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By T. Prof. Egleston

ALL industrial establishments whose operations depend upon chemical reactions use gases. In the simplest case the oxygen of the atmosphere, heated or not, as the case may be, is used, and in other cases, gases which are produced by a special apparatus of more or less complex composition. The manufacturer depends, for the success of his operations, entirely upon having these gases arrive at the right time, in the proper proportions, at the required temperature. It often requires but a slight variation in their composition to make a given process a success or a failure. In most cases the gas used is formed from fuel, and according as variations in its composition are produced by alterations in the manner of charging the grate, not only different, but often directly opposite, results are obtained. The great industrial question of the present time, and one upon which the prosperity of the world depends, is how to get the greatest amount of useful effect from fuel, whether the caloric is used directly or is transformed into horse-power. In almost all industrial pursuits this translates itself into the question of how to construct a fireplace and its adjuncts in such a way that the heat of the flame and of the products of combustion shall be made to produce a maximum effect. Unfortunately, until very recently, except by comparison, there was no means of ascertaining whether the loss of useful effect was 80, 40, or 20 per cent. of the total amount of fuel employed. It seems now strange that there should have been furnaces so constructed as to produce 20 per cent. of carbonic acid in the fireplace, but this has been proved by analysis to have been true. It does seem incredible that, notwithstanding the immense number and variety of furnaces used for different processes, and the great difference in kind, quality, and quantity of fuels consumed, there should formerly have been used for them all, the same stereotyped fireplace, varied only in its dimensions of height, length, and breadth. It is true that, with a good fireman, excellent effects may be, and have been, produced, but the manufacture is here, as in many other cases, dependent on the intelligence of the workman, a very uncertain reliance for capital to rest upon. The workman, unless he receives a prime for fuel saved, or is fined for excessive use of it, may be said

Jan 1, 1874

By C. A. Heberlein

INTRODUCTION THE present war in Europe seems to have stimulated the demand for quicksilver. In July last, the price ranged around $35 per flask of 75 lb., while to-day it seems to fluctuate between $47.50 and $50. The use of quicksilver in the form of fulminate, containing 70 per cent., and as corrosive sublimate, containing 73.8 per cent., must be extensive and a further market advance may be expected. With such an advance, some revival in quicksilver mining maybe looked for, particularly in California, where many abandoned properties exist. What can be done with low-grade quicksilver ores under favorable conditions, particularly with low mining cost, may be seen from the following description of the Oceanic mine, near. San Luis Obispo, Cal. Its operations date back to 1876, when rich sand ores were discovered. In three years 7,400 flasks of quick-silver were produced, but since then the deposit has been only sporadically worked. Until two years ago various attempts had been made by the Oceanic Quicksilver Co. to mine the more refractory "mud rock," which was encountered lying beyond the "sand rock." Mud and sand rock in varying quantities were treated together with poor results, but operations were successful with sand rock of fair percentage. About two years ago,, when all the sand rock had been exhausted, Murray Innes purchased the Oceanic mine. He found large quantities of low-grade mud rock, varying from 6 to 8 lb. of quicksilver per ton, which at the prevailing low price of quick-silver demanded very cheap mining costs, in conjunction with high but cheap metallurgical extraction. At that time the extraction of quicksilver from mud rock ranged between 40 and 50 per cent., as far as I am able to, learn.

Jan 2, 1915

By Donald W. Barnett

U.S. environmentalists have tended to oppose all new energy developments. Their efforts may be counterproductive because opposition to, say, offshore oil directly leads to the continued use of other energy sources that may have a higher social cost. Rather than attempting to eliminate all pollution from energy production, which would be prohibitively expensive, one should minimize the social cost of energy production for the given demand. Linear programming is used to rank various oils (California State and O.C.S., Gulf of Alaska, Prudhoe Bay, Athabasca tar sands, oil shale and certain foreign crudes) in terms of their social desirability. The objective is to minimize the cost of supplying the California market, subject to resource, sulphur and oil spill constraints. Social desirability is indicated by the inclusion of the oil in the optimal solution and the size of the associated shadow price. the larger the shadow price, the greater the benefits of increased production. The more negative, the greater the cost associated with forcing consumption of that fuel. The environmental shadow prices indicate the size of the trade-off between a particular environmental standard and minimum cost. The trade-offs can be surprisingly large. any reasonable spill standard can be achieved by changing the development pattern. Generally, the further offshore, the smaller is the environmental degradation, but the more expensive is the oil. Foreign oils can be economically and environmentally inferior to domestic oils. Crude from the California O.C.S., San Joaquin Valley end Prudhoe Bay appears a valuable resource, while the Gulf of Alaska, synthetic and foreign crudes appear marginal to submarginal.

