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By John Birkinbine

Much has been contributed to the Transactions of the Institute concerning the construction and operation of American blast-furnares ; but the following compilation is offered as possibly furnishing additional information upon the general features, dimensions, locations, capacities, etc., of the blast-furnaces of the United States; while, incidentally, the ores upon which they rely are noted in a general way. The paper is presented chiefly as a compilation, and the figures given are selections from most reliable sources, or averages calculated from official statistics, placed for convenient reference, with a view of assisting those who consult the Transactions in determining the present relative merits and importance of various sections of the country. The scope of the paper has been restricted to as few topics as possible, and all the details of special plants, or notable outputs have been ignored. While every effort has been made to give correct figures and data, the changes which are constantly taking place in the iron-producing industry, will, undoubtedly, by the time the paper is in print, develop some errors. It is difficult to determine which of the blast-furnace plants of the country should or should not be considered as upon the active list. A number which have not been in operation for years are still reported as active, some of which will scarcely be put in blast again, and others are handicapped so that they can only operate in times of abnormal profits. It is therefore scarcely probable that there are over 600 blast-furnaces in the United States which can properly be considered as active; but so many considerations affect the various plants, that, it being impossible to determine the exact number, I have relied upon the annual reports presented to the American Iron and Steel Association. Concerning the number of plants which could be stricken from the list, the Secretary of this Association says: "In January last (1885) we enumerated 669 furnaces, which included many stacks which had not been in blast for a very long time, and others which could not be operated except during short periods of exceedingly high prices for pig iron. We have gone over this list very carefully and have eliminated 10 anthracite, 19 bituminous, vol. xiv.—36

Jan 1, 1886

This is the fourth in a series of reports on properties of commercial motor fuels, made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the Department of the Interior. The first report gave data on motor gasolines sold during the winter of 1935-363/. The second report gave the same data for motor gasolines sold during the summer of 19363/. The third report of the seriis gave the same data for motor gasolines sold during the winter of 1936-375/. This report covers 63 brands of gasoline represented by 1,136 samples excluding the Pacific Coast. Those from the Pacific Coast were averaged by the Pacific Coast technical group before being submitted and are published exactly as they were submitted. In some areas reports were received from five or six companies on the same brands of gasoline, whereas in other areas only one company reported on a brand. Thus, it can be seen that some of the data are more representative that others.

Jan 1, 1937

By W. H. Bassett

IN their paper on the directional properties in cold-rolled and annealed commercial bronze,1 Phillips and Samans suggest that cupronickel, under distinctly different treatments, shows both "45° ears" and "90° ears. " Fig. 1 shows the ears on some cupronickel cups made some 17 years ago for bullet jackets for small arms ammunition. In this case the material heated to 425° C. had "45° ears, while that annealed at 950° C. showed FIG. 1.-CUPRONICKEL, 0.032-in. GAGE, CAST WITH MAGNESIUM. ANNEALED AT TEMPERATURES INDICATED (DEGREES CENTIGRADE) AND CUPPED. long "90° ears" when drawn with the same tools. The method of cupping, the shape of cupping tools, etc., were found to have very little influence on the earing tendency, but the deeper the cup was drawn, the higher the ears would be.

Jan 1, 1932

By E. P. Pfleider

DIAMOND drill research work was initiated at the School of Mines, University of Minnesota, in late 1949. The Drilling Symposium held in Duluth that spring highlighted the problem of high cost and core recovery and the need for controlled testing. An advisory committee made up of informed representatives of both mining companies and drilling companies was formed to suggest and advise on a program of drill research. A Hy-Mac hydraulic drill unit, see Fig. 1, especially designed for experimental testing, was obtained for this work by the School of Mines through the courtesy of the Carboloy Co. It is an extremely flexible unit, capable of exerting a forward thrust of about 1750 lb and turning at speeds from 650 to 2200 rpm. The feed arrangement is so designed that the advance can be set either at a constant rate or permitted to vary at a fixed pressure, see Fig. 2. The

