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By C. A. Sobotowski, J. Eagan

Computer programs applicable to coal mining have been available for some time, especially in the academic sector. However, the computer has not routinely been applied to actual mining operations. This paper discusses how a computer system was set up as an important tool in mining design and decision making. The project was completed within the allotted timeframe of two months by taking advantage of existing technology. Key points include the selection of programs to meet the specified needs of the project, conversion of the programs to be compatible with a computer of a different manufacture, simplification of the data entry process, development of procedures for using these programs, and an explanation of how the reports generated from the programs were used for mine planning and decision making.

Jan 1, 1983

F. G. SMITH.-Probably someone will ask whether I discovered why the bottoms of the large shells broke out. I did not, as a result of this investigation. An experiment was made along the lines indicated in this paper, to determine whether abnormal grains greatly affected the physical properties of brass. Two ordinary test bars were annealed for 1/2 hr. at 750° C. and physical properties determined on one. The other was covered with indentations made with a peen hammer and then reannealed. for 5 hr. at 750° C. It was found in the tensile test to be made up of large grains 1/4 to 1/2 in. in diameter. The physical properties, however, differed from those of the first bar only as much as might be expected after a 5 hr. anneal under normal conditions. It appears then that the large grains produced in this manner do not ruin the physical qualities of the brass.

Jan 12, 1919

The separate outputs of Burma and India in 1937 were 274,664,365 gal. valued at £4,474,147 and 75,657,857 gal. valued at £1,030,591, respectively. The corresponding figures for the year 1938 were 263,823,-265 gal. valued at £3,766,810 and 87,082,371 gal. valued at £1,234,563, respectively, which is a slight increase in total quantities but a fall in value for the combined outputs of Burma and India. The appreciable increase from India in 1938 is due to an increase of over 11 million gallons from Attock and a little from Digboi, while the decrease from Burma is due to a fall of nearly 9 million gallons from Yenangyaung, over 3 million gallons from Yenangyat (and Lanywa) and half a million gallons from Minbu (Table 1). The 'amount' of gasoline produced from natural gas during the year 1938 was 10,587,291 gal. in Burma and 496,163 gal. in the Punjab.

Jan 1, 1940

The separate outputs of Burma and India in 1937 were 274,664,365 gal. valued at £4,474,147 and 75,657,857 gal. valued at £1,030,591, respectively. The corresponding figures for the year 1938 were 263,823,-265 gal. valued at £3,766,810 and 87,082,371 gal. valued at £1,234,563, respectively, which is a slight increase in total quantities but a fall in value for the combined outputs of Burma and India. The appreciable increase from India in 1938 is due to an increase of over 11 million gallons from Attock and a little from Digboi, while the decrease from Burma is due to a fall of nearly 9 million gallons from Yenangyaung, over 3 million gallons from Yenangyat (and Lanywa) and half a million gallons from Minbu (Table 1). The 'amount' of gasoline produced from natural gas during the year 1938 was 10,587,291 gal. in Burma and 496,163 gal. in the Punjab.

Jan 1, 1940

By N. Mao

This paper presents the results of a research effort to develop a technique for estimating in situ stresses by measuring stress-induced velocity anisotropy around a borehole. Relevant parameters required to make the estimate were identified and measured in the laboratory on a 35.6 cm (14.0 in) cube of Nugget sandstone with a 10.2 cm (4.0 in) diameter hole, under biaxial loading. Two pairs each of radially and tangentially polarized transducers were placed inside the hole with displacement directions either parallel or perpendicular to the principal stress directions. With this configuration, relative travel times were measured by both a pulsed phaselocked loop technique and a cross correlation of digitized waveforms. The biaxial velocity data were used to back-calculate the applied stress. The standard deviation of the differences between the calculated and applied stresses is 0.62 MPa (90 psi) for a stress level up to 8.63 MPa (1250 psi).

