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By A. B. Kinzel, Thomas R. Cunningham

Silicon, unfortunately, is not in the same category as some other metals with respect to the absolute value of the highest purity material prepared. Tucker, in England, and Becket, in this country have developed procedures for the purification of silicon, and Becket's process has made industrially available silicon of a purity of 99.8 per cent or better. However, even the term "silicon metal" may be a paradox to some people, although not more so than the term "amorphous" as applied to silicon. These terms come from commerce, and "metal" is used to distinguish industrially high-purity silicon from ferrosilicon, silicon-aluminum, and other high-silicon alloys. Alloys of iron and silicon with 95 per cent Si or less are known as ferrosilicon, with a designation of silicon content where necessary, arid the term "silicon metal" is invariably applied to the grades containing 96 per cent Si and higher. The Becket method of purification was referred to in a monograph on the Alloys of Iron and Silicon, and the Tucker procedure was described in some detail in that publication.' In order to get silicon of still higher purity, a sample, prepared by the Becket method, analyzing 99.84 per cent Si, 0.020 Fe, 0.016 Al, 0.005 Ca, 0.025 C, 0.033 per cent 02, 0.006 H2, 0.006 N2, and 0.001 per cent Mn, was crushed to pass a 100-mesh sieve and further purified by a modification of Tucker's procedure. This modification differs from Tucker's method in that after treatment the 100-mesh alloy was centrifuged to remove the last traces of acid. Our directly determined analysis of this purified sample shows: Si, 99.952 per cent; Fe, 0.009; Al, 0.012; Ca, 0.003; C, 0.006; or 99.982 per cent. Silicon by difference equals 99.97 per cent. The variation between silicon by difference and silicon as directly determined is important. Although Tucker mentions the amount of insoluble matter in commercial silicon both before and after his treatment, he does not mention the existence of carbon in the alloy; nevertheless, he reports silicon by difference. Any final figure as to purity obviously results from agreement between direct determination and

Jan 1, 1940

By Robert L. Thoms, Richard M. Gehle

Hydraulic fracturing is of considerable interest as a possible release mechanism during operation of storage caverns in salt formations. However, field data are lacking on fluid pressures required to initiate and propagate fractures over a range of depth in U.S. salt domes. A currently active research project is outlined which has the objectives of gathering field data on hydrofracture gradients in inland and coastal domes of the Gulf Coast. A wireline minifracturing system with downhole microprocessor controls is briefly described.

Jan 1, 1985

By Allan J. Clark

In his paper on "The Accumulation of Amalgam on Copper Plates,"f Mr. R. T. Baylies records the fact that at the Drumlummon mill, at Marysville, Montana, a series of tests proved that silver, instead of showing a strong affinity with the amalgamated surface of the copper plates, gave evidence of a persistent tendency to escape amalgamation; the fineness of the amalgam, as measured in gold, being highest nearest to the battery, and giving place to a constantly-increasing proportion

Jan 1, 1900

By T. F. Witherbee

ON the 22d of November, „1879, white iron unexpectedly appeared while working the Cedar Point Furnace, Port Henry, N Y., on the following burden, calculated to turn out mill and foundry iron: Anthracite coal, - 3000 pounds. Connellsville coke, - 1500 pounds. Total, - 4500 pounds. Old Bed ore, - 3750 pounds. New Bed fine ore, - 2000 pounds. New Bed chunk ore, - 1000 pounds. Kearnev hematite ore, - 750 pounds. Total, - 7500 pounds. Magnesian limestone, - 1865 pounds. Common limestone, - 885 pounds. Total, - 2500 pounds. The production per week since making mill iron-from September 1st, 1879, to date, seven weeks-was 412 gross tons. Ore was not immediately taken off, as nothing serious was looked for. The iron for the next week graded from No. 4 to white, and in. six days the make was 274 1/2 tons. At 10 P.M., Friday, the 28th, a slip of-..4 feet occurred, and on Saturday, at 5 A.M., another of 3 feet on the south side and. 7- feet on the north side took place. At this time it was found that the south side had been hanging for over a week--a fact which had not been reported. Throwing off the wind, to produce slips. and reduce pressure, had been tried with no effect. The stock, as seen through the tuyeres, seemed to consist almost entirely of coal, with just enough infusible cinder to cement it into a mass through which the blast could not be forced. At 3.50 A.M., Sunday, the 30th, the first cinder seen in seventeen hours came into tuyeres Nos. 1, 2, 3, and 6, At 9.30 A.M. No. 3 was taken out to see if the stock

