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By K. C. Gilbart, Edgar Stansfield

One of the most striking features of the coal series passing from peat through brown coal, lignite, etc., up to anthracite is the gradual reduction of moisture content with the increased coalification of the original plant material. Thus drained peat from a bog may contain 90 per cent water, brown coal contain 50 per cent, lignite 30 per cent, while a bituminous coal may contain only 1 per cent moisture. Moisture, therefore, is one of the important factors to be considered in coal classification, especially with the lower rank coals. With bituminous and higher rank coals the moisture content is less satisfactory for classification; it may even pass a minimum value and then increase with increasing rank to anthracite and superanthracite. Coal in an undisturbed seam contains moisture which is an integral part of the coal, but it may also be wet with free, underground water percolating through the seam. Only the former must be considered in evaluating the moisture content of the coal for classification purposes; this will be called the "true moisture" of the coal. When the seam is mined and sampled the sample taken may show the true moisture; on the contrary, it may contain in addition free mine water or, especially in dry, well ventilated mines, it may contain less than the true moisture. Coal contains unstable organic compounds which may decompose, with the production of moisture, when the coal is exposed to air at ordinary temperatures, or is heated with or without exposure to air. The potential moisture of a coal therefore is higher than its actual moisture. The lower the rank of the coal, the greater its instability, as a rule, and the greater the care necessary to avoid oxidation or decomposition in any investigation of moisture content. The majority of coal workers have preferred, on account of the difficulty in evaluating the true moisture of a coal, and for other reasons, to classify coals by analyses calculated to the dry-coal basis. A number of workers familiar with lower rank coals have recently insisted that the classification of such coals can be satisfactory only if analyses on the moist-coal basis are employed. The moisture-holding capacity of coal is therefore intimately connected with coal classification, and in this paper a procedure is outlined for determining the true moisture of a coal,

Jan 1, 1932

By Gerhard Derge, Arthur H. Grobe, Harold Markus

The high corrosion resistance possessed by tin under most circumstances, combined with its generally satisfactory appearance and useful physical properties, has led to many and varied uses for the metal. These uses have been partly limited by the fact that tin is an expensive metal, therefore many applications have been developed in which tin has been employed in combination with lead, either by coating, as in tin-lined collapsible tubes, or by the formation of alloys containing various proportions of tin-rich and lead-rich phases, as tcrne plate. A detailed knowledge of the corrosion characteristics of the tin-lead couple therefore is of general interest and has become specially important at the present time, when every effort is being made to conserve tin as much as possible. The present study has been limited to carbonate solutions with a pH range from 8.4 to 11.2 so that the results may be related to earlier work on the corrosion of tin and its alloys. 1-3,6 In these papers, the effects of a number of anion and cation additions to these solutions have been observed. Apparatus and Method The electrodes for the corrosion cell were cut from rolled sheet about 1/16 in. thick. The length of all specimens was held constant at 7 in., while the width was varied from M to 2 in. These electrodes were fastened to brass electrode supports, which were attached to rubber stoppers fitting into tall-type one-liter Pyrex beakers that contained the electrolyte. The lead electrodes were prepared from Omaha pig* and the tin was rolled from a slab of Chempur.† After cutting to size, the sheets were polished with No. I emery paper and cleaned with carbon tetrachloride. The edges, back and upper parts of the specimen were coated with a synthetic lacquer, which was supplemented with beeswax for the lead electrodes. The binding posts were coated with beeswax after the electrodes had been clamped. The pH of the electrolyte was controlled by adjusting the ratio of carbonate to bicarbonate. Approximately 600 ml. of electrolyte was used in each beaker. The entire assembly was placed in an oil bath thermostatically adjusted to operate at 30°C. + 0.1". Potentials were measured against a saturated calomel electrode connected to the cell by an agar-agar salt bridge. The carbonate solution used in the salt bridge was the same as that used in the corrosion cell. Currents were measured with a milliam-

Jan 1, 1942

By Harold Markus, Arthur H. Grobe, Gerhard Derge

The high corrosion resistance possessed by tin under most circumstances, combined with its generally satisfactory appearance and useful physical properties, has led to many and varied uses for the metal. These uses have been partly limited by the fact that tin is an expensive metal, therefore many applications have been developed in which tin has been employed in combination with lead, either by coating, as in tin-lined collapsible tubes, or by the formation of alloys containing various proportions of tin-rich and lead-rich phases, as tcrne plate. A detailed knowledge of the corrosion characteristics of the tin-lead couple therefore is of general interest and has become specially important at the present time, when every effort is being made to conserve tin as much as possible. The present study has been limited to carbonate solutions with a pH range from 8.4 to 11.2 so that the results may be related to earlier work on the corrosion of tin and its alloys. 1-3,6 In these papers, the effects of a number of anion and cation additions to these solutions have been observed. Apparatus and Method The electrodes for the corrosion cell were cut from rolled sheet about 1/16 in. thick. The length of all specimens was held constant at 7 in., while the width was varied from M to 2 in. These electrodes were fastened to brass electrode supports, which were attached to rubber stoppers fitting into tall-type one-liter Pyrex beakers that contained the electrolyte. The lead electrodes were prepared from Omaha pig* and the tin was rolled from a slab of Chempur.† After cutting to size, the sheets were polished with No. I emery paper and cleaned with carbon tetrachloride. The edges, back and upper parts of the specimen were coated with a synthetic lacquer, which was supplemented with beeswax for the lead electrodes. The binding posts were coated with beeswax after the electrodes had been clamped. The pH of the electrolyte was controlled by adjusting the ratio of carbonate to bicarbonate. Approximately 600 ml. of electrolyte was used in each beaker. The entire assembly was placed in an oil bath thermostatically adjusted to operate at 30°C. + 0.1". Potentials were measured against a saturated calomel electrode connected to the cell by an agar-agar salt bridge. The carbonate solution used in the salt bridge was the same as that used in the corrosion cell. Currents were measured with a milliam-