Jan 1, 1977

By Theodore H. Eyde

The porphyry-copper province of southwestern United States and northern Mexico constitutes the largest copper-producing region in the world. More than 20 deposits discovered since World War II are being exploited or in the process of exploration and development. Because of the remarkable success in discovering new deposits, exploration activity continues at a very high rate and deeper targets are explored each year. Exploration programs for deeply buried porphyry-copper deposits require a reevaluation of the conventional exploration techniques. Though surface induced-polarization techniques have about reached their practical detection limit, aeromagnetics will play an increasing role in the exploration activity as will downhole logging tools. In addition to a valid geological concept, any successful exploration program for porphyry-copper deposits in the southwest must have two other essential ingredients: money and guts. Unfortunately many exploration programs in the southwest are underfunded and doomed to failure. Future exploration will demand more joint venturing in which larger and more expensive exploration programs can be successfully funded by groups of companies or syndicates.

Jan 1, 1975

By Basil B. Zavoico

The developments in the Russian oil industry during 1935 marked a very definite turning point from the time when the industry was being educated to the modern methods of oil-field finding and development, refining, transportation and marketing, to the time when the industry has thoroughly assimilated the modern technique and is now firmly standing on its own feet, as is shown by the remarkable qualitative, if not quantitative, progress in 1935. The oil industry promises that 1936 will be a record year in every respect with both quantity and quality approaching the desired high levels and standards. More particularly the Soviet Government is beginning to be successful in the development of new fields and such new production in geographically strategical points of the country will be in the coming years a factor of great importance in the industrial life of the country. The most notable achievements of the last year have been: the very successful development of the Ishimbaevo oil field in the Lower Oural-Permian Basin; the discovery and development of several promising oil fields in the Puta district of Azerbaijan, while large flush production of Baku area was extended 50 miles due southwest into the Saliani-Aliat district, where a 3000-bbl. well was completed early in 1936 at Pirsagat. Also, an apparently important discovery was made at Zikh, on the Apsheron Peninsula proper. These discoveries, as well as several important strikes in the deeper producing sands in the older fields of the Apsheron Peninsula, have greatly augmented the proven reserves of Russia and made them available either at the points where transportation facilities were already present or at points not too far distant from major industrial centers of the country. Of course, not all objectives were achieved during the past year, and several major difficulties remain to be solved in the coming years, the more important of which are: (1) supply of equipment and of parts; (2) the unavailability of competent technical men in sufficient numbers, which more particularly affects the distant fields; and (3) the problem of distribution of oil products throughout the country, especially the question of handling the needs of small consuming areas, which, while individually unimportant, in the aggregate require huge distribution.

Jan 1, 1936

By Basil B. Zavoico

The developments in the Russian oil industry during 1935 marked a very definite turning point from the time when the industry was being educated to the modern methods of oil-field finding and development, refining, transportation and marketing, to the time when the industry has thoroughly assimilated the modern technique and is now firmly standing on its own feet, as is shown by the remarkable qualitative, if not quantitative, progress in 1935. The oil industry promises that 1936 will be a record year in every respect with both quantity and quality approaching the desired high levels and standards. More particularly the Soviet Government is beginning to be successful in the development of new fields and such new production in geographically strategical points of the country will be in the coming years a factor of great importance in the industrial life of the country. The most notable achievements of the last year have been: the very successful development of the Ishimbaevo oil field in the Lower Oural-Permian Basin; the discovery and development of several promising oil fields in the Puta district of Azerbaijan, while large flush production of Baku area was extended 50 miles due southwest into the Saliani-Aliat district, where a 3000-bbl. well was completed early in 1936 at Pirsagat. Also, an apparently important discovery was made at Zikh, on the Apsheron Peninsula proper. These discoveries, as well as several important strikes in the deeper producing sands in the older fields of the Apsheron Peninsula, have greatly augmented the proven reserves of Russia and made them available either at the points where transportation facilities were already present or at points not too far distant from major industrial centers of the country. Of course, not all objectives were achieved during the past year, and several major difficulties remain to be solved in the coming years, the more important of which are: (1) supply of equipment and of parts; (2) the unavailability of competent technical men in sufficient numbers, which more particularly affects the distant fields; and (3) the problem of distribution of oil products throughout the country, especially the question of handling the needs of small consuming areas, which, while individually unimportant, in the aggregate require huge distribution.