Jan 1, 1881

By T&apos Ke, ing-sui

NUMEROUS investigators have observed that internal friction accompanies cold-working of metals and the effect of annealing is to reduce this internal friction.1,2 However, - most of the experiments were made at high stress amplitudes and the principal purpose was to study the increase of internal friction as a result of the applied cyclic stress during measurement. In order to study the internal friction introduced by cold-working applied prior to the measurement, the stress level applied during the measurement of internal friction must be sufficiently small. The results of measurement are significant and can be used for a base of comparison only when the applied cyclic stress is so small that the internal friction is independent of stress amplitude. Internal friction of cold-worked metals under small stress level has been studied by a number of workers8 -" he internal friction was measured around room temperature with a frequency of vibration of the order of kilocycles per second. The purpose of this paper is to report a study of the change of internal friction when severely cold-worked aluminum was annealed at successively higher temperatures until it was completely recrys-tallized. The measurements of internal friction were made over a range of temperature extending from room temperature up to the temperature of prior anneal. The frequency of vibrations used was about one cycle per second. The apparatus used for the internal friction measurements to be reported in this paper was a torsion pendulum with the specimen in wire form as the suspension fiber. The description of this apparatus and the method of measurement have been previously given.7,8 The applied stress was sufficiently small SO that the magnitude of internal friction is independent of stress level at each temperature range concerned. Corresponding to this stress the maximum shearing strain on the surface of the specimen is of the order of l0-5 and lower. The in- ternal friction (Q-1) is reported as 1/p times the logarithmic decrement. Internal Friction Versus Temperature of Anneal: Fig. 1 shows the internal friction measurements performed upon 99.991 pct aluminum subjected to 95 pct reduction in area. The final diameter of the wire is 0.033 in. This figure gives a general survey of the effect of temperature of anneal and of temperature of measurement. The internal friction of the cold-worked specimen was first measured at room temperature. It was then annealed at 50°C for one hour and the internal friction measured at 50°C and at room temperature. The same wire was successively annealed at higher temperatures for one hour and measurements were taken at the annealing temperatures and lower temperatures as before. Such a procedure was followed in order to stabilize the internal friction at the temperature of measurement so that during the measurement which generally takes about half a minute, there is no detectable change in internal friction. This series of measurements .was made up to 450°C. After each annealing a short test piece of the specimen, which had received the same past thermal and mechanical treatments, was taken out for metallographic examination. It is seen from fig. 1 that up to the annealing temperature of 250°C we have the following observations: for any given temperature of measurement, the internal friction is lower the higher the temperature of prior anneal. When the annealing temperature is 290°C or higher, the internal friction at the annealing temperature drops abruptly to a value which is much smaller than that for the previous curve. Metallographic examinations showed that the recrystallization of the specimen was completed after the annealing at 290°C. Fig. 1 shows that, as far as internal friction is concerned, there is no abrupt transition between the processes of recovery and recrystallization. Averbach has also reached the conclusion that recovery may be a process analogous to recrystallization on the basis of X ray extinction measurements in brass." The effect of annealing temperature upon the internal friction at room temperature is shown by curve I of fig. 2. In this figure the internal friction at room temperature was plotted as a function of annealing temperature. It is seen that the internal friction decreases rapidly at first with an increase