Jan 1, 1942

By C. G. Dunn, J. L. Walter

The c/laracterzstics of cube-oriented nuclei ard other matrix grains that are associated with secondary, recrystallization to the cube texture in high-purity silicon iron were investigated by me-tallographic and X-ray methods. The results show that the structure consists of relatively perfect grains of average diameter between one and two times the sheet thickness ad that the texture has a moderately strong (110) [001] component and a weak (100) [001] component. The results also indicate that matrix stability results from the two-dimensional nuture of the graitzs and that cube-orzented nuclei are neither more Perfect nor larger grains than other matrix grains but have a preferred [001] direction in the rolling direction and have a more effective driving force for growth than other grains because of a low (100) surface energy. THE structures and textures of fine-grained rnatrices determine to a large extent the kinds of secondary recrystallization textures that form on annealing. The understanding of secondary recrystallization processes therefore depends on adequate information about the initial matrices. Matrices usually have three characteristics: 1) they consist of fine-grained primary recrystallization structures, 2) the fine-grained structures are stable toward normal grain growth, and 3) they contain secondary recrystallization nuclei. Stability toward normal grain growth may be due to either a strong single orientation texture (texture inhibition)' or a dispersed second phase (dispersed phase inhibition).2"4 If normal grain growth is not inhibited by either of these two factors, it nevertheless stops when the average grain size is between one and two times the sheet thick- ness.5 This thickness effect satisfies one of the characteristics of a matrix for secondary recrystallization. Its importance in the development of the cube texture in high-purity silicon iron by secondary recrystallization was pointed out by the authors in a recent paper on tertiary recrystallization7 and will be discussed further in the present paper. Assmus, Detert, and he8 have provided some information on a matrix for secondary recrystallization to the cube texture in silicon iron. They found a (110)[001] or Goss texture with enough spread about the rolling direction to include a small amount of the (100)[00l] orientation. The distribution of the [00l] directions was strongest parallel to the rolling direction for both (100) primaries and cube secondaries. These authors found no correlation between size of a matrix grain and orientation and concluded that some property other than size must be the distinguishing characteristic of the cube-oriented nucleus. No consideration was given, it

Jan 1, 1961

ROBERT PEELE, New York, N. Y. (written discussion *).-This excellent paper is one of a number of recent detailed descriptions of the, methods and plant in use at prominent mines of the country. The publication of such papers cannot be too highly praised. In the past, the interchange of inside information has often been hampered by the disinclination of some mining companies to permit publication of details of their work. These companies apparently have not realized fully that free discussion is of mutual benefit; that members of mine staffs are aided in. keeping up to date, in improving old methods and devising new ones to meet changes in conditions, and, by a wholesome feeling of rivalry, are stimulated to introduce economies and do better work. In writing this paper, Messrs. Haight and Tillson have packed a large amount of information into a relatively small space, and the numerous illustrations, chiefly reductions of working drawings, are valuable. The authors are also to be commended for their highly detailed Table of Contents, which adds to the usefulness of the, subject matter. The method of mining at Franklin does not fall readily into any of the accepted classifications. It is a combination of shrinkage stoping and mining of the pillars by a modified top-slicing method. Attention may be called to the fact that, in the wider parts of the orebody, the stopes, 17 to 18 ft. (5.2 to 5.5 m.) wide are transverse; in the narrower parts, they are longitudinal, that is, in the direction of the' strike. This varia-tion is made necessary by the shape and character of the deposit, and distinguishes practice at Franklin from that in some of the western mines. The direction of the stops is changed from transverse to longitudinal when the orebody narrows sufficiently to make the length of a transverse stope approximately equal to its width. Some of the longitudinal stopes exceed 120 ft. (36 m.) in length, and when the hanging wall is bad, requiring prompt filling, three operations' proceed simul-taneously in the same stope, viz., ore is broken at one end, while drawing down goes on in the middle, and filling at the other end. Each transverse stope or chamber is begun by a crosscut from foot to hanging wall, which is afterward enlarged to the stone width and to a height of 12 or 15 ft. (3.7 or 4.6 m.). This preliminary work is done only once for each stope, because the stope is carried up far enough to continue stoping

