Search Documents

By W. O. Hotchkiss

An essential mental equipment for planning exploration is the fullest possible knowledge of the way in which the orebodies occur in the region to be explored, also the realization that in no mining district is this knowledge complete, and that new facts of importance will be revealed to the explorer in every exploration if he is in the proper frame of mind to grasp them. The geology of the ore deposits of the Gogebic Range for a long time was thought to be relatively simple, but work in recent years, by several men, has proved that this is not the case. We now realize that we are far from knowing all the factors that have resulted in the localization of ore deposits. For example, we have long known that the intersections of the dikes and the foot wall were favorable places to look for ore, but only within the last few years have we learned that there are several horizons in the various members, well north of the foot wall, that are likely to carry ore. The influence of the numerous cross faults on orebodies is not known or appreciated beyond a general realization that they are important. Just how they may be favorable or unfavorable to the localization of ore is not known. Such elementary information as the positions of these faults is just beginning to appear on the mine maps. Such being the condition, one can hardly overestimate the importance to the various operators and fee owners of careful studies of conditions in their properties for the purpose of assuring themselves that they are not missing valuable ore—that they are doing all the exploration that their situation demands in order to secure maximum returns. Valuable ores have been missed in the past and will be missed in the future. Only with a complete knowledge of all the factors that have united to produce ore could anything else be expected. The purpose of this paper is to call attention to these facts briefly and to suggest a few of the principles that should guide effective exploration. The foremost principle is that the man who starts out with the idea that he knows all about the mine geology of the Gogebic Range is starting with a heavy handicap.

Jan 1, 1923

By Ernest Klepetko

A notable amount of fossil resin exists in many of the bituminous coal beds of Utah, The upper part of these show a marked concentration of resin, which occurs primarily in the fracture seams. In general, these seams are less than 1/8 in. thick, but it is not uncommon to find coal with areas as thick as 3/8 in. The resin is of the hard kauri variety, with coloration varying from deep blood red to lemon yellow and almost colorless. There is also an almost black variety, which is not readily soluble in the same solvents as the lighter colored resins. These resins are valuable for many industrial purposes. When refined, they are suitable for uses similar to those for which lac resins are usually employed. They are particularly desirable for preparing dielectric varnishes. They are also desirable in preparing printing inks, waterproofing agents, special synthetic rubbers and rubber cements, They are especially suitable as an admixture in synthetic rubbers and cements, as they supply the essential tackiness the synthetics lack. The following chemical trade characteristics' have been found by Inter-Chemical Co. research chemists in the refined resins: Specific gravity (melted)....... I. 03 -1.06 Acid number.................. 6-8 Softening point, mercury method 160°-165°C Iodine valus (Wijs)............ 140-150 Refractive index............... 1.544 Color (Hellige, 25 pct toluol)... 14 Molecular weight, average...... 732 purity, 99 + pct pure hydrocarbon "Unaffected by alkalies and resistant to one hour fusion with solid potassium hydroxide. Completely soluble in aliphatic and aromatic hydrocarbons. Insoluble in alcohols, ethyl acetate and other commonly used alcohols and esters. Compatible with natural and synthetic rubbers, chlorinated and cyclized rubbers, waxes, vegetable oils, mineral oils, rosin, ester gum, phenolic and modified phenolic resins and other natural and synthetic resins of like solvent solubility."* The recovery and refining of these fossil resins has been the subject of much research work and has intrigued many investigators. Broadly speaking, the problem involves separation of the resin from the coal into a very high-grade concentrate, and subsequent treatment of this concentrate to produce an acceptable refined resin for its various usages. Obviously it is also desirable to recover the residua] coal without excessive size degradation. The late W. D. Green, concentration engineer for Combined Metals Reduction CO., obtained U. S. Patent No. 1773997 for the recovery of resin from coal through