Jan 1, 1936

By W. A. Turcotte, A. D. Paananen

Introduction The large reserve of fine grained oxidized iron-formation at the Tilden mine has been the object of research and development efforts to concentrate the iron oxides as far back as 1949. Due to the nonmagnetic nature of the ore and the fine grinding required to liberate the iron oxide minerals, this crude ore was not amenable to concentration by conventional methods. The iron oxides of the Tilden, ore body have a grain size of less than 25 microns and recovery of the finer, well-liberated iron oxides is essential. Conventional methods of desliming employing cyclones or thickeners were not feasible because of the excessive loss of iron oxides in the finer fractions. Development of selective flocculation-desliming was a key to commercialization of the process. Operations started in late 1974 with Algoma Steel Corp. Ltd., J & L Steel Corp., The Steel Company of Canada Ltd., Wheeling-Pittsburgh Steel Corp., Sharon Steel Corp., and The Cleveland-Cliffs Iron Co. as participants. Cleveland-Cliffs operates and manages the operation. Development of the Tilden Flowsheet The geology and ore reserves of the Tilden mine have been detailed in a paper by Villar and Dawe (1975). A joint program was undertaken in 1961 with the US Bureau of Mines in Minneapolis using the flowsheet developed by the Bureau employing the selective flocculation-desliming and calcium activated anionic silica flotation method (Frommer, et al, 1966; Frommer, 1964; Frommer, Wasson, and Veith, 1973). During this time, parallel testing at Cleveland-Cliffs Research Laboratory and Pilot Plant centered on the same type of desliming but was followed by the cationic flotation of silica with amine collectors (Columbo and Jacobs. 1976). The cationic silica flotation system was eventually chosen for its overall efficiency and simplicity. Regardless of the flotation method chosen, the technique of selective flocculation-desliming prior to flotation is the key to the success of the process. The flowsheet is described in detail by Villar and Dawe (1975). [Figure 1] shows a simplified one-line flowsheet of the Tilden concentrator. A total tailings thickener has been added to the original flowsheet and was placed in operation in 1978. The total-tailings thickener overflow reports to the reuse water pond and the underflow is pumped approximately 8 km (5 miles) to a storage basin. A flowsheet of the reuse water system is shown in [Fig. 2]. Selective Flocculation-Desliming Data have been published on the mechanisms and factors affecting selective flocculation in iron oxide-silica systems. The intent of this paper is not to discuss the theoretical aspects of selective flocculation, but rather to present experience gained from the commercial Tilden operation and from bench and pilot plant testing of fine-grained oxidized iron ores. From the bench and pilot plant testing prior to plant startup, certain reagent combinations and rates for the commercial Tilden plant were established. In the experience gained from three years of plant operation at Tilden, some of these reagent dosage rates have required significant adjustments due to changes in reuse water quality and to meet the requirements of varying ore types. Reuse Water The process water quality is a major concern at the Tilden mine and is constantly being monitored for selected chemical and physical characteristics. This monitoring has continued on a regular basis in order to gain a more thorough understanding of the interactions taking place in a dynamic water system and particularly as water quality is influenced by seasonal variations. Control of the reuse water chemistry is essential to the Tilden process both in the selective flocculation-desliming and flotation stages of concentration. With roughly 75% of the reuse water used in grinding-desliming operations, it is readily apparent that the biggest "reagent" in the selective flocculation-desliming process is water. Not enough can be said about the close control that must be exercised on the overall reuse water system. Control of the chemical treatment of the feed to the total tailings thickener is of utmost importance in order to produce a reuse water for the concentrator that is compatible with all stages of the concentrating process. There are many analyses made which aid in judging the quality of the water. Some of these are shown in [Table 1]. Five are particularly important and are monitored daily so that reagent adjustments can be made as required: suspended solids, calcium hardness, pH, dissolved silica concentration and temperature.