Jan 1, 1918

By Park Wright

THE fact that granite has been encountered by the drill by those in search of oil and gas in Kansas is becoming more and more a matter of interest, not only to the oil producer but to everyone directly and- indirectly connected with the oil business. It is, therefore, time that someone should offer an explanation for its presence and form a definite opinion based on all the data available in regard to the effect it will have on the future prospects of the area affected as probable oil- and gas-producing territory. At present there seems to be no consensus of opinion. To the writer's knowledge, only one attempt has been made to explain; by Erasmus Haworth, State Geologist of Kansas, in a paper entitled Bulletin, Number Two on Crystalline Rocks in Kansas. The purpose of the present paper is to offer a theory for the presence of the granite and to draw conclusions which will aid in determining the prospective oil and gas value of the area in question. In taking up this question it will be well to consider first the tests in which granite has been reported, with a general history of each. The accompanying map (Fig. 1) shows the location of all wells described. The first well in which granite was reported was that drilled just south of Zeandale in section 27, township 10 south, range 9 east, by a local company which had taken up a block of leases in that vicinity. At a depth of 958 ft. (291.99 m.) granite was encountered. Drilling was continued to a depth of 1,093 ft. (333 m.) in the same formation, at which depth the hole was abandoned. Another well was started 1 mile east of the first well and the same rock was found at a depth of 945 ft. (288 m.). Drilling was continued to a depth of 1,200 ft. (365.76 m.) with the bit in the sane formation. Samples of the drill cuttings have been examined and they are undoubtedly crushed granite. The next well in which granite was found was that drilled by DeLaat and Shepard, independent wildcat operators, in section 34, township 19 south,. range 7 east, near the town of Elmdale. Granite was struck at 1,707 ft. (520 m.) and the hole was abandoned in the same formation at 2,525 ft. (769 m.). Mr. DeLaat watched the drilling of this well very closely and he has described to me in some detail the formation immedi-

Jan 8, 1917

By David R. Poirier

Activity data of carbon as a function of both temperature and composition throughout the stable austenite range is correlated by mearts of an equation derived from a quasi-chemical model. The carbon activity data of austmite for temperatures between 800° and 1200°C are utilized in conjunction with the activity of carbon calculated for the y solidus using the activity of carbon in liquid iron and published austenite-liquid equilibria. The results agree very well with Chip-man's correlation; however, a small difference in the activity of carbon in the high-temperature range of the austenite field is evident. Excellent agreement is found for the heat of solution of graphite in infinitely dilute austenite; from this study the value is 10,550 cal as compared with Chipman's value of 10,680 cal. AS part of a program to study microsegregation in dendritic solidification of ternary Fe-C-Cr alloys, it was desirable to be able to describe the equilibria between austenite and liquid iron in Fe-C-Cr alloys. In this regard, it was necessary to correlate existing data on the activity of carbon in Fe-C austenite as a function of both temperature and composition. At that time, Chipman's analysis1 of the thermodynamics of binary Fe-C austenite was not available. It will be shown that this study and Chipman's study agree rather well throughout the stable austenite range of temperature and composition; however, some small differences appear at temperatures greater than the eutectic temperature. Benz and Elliott 2 presented isoactivity lines for austenite superimposed on their revised Fe-C phase diagram. Using an expression from Darken and Gury 3 representing Smith's4 activity data between 800" and 1000°C, they found that the activities extrapolated above 1000°C to the solidus did not agree with the activities determined from the corresponding liquidus compositions. It is the purpose of the following argument to reconcile carbon activity data of austenite with the activity in liquid Fe-C alloys as determined by Rist and Chipman. 5 In addition, a simple analytical expression is sought for computational convenience. ACTIVITY DATA OF CARBON IN ZRON Fig. 1 shows the activity of carbon in Fe-C austenite as determined by Smith, 4 Schenck and Kaiser, 6 Scheil et a1.,7 and Bungardt et al.' The lines are merely drawn to separate the data into the respective isotherms. These data are inadequate to determine the activity of carbon at temperatures greater than 1200°C. The activity coefficient in Fe-C liquid alloys was assumed by Rist and chipmans to obey the following

Jan 1, 1969

By Ernest L. Ohle

IN 1943 diamond drilling from the surface in an area 2 miles southwest of Leadwood, Mo., discovered a lead deposit of a markedly different character from the usual southeast Missouri type. Subsequent drilling of about 500 holes indicated several million tons of ore, and in 1950 a 701-ft vertical shaft was sunk into the orebody. This paper describes the geology, of this interesting occurrence insofar as it is known from the drilling and the small underground exposure at the bottom of the shaft. Geology The location of the Southeast. Missouri Lead Belt and of 'the Hayden Creek property are shown in Fig. 1. As shown here, there are two separate producing areas, one from which the larger tonnage has come, located near Bonne Terre, Flat River, Desloge, and Leadwood, and the other to the south around Fredericktown and including famous old Mine LaMotte. The best published description of Lead Belt geology is by Tarr.* In pre-Cambrian time in this cherty dolomites. Several of these formations may be found in direct contact with the pre-Cambrian as their deposition progressively overlapped the older rocks on the flanks of the igneous knobs and ridges. Immediately overlying the pre-Cambrian there is, not uncommonly, a thin basal conglomerate of granite or porphyry boulders, which is incorporated into the overlying sediments. Deposition of the lower part of the rock section was fairly continuous, and the Lamotte sometimes grades almost imperceptibly into the lower sandy Bonneterre. Since the sediments were deposited on an uneven floor, they tend to reflect the irregularities in that floor. Most of the steep dips found in the district, that is, dips in excess of 10°, are original dips and not caused by deformation. Such domelike structures in the sedimentary rocks around the igneous knobs have localized a considerable number of the orebodies in the district and particularly those in the Fredericktown area. Many of the larger orebodies, however, have no close relation to the pre-Cambrian topography. Most of the lead production has come from the lower 150 ft of the Bonneterre formation, where disseminated ore spreads laterally parallel to the bedding for great distances. Average stoping height is about 20 ft, but in a few places there are stopes over-175 ft high.