Jan 1, 1984

By U. C. Tainton

FOR the last 15 years lead has been the standard material for anodes in electrolytic zinc production and it has been generally accepted that this lead should be as free as possible from impurities. Laist1 says, "Next in importance to the purity of solution is the purity of the electrodes and tank lining material. The purest lead obtainable should be used for anodes." The same conclusion is expressed by Ingalls2 and by two German investigators who say that experiments have demonstrated that the purer the lead, the greater is its resistance to corrosion during electrolysis.3 Pure lead, however, while the best material hitherto available for anodes, is not entirely free from objection. The plain lead anode gradually disintegrates under electrolysis, so that the life of an anode, say ¼ in. thick, is frequently not more than two years. Part of the lead from the anode finds its way to the cathode, lowering the purity of the deposited zinc and decreasing the hydrogen overvoltage. The rest of the lead that comes from the disintegration of the anode goes into the manganese dioxide which is precipitated in the cells, rendering unsaleable what might otherwise be a valuable by-product. Yet a further disadvantage of plain lead anodes comes from their tendency to bend or buckle during electrolysis, as a result of intercrystalline oxidation. This makes it necessary to use a fairly wide spacing between anode and cathode to avoid short circuits, and thus leads to a higher power consumption than would otherwise be necessary. The power consumption is also affected by the high decomposition voltage at a lead peroxide surface.

Jan 1, 1929

By I. N. Knapp

Introduction.—The spccial object of these notes is to describe the mixing, testing, and use of mud-ladened water for rotary drilling in such a way as to make them helpful to the driller, the operator, or the engineer in solving his own special drilling problems. The structures, apparatus and tools used are indicated in a general way. No attempt is made to describe the art of rotary drilling; only such descriptions as are necessary to make plain the use of mud are given. The information is the result of actual experience in drilling in Coastal Plain formations. The materials encountered in the wells drilled were unconsolidated sands, gravels, and clays, in which thin layers of sandstones, shell conglomerates, and shales began to appear at about 1,200 ft, in depth, although one well was drilled to 3,018 ft. without encountering any cemented or indurated materials. Unusual Conditions.—-The general surface of the ground where the drilling was done being hardly a foot above mean tide, and the daily tidal variation being about 15 in., it was found necessary to plank over the sod surface with 3-in. plank to work from. A 30 by 30 ft. planked area was sufficient to carry the derrick with equipment and 2,500 ft. of 4-in. drill pipe stacked in it. The derrick was set up 3 ft. on cribbed blocking arranged to spread the load over the planking. The engine, bailers, and pipe yard were also carried on 3-in. planking. Drilling 0utfit.—This consisted of a derrick, 20 by 20 ft. and 84 ft. high, two 35-h.p., "oil country" boilers, one double 8 1/4 by 10 in. reversible engine, two 10 by 6 by 12 in. duplex mud pumps, one 15-in. rotary, "hoisting works" with chain drive, hoisting block with line, crown block with pulleys, rotary jetting swivels, hose, complement of tools, pipes and connections, and a mud mixer, with engine. Hydraulic Rotary Drilling Method.—This method of drilling is an adaptation of Fauvelle'sl invention made in France in 1833 for drilling

Jan 1, 1915

By Henry B. Smith, S. Paul Lindau

ThREe years ago it was decided by the management to granulate the matte that is produced in the smelter of the St. Joseph Lead Co. at Hereulaneum, Mo., thereby doing away with a large amount of labor in handling the matte and in subsequent crushing. On Mar. 1, 1915, the granulator was put in operation and up to Jan. 1, 1916, 18,735 tons had been granulated. The four blast furnaces have a daily output of about 280 tons of pig lead and 100 tons of matte assaying about 11.0 per cent. Pb. It is expected that projected improvements in roasting methods will eliminate more sulphur from the charge, and cut down the matte-fall to about one-half of the present figure. The blast furnaces are tapped into movable forehearths or settlers, 6 ft. by 4 ft. by 22 in., the slag overflowing into 27-cu. ft. slag cars which are hauled to the dump by electric locomotives. Previous to the adoption of granulation, the matte was tapped from the forehearths into small slag pots which were dumped after cooling. The matte cakes were broken with sledges, and transported to the crushing plant for fine crushing and screening. Here the matte was reduced to 1/4-in. size before being fed to the roaster bins. A Wedge and a Holthoff mechanical furnace are used for preroasting before sintering on the Dwight and Lloyd machines. The matte is returned to the furnaces as an iron flux until the gradually accumulating copper content reaches about 7 per cent., after which it is put aside to be concentrated in a small copper blast furnace, the resultant high-grade matte being sold. When the matte does not settle readily from the slag, two settling devices are often used, the second one being a large catch-pot, which gathers any matte that may overflow from the forehearth, the slag then overflowing from the catch-pot into the slag cars. When full of matte, the catch-pot is removed, allowed to cool, and the contents broken and crushed. a With the present plan of granulating, the matte is tapped into 6-cu. ft. iron ladles. These are transported to the granulating plant by a 5-ton