Jan 1, 1981

By B. Alexander, G. Derge W. Peifer

This is part of a research project in the Metals Research Laboratory of Carnegie Institute of Technology, sponsored by the Carnegie-Illinois Steel Corporation. In organizing our program it became apparent that the problem of analyzing molten steel for hydrogen must be divided into two parts: (I) the correct analysis of a given sample, and (2) the correct sampling of the bath. Emphasis has been placed upon these divisions in the order named because methods of sampling cannot be evaluated until a satisfactory method of analysis is available. Vacuum fusion was selected from the list of possible analytical methods because it seemed to us to offer the best possibilities for giving rapid, accurate results on solid steel samples. A number of objections have been raised against this method as usually practiced. We have sought to meet some of these by proper design of the apparatus. Experiments will be described which show that others are not valid. In the conventional apparatus the sample is held under high vacuum for a period of several hours before it is actually analyzed and one might expect considerable hydrogen to escape during this period. We have provided a means of introducing the sample to the vacuum just before analysis. Another difficulty has been that the entire apparatus has been designed primarily for the purpose of analyzing for oxygen, which constitutes upward of go per cent of the total gases evolved from the sample The volume and pressure measurements have therefore been insensitive to the relatively small amounts of hydrogen present. This difficulty obviously can be taken into account in any apparatus designed especially for the amounts of hydrogen expected. Analysis in Vacuum-fusion Apparatus A number of experiments were carried out to determine the importance of several factors that have been stated as possible sources of error or uncertainty in vacuum-fusion analysis for hydrogen; namely, that hot graphite will absorb some of the gases, that metal vapor will cause discrepancies, and that low results may be obtained as a result of the water vapor (produced by the oxidation of the hydrogen) dissolving in the butyl phthalate of the manometer, or that the blanks obtained from the apparatus are so great as to make the method inaccurate. The experiments also checked on the accuracy and feasibility of using differential freezing as a method of gas analysis in a vacuum-fusion apparatus.

Jan 1, 1945

By Arthur F. Taggart, T. C. Fitt, A. W. Thomas

IT was noticed early by operators that high recoveries and flocculation of the sulphide minerals were closely correlated in agitation-froth flotation. Later, this readily visible flocculation was found almost invariably to be due to the binding together of the oiled sulphides by minute air bubbles, and is now known to be characteristic of pulps in which at least one of the mineral species is coated with an insoluble collecting oil. In 1930 it was reported1 that in differential flotation a correlation exists between Brownian movement of particles in the pulp and their nonfloatability, and that Brownian movement and dispersion are likewise correlated, whence it would appear to follow that dispersion of a mineral particle in a flotation pulp denotes a particle condition unfavorable to flotation. In 1934 it was postulated2 that Brownian movement, dispersion and nonfloatability all flow from the condition of the surface of the dispersed particles. It was also postulated at that time that the surfaces of dispersed particles are ionized, the ionized compound being a product of reaction between a component of the particle and a. component of the pulp, of a mass solubility of the general order of a fraction of a milligram to 15 to 20 mg. per liter. It was then further asserted, and has since been confirmed by Bankoff,3 that sulphides so conditioned with soluble collectors as to be floatable flocculate without the intervention of air bubbles as binding media. The present paper comprises an inquiry into the nature of the bound and counter ions in zinc sulphide dispersed by sodium arsenate. A part of its findings was mentioned in the 1934 paper above cited.2 The tests show that: I. When powdered granular zinc sulphide is immersed in aqueous solutions of sodium arsenate, arsenate ion is abstracted from solution and anchored to the solid surface, while sulphate and lower sulphoxy ions are concurrently displaced therefrom in substantially stoichiometric quantities. 2. The ion counterbalancing the anchored arsenate ion is zinc. 3. Dispersion and Brownian movement of zinc sulphide are concurrently maxima at an arsenate-ion concentration lying between 0.01 and 0.001-molar sodium arsenate. 4. Any condition or reaction that tends to remove the zinc arsenate coating from the zinc sulphide particles decreases dispersion and Brownian movement concurrently. EXPERIMENTAL Three samples of zinc sulphide were used. Lot I was C.P. zinc sulphide, washed well beyond absence of chloride, as shown by test with silver ion. Lot 2 was prepared by precipita-