Jan 1, 1952

By C. H. Frick

Before presenting the main topic, as indicated by the title, this paper will give some of the high-spot history of the anthracite industry. Introduction The earliest recorded use of anthracite was in the year 1762, when a company of Connecticut pioneers discovered anthracite near the present city of Wilkes-Barre, Pennsylvania. In the early days of the industry, the coal was used only in large pieces, the smaller pieces being discarded to waste piles. As the output of the industry increased during the nineteenth century, uses were developed for somewhat smaller sizes down to and including pea coal. Early in the twentieth century, sizes smaller than pea, such as No. I and No. 2 buckwheat, were developed and used. Accumulations of piles from current mining operations were still increasing; that is, the smaller sizes were still being discarded. It was not until after World War I that preparation of the so-called steam sizes began commercially. This was largely No. 3 buckwheat, which is screened through a 3/16-in. round-hole screen and over a 3/32-in. or a 1/16-in. round-hole screen. Use of Smaller Sizes The earliest recorded experience in burning the small sizes of anthracite for steam production, other than in a previous small experiment, was in the year 1913, when a size known as "boiler fuel" was introduced—a mixture of rice and barley (No. 2 and No. 3 buckwheat). At that time, there was still no method known for burning the still smaller sizes. At the present time, various sizes down to and including No. 5 buckwheat are being prepared (Table I) from current mining and bank-reclaiming operations. The sizes of No. 4 and No. 5 buckwheat and smaller are generally being used for steam production in large boilers. The Pennsylvania Power and Light Co., following World War I, used 680,000 tons of anthracite per year, burned largely on stokers for production of steam, whereas for the year 1943 it used 1,940,000 tons of stoker sizes and 400,000 tons of smaller sizes for grinding and burning in pulverized form. This company has taken a very large part in the research and development of ways and means of burning these smaller sizes of anthracite, including the grinding of the very small sizes. This paper is particularly concerned with the latter feature.

Jan 1, 1949

By N. F. Schulz

The purpose of this investigation was to evaluate the effects of variables in equipment and procedure on tube test results. This information was then to be used to formulate specifications, preferably within the practical ranges of existing machines, for test procedures capable of yielding precise and meaningful data concerning the magnetic separation of any magnetite ore, regardless of its origin. A survey of current practice was conducted among laboratories using the Davis tube test. Many tube tests were performed to experimentally evaluate the variables most likely to affect test results. A simple method was then sought for adequately interpreting tube test results. The Davis magnetic tube concentrator is a laboratory machine designed to separate a small sample of pulverized magnetic iron ore into magnetic and non-magnetic fractions. It was developed in 1921 by mechanization of a test previously performed manually No significant changes have been made in the design of the apparatus since that time. The Davis magnetic tube test continues to serve as a practical basis for judging the amenability of an ore to magnetic separation and for controlling magnetic separation plant operations. The apparatus consists of an inclined cylindrical glass tube supported adjacent to closely spaced pointed poles of a powerful C-magnet. (Fig. 1). To conduct a tube test, a sample of suitably prepared ore is poured into the water-filled tube. With wash water flowing through, the tube is oscillated to gradually reject the non-magnetic and weakly magnetic ore particles until the desired degree of separation is attained. Both the magnetic concentrate and the tailings may be recovered for examination. MAGNETIC SEPARATION BY THE DAVIS TUBE Mechanical separation of a specified mineral component from an ore usually requires comminution to fine sizes for sufficient liberation. Some distinguish- ing property of the mineral is then exploited to sort the desired mineral particles from the gangue particles. The magnetic separation of iron ores is based on the fact that magnetite, Fe3O4, is strongly attracted by a magnetic field while the gangue minerals are not. Maghemite, ?-Fe2O3, which may occur in certain chemically processed ores, responds similarly to magnetite. The magnetic process is practical only when the loss of iron in the form of relatively nonmagnetic hematite, Fe2O3, goethite, Fe2O3.nH2O, or other iron mineral can be tolerated. In the Davis magnetic tube concentrator, magnetic attraction holds magnetically susceptible particles in a magnetic field. Forces due to gravity, inertia, and fluid-solid friction tend to remove the less susceptible particles from the field. The probability that a given middling particle will be rejected from the tube in a given period of time is an inverse function of its magnetite content, with some modification due to particle size and mineral specific gravities. The net result is that ore particles tend to be rejected in their order of increasing magnetite content, while the retained portion or magnetic concentrate increases in grade continuously during the process. MAGNETIC SEPARATION CHARACTERISTIC The magnetic separation characteristic or MSC of a magnetite ore is the correlation between concentrate