Jan 1, 1952

By R. W. Raymond

Jan 1, 1905

By C. V. Millikan

TEMPERATURE measurement in wells is an old practice and geothermal gradients have been of interest to geologists for many years.1,2 Their application to the operation of oil wells is a more recent practice. It has long been recognized that temperature anomalies occur in drilling and producing wells but thermometers that could obtain a satisfactory record of the anomalies were not available.3 The normal geothermal gradient is con-sidered as being about one degree Fahren-heit for each 60 ft. of depth.4 This "nor-mal" gradient varies in different areas, but whatever it may be in an area there is little variation from the surface to as deep as the drill penetrates. The normal gradient is appreciably changed by gas expanding from the reservoir into the borehole or by the movement of fluid through a borehole while drilling, producing, or circulating. It is the resulting anomalies and abnormal gradients from which conditions in wells can be interpreted. Some of the applications of such interpretations are locating the position of oil or gas sands, permeable strata in a reservoir zone, gas-oil contact, source of water, casing leaks, and the top of cement behind casing.

Jan 1, 1940

By Klaus Beckmann

Gentlemen : My object reads "Longwall Rapid Advance of Coal Mining in the Federal Republic of Germany". It is true that the percentage of coal obtained in your country from longwall faces, with at present 1.2, is still rather low, but it increased considerably since 1966 with 0.4 %. The coal mines of the Federal Republic of Germany ever used longwall as the classical method of coal getting. All attempts to introduce bord and pillar mining did not lead to any wider application of this method. The principal reasons, for this appear to have been: - the deeper depth of our workings, - the wish to keep working losses as low as possible and to utilize the deposits opened up by deep and therefore expensive shafts to the furthest possible degree, - the dense sequence of seams and the mutual influencing of the working points, - the high number of disturbances in the geologically much stressed deposits, - and the necessary considerations to the protection of the densely built-upon surface.

Jan 1, 1970

By Perring CS, Hill RE, Barnes SJ, Vallance SA

The Maggie Hays nickel sulphide deposit is located at latitude 32¦ 15 'S, longitude 120¦ 30' E on the Lake Johnston (SI 51-1) 1:250 000 map sheet. The deposit occurs in the Lake Johnston greenstone belt, in the Southern Cross Province of the Archaean Yilgarn Block, 500 kilometres east of Perth, Western Australia (Figure 1). The remoteness of the Lake Johnston greenstone belt and its poor access, restricted previous exploration activities and the full appreciation of the geology and its Ni-sulphide potential. It was not until 1991, when Forrestania Gold NL commenced exploration activities, that the geology of the ultramafic units and their potential to host significant concentrations of Ni sulphides were clearly established. This paper, which describes the geology and the characteristics of the Maggie Hays deposit, is based on the results of exploration by Forrestania Gold NL and a collaborative research agreement between CSIRO Division of Exploration and Mining and Forrestania Gold as reported by Perring, Barnes and Hill (1994), Perring and Hill (1995), Perring (1995 a and b) and Barnes, Perring and Reilly (1995). A comprehensive description of the geology, petrology and geochemistry of the deposit is being prepared for publication by CSIRO (Pemng, Hill and Barnes, in press).

Jan 1, 1996

By J. J. Frawley, W. J. Childs

PREVIOUS studies have shown that if a supercooled liquid metal was perturbed by vibration the probability of nucleation is is During a recent investi- gation to determine quantitatively the amount of energy needed to cause nucleation in a given supercooled liquid specimen, it was found that at low-energy values in the megacycle range, below the threshold energy value for cavitation, the amount of dynamic supercooling was greater than the amount of static supercooling. That is, if a specimen had a given amount of thermal supercooling under static conditions, its thermal supercooling could be increased by the addition of low-energy sound waves. The material used in this investigation was high-purity bismuth. This material was chosen because of its low melting point and the high degree of supercooling which could be easily obtained. The sound gener- ator employed in this work was a commercially built Sperry ultrasonic testing unit. This unit was equipped with a barium titanate crystal as a piezoelectric transducer. These sound waves were transmitted to the supercooled melt by a Pyrex rod, as shown in Fig. 1. The transducer was coupled to this Pyrex rod wave carrier by motor oil. The Pyrex wave carrier was approximately 1.5 ft long to prevent damage to the transducer by heat. The diameter of the Pyrex wave carrier appears to be critical. In the initial tests a wave carrier of 0.5 in. in diam was employed. However, the sound waves had no effect on the amount of dynamic supercooling. When the diameter of the wave carrier was increased to approximately the inside diameter of the Pyrex crucible, the sound waves were more effective. Approximately 200 g of metal was melted under a stannous chloride flux in a 30-ml beaker by induction heating. The temperature was recorded by a Pyrex-encapsulated chromel-alumel thermocoule which was placed in the beaker after the bismuth melted. The Pyrex wave carrier was immersed slightly below the surface of the liquid bismuth and the specimen was reheated to about 500°C. It was observed that the amount of supercooling depends on the amount of superheating the specimen receives; therefore, for meaningful results the amount of superheating was the same for all heating cycles. The specimen was allowed to cool in air and the change in temperature was continuously monitored with a potentiometric strip-chart recorder.

