward the industrial minerals and aggregate industry sectors. This programming focus is particularly relevant for this annual meeting, as it will be hosted in the center of America’s transportation hub and industrial mineral center. Cincinnati, located on the Ohio River, is key to the movement of America’s supplies and construction material needs.

Jan 1, 2003

NEW MEMBERS The following list comprises the names of those persons who became members during the period Sept. 10 to Oct. 10, 1914: Members ALLEN, MILTON A., Min. Engr., Alaska Gastineau Mining Co., Juneau, Alaska. ALLPORT, ROBESON H., Gent Supt Colonial Coal & Coke Co., Dorchester, Va. ALSDORF, FREDERICK C.... Murray Apartments, 1026 Orange St., Los Angeles, Cal. ANDERSON, CARL A., Min. Engr 920 Wooward Ave., Portland, Ore. ARMS, CHARLES SEELYE, Asst. Met Willys-Overland Co., Toledo, Ohio. BAILEY, PHILIP P., Min. Engr McGill University, Montreal, Canada. BECK, CHARLES SMITH, Engr Detroit Copper Co., Morenci, Ariz. BEESON, ALEXANDER G., Chief Engr., Pittsburg-Buffalo Co. and Four States" Coal & Coke Co., Washington, Pa. BINGHAM, RAYMOND A Box 173, Bridgeport, W. Va. BJORGE, Guy N., Geol., Old Dominion Copper Mining & Smelting Co.,. Globe, Ariz.

Jan 11, 1914