Jan 1, 1943

By J. B. Cheatham

An analysis of indexing is given for an idealized plastic rock. Indexing refers to chipping from a bit tooth to a previously formed crater. A method is indicated for computing the dependence of chip size and shape as well as force on the tooth for various tooth shapes as a function of crater configuration and distance to the previous crater. Pressure on the tooth is found to vary with depth of penetration after a critical depth has been reached. Damp sand model experiments indicate that simple solutions using linear and logarithmic spiral slip-line fields for Coulomb plastic materials give reasonable approximations to the failure patterns. Both idealized roller cone bits and fixed blade or drag bits are considered, and methods are presented for approximating the force on the bit and the chip volume when the rock is subjected to sufficiently high pressure to behave plastically. One of the primary objectives of drilling research investigations is to develop theoretical equations which can be used to predict the behavior of rock under drilling loading conditions. Since rocks usually fail in a brittle manner at atmospheric conditions, much current research is directed to studies of the brittle failure of rock under the action of drilling too1s. 1,2 The results of triaxial test on rocks indicate that both rock strength and ductility increase at high confining pressures.3 Recent results from single bit-tooth indentation experiments on dry rocks indicate that the transition from brittle to ductile failure under a bit tooth can occur at pressures sufficiently low to be of interest in oil well drilling.4 Single bit tooth experiments and analyses are not directly applicable to the drilling process since one of the important facets in drilling is the interaction between a bit-tooth and the previously formed crater. This interaction is referred to as indexing.' The purpose of the present paper is to indicate how plasticity theory can be applied to the analysis of indexing for plastic rock. Drag bit or fixed-blade drilling is considered and a discussion is given of the drilling action of an idealized roller cone bit. Results of simple experimental studies using a damp sand model are given as a method of visualizing the failure patterns in rocks under high confining pressures. These results are compared with plasticity theory using simple solutions based on linear and logarithmic spiral slip-lines. Discontinuous stress fields are proposed for drag bit drilling based upon the soil mechanics analysis of Shields. SINGLE BIT TOOTH RESULTS Single bit tooth indentation experiments using dry rocks under pressures from 0 to 5000 psi have indicated a correlation between the shape of a force-displacement curve and the nature of the rock failure beneath the tool.4 Continuous linear curves are in-

Jan 1, 1965

By J. R. Lucas, H. E. Rutherford

The primary objective of this research was to evaluate the feasibility of ultrasonic testing for the purpose of analyzing the structure and properties of rock material. A secondary objective of this study was to determine experimentally the elastic wnstants of various rock specimens with the use of ultrasonic equipment. Elastic constants can definitely be determined quickly and accurately by ultrasonic investigation. With proper equipment there are indications that ultrasonic waves could be utilized in the detection of flaws, such as fractures and planes of weakness, measurement of thickness, and the study of structure of rock material. Ultrasonic principles have been applied in many industries for the purpose of determining the structural characteristics of various materials. The principal applications of interest here are detecting flaws, measuring thicknesses, and determining elastic constants. The main advantage of ultrasonic analysis is that it is nondestructive. It also has extreme sensitivity, high penetrability, good accuracy, rapid response, and the necessity to have access to only one side of the specimen. These various applications and advantages lead one to think that ultrasonic principles might be applied to rock material in situ for purposes of analyzing its structural characteristics. Therefore, the primary objective of this research was to evaluate the feasibility of ultrasonic testing for the purpose of analyzing the structure and properties of rock material. A secondary objective of this research was to determine experimentally the elastic constants of various rock specimens with the use of ultrasonic equipment. The term ultrasonics is given to that branch of acoustics dealing with periodic sounds whose fre- quencies are above the audible range or above approximately 15,.000 to 20,000 cps. The first practical production of this high frequency sound was made possible after World War I due to developments of electronically controlled sound wave sources. At the present, the maximum practically attainable ultrasonic frequency is approximately 1000 megacycles per sec. Sound waves of sufficiently high frequency can be made to travel in a beam with little spreading. Therefore, such a beam can explore a material and detect nonhomogeneities in it by reflection. This is the principle of the ultrasonic reflectoscope invented by F. A. Firestone' in 1942. An ultrasonic beam, on pulse-penetratink a solid material medium, produces an echo when it strikes a flaw which has different acoustical properties than the surrounding medium. This echo can be detected by the same transducer which sends out the original pulse. This principle is the basis of the important industrial techniques of nondestructive ultrasonic testing of metals and other solid material. Later developments in the field of ultrasonic testing of solid material have been mostly improvements in equipment and instrumentation. To date, most of the industrial applications of ultrasonic analysis of solid bodies have been in the aircraft, electrical, and nuclear energy fields on the nondestructive testing of metal. The one solid material similar somewhat to rock material, upon which some work has been done to apply ultrasonic testing techniques to study structural integrity, is concrete. Jones and Gatfield3 briefly summarize this work on concrete. Their basic conclusion was that the strength of concrete was a function of the change of the longitudinal sound wave velocity in the concrete. Only recently has any extensive study been made to apply ultrasonic testing techniques to rock material. Lutsch studied rock material by an ultrasonic pulse method to determine the extent and degree of fracture of rock faces. Lutsch states that the number of observed reflections is a measure of the degree of fracture and that only ultrasonic waves are able to detect fractured zones subjected to high pressure. Suzuki, Sasaki, and Siohara5 studied the characteristics of the sonic wave in rock for propagation over a wide range of wave lengths. They indicated that, in rock, the propagation constant and attenuation of the