Jan 1, 1917

By B. H. Sage

AN apparatus is described for the measurement of the pressure-volume-temperature relations of pure substances, simple mixtures and complex mixtures with an over-all absolute uncertainty, which is usually not more than 0.2 per cent. The equipment is suitable for studies in the gaseous, two-phase, and liquid regions. The behavior of such systems may be investigated at pressures as high as 10,000 lb. per sq. in. for temperatures between 70° and 600° F. The methods of measurement and the construction of the apparatus are described in some detail. The measurement of the volumetric behavior of multicomponent systems requires the simultaneous measurement of the pressure, volume, temperature and weight of each component of the system. In the present apparatus a sample having constant weight is investigated at a number of independently controlled pressures and temperatures, there-fore it is necessary only to establish the weight of each component added before a given set of measurements. This method is in distinction to that in which the total volume remains constant and the pressure is varied by addition or removal of material, the system having variable weight. An objective in the design of the apparatus to be described was to develop equipment that would yield results involving no uncertainties larger than 0.25 per cent throughout the range of pressures from 150 to 10,000 lb. per sq. in. at temperatures between 70° and 600° F. Although this over-all absolute uncertainty of measurement may not appear to be small, it necessitated care in the plans for control and measurement of each of the fundamental variables. In general, any uncertainty greater than 0.05 per cent in the pressure, volume, absolute temperature or weight of each component was considered undesirable; therefore the attempt was made to obtain a precision of measurement in each case such that the absolute uncertainty would be only half this amount except in certain regions near the ends of the experimental range of the variable under consideration.

Jan 1, 1939

By Harlowe Hardinge

The sound made by ball, pebble and rod mills has long been used by the operator as the "telltale" of their operation. The nature of this sound depends upon local conditions and the type of mill used. By experience an operator can tell whether the mill is running properly or not. Some operators are able to detect the difference in sound much better than others and get better results running the same mill under the same conditions. The automatic operation of a mill using sound as the fundamental means for maintaining control presents many problems. The satisfactory solution of these problems requires, for given operating conditions, a greater average output, with improved product for subsequent processing, than can be obtained by manual control. Relation of Sound to Useful Grinding Energy Experience has taught us that there is a difference in character as well as in intensity of sound between a mill grinding wet and one grinding dry, in open or closed circuit, to obtain a coarse or fine product, on the same material, to say nothing of the effect with a variety of different materials. Broadly speaking, a wet-grinding mill operates best at a lower sound level than the same mill grinding dry, with other conditions the same. Several reasons for this variation in sound intensity under these conditions can be advanced, but the important point is that there is a difference, based upon practical results. Since these reasons may be more or less involved, and may be subject, to much discussion, only one will be considered here. It is apparent that two balls hitting together or a ball striking the lining, if there is no intervening material, will produce the maximum sound. If a complete cushion of material is placed between the balls or ball and liner, so that the energy is dissipated without doing useful work, the balls will be unable to create enough pressure or force to fracture the particles, and the sound will be at a minimum. At some point in between—that is, where there is sufficient material between the balls or ball and liner so that the ball will fracture the particles without mashing them unduly—the sound

Jan 1, 1939

By Harlowe Hardinge

The sound made by ball, pebble and rod mills has long been used by the operator as the "telltale" of their operation. The nature of this sound depends upon local conditions and the type of mill used. By experience an operator can tell whether the mill is running properly or not. Some operators are able to detect the difference in sound much better than others and get better results running the same mill under the same conditions. The automatic operation of a mill using sound as the fundamental means for maintaining control presents many problems. The satisfactory solution of these problems requires, for given operating conditions, a greater average output, with improved product for subsequent processing, than can be obtained by manual control. Relation of Sound to Useful Grinding Energy Experience has taught us that there is a difference in character as well as in intensity of sound between a mill grinding wet and one grinding dry, in open or closed circuit, to obtain a coarse or fine product, on the same material, to say nothing of the effect with a variety of different materials. Broadly speaking, a wet-grinding mill operates best at a lower sound level than the same mill grinding dry, with other conditions the same. Several reasons for this variation in sound intensity under these conditions can be advanced, but the important point is that there is a difference, based upon practical results. Since these reasons may be more or less involved, and may be subject, to much discussion, only one will be considered here. It is apparent that two balls hitting together or a ball striking the lining, if there is no intervening material, will produce the maximum sound. If a complete cushion of material is placed between the balls or ball and liner, so that the energy is dissipated without doing useful work, the balls will be unable to create enough pressure or force to fracture the particles, and the sound will be at a minimum. At some point in between—that is, where there is sufficient material between the balls or ball and liner so that the ball will fracture the particles without mashing them unduly—the sound