Jan 1, 1951

By P. Barnes

THE object of this paper is to make a brief comparison of the out-lines of several forms of ports for steel-melting furnaces, in reference chiefly to the proper mixture of the gas and air, and to the direction in which the flame is thrown down into. the interior of the furnace. In the illustrations on the accompanying plate, Fig. 1 shows a form of port designed by M. Pernot, of St Chamond, France. This is used with the dome roof preferred by him for the revolving bottom that bears his name. From No. I has been derived No. 2. This is shown on the plans of Mr., A. L. Holley, and from them three large furnaces have been built and put into operation by the Springfield Iron Company. Fig. 3 shows an outline proposed by Messrs. Richmond & Potts for the Pernot furnace. In this the ports are brought in under an arched. roof of nearly the ordinary form., instead of over the top of the roof, as with the done of M Pernot, Fig. 4 shows a furnace as built by Krupp of Essen, Prussia, for fluid refining, or “washing” -to use the briefer French term. In this the gas and air come into contact in broad sheets one above the. other. Fig. 5 shows the form used by Messrs, Richmond & Potts

Jan 1, 1881

By N. H. Harrison, J. K. Rodgers, S. Regier

This paper presents comparisons of data obtained from a laboratory reservoir study and from a calculated behavior prediction with the actual production history of a condensate reservoir. A small non-commercial discovery was depleted under closely controlled conditions and the well fluids were sampled at frequent intervals. Data on the reservoir and production variables were accumulated on a fixed schedule. A laboratory reservoir study war made using the initial well fluid samples as charging stock. The production procedures and operating conditions were held constant throughout the study wherever possible and in general paralleled the field work. The well fluid compositions and the cumulative recoveries ar a function of the reservoir pressure were also calculated using conventional flash vaporization procedures and equilibrium constants. Comparisons based on the composition of the well fluid show good agreement, the laboratory study agreeing within experimental accuracy with the field work and the calculated data comparing equally well. The gas-oil ratios are also in good agreement, but with somewhat greater deviations at the higher pressures. In the overall picture, it is believed that a model st,~tiy can predict within experimental accuracy the production history of a condensate reservoir. Better equilibrium constants for the heavier hydrocarbons are needed in order to attain improved composition accuracy by calculation. INTRODUCTION In Aug., 1955, a gas condensate well was completed in San Juan County, Utah, that was initially thought capable of good commercial production. These conclusions were derived principally from core data and electric logs, which indicated good permeability, porosity and gas content. However, after the usual series of potential tests it was found that the reservoir pressure had declined some 22 per cent, and it was obvious that the zone tapped was but a small pocket or trap. It became apparent that, with a controlled depletion of a small reservoir, a unique opportunity was available to compare laboratory and calculated studies with an actual field depletion and to further the present knowledge of condensate reservoirs. FIELD WORK The Coalbed Canyon Well No. 1 was conventionally completed in the Paradox limestone formation to a total depth of 5,912 ft. The producing zone from 5,762 to 5,806 ft was perforated with four jet shots per ft. The wellhead and field equipment were also conventional, the major items consisting of a two-pass indirect fired line heater, a high- and a low-pressure separator with the necessary controls and accessories, gas meters, back-pressure regulators, flare stacks and condensate stock tanks. The initial testing of this well con-sisted of a series of flow potential and pressure build-up tests during which some 30 MMcf of gas was produced. The reservoir pressure declined from an estimated 2,300 to 1,782 psig during this period, from which it was concluded that the reservoir was very small. In order to approach steady-state conditions in the reservoir and so provide optimum conditions for making comparisons, the field depletion was programmed to approach, if possible, constant production conditions. Bi-hourly readings were taken of the tubing pressure, the pressure and temperature of the separators, oil and gas rates, and other pertinent operating data. The gas rate, as indicated by the orifice meter, was held constant by the adjustment of the choke in the line heater. The temperature of the first stage separator was held constant by adjustment of the line heater jacket temperature. Practical considerations of production made the maintenance oi a constant gas rate impossible. The test started with a gas rate of 4 MMcf/D and a separator pressure of 250 psig. This rate was maintained until the choke was fully opened. The gas rate then declined with the falling tubing pressure and production was continued until the rate was about 2