Jan 1, 1969

By J. R. Koehler

The failure of yield pillar-based gate mad designs to provide adequate ground control performance is primarily related to the use of "critically" sized chain pillars. A "critical" pillar is one that falls into a range of pillar sizes that are too large to either yield nonviolently or yield before the roof and floor sustain permanent damage, but are too small to support full longwall abutment loads. To directly compare the in-mine performance of critical and yielding pillar designs, the U.S. Bureau of Mines recently completed a field study in a tapering gate road at the Sunnyside No. 1 Mine, Sunnyside, UT. Extreme pillar stresses and associated coal bumps characterize the response to first panel mining of a 16.8-m-wide critical design. Significantly lower pillar stresses, early yielding of the pillar and adjacent panel rib, and an absence of coal bumps suggest that a narrower 12.2-m-wide design more closely approaches proper yield pillar dimensions. Probehole drilling of several 10.6-m-wide pillars revealed low stress levels and substantial pillar and panel rib yielding prior to abutment onset. suggesting a properly functioning yield pillar design.

Jan 1, 1995

By W. T. Weller

In Part I, a study of pressure build-up curves calculated for conditions under which both oil and gas flow led to the conclusion that the presence of a dispersed free gas phase in an oil reservoir must be taken into consideration to estimate accurately average reservoir pressure and permeability from build-up curves. Familiar methods based on the assumption of no free gas can be extended to the two-phase case by using total compressibility and mobility in place of single-fluid compressibility and mobility. These methods give correct values for average pressure and permeability when gas saturation is small. Errors become larger as the gas saturation increases. However, for the use to which the results will be put, the methods are satisfactory for reservoir engineering purposes. An improved method of calculating the performance of depletion-type reservoirs is presented in Part 2. Because the mathematical relationships describing simultaneous flow of oil and gas are quite involved. simplifying assumptions are made to provide means of obtaining approximate solutions of reasonable accuracy. One such approximate method now in use is the constant-GOR solution. It involves the assumption that at any instant, the ratio of total gas flow rate (both free and disolved) to oil flow rate is the same at all points in the reservoir. The approach is not applicable unless the free gar saturation in the reservoir is everywhere greater than the critical gas saturation. This paper presents a modification which, by avoiding the constant-GOR assumption, makes the method applicable to all reservoir conditions, and so far appears to be more accurate than the constant-GOR solution and to he comparable in required compuctation time. PART I— BUILD-UP CURVE ANALYSIS INTRODUCTION Pressure build-up characteristics of shut-in wells have been used for many years by engineers to evaluate average reservoir pressure, effective permeability thickness of the pay section, effectiveness of well completion (skin effect) and reservoir size. A number of methods of analysis have appeared from time to time."" Without exception, these methods are based on the assumption that the reservoir contains but one fluid of constant small compressibility and constant mobility. It has been suggesteda" hat these single-fluid methods may be applied to data from reservoirs containing both oil and gas by substitution of some effective total properties of the multiphase system in place of the corresponding single-phase properties. The present investigation was undertaken primarily to evaluate this approach. METHOD A number of theoretical build-up curves were calculated for conditions of two-phase flow, under the assumption of certain reservoir and fluid properties, and were analyzed by single-fluid methods with appropriate total compressibility and total mobility values for the corresponding single-fluid properties. Results of the analyses were compared with the assumed conditions. The theoretical build-up curves were completed by procedures similar to those of West, Garvin and Sheldon." Since these calculations require a considerable amount of computer time, an attempt was made to derive an approximate calculation method. The attempt was unsuccessful for calculating build-up curves, but the effort did result in a new approximate method of calculating the performance of solution gas drive reservoirs, which appears to be an improvement over the constant-GOR method" used previously (see Part 2). The West, Garvin and Sheldon calculations involved the following assumptions: (1) the reservoir is circular and completely bounded, with a completely penetrating well at its center; (2) the porous medium is uniform and iso-tropic, with a constant water saturation at all points; (3) gravity effects can be neglected; (4) compressibility of rock and water can be neglected; (5) the composition and equilibrium are constant for oil and gas; (6) the same pressure exists in both the oil phase and the gas phase; and (7) no afterproduction occurs, i.e., the well is shut in at the sand face for build-up. These assumptions make it possible to describe two-phase flow of oil and gas by the partial differential equations:

Jan 1, 1967

By Eugene H. Cowles

Now that a determined public effort is being made on this side of the Atlantic to create a steel ship-building industry, the materials that are demanded for this purpose assume a new interest to the American metallurgist. In the past, the uses of metals in this country have been almost exclusively connected with the land, while in England their application to marine purposes has been equal in importance to that on shore. In the future the same should be the case here. This is the reason for bringing a somewhat nautical or rather naval topic before a body the chief interests of which are supposed to lie in the mines and mountains of the interior of the country. A modern war-ship or " ocean-grayhound" (like the City of Paris) is an epitome of philosophy and human skill. In her graceful lines we have, as Ruskin might quaintly say, a " builded geometry ;" while in her wonderful machinery for motion, offensive and defensive, we have the summation of the ideas of a host of students who have, at one time or another, during the course of a hundred years of her evolution, contributed their intellectual mites to render her a thing of beauty and of power. Notwithstanding her present perfection, the modern ship contains room for further improvement. One of the most important things about her is the propeller. This active member is of more impor-

Jan 1, 1890

The first step in the mining and processing of nearly any mineral ore is comminution. Since the oil embargo of 1979, the mining companies have been striving to reduce energy consumption and costs. The first serious step was the introduction of in-pit crushing in the early 1980s. With in-pit crushing accepted as a standard design mode, the energy saving emphasis turned to comminution practices. A great deal of attention has been focused on blasting and grinding. The one step that has not been addressed is the primary crusher. This paper will address the opportunities for comminution improvement through optimisation of the primary crusher.

Jan 1, 2004

In accordance with the new concept described in the paper presented at the TMS annual meeting in 1989, 1 a new zinc cellhouse was constructed and successfully operated. The new concept was proposed in order to reduce energy requirements and to mechanize the electrode handling in the cellhouse. Major modifications involved the use of an electrode unit consistfog of assembled anodes and cathodes with frame bodies between each cathode and anode. The space between a cathode and an anode could be halved by this unit structure. In this paper actual operation data are summarized and discussed in comparison with the calculated figures.

Jan 1, 1990

Through the stress synthesis of many exanples of macrostructure from eastern to western parts of China, it can be concluded that in Chinese tectonics there are two push- twisting forces, one of which ("Rl", from SE to NW) came from the Pacific Ocean plate thrusting over the Chinese continent plate in the eastern part of China; the other ("R2", from SW to NE) resulted from the thrusting of the India plate. The meeting line could be situated along the belt from 104¦-106¦E longitude in the middle part of China. To the south of Qinling the meeting line was an abyssal and giant fault situated from Longmen to the Er Inland Sea where the Tibet-Gansi fold system was intersqueezed to the Sidluan platform; to the north of Qinling, situated on the Fengxiang subsidence of the Eerduosi basin, the meeting line was located about 105¦E in Mongolia and appeared in the form of an arcuate structure, i.e. the Mongolia arcuate structure, which could extend to Beijiaer Lake towards the north. A new special type of structure named rotation-apart structure occurred from Gansu, Qinghai province to Ningxia, Neimeng autonomous region, in the west of Shandong province and in the western part of Chaidamu Basin.