Jan 1, 1962

By Frank T. Wheby

The cost of tunneling is highly sensitive to the rock characteristics through which the tunnel is to be driven. These characteristics affect in a major way the rates at which tunnels and shafts can be driven and the degree to which the openings must be supported to maintain them in a permanent stable condition. Tunnel and shaft design and cost criteria have been computerized, permitting estimates of tunnel-shaft systems to be made directly from inputs of rock mechanics characteristics and other data. Curves of quantities of steel, rock bolts, and other rock support items as related to tunnel size and rock quality designation are presented. An illustrative example of the use of the program in calculating the cost of a hypothetical tunnel system is included.

Jan 1, 1971

By D. E. Marks, Arnold, C. W, R. J. Robinson, A. E. Hoffmann

The efficiency of operation of a fixed-bed adsorption unit is infEuenced both by the absolute adsorption capacity of the bed and by the rate of adsorption. This paper describer studies of adsorption rate which were conducted in an experimental unit designed such that conditions existing in the treatment of high-pressure natural-gas mixtures could be duplicated. Variables investigated included pressure, temperature, gas composition, adsorbent particle size, depth of packed bed and gas velocity. The adequacy of a simplified mathematical model for predicting the observed phenomena was tested. A correlation is preserited which relates adsorption rate to the process variables stlldied. This correlation is useful in combination with the matheinatical model. INTRODUCTION Of the techniques available for contacting adsorbent particles with fluid streams to be treated, fixed-bed adsorption columns offer definite advantages in simplicity and ease of operation. As a result, they are often used in preference to others for such petroleum industry applications as dehydration and purification of natural gas and hydrocarbon recovery. Fixed-bed adsorption units usually consist of two or more towers filled with a desired adsorbent and operated in a cyclic manner. While one is being used to process the main flow stream, the others are undergoing regeneration to remove the adsorbed phase. When the tower on stream becomes saturated with the preferentially adsorbed material, the roles of the towers are switched, and the freshly regenerated tower is placed on stream. Cacle duration is determined by the bed capacity under the process conditions and by the flow rate through the bed. The sharpness of separation which can be effected is a function of both the absolute capacity of the bed and the rate of adsorption in the bed. The effect of rate for a particular set of conditions is evidenced by the sharpness or diffuse-ness of the adsorption front as it advances through the bed. Since data needed for design of adsorption units to treat high-pressure natural-gas systems were not available, an experimental program was designed to investigate the effects of different variables upon adsorption rate in fixed beds. In the present paper, effects of gas composition, column length, temperature, pressure, adsorbent particle size and flow rate (actual linear flow rate of the gas) are shown, and utility of a simplified mathematical model for describing the process is discussed. As gas enters the top of a cool, clean bed of adsorbent, preferentially adsorbed materials are stripped from the main flow stream by the uppermost particle layers. As these layers become saturated with a particular component, new supplies of this component are carried further down the column until fresh adsorbent is encountered. An adsorption wave thus moves through the column as material is supplied to saturate succeeding elements of the bed. Adsorption from a Multicomponent gas stream occurs as a succession of such moving waves corresponding to the different components in the gas. The leading edge of an adsorption wave for a component of a natural-gas stream moving through a bed of a common commercial adsorbent such as silica gel would be sharp but for the influence of certain broadening fac tors. These factors include a nonuniform velocity profile in the bed, longitudinal dispersion or mixing in the main gas stream, and the time required for a molecule to migrate from the main gas stream and be adsorbed at a site within the body of an adsorbent particle. If packing is uniform and the ratio of column to particle diameter is greater than approximately 15:1, the first factor is relatively unimportant' Longitudinal mixing is of importance only for the case of moderately high mass transfer with extremely slow flow rates.' The sharpness of an adsorption front, therefore, is, primarily a function of the rate of adsorption or the time required to saturate a particle of zdsorbent. Two methods for defining adsorption rate are used in this work. The first is a normalized or relative rate which describes the rate of saturation of a differential element of the packed bed. This can be measured by observing the time required for the concentration of the preferentially adsorbed material in the effluent gas from the bed to rise from zero to a value equal to that in the inlet gas stream. The second definition describes the absolute rate of mass transfer from the gaseous to the adsorbed phase. This definition is used in a mathematical description of the adsorption process. If the concentration of a component in the gas strcam leaving an adsorption column is measured and plotted as a function of time, a curve such as that shown in Fig. I results. It is seen that for a period of time the effluent gas is devoid of the component under consideration. As the bed approaches saturation, a small percentage of this material will appear in the effluent gas. The concentration will then rise with time, or increasing cumulative gas flow, until it is equal to that in the inlet gas stream. If adsorp-