By H. L. Luo

SYSTEMATIC investigations of the Fe-Ga system have been reported only very recently."' The maximum solid solubility of gallium in a-Fe is nearly 50 at. pet at 900°C. However, from Ref. 1, it was not evident that the a-Fe solid solution could be retained successfully beyond 17.38 at. pet Ga by solid-state quenching. The present investigation reports the retention of a-Fe solid solution at 50 at. pet Ga by quenching from the liquid. An ordered phase of CsC1-type B2) structure was observed between 34 - 50 at. pet Ga. Since it was considered very probable that the CsCl structure would occur at high temperatures, alloy filings were also quenched by the conventional quenching technique. In addition to the CsCl phase, a second ordered phase of BiF3-type (DO3) structure was found in the range 25 - 30 at. pet Ga. Alloys were prepared from elements of 99.99 pet purity or better, induction-melted in alumina crucibles under hydrogen. After reweighing, the alloy ingots were cast into wires under argon. From the weight losses and the reproducibility of the lattice parameters, compositions were estimated to be within ± 0.3 at. pet. The techniques of quenching from the liquid state were reported before.3-5 Prior to quenching, a small section of cast alloy wire (30 - 50 mg) was melted in an alumina insert under an argon flow. The quenched specimens were in the form of flakes, typically 1 sq mm in area. For solid-state quenching, alloy filings passing 200 mesh were sealed under a reduced helium atmosphere in a thin-bottom silica tube. After heating for -30 min at the desired temperature in a vertical furnace, the sealed tube was rapidly dropped into ice water so that the thin bottom of the tube broke on impact. The quenched alloy filings were always ferromagnetic and could be collected by a magnet. X-ray diffraction patterns were taken with iron-filtered cobalt radiation in a 114.6-mm-diam Debye-Scherrer camera. High-angle lines were always resolved and spacings were computed relative to ? (CoKa1) = 1.78890Å. Lattice parameters were obtained from extrapolation against the Nelson-Riley function. The variation of lattice parameter with composition is shown in Fig. 1, together with the data of Dasarathy and Hume-Rothery.1 Uncertainties in the present measurements are within the dimensions of the symbols or indicated by error bars. X-ray diffraction lines indicative of CsC1-type ordering could be clearly identified for alloys of 34 - 50 at. pet Ga quenched from the liquid and alloys of 35 - 41 at. pet Ga quenched from -975°C. Within experimental error, no difference in

Jan 1, 1968

By R. E. Gilchrist, R. R. Harvey, M. R. Dean

A simple and rapid three-component analysis procedure has been developed for use in fluid-flow studies. The method is based on refractive index measurements, combined with refractive dispersion measured between the Ha and H wave lengths. The procedure requires. calibration curves for the three-fluid system. The only restriction on the fluids employed is that only one be an aromatzc or olefinic compound. Individual sample measurements require only a few minutes. Composition results within the limits of accuracy required for fluid-flow analog studies are obtained. INTRODUCTION The simultaneous analysis of three-component mixtures is a problem often encountered in fluid-flow analog systems. In petroleum production research, the problem is usually encountered in experiments on the displacement of fluid from a porous medium. In the case of immiscible displacement, simple volumetric measurements of the produced fluids are usually sufficient, the analog fluids often being the actual reservoir fluids themselves — oil, water and gas. However, modern secondary recovery of petroleum sometimes involves production under miscible conditions, in which the oil is displaced by liquefied petroleum gas which, in turn, is displaced by dry gas. Since this type of displacement is done under conditions of pressure and temperature that are not easily reproduced in the laboratory, studies are often performed with analog fluids at essentially atmospheric pressure. Since the number of samples taken during one of these experiments is usually quite large, the time required for analysis becomes an important factor. In the past, the difficulty of conventional analysis has been avoided by the addition of various tracers to one or more of the components, or by the use of a tracer fluid as one of the components. With these techniques, a relatively large amount of analytical time is still required. Moreover, in the case of added tracers, the tracer material may migrate in part to one of the other fluids, may be adsorbed on the solid surfaces of the model, or may introduce side effects not characteristic of the prototype fluid. The substitution of a tracer fluid for one of the components can severely limit the choice of analog fluids. Optical refractometry provides a rapid and economical method of analysis of two-fluid systems or of monitoring small changes in composition of an essentially one-component system. Refractometric methods are capable of high degrees of accuracy, require only very small samples and can easily be adapted to automatic methods. They are not generally applicable, however, where three or more fluids are present over wide ranges of concentration. The method of three-component analysis described here has three essential characteristics. 1. It is based on refractometric measurements and thus preserves all of these desirable properties. 2. It does not make any stringent demands on the choice of fluids that can be analyzed. 3. It is capable of accuracy sufficient for fluid-flow analog studies. THEORETICAL The difference in the refractive index of a substance at two different wave lengths of light is known as its dispersivity. When the difference is taken between the specific refractions at the two wave lengths, the quantity is referred to as the specific dispersivity. Specific refraction was defined empirically by Gladstone and Dale1 as r = n-1/d....[1] where n is the index of refraction and d is the density. The definition is given more correctly by the expression r =n2-1/n2+1 1/d..........(2) 1References given at end of paper. MICIFTV OF PETROLEUM ENGINEER JOURNAL.