Jan 1, 1987

By Gonzalo Díaz, Diego Mesa, Willy Kracht

"It is well known that frothers affect the amount of water that is transferred to the froth, which has an effect on both the froth stability and the water recovery. On the other hand, since non-selective recovery by entrainment is directly related to water recovery, it can be said that frothers have an indirect effect on flotation selectivity. Recent research on this subject has shown that the non-selective recovery by entrainment, which is characterized by the entrainment factor, is frother dependent. In other words, the entrainment factor is not unique, but depends on frother type.Having different entrainment factors implies that for the same water recovery, the amount of undesired particles reporting to the concentrate may vary if one changes the frother type, which suggests, as a possible explanation, that it is not only the amount of water in the froth what is affected by frother type, but also the froth structure.The purpose of the current work is to study the effect of frother type on foam structure (two phase froth). A quasi-2D cell operated with a slot sparger was used to study the foam structure in the presence of three different frothers: Methyl Isobutyl Carbinol (MIBC), OrePrep®549, and Octanol at the same gas flow rate and reagent dosage. The foam structure was studied using image analysis, and an algorithm based on textural analysis was developed to classify the foams. The results show that it is possible to classify foams according to the frother used, which proves that frothers have an effect on the foam structure.INTRODUCTIONFrothers are usually dosed paying attention to froth stability, condition that is commonly estimated by sight, according to the operator's criteria and experience. This happens because there is not an established procedure or technique for frother characterization, generating qualitative descriptions such as “powerful” or “selective” frothers, which lack of scientific thoroughness and remain under subjective factors. Nevertheless, several works have been done in this line of research. Moyo et al. (2007) classified frothers based on their water-carrying capacity, proving that this characteristic is related with gas holdup and frother type. Previously, Trahar (1981) had related water recovery and gangue particles recovery, defining the entrainment value (ENT). Nowadays it is known that entrainment affects both hydrophilic and hydrophobic because it is not a selective process. In the last decade some studies (for example the one of Konopacka and Drzymala (2010)) delved into different entrainment behaviours dependent mainly on the flotation type (batch or continuous, agitated or columnar, etc.), but there were no studies on the effect of frother type regarding entrainment, since Rahal et al. (2001) argued that the ENT factor was independent of the frother type and concentration, and froth height."

Jan 1, 2016

By A. C. Bonnier

"INTRODUCTIONI have been asked to make available our method of determining the ""Live Inventory"" within a gravity type thickener. The ""Live Inventory"" being that tonnage compatible with the optimum underflow density that satisfies the process requirements.One prerequisite of the calculations is the proper determination of the final pumpable underflow density. A further requirement is that, prior to shutdown, the thickener has been operated properly, particularly that it has not been operated for storage capacity.Until recently I had few chances to check the method. However, I was most fortunate to have had a recent opportunity covering several months on a 300 ft diameter thickener at a plant in the U.S.A., wherein the method was tested and verified many times. The method proved accurate in that our calculated tonnage checked with the actual dried physical inventory of the drying facility.At the precise moment that the feed to the thickener was shut down, a per cent solid determination was made at the critical place and the tonnage in ""Live Inventory"" determined. Let us say that at the moment the thickener U' Flow solids was 20%. The thickener then was allowed to cperate until the U' Flow solids dropped below 20%, at which time the thickener was deemed to be relieved. Anything much less than 20% was not suitable to the subsequent centrifuge operation.Most large metallurgical thickeners have a configuration of three slopes at the thickener ""bed"". These slopes are dictated by the raking blades and are shown on the manufacturers' erection drawings. The first slope is from the outer periphery and generally takes up a distance of about 60% of the radius, the second slope generally taking up the remaining 40%. Within this 40% area, there is usually another slope taken up by the cone on ""B"" type thickeners or an actual steeper inner slope on ""C"" type thickeners."

Jan 1, 1989

By Jamai Rostami

Mining, perhaps more than other industries, has been under pressure to achieve higher productivity, while reducing costs and environmental impacts. This has encouraged a move toward large-scale operations and greater integration and automation of systems. Mechanization is being used increasingly to raise production and reduce labor requirements. Yet, while transportation, ventilation and other activities have benefited from this trend, mechanization of rock excavation (for development and production) has lagged. The switch to a mechanized excavation system can be complex, requiring a thorough study of operational and cost benefits to be successful. To justify the high capital cost of mechanical mining equipment, production rates and the true costs of machine mining must be accurately estimated. To evaluate the cost effectiveness of mechanical mining for a particular operation, the total production cost (capital and operating) must first be estimated. This requires a reliable estimate of the production rate of the candidate mechanical excavator. Previously, the variable nature of rock caused performance prediction of these machines to be more an art than a science. Additionally, some of these machines are highly sensitive to operator skill. They all depend on their backup systems. The effects of interaction with the overall mining operation can be difficult to forecast. And a new system must surmount psychological barriers before it can become truly operational.

