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By W. H. Blauvelt

The technical and engineering problems in the manufacture of coke are today the problems of the byproduct oven. Except in a few special localitics, practically no beehive ovens have been built in the United States for the last 5 or 6 years except as renewals of old plants, and during these years the total number of beehive ovens in existence has been steadily falling. On the other hand, the number of byproduct ovens has increased from 4624 in 1911 to a total of about 7660 in operation at the end of 1917; with 2800 building, this makes a total of about 10,460 which will be in operation in 1918, or shortly thereafter. Preliminary Government estimates place the total production of coke for 1917 at 56,600,000 tons, the largest tonnage in the history of the industry. Of this 34,000,000 tons, or 60 per cent., was beehive, and 22,-600,000 tons, or 40 per cent., was byproduct coke. Some time in 1918 the production of byproduct coke should pass the beehive output, and when the byproduct ovens now building are completed the total byproduct capacity will be about 40,000,000 tons of coke per annum, which is over 70 per cent. of the record-breaking total coke production of 1917. The reasons for these changes in the coking industry are familiar to all of us, and need not be discussed here. Improvement in Oven Design Since the byproduct oven was brought to this country from Europe, in 1892, it has been radically improved, and from the point of view of American metallurgical practice it is safe to say that the American ovens arc superior to those of Europe. The points of superiority are mainly those of larger units and larger output per unit, and the greater extent to which labor-saving machinery has been introduced. The increased output is largely due to the use of silica refractory material, which permits higher heats and shorter coking time than are employed in Europe. The modern American oven will carbonize commercially more than 20 tons of coal per day, and contrary to the European idea that slower

Jan 1, 1920

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions4/ issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous .sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1958

By David Schlain

The galvanic corrosion properties of titanium and zirconium were investigated by the Bureau of Mines. The dissimilar metals involved in these experiments included magnesium, magnesium alloy FS1, aluminum alloys, zinc, steel, tin, lead, copper, Monel, nickel, and several stainless steels. Couples were immersed in synthetic ocean water, tap water, 5-percent ammonium sulfate solution, 5-1/2-percent sodium chloride solution, sodium hydroxide solution, 0.1 N hydrochloric acid, and various concentrations of sulfuric acid.

Jan 1, 1956

By N Van Buc, E Coroiu

The rapid socio-economic growth of Hanoi City coincides with a corresponding growth of the transport demand. Today, the transport in Hanoi is completely dependent on private modes of transport. Because of the lack of an efficient public transport system and the expected rapid increase in traffic volumes, the movement of people and goods in the urban areas of Hanoi will cause congestion in the present city transport network. The solution of the construction of new roads, or the widening of the existing streets, is very expensive in urban areas and usually causes many social problems due to the resettlement of people. From the point of view of the number of inhabitants, Hanoi City is now over one million. Above this number the international experience shows that the public transportation must be a mass transport system with large capacity, commercial speed and also independent as much as possible from the street network. According to the Hanoi Master Plan for 2020, the Hanoi urban population will be over 3.5 million persons. Also, in the next 15 years, the distances between centre-destination points will be doubled by comparison to 1995.

Jan 1, 1999

In early-1989, subsidence due to voids at the top of previously filled stopes and stopes awaiting filling,began to threaten the 15 level fill conveyor horizon. This together with the need to maintain production targets meant that a method was required to significantly increase fill placement.Alternative methods of placing dry fill underground were investigated. One option was to drill 200 mm boreholes from surface directly into stopes 600 - 800 metres underground. A drilling program was successfully undertaken, and resulted in the placement of more than 800 000 tonnes of dry aggregate fill via four boreholes.This paper details the drilling program undertaken and discusses the difficulties encountered, the fill placement system and the project costs.