Jan 1, 1964

By J. W. Marx, R. H. Langenheim

The injection of heat-bearing fluids may offer a wider application to secondary and tertiary recovery from conventional oil reservoirs than inderground combustion since the process is more easily controlled and the reservoir requirements, in general, are less critical. In all cares, conduction heat losses to overburden and un-derburden will impose an economic limit upon the size of the area which can be swept out from any one injection point for any given set of conditions. The present report describes a method for c.rtin~ating thermal invasion rates, cumulative heated area, and theoretical economic limits for sustained hot-fluid injection at a constant rate into an idealized reservoir. Full allow-ance is made for non-productive reservoir heat losses. Required solutions can be obtained directly from the numerical tables given here, as soon as all operating conditions are specified, withou extensive mathematica1 ~nanipulation on the part of the user. The injection of a heat-bearing fluid into a reservoir is frequently proposed as a means of secondary or tertiary oil production. This form of thermal recovery may offer a wider application to conventional oil reservoirs than underground combustion since the process is more easily controlled and the reservoir requirements, in general, are less critical. Because of its large gross heat capacity, steam appears to be the most efficient heat injection medium, although mixtures of steam and other gases, hot water, hot oil and hot non-condensable gases also have been employed. Whatever the nature of the injection medium, economic evaluation of such thermal recovery processes will depend upon thermal invasion rates, or rates of productive reservoir heating, at any given time after the start of heat injection. In all cases, conduction heat losses to overburden and underburden will impose an economic limit upon the size of the area which can be swept out from any one injection point, for a given set of reservoir conditions, at any given heat injection rate. The present report describes a method for estimating thermal invasion rates, cumulative heated area and theoretical economic limits for sustained heat injection at a constant rate into an idealized reservoir, making full allowance for non-productive reservoir heat losses. Required solutions can be obtained directly from the nu- merical tables given here, as soon as all operating conditions are specified, without extensive mathematical manipulation. It should be noted that ordinary water flooding may be used to move an annular-heated zone outward, even though the economic areal limit for straight heat injection has been reached. Thus well spacing need not be confined to the areal limits as determined here. However, the present calculations do not cover such supplementary heat scavenging programs. The operating element consists of a radial flow system, concentric about the point of injection, with the idealized step function temperature profile illustrated by the dashed line in Fig. 1. The solid curve shown in Fig. 1 gives a qualitative picture of the true radial temperature distribution. It will be shown later that the expressions given below, which are derived from the simplifying step idealization (dashed line in Fig. I), also can be interpreted in terms of the more realistic temperature distribution shown in Fig. 2. For this case, the thermal invasion radius is simply redefined as the distance from injection well to the mid-point of the temperature distribution.

By C. Y Garber

Interest in the sink-float plant operated by the Bunker Hill and Sullivan Mining and Concentrating Co. at Kellogg, Idaho, has recently been largely confined to the preparation and reconditioning of the galena medium. The ease and simplicity of these operations in a concentrating mill producing a flotation lead concentrate has occasioned enough comment to possibly justify a brief description. The subject is treated from an operator's viewpoint only; no effort is made to discuss it in a theoretical or technical manner. Plant at Bunker Hill The sink-float plant was first operated in December 1941. It was built for the purpose of quickly increasing mill capacity with a minimum of equipment. It is the Huntington-Heberlein sink and float process using galena medium and is operated under license from the Sink and Float Corporation, New York city. Lead-zinc ore from the Bunker Hill mine is crushed to pass a 1¼ in, screen and is then washed and separated on vibrating screens having 4½-mm. round-hole punched plates. The screen under-size, amounting to 33 per cent of the mill feed, is dewatered and sent to the ball-mill feed bins. The screen oversize goes to the sink-float plant, where 50 per cent of the oversize, or 33 per cent of the mill feed, is float, which is washed free of medium and disposed of as a tailing. The remaining 33 per cent is sink, which, after washing, is crushed to pass 36 in. and joins the under-size in the ball-mill feed bins. The normal plant capacity is 1700 tons per 24 hr. About 1.7 per cent of the total lead and 3.3 per cent of the total zinc in the feed is lost with the sink-float tailings (Table I). More complete descriptions of the H. H. process and Bunker Hill sink-float plant are given in several recent articles, listed at the end of the paper. Preparation OF Medium at Bunker Hill New medium is made intermittently as needed, usually 12 hr. in each 6 days. A small portion of the current mill flotation concentrate is diverted from the lead cleaner cells to a I-in. vertical sand pump and pumped to a two-cell 36-in. Agitair flotation machine, where NaCn and ZnSO4 are added and the grade of concentrate is improved as shown in Table 2. Tailing from this operation is returned by gravity