Jan 1, 1949

By C. H. Hewitt, J. T. Morgan

The Fry cocurrent in situ combustion project was carried out in a 3.3-acre portion of a lenticular body of Robinson sandstone of Lower Pennsylvanian age. This particular sand body is about 12,000 ft long and 3,500 ft wide; it varies in thickness from 0 to 55 ft, trends northeast-southwest, and occurs at depths between 880 and 936 ft. The reservoir is made lip of three distinct types of sandstone, each having characteristic reservoir properties. (See Table I.) Textural gradients, sedimentary structures, erosional basal contact, absence of marine fossils, and geometry of the sand body all indicate that the sandstone is of fluvial origin and part of an extensive complex of river-deposited sedirnents. Geographically oriented cores reveal that the direction of depositing currents was to the southwest, parallel with the sand-body trend. Directions of maximum pernleability also parallel the northeast-southwest trend. The layered nature of the sandstone reservoir and its directional properties have controlled the areal distribution of produced gas, the ignition behavior, and the vertical profile and horizontal extent of the conbustion zone. INTRODUCTION This paper is the first of a series of three papers that describe Marathon Oil Co.'s Fry in situ combustion test. This first paper contains the results of a detailed study of the geology and reservoir characteristics of the Robinson sandstone reservoir in which the Fry test was conducted. The second and third parts of this series report on the field operations' and performance. The geologic work reiated to cores cut through the combustion zone, and to the effect of reservoir properties on the combustion process is included in the third paper.' GEOLOGIC STUDY OF THE FRY RESERVOIR The close spacing of continuous cores in the Fry combustion site provided an unusual opportunity to study the details of distribution of lithology and reservoir properties within a petroleum reservoir. The objectives of the study were: 1. To determine the distribution of rock types within the Robinson sandstone in the Fry area; 2. To determine the relationship of porosity and permeability to rock properties and establish the distribution and homogeneity of reservoir properties; 3. To determine the origin of the Robinson reservoirs so that attempts could be made to predict the size, shape, distribution, extent and continuity of Robinson reservoirs; and 4. To determine what effects, if any, the reservoir rocks might have on the combustion process, so that the process might be better evaluated. AVAILABLE MATERIALS Continuous cores were cut from 14 wells in the vicinity of the Fry site. Ten of the cores are from within the 3.3-acre pattern; six of the 10 were cut prior to combustion, and four were cut through the combustion zone. Cores from the Emma Fry No. 15, Wampler 0-2 and Fry B wells (Figs. 1, 2 and 9) were geographically oriented by the Eastman Oil Well Survey Co. Maps, electric

Jan 1, 1966

By J. D. Forrester, Erich Sarapuu, T. C. Cheasley

RANKING high in the nation's wealth of natural resources, readily available liquid and gaseous hydrocarbons are nevertheless falling steadily in supply, while industrial requirements for hydro- carbon compounds are greater today than during the peak period of World War II. Theoretically, several processes will increase the future supply of liquid and gaseous fuels, but the practical application of these methods depends on two controlling factors: 1-that enough carbon- bearing material be available to warrant industrial exploitation, and 2-that the given process be physically, chemically, and economically applicable. With regard to the first factor, the Western Hemisphere is fortunately well supplied, see Table I.

Jan 9, 1954

By A. Heim, M. Gondouin

Invasion experiments were run on Berea sandstone cores to get laboratory measurements of resistivity and saturation profiles characteristic of water and oil sands invaded by mud filtrate. Injection rates were as low as 1.13 cm/D, and the cores were 30 to 36 in. long, cut parallel to the bedding planes. In the water-sand case, the resistivity profiles revealed the existence of an extensive transition zone between flushed and uncontaminated zones. In the linear geometry of the experiment, the width of the transition zone increased as the square root of the injected fluid volume. For the oil-sand case the core was prepared by displacing the formation water with kerosene to minimum water saturation. During the subsequent invasion experiment. oil saturation was measured directly by means of an oil-soluble radioactive tracer, and resistivity profiles along the core were taken at the same time. These data were interpreted in terms of an oil-water front, followed by a formation water bank, a zone of mixed waters, and finally, invaded mud filtrate near the borehole. Micro-fingering and capillarity seemed to affect considerably the resistivity profiles observed in the invaded oil-sand experiment. Beyond the regular conductive annulus or "low zone", it was found that a resistive "anti-annulus" could also be formed. As a result of these experiments, some simplified invasion profiles have been accepted and are being used in Grand Slam* interpretations. INTRODUCTION The importance of the mud filtrate-invaded zone in interpreting electrical logs has long been recognized.',* In trying to account for its effect, only very simple models of the resistivity profiles in the radial direction from the borehole have been used. In fact, most log interpretation charts have been based on resistivity models consisiting of two media of uniform resistivity (R, and R,) abruptly separated at the diameter of invasion. Such a clean separation of the media of different resistivities seems unrealistic, since flushing may not be perfect and may vary with radial distance into the formation.3** The nature of the transition zone, when it is within the radius of investigation of the surveying devices, may affect the log readings. Campbell and Martin' verified that a conductive annulus containing a high percentage of formation water may be formed when mud filtrate invades an oil-bearing sand. Interpretations which are to include the effect of such an annulus require the addition to the model of a conductive zone located at the outer rim of the invaded zone.' Using the Buckley-Leverett relations,6 aturation profiles may be derived, from which resistivity profiles can be calculated. Results of such computations by K. S. Kunz and J. H. Moran were given in a paper by Dumanoir. Tixier and Martin,7 and led to the construction of log interpretation charts which were based on a representation with three media of resistivities R, R0 and R1. Fig. 1 shows a schematic representation of a resistivity profile which includes an annulus. Campbell and Martin realized that, during the invasion of an oil sand, both capillarity and mixing would contribute to rounding of the profile shown in Fig. 1. Capillarity tends to draw some of the formation water from the annulus into the uncontaminated (Rt) zone, whereas mixing of the mud filtrate with formation water of the