By R. D. Parker

LARGEST of any hoist installation ever manufactured in Canada is that being erected at No. 5 shaft, Creighton mine, of the Inter- national Nickel Company of Canada, Limited. It is a bicylindrical conical- drum hoist with the drums arranged in tandem, and driven by two direct- current motors through single reduction gearing. This hoist was designed by the Canadian Allis-Chalmers, Limited and manufactured at their works in Lachine, Quebec.

Jan 1, 1936

By Robert W. Phelps

It is gratifying to observe the growing interest in the study of oil-well spacing. It should always be held in mind that the problem of optimum spacing is to obtain the maximum return of capital per acre drained. This naturally evolves.into a mathematical consideration. As mathematics is the basis of all science, an effort should be made to develop formulas which involve data obtainable in the early stages of development. The first information from a discovery well in a new field would be the character of the sand, rate of initial production of oil and gas, viscosity of the oil, rock pressure, etc. Later, from this well, if Herold's theories of hydraulic, volumetric and capillary controls are accepted, could he determined the ultimate production as without interference from drainage by subsequent well completions, and under which control the well is producing. If it should prove to be producing under capillary control, a rough estimate could be made of it's radius of drainage. With but one well, the radius of drainage, or the interference of drainage of individual wells by close spacing, would be estimated by comparison with similar conditions in other fields in which the development has progressed sufficiently to furnish the data. A second well that is spaced sufficiently close so that an interference can he observed after its ultimate production is estimated, will furnish data to develop a desirable spacing of wells which can be inaugurated for that area and which is capable of producing a uniform amount of oil under like conditions. In some fields this area will be extensive, in others each well location will require an individual study. In 1924, Cutlerl developed a scheme whereby he determined by tabulation a spacing of oil wells for the maximum return per acre. After a study of production in a number of fields, he developed the following as a tentative rule: "The ultimate production for wells of equal size in the same pool where there is interference (shown by a difference in the, production decline curves for different spacing) seems approximately to vary directly as the square roots of the areas drained by the wells. This rule may also he stated thus: The recovery from wells of equal size

Jan 1, 1929

By Eric Hedburg

This paper was originally prepared as a picture of the situation presented by the mining industry referred to at the end of the year 1899; and some of the descriptions and drawings of special mines, etc., may not completely show their condition a year later. The statements made as to the cost of mining and concentration, however, still hold good. As to other general statements made in the paper, it is believed that the following additional facts cover all that is required to complete them for the additional year. The condition of the mining industry in the Joplin district was better at the close of 1900 than at any time during several preceding years. Values seemed to have adjusted themselves, in considerable degree, to the commercial and technical circumstances, the cost of mining-supplies of all kinds had returned to a normal basis, and the product of ore found a ready sale,

Jan 1, 1902

By Oliver Bowles

When a new type of equipment revolutionizes methods of quarrying one kind of stone, producers of other kinds focus their attention on its potentialities in their particular fields. The purpose of this paper is to discuss the accomplishments of the wire saw in slate, to show its more limited attainments in other kinds of stone, and to point out the possibilities of much wider application. A wire saw consists of a 3/16-in. or ji-in. three-strand wire cable that runs as a belt and cuts the rock by abrasion. (Fig. 1. The teeth of the saw are sand grains carried in the grooves between the strands. Accomplishments in Slate† Initial experiments with wire saws by the U. S. Bureau of Mines in the Colonial Slate Quarry, Wind Gap, Pa., in 1926, attained success so immediate and pronounced that within two years in virtually every quarry in the neighborhood of Wind Gap, Pen Argyl and Bangor, the most productive slate area in the United States, wire saws were substituted for channeling machines. An 80-ft. cut in slate is shown in Fig. 2. The technique of operation has been described in several reports (references at the end of the paper). The present purpose is to summarize the accomplishments in a large, typical slate quarry after nine. years of experience. Parsons Bros. Slate Co., at Pen Argyl, Pa., substituted two wire saws for six channeling machines in 1927. The following comparisons are made between the present method with wire saws and the former channel-ing-machine method. Rate of Sawing.—The average rate of cutting with a wire saw in the early days of its operation, as determined by the Bureau of Mines', wits 14 to 17 sq. ft. per hour. Parsons Bros. Slate Co. estimates the present rate of cutting at about 25 sq. ft. an hour, whereas the channeling-rnarhirle