Jan 1, 1947

By C. Y. Garber

Interest in the sink-float plant operated by the Bunker Hill and Sullivan Mining and Concentrating Co. at Kellogg, Idaho, has recently been largely confined to the preparation and reconditioning of the galena medium. The ease and simplicity of these operations in a concentrating mill producing a flotation lead concentrate has occasioned enough comment to possibly justify a brief description. The subject is treated from an operator's viewpoint only; no effort is made to discuss it in a theoretical or technical manner. Plant at Bunker Hill The sink-float plant was first operated in December 1941. It was built for the purpose of quickly increasing mill capacity with a minimum of equipment. It is the Huntington-Heberlein sink and float process using galena medium and is operated under license from the Sink and Float Corporation, New York city. Lead-zinc ore from the Bunker Hill mine is crushed to pass a 1¼ in, screen and is then washed and separated on vibrating screens having 4½-mm. round-hole punched plates. The screen under-size, amounting to 33 per cent of the mill feed, is dewatered and sent to the ball-mill feed bins. The screen oversize goes to the sink-float plant, where 50 per cent of the oversize, or 33 per cent of the mill feed, is float, which is washed free of medium and disposed of as a tailing. The remaining 33 per cent is sink, which, after washing, is crushed to pass 36 in. and joins the under-size in the ball-mill feed bins. The normal plant capacity is 1700 tons per 24 hr. About 1.7 per cent of the total lead and 3.3 per cent of the total zinc in the feed is lost with the sink-float tailings (Table I). More complete descriptions of the H. H. process and Bunker Hill sink-float plant are given in several recent articles, listed at the end of the paper. Preparation OF Medium at Bunker Hill New medium is made intermittently as needed, usually 12 hr. in each 6 days. A small portion of the current mill flotation concentrate is diverted from the lead cleaner cells to a I-in. vertical sand pump and pumped to a two-cell 36-in. Agitair flotation machine, where NaCn and ZnSO4 are added and the grade of concentrate is improved as shown in Table 2. Tailing from this operation is returned by gravity

Jan 1, 1947

By Clarence Zener

The heat-treatment of steels will not pass from the stage of an art into that of a science until the mechanism of the phase transformations associated therewith is thoroughly understood. Such an understanding will involve two distinct types of inquiry: (I) the direction of the transformation, (2) the speed of the transformation. The first type of inquiry, which involves only the equilibrium relations between the various phases in steel, is the subject of the present and of a succeeding article; the second type, which involves the kinetics of transformations, will be the subject of a later article. In order that a theory of equilibrium relations may give useful information, certain experimental data must be put into the theory. It is customary for these data to be of a thermal nature. In the system discussed herein—steel—such thermal data are very scarce. In medium-alloy steels another type of data might possibly be used. In these steels the concentration of solute is so low that it may be possible to use the approximation of dilute solutions, an approximation that leads to linear relationships. The unknown functions, or constants, may then be determined in some cases from the binary iron-alloy system and in other cases from the ternary iron-carbon-alloy system. From the functions, or constants, so determined may then be computed the equilibrium relations in more complex medium-alloy steels. In the present article this second approach is used, the necessary experimental data 'being obtained from the simple binary and ternary equilibrium diagrams. Fundamental Equations In this article are derived the equilibrium relations between the gamma, alpha and cementite phases. In these three phases all important alloying elements except carbon form substitutional solutions, each alloying atom occupying a potential site for an iron atom. Carbon, on the other hand, forms an interstitial solution. In the face-centered cubic gamma phase, the interstitial positions are at the center of the unit cube and at the centers of the cube edges. There are therefore four interstitial positions per unit cell, or one per iron atom. In the body-centered cubic alpha phase, the interstitial positions are probably at the face centers, and also at the centers of the edges, which are crystallographically equivalent to the face centers. There are therefore six interstitial positions per unit cube, or three per iron atom. In cementite, (Fe, Alloy)3C, the carbon atoms may. be regarded as filling all the lattice positions of a given type. The introduction of the fundamental the of equilibrium has presented the author with a quandary. These equations are formally so similar to other equations that have been derived1,2 for related systems that they may appear to some readers

Jan 1, 1947

By Clarence Zener

The heat-treatment of steels will not pass from the stage of an art into that of a science until the mechanism of the phase transformations associated therewith is thoroughly understood. Such an understanding will involve two distinct types of inquiry: (I) the direction of the transformation, (2) the speed of the transformation. The first type of inquiry, which involves only the equilibrium relations between the various phases in steel, is the subject of the present and of a succeeding article; the second type, which involves the kinetics of transformations, will be the subject of a later article. In order that a theory of equilibrium relations may give useful information, certain experimental data must be put into the theory. It is customary for these data to be of a thermal nature. In the system discussed herein—steel—such thermal data are very scarce. In medium-alloy steels another type of data might possibly be used. In these steels the concentration of solute is so low that it may be possible to use the approximation of dilute solutions, an approximation that leads to linear relationships. The unknown functions, or constants, may then be determined in some cases from the binary iron-alloy system and in other cases from the ternary iron-carbon-alloy system. From the functions, or constants, so determined may then be computed the equilibrium relations in more complex medium-alloy steels. In the present article this second approach is used, the necessary experimental data 'being obtained from the simple binary and ternary equilibrium diagrams. Fundamental Equations In this article are derived the equilibrium relations between the gamma, alpha and cementite phases. In these three phases all important alloying elements except carbon form substitutional solutions, each alloying atom occupying a potential site for an iron atom. Carbon, on the other hand, forms an interstitial solution. In the face-centered cubic gamma phase, the interstitial positions are at the center of the unit cube and at the centers of the cube edges. There are therefore four interstitial positions per unit cell, or one per iron atom. In the body-centered cubic alpha phase, the interstitial positions are probably at the face centers, and also at the centers of the edges, which are crystallographically equivalent to the face centers. There are therefore six interstitial positions per unit cube, or three per iron atom. In cementite, (Fe, Alloy)3C, the carbon atoms may. be regarded as filling all the lattice positions of a given type. The introduction of the fundamental the of equilibrium has presented the author with a quandary. These equations are formally so similar to other equations that have been derived1,2 for related systems that they may appear to some readers