Jan 1, 1994

By E. H. Edwards, J. Washburn, E. R. Parker

The mechanism of strain hardening was discussed in connection with some recent observations on the stress-induced motion of dislocation boundaries and on the simple shear deformation of zinc, cadmium, and copper crystals. THE nature of work hardening accompanying plastic deformation of metals has long been the subject of speculation. As early as 1925, Becker' suggested a thermodynamic process to explain slip based on the statistical probability for the occurrence of local glide steps. The theory that plastic glide was due to the presence of lattice defects known as dislocations was first introduced in 1934 by Taylor: and Orowan, and Polanyi.4 Taylor presented a rather complete analysis of the behavior and interaction of dislocations. He assumed a certain type of stress field to be associated with a single dislocation, and postulated that work hardening would result from plastic flow in two ways. First, dislocations following one another across a slip plane might encounter a barrier which would impede their movement, thereby gradually diminishing and eventually stopping plastic flow on that plane. The second mechanism involved the concept of dislocations traveling in opposite directions on nearby planes attracting one another to form a meta-stable lattice. The interaction of dislocations in such an array was shown to be large enough to require an increase in stress before plastic flow would continue. Kochendorfer5,6 extended the concept of work hardening involving a back stress due to an accumulation of like dislocations on a slip plane. He suggested that the formation of a new dislocation is hindered by those dislocations already present. The hardening resulting from the interaction of newly forming dislocations with bound dislocations was designated as "formative hardening," and indicated to be the only type of hardening necessarily connected with the slip process. In another detailed picture of work hardening, Mott and Nabarro7 assumed that sufficient dislocations are primarily present in the crystal as a consequence of growth irregularities (mosaic structure) to initiate slip. Work hardening resulted from the interaction of migrating dislocations with localized internal stresses produced during deformation. More recently, however, Mott8 as modified his treatment to include the generation of dislocations at Frank-Read sources and he accounts for the hardening by the formation of sessile dislocations. It has been widely accepted that metals of hexagonal structure, usually possessing only one set of glide planes, exhibit mechanical behavior markedly different from those having cubic structures. However, the differences in behavior of the two classes may be less fundamental than suggested. Rohm and Kochendorfer9 have shown that a single crystal of aluminum subjected to approximately simple shear gives the type of stress-strain curve associated with the hexagonal metals. Similar behavior has been demonstrated for gold and silver crystals by Andrade and Henderson.'" Thus when glide in cubic metals is restricted to one plane, the strain hardening characteristics closely resemble those of the hexagonal metals. It would appear, therefore, that an investigation of some of the strain hardening properties of single crystals sheared in simple glide might provide a more complete understanding of the phenomenon of work hardening. This report relates a number of recent observations made on single crystals of copper, zinc, and cadmium tested in simple shear. In addition, pertinent observations of effects accompanying stress-induced movement of dislocation boundaries are reported. Experimental Procedure and Results Details of the production and advantages of the type of single-crystal shear specimen employed for the following tests have been presented in a previous publication.n The method of testing makes

Jan 1, 1954

By John H. Ratcliffe, Hans T. Lundberg

In airborne gravity surveys effects of acceleration and irregular movements of the aircraft must be balanced out or overcome. The gradient of vertical gravity is recorded, therefore, by using two masses instead of one. As the amplitude variations are infinitesimal and difficult to measure accurately, at of gradient during flight is positive or negative. The positive portions of the pattern can then be indicated and contoured. Even with these simplifications, the source of energy must be exceptionally stable. General Principles: In the conventional gravimeter the weight of a standard mass is determined at a number of selected points within the survey area. In most systems weight is determined by comparing the gravity pull with extension or torque produced in a wire spring. The instruments employed are sensitive to the slightest movement; they cannot be used on a moving platform unless velocity is kept strictly uniform.

Jan 8, 1959