Jan 1, 1965

By H. S. Munroe

THE native copper of Lake Superior occurs in the form of fine grains and scales, disseminated in small percentage through the copper-bearing rock ; and in large and small masses, from a few pounds to several hundred tons in weight. Formerly the bulk of the copper came from the mines of Ontonagon and Keweenaw counties, producing mass copper. At present these mines furnish less than one-tenth of the total product, and fully one-half of this is from a single mine. The masses are usually found irregularly distributed in nearly vertical fissure veins, and require much dead work in sinking, drifting, and stoping for their development. The risk and expense attending the working of these mines have made them, with few exceptions, anything but profitable. * Read at the Montreal meeting, September, 1880.

Jan 1, 1880

By Meissner, C. A.

THE tendency all over Europe, just as it is with us, is to go to the use of turbines for new construction or replacement of old steam or even gas engines. 'The lower construction cost and the lower operating cost, when they can have high steam temperatures and pressures, together with their efficiency, is the cause of this change to turbines, both high and low pressure. The present trend is to equip plants with modern, efficient steam boilers, turbines, etc., and gradually work into high-pressure superheated steam equipment to accomplish a saving. One company has just completed a 375 to 400 lb., 700 deg. superheated steam installation and turbo-blowers with this end in view. Some of our new steam plants are using 350 lb. working pressure.

Jan 1, 1928

By A. Gittens

In two recent papers stevens13,14 has compared the methods used by various investigators to calculate the contribution of grain boundary sliding to the total creep strain. In previous work Gittins15 has shown that the strain due to grain boundary sliding Egb may be estimated from the lateral, d, and vertical, v, displacements of a longitudinal marker line as it crosses a grain boundary. He obtained the formula, where nL is the number of grains per unit length measured on the specimens before creep, and \p and ?2 are, respectively, the angle between the grain boundary and the stress axis in the plane of the surface and normal to the surface (see Ref. 13, Fig. 1). The subscript L indicates that observations are made in a longitudinal direction parallel to the stress axis. It was generally found more convenient to measure the grain size of a specimen before creep; this was necessary to characterize the specimen. Stevens13,14 however prefers to define Egb in terms of NL, the number of grains per unit length after creep. Since nL - NL(l + €1) where cr is the total strain, Eq. 1 11 becomes The quantities d and ?, can be determined directly from the marker lines, while v and ?2 are found by sectioning normal to the surface. In the interior when symmetry considerations suggest that v = d and ?1 - ?2 the strain due to grain boundary sliding may be estimated from a suitable internal longitudinal marker line by the equation To determine cgb at the surface using either Eqs. |1| or [2] requires a large number of observations, particularly if many estimates of cgb are required, and also it is impossible to determine the variation of cgh with creep strain on the same specimen because the specimen must be sectioned to determine ?2. Gittins15 found that for a number of materials the sliding vectors d and v were related to each other so that provided one was measured the other could be estimated. Also during creep, grain boundaries tend to migrate to meet the surface at angles close to 90 deg,16 so that the term nL(v/tan?2)L was comparatively small when 4,- 90 deg. By determining the frequency distributions of ?2 on control specimens this term can be estimated without sectioning the creep specimen. In this way an empirical equation based on Eqs. |1| and |2| enables cgb to be determined with reasonable accuracy with fewer observations of the angles and sliding components. For B brass, the relationship between the sliding vectors indicated that ceb = 0.85nLVL . In Table I of Stevens paper this equation is stated to be incorrectly derived. However it should be pointed out that this is an empirical equation derived from Eq. |1|, based on a knowledge of the relationship between d and v and on the frequency distributions of ?1 and ?2 for a particular material under given experimental conditions. It was used only when these relationships were known, to reduce the number of observations required to estimate cb. Therefore the comment "derivation incorrect does not apply. Gittins did in fact make use of Eqs. |1| and 131. Author's Reply I must apologize to Dr. Gittins for the inadvertent misrepresentation of his work. Other slight errors in Table I have been pointed out to me. Langdon (No. 12 Table I), Gifkins (No. 7, Table I), and possibly other workers did not measure the number of boundaries per unit length after creep (A') but the corresponding quantity bejove creep (n). As Dr. Gittins points out, a completely analogous set of equations to those given in the paper can be derived by the same method: using the number of boundaries per unit length before instead of after creep. The basic equations corresponding to Eqs. [2] and 171 of the paper, from which all the others can be derived, are