Jan 1, 1992

By J. Blodget Britton

To the question, "Do the Pennsylvania anthracites contain phosphorus ?" asked at the last meeting of the Institute during the discussion on the metallurgical value of Western lignites, I can now give a definite answer. Through the kindness of a gentleman connected with the Philadelphia and Reading Railroad, and another connected with one of the principal ironworks on the Lehigh, there was sent to the Iron-masters' Laboratory a number of samples of the coals now largely shipped from the Schuylkill and Lehigh regions. Seventeen of these I examined for their contents of ash and phosphorus, and obtained results as follows

Jan 1, 1873

By E. Bonsall, J. J. Brummer, A. R. Graham

"A method and device are described for sampling diamond-drill core by cutting a continuous fillet of constant cross section from the cylindrical surface of the core throughout appropriate sample lengths. The apparatus employs a tapered, abrasive-set, cutting wheel, the conical cutting surface of which projects slightly into a rectangular core-guiding trough set parallel to the axis of rotation. The depth of fillet and thus the amount of sample per unit length can be regulated by adjusting the core guides. The freshly cut fillet itself, by engaging in a guide beyond the cutting wheel, acts to prevent rotation of the core during operation of the device.The cuttings which form the sample are normally collected in a tray below the cutting-wheel and appear at about 80 per cent -100 mesh. They require little or no further treatment or comminution before analysis. Speed, economy and convenience of sampling are thus greatly increased as compared with conventional sampling by im-1>act breaking or sawing, followed by crushing, grinding and sub division for assayAssays from fillets (about 1/20 the cross-sectional area of the core) and from 180-degree segments, from the same ninety-three core-samples, representing 431 feet of nickel-copper mineralization, gave the following results:"

Jan 1, 1968

By John R. Anderson, Michael B. Bever

Carbon may affect the alloys of copper in several ways. Provided an alloying element does not oxidize preferentially, even minute quantities of carbon dissolved in liquid alloys of high copper content will form insoluble carbon oxide gases under oxidizing conditions. Gas porosity in castings of high-copper alloys can originate in this way. In certain alloys of low copper content carbon may have considerable solubility and may be an effective deoxidizer. In these alloys carbon will tend to suppress porosity. Carbon that is dissolved in the molten alloy is likely to be retained in the solidified metal. The effects of carbon on the physical properties of the metal are determined by the form in which it is present. Depending on the alloying elements and also on the cooling rate, carbon may precipitate as graphite, may form a carbide or may remain in solid solution on cooling. As solid copper does not dissolve a measurable amount of carbon, a carbon-bearing solid solution can occur only if the copper is alloyed with a large excess of an element that forms such a solution. The effect of graphite or of carbides on the properties of an alloy will depend on the size and distribution of the precipitated particles. As Hensel pointed out in discussion,' the formation of an alloy carbide may interfere with the age-hardening properties of a copper alloy. One would also expect that the presence of carbides or of graphite will under certain conditions promote corrosion or high-temperature failure in nonferrous alloys. Since carbon has an effect on the soundness of castings and affects the structure and behavior of solid copper alloys, its solubility in the liquid alloys is of practical importance. The isothermal change of carbon solubility with alloy composition is of interest from a theoretical standpoint. The binary alloys of copper with manganese and with nickel are used industrially and serve as a base for more complex alloys. The solubility of carbon in each of these metals is known, but its solubility in their alloys has not been determined. Earlier Data The solubility of carbon in molten pure copper is about o.oooi pct at II00°C and 0.0004 pct at 1475°C.l Various authors2""6 have published data on the solubility of carbon in molten manganese. There is agreement on a value of about 6.7 pct in the temperature range r2170 to 1245°c This solubility value corresponds to the formula Mn3C. It increases very little with increasing temperature. Corson7 states that carbon is soluble in copper-manganese alloys and that the

Jan 1, 1947

While the production of this state has not realized the early hopes that this coal would replace eastern coal on the Pacific Coast, it has been steady though small. Nearly all of the tonnages given are from Goodyear's, The Coal Mines of the Western Coast of the U. s., a carefully com- piled and accurate account of the development of the industry along the Pacific. [ ]