Jan 1, 1939

By Peter R. Morris, Alan J. Heckler

THREE angles are required to specify the orientation of a crystallite with respect to a physical reference frame. The distribution of crystallite orientations in a polycrystal is thus a function of three angular variables. The most widely used experimental techniques for studying orientation in polycrystals lead directly to the pole figure representation, i.e., the distribution of the poles of certain crystallographic planes in terms of two angular variables. In recent years1-5 methods have been developed which permit determination of the (three-angle) crystallite orientation distribution from several (two-angle) pole figure distributions. In this work Roe's method has been applied to the study of orientation in hcp materials. The method is illustrated for commercial purity titanium sheet (Ti-70) which was cold rolled (65 pct reduction), annealed at 1450°F for 3 min, and air cooled. The grain shape was observed to be equiaxed after this treatment. EFFECTS OF PHYSICAL, CRYSTALLOGRAPHIC SYMMETRY In Roe's method the crystallite orientation distribution, w(?,?,F), is expanded in a series of generalized spherical harmonics 11(?,?,F) = E E E W^Zirmtye-tote-in* [l] 1=o ,,,=-I ,,=-I where { = cos 8. The set of Euler angles employed here is illustrated in Fig. 1. The axis for each rotation is denoted by a double arrowhead. The positive sense of each rotation is that of a right-handed screw advancing in the direction of the double arrowhead. The X, Y, and Z directions correspond to the rolling direction, cross direction, and normal direction, respectively. In the initial orientation (10.O), (12.O), and (00 . 1) planes are perpendicular to the X, Y, and Z directions, respectively. The IC/ rotation about the Z axis is carried out first by rotating X into X', Y into Y', and leaving 2 unchanged, i.e., Z' = Z. The 8 rotation about the Y' axis is carried out second by rotating X' into X", 2' into Z", and leaving Y' unchanged, i.e., Y" = Y'. The I$ rotation about the Z" axis is carried out last by rotating X" into X"', Y into Y"', and leaving 2" unchanged, i.e., 2"' = 2". Any specified orientation of the X'", Y'", and Z'" crystal-fixed axis system relative to the X. Y, and Z physical axes (rolling direction, transverse direction, and sheet normal direction, respectively) can be obtained by appropriate IC/, 8, and (F rotations. The Zl,, of Eq. [l] are the Jacobi polynomials, augmented by the square root of the weight function. The Zl,, are symmetric in m,n, i.e., Zl,,= Zlnm. For orthotropic physical symmetry and hexagonal crystallographic symmetry, the coefficients, W!,,, of the series are all real, W!mn = Wzfi, = Wlm~ = Wlfi~, 1 and m are even and n is restricted to 6k, where k = ...,-2,-1, 0, 1, 2, .-.. The determination of the Wlmn from pole figure data has been previously described.'~~ The Zl,, may be written in multiple angle form

Jan 1, 1970

By C. A. Heiland

The Eötvös torsion balance permits the measurement of certain second derivatives of the gravity-potential, which are known as the gradients of gravity and the curvature values for an equipotential plane of gravity. These quantities are influenced on level ground by the configuration of the masses underneath. Hence, the torsion balance has gained great importance for the location of geological structures and thus indirectly for the discovery of oil and other mineral deposits. If the ground is not level, however, the measurements become more difficult, because the superficial mass-irregularities also produce more or less considerable disturbances. It is necessary, therefore, to determine the shape of the surrounding topography by leveling as well as by consulting topographic maps and to compute its influence upon the torsion balance. The correction thus determined is called, in general, the topographic correction; it is composed of two constituents, the terrain correction and the cartographic correction. The terrain correction would be that part of the topographic correction as derived from the direct leveling of the area surrounding the station, whereas the data for the computation of the cartographic correction are obtained from a topographic map, usually beginning with a radius of LOO meters, as under most circumstances it is difficult to level along a arger concentric circle about the station. Principle of Topographic Correction The principle of all topographic corrections is to assume a homogene-ous compositon of the masses around the station in regard to specific gravity as well as a mathematical shape of the topography. The results become the more accurate the closer this mathematical shape is to the actual configuration of the terrain, but naturally the amount of necessary computation also increases. If a standard correction with fixed dis-ances is adopted, the middle error of this method will, therefore, increase as the irregularity of the terrain. Hence, the application of the torsion balance in mountainous areas may be successful only if the disturbances due to heavy masses underneath the surface are so large as to exceed onsiderably the increased middle error due to rugged topography, or,

Jan 1, 1929

By F. L. Rip, B. C. Haydon

Manganese silver ores are well known to be refractory toward cyanidation. Roasting and sulfurous acid pre-leaching have been suggested for improving their amenability. This paper describes the development and implementation of the sulfurous acid pre-leach process for retreatment of manganese silver tailings at Tonopah, Nevada. The history of the material is summarized and the mineralogy is described. A brief review of an earlier application of sulfurous acid pre-leaching of a manganese silver ore is presented.