Jan 1, 1968

By A. Hultgren

PAGE Outline of Progress of Knowledge and Theories about Gas Evolution in Steel Ingots, and Its Influence on Crystallization and Segregation 2 Object of Present Investigation 16 theoretical Discussion of Process of Solidification 17 Gas Given Off from Rimming Steel during Solidification 17 Equilibrium Diagram of the Iron-carbon-oxygen Alloys 19 Solidification of Pure Iron-carbon-oxygen Alloys 25 Solidification When Carbon Monoxide Is Given Off at Constant Pressure... 25 Solidification When Gas Evolution Is Suppressed 26 Schematic Application on Solidification of Rimming-steel Ingots 27 Influence of Manganese, Sulphur and Phosphorus 28 Experimental Work 30 Liquid Steel and the Mold Gas 30 Ingots Investigated and Methods Used 33 Ingot Structure 42 Structure of Rim Zone 42 Structure of Core 49 Structures Obtained under Special Conditions of Freezing 50 Distribution of Metalloids 55 Other Observations Made 60 General Discussion of Solidification Process 63 Condition of Liquid Steel before Casting 63 Rimming Period 70 Composition of Rim Zone 93 Freezing after Top Is Closed 96 Slag Inclusions and Ingot Scum 102 Reaction between Gas in Blowholes and Surrounding Solid Steel during Cooling 103 Summary 105 Appendix-Preparation and Etching of Ingot Sections 106 References 107 IN 1934, Jernkontoret (The Swedish Ironmasters' Association) appointed a committee for the study of the structure of rimming-steel ingots and the various phenomena associated with their solidification. The members of the committee, including those who have joined it later, have been: I. Bohm, B. D. Enlund, B. Kalling, M. Tigerschiöld, 1. Wohlfahrt and the authors. The present paper? is a somewhat

Jan 1, 1939

By Kenneth M. Ritchie

Mineral wool is a term applied to man-made fibers of silicate glass with useful properties resulting from their fibrous nature. In contrast with crystalline fibrous minerals such as asbestos, mineral wool fibers are amorphous, solid filaments produced by drawing from molten liquid and subsequent cooling. Chemically they are silicate glass with varying percentages of metallic oxides, especially those of aluminum, calcium, magnesium, iron, and in glass wool, sodium, potassium and boron. Other elements such as manganese, titanium, sulfur, etc., result from their presence in the raw materials used and are not purposely added. In the United States, mineral wool is a generic term and may be applied to rock, slag or glass wool. In Europe, glass silk and silicate cotton are products in the same category, but the term mineral wool is less commonly used. Current usage is to ignore the actual source and to differentiate products on a composition basis; thus rock and slag wools have about 35-45 pct of silica, while glass wool has 54 to 60 pct. Much mineral wool of slag origin is called "rock wool," and this practice is increasing, although wool made of slag from lead or copper refining is often referred to as "lead slag wool." Its greenish-gray to greenish-black dark color, due to 5-25 pct Fe (reported as FeO), distinguishes it from "white" wools made from iron, blast furnace slag containing only 1-2 pct FeO or Fe203. Most mineral wool is used for thermal insulation against heat and cold; sound absorption and isolation are probably the next most important uses. Both its thermal and acoustic values result primarily from the physical structure of the heterogeneous mixture of fibers and air which is the form in which the fibers are first obtained and handled. For this reason, within fairly wide limits, differences in chemical composition are relatively unimportant, and for most conventional applications all types are competitive in properties and value. Mineral wool intended for extreme conditions of high temperature, acid resistance and special purposes must have a chemical composition which will insure the desired properties. This may differ greatly from that of ordinary wools; for example one product approximately 98 pct Si02 and another consisting of 50 pct A1203 and 50 pct Si02 are produced and sold for high temperature service up to 2000°F or more. These are considerably more expensive to manufacture and their cost limits their use. Historical The manufacture of mineral wool consists fundamentally of a process which subjects molten material to shear and/or tensile forces that draw them into fibers. The liquids are cooled at a rate which solidifies them quickly. As a solid glass they are technically super-cooled liquids since they have no true melting point. The drawing out of glass into thin rods, filaments and tubes was known from very early times, and present day continuous production of glass filament for textiles was evolved gradually by adapting hand methods to automatic machinery. Rock and slag wool manufacture had a somewhat different development. Early explorers reported finding filamentous material