Jan 1, 1942

By I. Cadoff, E. Miller, K. Komarek

Jan 1, 1960

Liebherr Mining Equipment Co., of Newport News, VA and Baxter Springs, KS, introduced the T282, a new two-axle, diesel-electric, AC drive haul truck with a payload capacity of 327-t (360-st). The T282 was unveiled at a press briefing in October 1998 at the company's Baxter Springs research and development1 manufacturing facility. In addition to an increase in pay- load capacity, the truck's AC drive system has been de- signed to allow for easy configuration to a trolley-assist system with minimal additional equipment. The T282 provides fuel savings, reduced maintenance requirements, and reduced downtime and maintenance costs, providing the mine operator with increases in productivity. Basic dimensions and weight of the T282 are: ? Overall length, 14.5 m (47.5 ft). ? Overall width, 8.7 m (28.7 ft). ? Loading height, 6.5 m (21.2 ft). ? Height - body up, 13.9 m (45.9 ft). ? Empty vehicle weight, 201 t (221 st). ? Operating weight - loaded, 528.6 t (582.6 st). ?Engine, Detroit Diesel 16V4000 at 2 MW (2,750 hp). ?Electric drive system, Siemens/Liebherr.

Jan 1, 1999

By K. M. Godiwalla, S. Ranganathan

The thermal state in submerged-arc furnaces (S.A.F.) producing ferro alloys is important for the conditions of both the grade of alloy produced as well as specific energy consumption. The temperature profile in the S.A.F. is affected by the endothermic chemical reactions and the rate of gas evolution. The gas evolution commences at about 900 C due to the reduction of iron in the ore. A first-principle-based 2-D model has been developed to predict the temperature profile in the furnace. In this study, four ores of different grades have been considered in order to simulate the thermal profile in the S.A.F. The influence of the composition of the ore on the thermal profile and its significance in rationalisation of charge distribution to optimise the process are discussed.

Jan 1, 2007

By A. Wilkinson

An investigation into the performance of support systems that are currently used in South African coal mines was conducted. Five most critical components of a support system have been identified. These components are resin, bolt, hole, machinery/equipment and the rock type. All five of these components are equally important as failure in any of these components will result in an inadequate support system. The performance of resin used in South Africa was investigated through in situ short encapsulated pull tests. The results indicated that in the majority of pull tests, failure took place at the rock-resin interface, indicating that the rock failed before the resin shear strength had been reached. It is therefore concluded that the strength of resin currently used in South Africa is adequate. It is found that although the maximum bond strengths achieved form both resin suppliers were similar, there was a considerable difference in the stiffhess of the resins. Roof bolt diameters and rib heights of bolts from three major manufacturers were evaluated (approximately 80 roof bolts from each manufacturer). The results showed there is a significant variation in bolt diameters and rib heights in the same batch in roof bolts supplied by certain manufacturers. The results also showed that on average there are insignificant differences between the parameters that determine the bolt profile (rib angle, spacing between the ribs and rib thickness). The influence of these parameters on bolt performance was very small and could not be established in situ. Roof bolts from four major suppliers were also evaluated through in situ short encapsulated pull tests. The results showed that the reinforcing system using roof bolts from all four manufacturers performed almost identically in sandstone, but somewhat differently in other rock types. The effect of bit types was evaluated. Both the stresses and the maximum loads obtained from the two-prong bits were greater than those obtained from a spade bit. Borehole annulus was found to be another important parameter that determined the support performance, and was investigated. The results from these tests showed that an annulus between 2.8 mm 4.5 mm resulted in the highest bond strengths. The results also showed that as the annulus drops below 2 mm, it appears to have a negative effect on the bond strength. The effect of wet and dry drilling on support performance was investigated. The results showed that wet drilling can-provide relatively greater system stiffnesses and slightly greater bond strengths. Short encapsulated pull test results showed very distinct differences between bolt system performance in different rock types and that sandstone produces significantly better results than shale and coal. From the results it is concluded that rock type is probably the primary factor influencing support system performance. A detailed investigation into the specifications of roofbolters that are currently being used indicated that the quality of installation of a support system is directly related to the performance of the equipment that is used to install the bolts. The important parameters, torque, thrust and speed of bolting equipment were investigated. The results showed that there are significant variations in these parameters in South African roofbolters.