Jan 1, 1938

By Oliver Bowles

When a new type of equipment revolutionizes methods of quarrying one kind of stone, producers of other kinds focus their attention on its potentialities in their particular fields. The purpose of this paper is to discuss the accomplishments of the wire saw in slate, to show its more limited attainments in other kinds of stone, and to point out the possibilities of much wider application. A wire saw consists of a 3/16-in. or ji-in. three-strand wire cable that runs as a belt and cuts the rock by abrasion. (Fig. 1. The teeth of the saw are sand grains carried in the grooves between the strands. Accomplishments in Slate† Initial experiments with wire saws by the U. S. Bureau of Mines in the Colonial Slate Quarry, Wind Gap, Pa., in 1926, attained success so immediate and pronounced that within two years in virtually every quarry in the neighborhood of Wind Gap, Pen Argyl and Bangor, the most productive slate area in the United States, wire saws were substituted for channeling machines. An 80-ft. cut in slate is shown in Fig. 2. The technique of operation has been described in several reports (references at the end of the paper). The present purpose is to summarize the accomplishments in a large, typical slate quarry after nine. years of experience. Parsons Bros. Slate Co., at Pen Argyl, Pa., substituted two wire saws for six channeling machines in 1927. The following comparisons are made between the present method with wire saws and the former channel-ing-machine method. Rate of Sawing.—The average rate of cutting with a wire saw in the early days of its operation, as determined by the Bureau of Mines', wits 14 to 17 sq. ft. per hour. Parsons Bros. Slate Co. estimates the present rate of cutting at about 25 sq. ft. an hour, whereas the channeling-rnarhirle

Jan 1, 1938

By Alan Morris

The investigation of the hot-working properties of metals and alloys furnishes a problem which has been attacked in many ways. Tensile, impact and hardness tests on heated specimens have furnished interesting data, but in most cases either the tests are difficult to make or the results hard to translate into terms of practical value. Some investigators have used the drop hammer to advantage. It furnishes a rapid and simple method of comparing the plasticity of metals at elevated temperatures. The indications obtained by its use are of value only in so far as their significance is understood and they can be intelligently used to predict the behavior of a given metal under given hot-working conditions. The work reported here was undertaken not only to add something to the existing volume of such data but also to contribute to our understanding of the results. Doerinckel and Trockels1 used cylindrical specimens and determined the work required to reduce the specimen to one-half the original height. Ellis2 studied the effect of constitution on the malleability of steel at high temperature. His method and that of Kent3 were similar to the one used in the present work. The tests described by Kent were made on samples of tin, zinc, aluminum, copper, lead, 70:30 and 60:40 brasses, with and without a small quantity of lead. He concluded that the test would "indicate whether a material can be forged at a given temperature without cracking." This interpretation must be used with caution. While it is probably true within limits, one must consider the severity of the forging operation. Again, it will not apply strictly to forms of hot working other than forging. For instance, an alloy running 61.0 per cent. copper, 3.25 per cent. lead, remainder zinc, will crack badly in the test, yet, it is extruded commercially. When the possibility of hot-working a new alloy is being considered a study of its drop-hammer test should help

Jan 1, 1931

By John Birkinbine

The press, trade publications, and special circulars, some elaborately illustrated, have been liberally employed within recent years in this country, to set forth the advantages of various locations as industrial centers, having as a basis the possibility of profitably producing pig-iron at these proposed centers: and special stress has been placed upon opportunities believed to exist at certain points for making iron of a quality suitable for the manufacture of Bessemer steel. The remarkable statements and prophecies made in some of these publications, have suggested the present paper, treating of the influence which location exerts upon the special industries named.

Jan 1, 1893