Jan 1, 1960

By Robert E. Wilson, J. K. Roberts

IN order to make clear the reasons for the basic importance of petroleum and natural gas in the world today, and the problems faced by our scientists and technologists in using efficiently these great natural resources and finding possible replacements for them, it will be necessary to present a brief discussion of hydrocarbon chemistry The most important use of petroleum products is as fuel, particularly for the various forms of the internal-combustion engine There are, of course, hundreds of thousands of chemical compounds that give off heat when they burn, that is, when they combine with the oxygen of the air If a capable chemist were assigned the problem of finding the ideal volatile liquid fuel for use in an engine, he would probably begin by referring to the tables that give the heats of combustion of the chemical elements Of all the ninety-odd elements, hydrogen shows up with by far the highest heat of combustion-about 52,000 British thermal units per pound Unfortunately, however, hydrogen is a very light gas, which can be liquefied only at very low temperatures To burn it as fuel in an automobile would require a balloon about as big as the car to hold the equivalent of a gallon of gasoline, or, the hydrogen could be compressed in heavy steel cylinders, but -this would require about 125 pounds of steel per pound of hydrogen. Obviously, then, hydrogen itself cannot be considered

Jan 1, 1947

By Thomas S. Lovering

Hot springs, geysers, steam-emanating fumaroles- these creatures of nature were until recently little more than geological curiosities, but today they are exciting the interest of engineers around the world for it has been shown that such hyperthermal areas can be profitably harnessed by man to provide heat and power for his communities. Although water from hot springs was used centuries ago to heat some Korean dwellings, is being used today by one-third of Iceland's population for similar purposes, and is finding industrial applications in New Zealand and elsewhere, the most dramatic use of geothermal energy has been its conversion into electricity. The largest installation at the present time is that at Larderello, Italy, where the Count of Larderello began to experiment in the production of electricity from geothermal steam in 1904. Eight years later after a quarrel with the local power company, the Count installed his first steam turbine, a unit of 250 kw capacity.

Jan 9, 1965

By John P. Bryant, Samuel Kincheloe

Plant nutrients are obtained by plants from both the air and the soil. Carbon dioxide, a gaseous form of carbon and oxygen, supplies the carbon which usually makes up 50% or more of plant structure. Plants are capable of absorbing carbon dioxide directly from the air. Most of this nutrient comes from the air, although some carbon dioxide is absorbed by soil water and taken into the plant as liquid. Growing plants use more water than any other substance. Plant nutrients in the soil dissolve in soil water; soil water entering the plant carries nutrients into the plant structure. Water is then given off into the air as the plant breathes or transpires. Inorganic or mineral nutrients essential to plants are supplied through the soil. Inorganic or mineral composition of plants usually is less than 5% of their weight. In most crop-growing areas, much of this nutrition is inadequately supplied from the soil and must be provided by fertilizers. Proper fertilization of a soil to improve its mineral level and productivity is the role of the fertilizer industry. The 13 essential plant nutrients which often must be added to soils or plants and are generally considered fertilizer minerals are categorized as primary minerals (nitrogen, phosphorus, and potassium); secondary minerals (calcium, magnesium, and sulfur); and micronutrients, or trace minerals (boron, iron, manganese, copper, zinc, molybdenum, and chlorine). These classifications are based on quantity of nutrients utilized by plants and have no implication as to function or degree of necessity. One point of major significance to the fertilizer industry is that not all nutrient carriers supply that nutrient in a chemical form which will be available to the plant. Thus, a product which may be considered a fertilizer mineral may require substantial processing or may require substantial processing or treatment before it becomes useful as a nutrient carrier. Fertilizer Industry Scope Until about 1900 demands for higher crop yields were met simply by bringing new agricultural lands into cultivation. Since that time great progress has been made in increasing yields through fertilization and improved varieties and cultural practices. The importance of the fertilizer industry to the economy and welfare of the US is widely recognized. Fig. 1 illustrates the relationship of lime and fertilizers to crop yields. In terms of tons of fertilizer products, the growth of the industry has been phenomenal, particularly between 1950 and 1980. Table 1 shows the increase in fertilizer usage. Primary Plant Nutrients in Fertilizers Primary minerals (nitrogen, phosphorus, and potassium) are designated as such because [ ]