Jan 1, 2005

By E. R. Mitchell

When we grow up in an urban environment and choose to become a part of a way of life, it is sometimes difficult to appreciate the cost of this decision in terms of pollution. Explained in this article is our dependence on technology and the amount of pollution that technology produces. Inventories of air pollution on both a personal and a national basis are given so that the reader may judge the magnitude of the problem. In doing so, it is hoped that the reader will understand the need for a responsible attitude toward pollution by everyone and how he can make a personal contribution.

Jan 1, 1971

By O. N. Carlson, K. E. Solie

The brittle-ductile transition temperatures of single and poly crystalline chromium metal were studied as a function of nitrogen concentration and chromium nitride distribution. It was observed that In recent years there has been an increasing interest in chromium-base alloys for high-temperature applications. The principal disadvantages, however, have been the difficulties of fabrication and the design problems associated with a material of such limited ductility. Various studies have been the effects noted in the poly crystalline material are essentially reversed in the single crystals. These observations are discussed in terms of existing theories for the brittleness of chromium. conducted recently directed toward a determination of the cause of this brittleness and to find ways for minimizing its effects. Allen et al.,' Wain Abrahamson and rant,' and weaver4 have carried out studies on the effects of interstitial impurities on the brittle-ductile transition of chromium metal of various degrees of purity. These investigations have shown that oxygen has little or no effect on the transition temperature of chromium in all conditions studied but that carbon increases the transition temperature under all conditions tested. Nitrogen was found to increase the transition temperature in the wrought condition and in the quenched or cast conditionS but reportedly has no effect in the furnace-cooled condition.

Jan 1, 1964

By Harry Deitzer

Within the industrial marketplace barium sulfate has an established role as a filler or extender pigment for use in a wide array of applications. The focus of this paper is to outline a number of these applications and in each one characterizes those features of barium sulfate which provide value. Following this is a discussion of the process techniques which have been used to develop value from a selected class of barite ores found in southern Missouri. It is appropriate to define some terms which may help in clarifying some concepts as presented. Use of the term barium sulfate refers broadly to the chemical compound BaSO4 Barite will generally refer to the naturally occurring barium sulfate ores and their properties. Barytes, whether bleached or not, will refer to barite ore made suitable for industrial applications.

Jan 1, 1993

"Butte originated as a placer mining camp. The first gold discovery was made in the year 1864, near what is now Main Street. Placer mining was vigorously prosecuted along Silver Bow Creek and in Missoula, Buffalo, Town and Parrot gulches for a period of five years, at the end of which time, in 1870, the camp was practically deserted. In the meantime, the quartz veins so prominently traceable over the hillsides were located, the first location being made by W. L. Farlin and called the Black Chief claim, and later restaked as the Travona. Reasoning from the presence of the gold placers, free-milling gold ores were eagerly looked for by the early prospectors. Claims covering the great Rainbow and other silver lodes were located in the sixties. The presence of valuable silver ores in these veins caused the staking out of many claims, believed to be valuable only for silver, but which later proved to be enormous copper producers.Treatment of these early discovered rich ores was first attempted in arrastres. Later, stamp mills were built. The Centennial dropping 10 stamps, was the first, and in 1875 Mr. Farlin built the Dexter 10-stamp mill, intro¬ducing chloridizing-roasting. More successful processes were soon introduced and several large mills built, among which were the Alice, Lexington, Silver Bow, Moulton and Bluebird, in all representing a total of 290 stamps. The silver mining industry reached its zenith in 1887 and declined rapidly in the early nineties, following the sudden drop in the price of silver in 1892.During this period of silver mining activity the business of copper mining was making rapid strides. Development of the veins, located as silver veins, had uncovered copper ore in many instances. There was great activity in ""claim staking'' in the years from 1871 to 1879, during which period most of the claims covering the present productive copper area were located."