Jan 1, 1947

Anders Richard Akerman entered the eternal rest on Feb. 23, 1922, after a long and distinguished career. All mining men in Sweden arc mourning him, because he was one of their greatest and a leader in the scientific metallurgy of the iron. He was born April 18, 1837, in Stockholm, where his father, Joachim Akerman, was a professor at the Technical University, but the greater part of his childhood was spent in Falun, where the family moved after his father was made principal of the mining academy. He was at first taught by a tutor, but in 1851 entered the high school in Vesteras and the University of Uppsala in 1855, from which he graduated as a mining engineer on Dec. 11, 1860. A week later, he entered the service of the Department of Commerce and entered the mining academy at Falun, from which he graduated Dec. 15, 1862. The following May, he was accepted as a student in the metallurgical section of "Jernkontoret" (the "Iron Institute") and on Oct. 22, 1864, he was made an assistant in the same section. Thus begun the cooperation with the Iron Institute which was to continue for so many years and to bear such rich fruit. He had, however, previously received two requests from the Iron Institute: One to assist Prof. V. Eggertz in the preliminary work of preparing a handbook on blast-furnace practice, the other to make a complete index of the proceedings of the Iron Institute ("Jernkontorets Annaler") volumes 1817-1864, which index was published in 1866. On Oct. 19, 1865, Akerman was requested by "Jernkontoret" to give during 1866, lectures in the metallurgy of iron at the mining academy of Falun, as Prof. V. Eggertz wished to devote his entire time to the study of assaying. This request was renewed Oct. 15, 1867, for the year 1868, and on April 17, 1869, he was made instructor in metallurgy and mining at the Technical University, to which institution the higher education in mining engineering was transferred at that time. Akerman thus entered his career as a teacher, which lasted until the end of 1891. On May 11, 1877, he was appointed assistant professor in metallurgy and mining; on Sept. 7, 1883, he was appointed acting professor in the same department; and two weeks later was appointed dean of the mining college. On May 21, 1874, he was instructed by the Crown to inspect the mining schools in Filipstad and Falun. As a teacher, Akerman was very popular and his lectures were excellent, in form as well

Jan 1, 1922

Anders Richard Akerman entered the eternal rest on Feb. 23, 1922, after a long and distinguished career. All mining men in Sweden arc mourning him, because he was one of their greatest and a leader in the scientific metallurgy of the iron. He was born April 18, 1837, in Stockholm, where his father, Joachim Akerman, was a professor at the Technical University, but the greater part of his childhood was spent in Falun, where the family moved after his father was made principal of the mining academy. He was at first taught by a tutor, but in 1851 entered the high school in Vesteras and the University of Uppsala in 1855, from which he graduated as a mining engineer on Dec. 11, 1860. A week later, he entered the service of the Department of Commerce and entered the mining academy at Falun, from which he graduated Dec. 15, 1862. The following May, he was accepted as a student in the metallurgical section of "Jernkontoret" (the "Iron Institute") and on Oct. 22, 1864, he was made an assistant in the same section. Thus begun the cooperation with the Iron Institute which was to continue for so many years and to bear such rich fruit. He had, however, previously received two requests from the Iron Institute: One to assist Prof. V. Eggertz in the preliminary work of preparing a handbook on blast-furnace practice, the other to make a complete index of the proceedings of the Iron Institute ("Jernkontorets Annaler") volumes 1817-1864, which index was published in 1866. On Oct. 19, 1865, Akerman was requested by "Jernkontoret" to give during 1866, lectures in the metallurgy of iron at the mining academy of Falun, as Prof. V. Eggertz wished to devote his entire time to the study of assaying. This request was renewed Oct. 15, 1867, for the year 1868, and on April 17, 1869, he was made instructor in metallurgy and mining at the Technical University, to which institution the higher education in mining engineering was transferred at that time. Akerman thus entered his career as a teacher, which lasted until the end of 1891. On May 11, 1877, he was appointed assistant professor in metallurgy and mining; on Sept. 7, 1883, he was appointed acting professor in the same department; and two weeks later was appointed dean of the mining college. On May 21, 1874, he was instructed by the Crown to inspect the mining schools in Filipstad and Falun. As a teacher, Akerman was very popular and his lectures were excellent, in form as well