Jan 1, 1983

By G. L. Kothny

DEVELOPMENTS of well-surveying instruments, coring and core orientation, were in an advanced state when drilling for oil began-these developments actually originated with the mining industry.1 Surveying of oil wells was not generally used in the United States until Alexander Anderson2 disclosed that the majority of wells drilled with rotary tools were crooked, with average horizontal drifts of about 516 ft. for holes 5000 ft. deep and about 793 ft. for holes 6000 ft. deep. This disclosure brought about the development of many additional instruments for surveying oil wells during the progress of drilling and after their completion. Surveying of boreholes, during the process of drilling at regular depth intervals, became a standard practice in the petroleum industry. Some producing states even established laws making check surveys mandatory, during drilling and under certain conditions also after completion. The surveying of boreholes also brought about changes and improvements in drilling practices. It provides information for the guidance of the hole while drilling, and for plotting the course as the work progresses, enabling the driller to take corrective measures immediately and with the least expense. The reasons for drilling straight holes are too well recognized to warrant any full discussion of them here. Straight holes are less costly to drill, because [ ] they reach the object on the shortest course. Table I shows the horizontal drift and loss in vertical depth for various angles of inclination. It is not surprising, therefore that many drilling contracts for oil wells today limit the drilling contractor to a maximum inclination off the vertical of 2° or 3°. In the mining industry the reasons for drilling straight holes are still more serious. A crooked hole may miss an ore body underground or provide incorrect information regarding an ore body. TYPES OF SURVEYING INSTRUMENTS The surveying instruments used in oil-well drilling may be classed in two types: I. Inclinometers, recording inclination only.

Jan 1, 1946

By C. J. Ramsburg

THE construction and operation of by-product coke-oven plants in America are essential to strong national defense and of the greatest importance to many widely diversified undertakings as well as to safety and health. CARBONIZATION PROCESS Coal used under a boiler or in a locomotive is consumed by combustion. Coal used in a by-product oven is distilled or carbonized, meaning that heat is applied to the coal, out of contact with air, causing a distillation that removes the volatile matter in the coal in the form of gas and vapor, leaving coke as a final product. From the gas and vapor distilled from the coal, many valuable substances can be secured, known as by-products. Hence the name "by-product oven." The simplest example of this principle can be shown by means of an ordinary clay pipe. If powdered coal is placed in the bowl of the pipe, the opening of the bowl is plugged with clay, and the bowl placed in a flame, the bowl will become hot, transferring the heat through the wall of the bowl to the coal within. When this coal attains a temperature of about 950°F., gas will begin to pour out of the pipe stem, and this gas may be lighted. A black liquid also will exude from the stem of the pipe. This is tar mixed with certain other products. What remains in the bowl after distillation is coke. A coke oven corresponds to the bowl of the pipe. A modern oven of the latest type is a refractory brick chamber approximately 42 ft. long and 14 ft. high, averaging 18 in. in width. The oven is filled with coal through closable charging holes in the oven top. Each end of the oven consists entirely of a self-sealing door, the removal of which permits the finished coke to be discharged by means of a power-operated pusher machine. The ovens are built in batteries, and the heating is effected by gas burned in vertical flues in the oven walls, each set of flues heating the walls of two adjacent ovens. Such ovens carbonize a charge of approximately 18 tons of coal in 18 hr., or have a daily throughput of 24 tons per oven, producing about I 7 tons of coke. In times of need, the output may be increased by raising the temperature of flues, thus shortening the coking time. There is one great essential difference in principle between distillation in a clay pipe and in a coke oven. In the 18-in. oven, the distillation proceeds from two parallel walls held at a high temperature (over 2000°F.) and instead of all the coal being heated at once, the distillation is a progressive one creeping inward. The average travel of this heating is 1/2 in. per hour from each vertical wall, and as the volatile products are formed progressively they must push away from the interior toward the wall through the previously formed hot coke, then up the walls and over the top of the coal charge, finally escaping through the outlet pipe. This results in a cracking of the components into many different and valuable substances not formed when the carbonizing temperature is low.