Jan 1, 1985

By M. F. Werneke, J. A. Jones

The use of a unique class of sulfhydryl collectors, the monoalkyldithiocarbamate salts (RNHCS2M) as direct collectors for malchite and azurite is presented. Microflotation and laboratory scale flotation tests were performed to define the collector properties of these reagents under a variety of flotation conditions. On the basis of the results, it is proposed that some property of the amine-hydrogen atom in the reagent has a signification influence on the unusual activity of these collectors for oxide copper minerals.

Jan 1, 1979

By Henry B. Estabrooks

As was true with many mining companies, the management of Tennessee Copper Co. followed with interest the successful application of AN-FO as an explosive in coal stripping, construction, open-pit mining, and finally in underground salt mines. Since Tennessee Copper's operations required about 1,250,000 lb of dynamite annually, the potential savings in explosives costs that could be realized by switching to AN-FO could not be ignored. From a cautious start, AN-FO is now being used for stoping, development work and secondary blasting in all mines of Tennessee Copper Co. AN-FO accounts for 80% of the explosives used in such work. Fragmentation, fumes, crew acceptance, and cost savings have been quite attractive without any decrease in safety.

Jan 11, 1962

By R. L. Perrine

This paper presents results obtained by consider ation of unstable miscible displacement within a porous medium as a quasi-turbulent displacement process, that is, a process characterized by fluctuations around a simpler, mean flow behavior. The instability usually results from the miscible displacing fluid having a viscosity lower than that of the displaced fluid. Such instability is evidenced in suitable experiments by the presence of viscous fingering. A unified theoretical relationship applicable to both stable and unstable displacement is derived. Parameters in the theory are obtained by empirical means. Although the theory describes an idealized conceptual model, agreement with experiment is quite reasonable up to moderately adverse viscosity ratios, such as 17:1. INTRODUCTION Many experimental studies of miscible displacement in porous media have been conducted with prediction of reservoir displacement efficiency as the ultimate objective. Most such studies have utilized lower displacing than displaced fluid viscosity, scaled to potential reservoir fluid pairs. Theoretical approaches have been largely limited to unit viscosity ratios, however, in spite of the necessity for an understanding of the mechanism of the unstable, adverse viscosity ratio displacement process. An obvious reason is the difficulty of describing in mathematical form the viscous fingering characteristic of these conditions. Observation of experiments conducted with dyed fluids in transparent systems suggests an analogy between unstable miscible displacement and turbulent flow in a pipe. In both cases there are fluctuations around a simpler, mean flow behavior. An important difference is that flow behavior of interest in the porous medium is entirely transient, contained within a transition zone between displacing and displaced fluids. Transient behavior complicates description in that coefficients in the equations become variables rather than constants. In the study reported here, the analogy with turbulent flow has been used in treating unstable miscible displacement as a quasi-turbulent displacement process. The purpose has been to derive, even if restricted to an idealized conceptual model, a unified theoretical relationship applicable to both stable and unstable displacement. A relationship meeting these specifications up to moderately adverse viscosity ratios, such as 17:1, is presented. One fluctuation parameter in the theory and dispersion coefficients are obtained by empirical means. The idealized theory is compared with experimental results. UNSTABLE MISCIBLE DISPLACEMENT AS QUASI-TURBULENT DARCY FLOW The miscible displacement of one fluid by another within a porous medium is considered in this study. Flow conditions are such that Darcy's law is applicable. It is further assumed that, by the stability criterion proposed by perrine,1 initial flow conditions lie well within the regime of instability. Thus substantial viscous fingering is assured. We wish to show how this flow regime can be represented as quasi-turbulent. That is, the Reynolds number for the established flow conditions is below that for inertial or turbulent flow within a porous medium, and lies within the regime for which Darcy's law is valid. Yet flow behavior can be described as the combination of some relatively simple average result, and characteristic fluctuations that are superimposed on the simpler behavior. Stated another way, flow behavior includes the movement of layers of fluids with different velocities past or over one another. Such descriptions are characteristic of turbulent pipe flow. The fluctuations in the present case are a direct consequence of the local viscous fingering which accompanies the unstable displacement process. Should displacement become stable, fluctuations would die out. It is of particular importance to note that fluctuations such as these can interact in a way that contributes to material transport by the basic flow. The basic transport equations required for engineering calculations must be modified to reflect this fact.