Jan 1, 1922

By Leon Dominian

Page I. Introduction......................237 11. Coal..................239 (a) Western Asia Minor.........239 I-. Lignites of the Marmora-Bgean zone.239 2. The Black Sea basin.............241 (b) Eastern Asia Minor..........244 (c) Syria................246 (d) Mesopotamia................ 246 (e) European Turkey.'.....'..... 247 111. Oil and Allied Hydrocarbons...............248 (a) Early Use of Oil and Bitumen in Turkey........248 (b) Syria........................ 250 (c) Mesopotamia.................... 250 (d) European Turkey.................. 256 I. INTRODUCTION Apart from local needs in the country's development, the interest attached to Turkish fuels grows chiefly out of the importance of the railway industry in Asiatic Turkey. Geographical conditions make of the tracks in this region the most essential link in a chain of world-girdling lines. By its position Asia Minor can be likened to a bridge in the through routes destined to connect European factories with Asiatic and African markets. An uninterrupted right-of-way from points in central Europe to populous Indian cities must necessarily pass through the valleys of Anatolia. Crossing thence the Taurus Mountains, its natural passage is indicated as the Mesopotamian lowland and the shores of the Indian Ocean. Similarly, land connection between Europe and Africa can be obtained only by passage through Asia Minor, Syria and Palestine. The occurrence of fuel within an area of such significance from the

Jan 1, 1917

By Charles O. Burgess

The improvement in the quality of cast iron by means of alloy additions has been a metallurgical accomplishment of recent years. Work in this field has shown that chromium is one of the most effective of such additions but, in general, the influence of chromium has been studied only in connection with other alloying additions, with irons other than foundry irons, or with relatively high percentages of chromium. The present study was initiated for the purpose of determining the influence of small additions of chromium (0.25 to 1.00 per cent) on the quality and resultant properties of cast irons of various foundry grades. The effect of small chromium additions on cast iron was investigated with particular reference to casting characteristics, hardness vs. section, strength, machinability, heat resistance and structure. Material Tested Three separate types of cast iron were investigated as to the effect of small chromium additions. The first series of these irons was prepared from remelted foundry cast iron at the Union Carbide and Carbon Research Laboratories, and the other two series consisted of cupola melts made under usual operating conditions. The first series was made by melting 30-lb. charges of foundry scrap iron containing 2.86 per cent carbon, 2.72 silicon, 0.50 manganese, 0.062 sulfur and 0.794 phosphorus in a carbon resistance furnace. The chromium was added as high-carbon ferrochrome just before pouring. The irons were cast at approximately 1250" C. (2282" F.). The analysis and physical properties of these irons are given in Table 1, test 1. The second set of cast irons was made in a cupola in accordance with normal practice, the charge containing approximately 42 per cent steel scrap and the chromium additions being made to the ladle. Analysis and tests of these heats are shown in Table 1, test 2. A small amount of copper was present in heat C of this series. Further data on the effect of chromium on strength were obtained from a third series of 13 cupola heats containing from 0.06 to 0.50 per cent chromium and made without steel additions. The heats were all

Jan 1, 1933

By Kendall E. Born

Production of crude oil in Tennessee during 1942 was approximately 8600 bbl., a decrease of 6500 bbl. from the production of 1941, and the lowest since 1934. As usual, the greater part of the production was from the Mississippian limestone pools in Scott and Morgan Counties. Some half dozen wells in Fentress and Clay Counties pumped intermittently produced about 1000 barrels. Natural gas was marketed from wells in Morgan and Fentress Counties for consumption in the Sunbright and Jamestown areas respectively. Figures are not available for the Morgan County production but 7,378,000 cu. ft. of natural gas was produced in the Jamestown gas field from six wells. The production of oil by counties is shown in Table I. Developments Drilling activities reached the lowest ebb since 1933. Only 10 wells were spudded during the year, one of which was drilling on Dec. 31, 1942. Of the nine completions, two were gas wells in the proven area south of Jamestown in Fentress County and seven were dry holes. The total footage drilled during the year was 14,198 ft.; the average depth of wells was 1578 ft. The completions are listed in Table 2. The distribution of tests according to physiographic divisions is given in Table 3. East Tennessee.—One well was drilled to 4219 ft., the second deepest well in the state, in Campbell County. The test was in the highly disturbed Valley and Ridge Province, an area long considered the most unfavorable in the state for the accumulation of oil and gas. Cumberland Plateau.-—There were no completions in the Cumberland Plateau area, although an old well drilled deeper found oil from 935 to 965 ft. in the Mississippi lime. This test has created a considerable amount of interest in the area and an active leasing campaign was underway early in 1943. Eastern Highland Rim.—Five completions on the Eastern Highland Rim brought in two small gas wells in Fentress County, which will be used to augment the supply for Jamestown. The producing horizons are shaly limestones of Ordovician (Trenton) age. Two wells in this area were drilled to the upper part of the Knox dolomite group. The most significant test during the year was the Stanolind Oil and Gas Company's test in Putnam County. This well, on a well-defined surface structure, was abandoned in the upper Knox dolomite group at 2130 ft. A show of oil was logged in the Knox at 1653 to 1661 ft. Northern Highland Rim.—Three tests widely separated in the Northern Highland Rim were dry.

Jan 1, 1943