Jan 1, 1942

By Warden A. Moller

The Fushun coal-field, now being opened up by the South Manchurian Railway Co., is connected with the main line by a branch, 30 miles long, from Sui Chia Tun, 10 miles south of hlukden, the oapital of Manchuria. The coal-field, which lies on the southern bank of the Hun river, 25 miles east of Xiukden, consists of a long narrow valley, running east and west between hills composed of granitic and volcanic rocks. At the foot of the northern hills, the Hun river flows westward towards the Liao river, which drains the greater part of South Manchuria. At the foot of the southern hills, resting immediately upon volcanic rocks, and overlain by 30 ft. of alluvium, is a thick layer of Tertiary shales, carrying near the base two coal-seams. In many places the lower of these two seams is in immediate contact with volcanic lavas and basalts, the flows of which were evidently both prior and subsequent to the formation of the coal-seams. This contact has practically destroyed the lower seam for commercial purposes. The value of the field lies in the upper seam, which, for a length of nearly 8 miles, varies from 100 to 130 ft. thick. Of this seam, 85 per cent. is good coal. The seam dips to the north conformably with the shales, at angles of from 25 to 30°, and appears to have an uninterrupted dip for about 1.5 miles before being possibly cut oft' by the northern hills. The coal-bearing shales extend east and west for a length of about SO miles, but towards the east the continuity of the seams is broken by intrusive rocks. The coal is of the sub-bituminous variety, low in ash, bright in appearance, and breaks with a conchoidal fracture. It has the usual qualities of Tertiary coal—quick steam-raising and poor stacking qualities. Pieces of resin, varging in size from

Jan 1, 1911

By Joseph Pogue

OVER a period of years the writer has presented a number of studies1 on various aspects of proration, in a progressive attempt to analyze critically and constructively the economic complexities of this interesting institu-tion, which in a decade has revolutionized the economics of oil production in the United States. In the course of the investigations leading to these papers, the changing nature of proration and the principles under-lying its evolution have gradually become clear, so that it is now possible to depart from the analytical method and to construct a synthesis of the steps that, if furthered by the industry, should carry proration past the economic hazards that still surround it to the goal of maximizing the value of the petroleum resource to the industry and the public alike. NATURE OF PRORATION Proration literally means the allocation of demand among competing producers on a pro rata basis, but the term now carries a much broader significance for it is employed to describe the entire process by which the production of crude oil in the United States is regulated. There is naturally much confusion of thought on the subject, for proration is an evolving system of control based upon principles of conservation and equity and embracing a body of practices that are tending to adjust themselves to the needs of the situation but are subjected to varying and divergent influences in the process. As it is now constituted, proration is a planned production measure designed to prevent waste, insure ratable takings, and balance supply and demand. The procedure is administered by State regulatory bodies through use of the police power of the States under authority of State conservation laws; the practice is supported by a considerable degree of voluntary conformance on the part of operators; and the Federal Government has accorded its cooperation by providing advisory quotas, circumscribing imports, checking movements of hot

Jan 1, 1939

Jan 1, 1954

BUFFALO C E Moyer, Chairman (Buffalo, N Y I R M Jordan, Vice-Chairman H A Morlock, Secretary CHICAGO M E Nickel, Chairman (Chicago, Ill ) A M Kroner, Vice-Chairman W R McLain, Secretary-Treasurer

Jan 1, 1959

By S. H. Ward, R. A. Barker

THE Juniper Prospect is in Carleton County, N. B., at approximately 46º 31' north latitude, 67º 20' west longitude. During the summer of 1955 an area in west-central New Brunswick was selected for aerial electromagnetic prospecting with American Metal Co.'s helicopter-mounted equipment. Generalized, small-scale government geologic maps had suggested that this area was located along the western border of the northeast-trending granitic backbone of northwestern New Brunswick and might be underlain by the Ordovician-Silurian sediments and volcanics that are the host rocks for the recently discovered sulfide deposits of the Bathurst-Newcastle district.

Jan 1, 1958