By Henry Souther

It is generally admitted that a god, practical and commercial set of specifications for the use of the many purchasers of cast-iron does not exist. A few good sets are in the hands of large buyers, but even these are very different, contradictory, and not intended to cover a wide range of product. Furthermore, most of them have been prepared to cover but one branch of the industry. It is strange that purchasers of cast-iron have not looked into this question long ago and demanded good, uniform cast-irou. Probably cast-iron has been discarded from many uses because of its failure in a few instances, even though the failure was due to ignorance of the quality of the iron, or perhaps to abnormally bad iron. Some foundrymen seem to consider all gray iron from a given foundry as uniform, especially if they know that it has been made from certain well-known brands of pig. It is likely that with standard specifications and the increase of knowledge necessary for their intelligent employ-

Jan 1, 1905

By Charles A. Ashburner

THE appliances which have been proposed, and the modifications in the construction of boiler-furnaces which have been made for the prevention of smoke, and the utilization of what are ordinarily called the waste products of combustion, have been innumerable.

Jan 1, 1882

By C. D. Stahl, S. M. Farouq Ali

This investigation attempts to describe and simulate the alcohol displacement process by means of a cell model, as employed in chemical engineering practice. The proposed model is more simple than previously proposed models. and utilizes parameters chosen on a theoretical basis. The model successfully reproduced the formation of the stabilized bank and the breakthrough of alcohol, the latter depending on one of the model parameters, which may be correlated with the length of the porous medium. Moreover, the effects of the phase behavior of the liquid system involved, as observed in experimental studies, were reproduced. Several variations of the basic model were devised and tested on a digital computer. These included the cases in which: (1) the actual value of fractional flow was used in cell-to-cell computations; (2) the number of cells was varied within the same run; and (3) incomplete rather than complete phase equilibrium was assumed within each cell. The proposed cell model clarifies the basic mechanism of the process. Detailed concentration profiles obtained for each cell, for instance, showed the mechanism of bank formation in relation to the phase behavior characteristics. The results obtained indicated a varying degree of phase equilibrium concommitant with changes in the velocities of the phases in an actual alcohol displacement. This condition was approximated by changing the number of cells during the simulation. Interesting information was obtained on the influence of path length on the efficiency of alcohol displacement, which has been the subject of some controversy. Certain limitations preclude the use of the proposed model as a substitute for experimental studies. The results obtained were, nevertheless, of value in interpreting the experimental results. INTRODUCTION During recent years considerable effort has been directed toward an understanding of alcohol displacement, the process whereby oil and water are recovered from a porous medium by the continuous injection of a solvent. The complex nature of the physical process involved has so far defied a complete mathematical treatment. Other methods of approach, amounting to an overall material balance, have been proposed, yielding useful information on certain aspects of the process.1-3 Taber et al, in particular, defined the displacement mechanism in terms of the phase behavior of the alcohol-oil-brine system invoIved.2 Wachmann reported a mathematical treatment of alcohol displacement subject to certain simplifying assumptions? Donohue proposed the use of a "cell model" for simulating alcohol disPlacement.5 The nature of the assumptions involved limited the utility of the model. The present work attempts to examine the variables involved in the simulation of alcohol displacement and discusses several possible versions of the basic cell model. Under certain conditions the model results are similar to the experimental results. In particular, the spontaneous formation of of the stabilized bank and the effects of the system phase behavior were successfully reproduced. PREVIOUS WORK ON CELL MODELS Cell models and the theoretical plate concept are often used in solving chemical engineering problems in which an explicit mathematical solution may be difficult or impossible to obtain. Examples of such applications occur in distillation, gas-liquid chroma tography,6 reactor technology, absorption, etc. In petroleum engineering, such a model was used by Attra7 to describe non-equilibrium gas drive, and by Higgins and Leigh ton8 to calculate sweep efficiency in water flooding. Aris and Amundsen pointed out the equivalence between the diffusion model and perfectly mixed cells connected in series.9 Deans proposed a three-parameter cell model to simulate two-component

Jan 1, 1966