Jan 1, 1913

By R. Heath Forbes

The route of a new, 4-mile long, electrical transmission line passed through residential neighborhoods and commercial areas of a small town in the South Carolina Coastal Plain. The new line consisted of 54 new poles and a one-mile underground section. Most of the new poles were constructed within 50 ft of existing structures, and in some cases, within 8 ft to 20 ft. A widely-space subsurface exploration consisting of 20 cone penetration test soundings indicated the subsurface conditions along the alignment generally consisted of saturated, loose to medium dense, fine slightly silty to silty sand. The pole foundations consisted of 20 to 30 ft long, prefabricated ?caissons? (essentially an open-end pipe pile with a prefabricated connection system at the top) with diameters of 28 to 56 inches. The steel caissons were installed with vibratory pile hammers. To help prevent damage and defend against possible allegations from nearby property owners, vibration and settlement monitoring was performed during all foundation installation activities. Limited structural condition assessments were also performed before and after foundation installation. For 53 of the 54 foundations, the ground vibrations recorded at distances coincident with the nearest structure locations ranged from 0.05 inches per second to 1.46 inches per second. With consideration of the dominant frequency, the majority of these values were below the commonly used USBM vibration limits. For a foundation installation that was only 8 ft from the nearest structure, a peak particle velocity of 3.06 inches per second was recorded, which exceeded the USBM limits. For all cases, the measured ground surface settlement was negligible (i.e., less than ¾ inch). Several spurious claims alleging vibration-induced damage were made, but the monitoring program provided an adequate defense. One claim involving artwork that fell to the floor during foundation installation at a distance of 8 ft from the house was deemed legitimate.

Jan 1, 2011

By Bengt H. Fellenius

"ABSTRACTAn example from a guidelines document for the Eurocode is discussed that addresses design for geotechnical strength of piled foundations in settling soil, generating drag force and downdrag. A modified example of geotechnical response is then analyzed in a failure mode, Ultimate Limit States (ULS), and stationary long-term state, Serviceable Limit States (SLS). It is shown that the Eurocode principles, when applied to correctly determined forces, results in an irrational and costly design. The results of the analysis of the modified example are applied to eight different codes pertaining to piled foundations from USA, Canada, Europe, and other countries. Several of the codes require that the drag force be included as a load in a ULS design, which an absurd and costly requirement, in some codes, in one case made even worse by combining drag force with live load. A major weakness of almost all codes is their minimal treatment and sometimes total absence of aspects of settlement of piled foundation. In contrast, my main argument is that design for capacity, whether in working stress approach, or by LFRD or ULS approaches, is not always safe unless a thorough settlement analysis shows that the design also meets the requirements of the SLS.1. INTRODUCTIONFirst, there were analysis, design, and construction establishing a State-of-Practice, SOP. Then, came codes and specifications summarizing the SOP, as interpreted by a committee. When the state-of-art, SOA, was not understood by that SOP-interpreting committee, the codes and specifications are uneconomical and, sometimes, also unsafe.The paper first presents an example quoted from two commentaries on the Eurocode 7 on design for geotechnical strength by the Eurocode (1997). The example is then modified to a more realistic case and analyzed in failure mode (ultimate limit states, ULS) and in the context of settlement (serviceability limit states, SLS). The analysis results are then applied to eight codes addressing piled foundation design and changes necessary for the referenced codes and specifications to be closer to the SOA are identified."

Jan 1, 2014

By John Hays, Hammond

IT is both a pleasure and an honor to be a guest of the Institute and I thank you, Mr. President and fellow-members, for giving. me the opportunity of meeting you this evening. My esteemed friend, President Smith, has requested me to do a bit of "reminiscing" as to the earlier years of my career as a mining engineer, which has now covered a period of fifty years. Let me reassure you by promising that my narrative will not include all the experiences I have had over that long period. You will, I trust, pardon what might seem egotistical but I do not see how a personal narrative could well be otherwise.

Jan 1, 1928