GENERAL GEOLOGIC DESCRIPTION The mineral deposit of this case study can be described as a "typical" porphyry copper deposit of the southwestern USA and northern Mexico mineral province. The copper mineralization is related to Laramide age intrusives of intermediate composition which have been intruded into older, mostly crystalline, host rocks. Post Laramide deformation and faulting have subjected the deposit to erosion, leaching, and enrichment processes, which have created a secondarily enriched chalcocite zone. Later basin and range faulting down dropped the ore zone, resulting in deep burial beneath late Tertiary conglomerates and gravels, thus preserving the deposit from further erosion and oxidation. Lower grade chalcopyrite mineralization constitutes the primary zone underlying the enriched blanket. MANAGEMENT OF SAMPLE DATA Sample data were obtained from exploration diamond drill holes that were collared vertically and drilled with surface rigs. Most of the holes were surveyed downhole and found to deviate significantly from the vertical. The data were keypunched from original drill hole logs to formats as described in Chapter 6. Three types of cards were prepared: 1) A heading card containing the following information: [Project Name Coordi-in_ Hole Collarnates Bear-clina-Total ID Northing Easting Elevinglion Depth] 2) Individual record cards following each heading card with the following information: [SampleMin. Zone interval Assay Fields Leached (enriched ID From-ToTotal Cu Oxide Cu primary)] 3) Where downhole survey data were available, a card was punched for each downhole survey point. The card image looked very much like the heading card, followed immediately after the heading card, and contained the following information: [Hole Sur Point Sur Point Sur Point ID Bearing Inclination Depth] The keypunched data were then processed by the drill hole survey program producing a record file which contained information as follows: [Line 1. Project Name Date Assay Field Identifiers Line 2. Hole ID Northing Easting Elevation Bearing Inclination Number of Samples Line 3 through N+ 2 (where N equals the number of samples in the hole) Top Min. of Min. Zone Zone Sample Sample Coordinates Sample Assays Leach InterLength Northing Fasting Elev Total Cu Oxide Cu (etc) face] MINERAL BOUNDARY PROBLEM AND TREATMENT According to the geologic description, at least three mineral zones are present within the ore limits, as well as fault boundaries and a buried topographic surface, each of which have to be considered. The interfaces of the various mineralogical and geological boundaries were identified as accurately as possible in each drill hole by the project geologist, the location of the interface was surveyed in the computer program in association with the nearest sample intercept to the interface (note last field of line 3). Thus, the boundary is represented as a point in 3D space at each intersecting drill hole. The linear interpolation (LINTERP) program then searched the last field of the surveyed record to find the top of each mineral zone, or geologic boundary, and read the coordinates associated with that sample point. The program then used the coordinates to compute an interpolated surface between all existing data points as described in Chapter 11. A contour map was plotted for each of the computed surfaces and reviewed by the project geologist. Where the surfaces were poorly defined due to lack of real drill hole information, the geologist, at times, inserted a "pseudo" drill hole intercept according to his best judgment and feeling for the configuration of the surface, and such points were entered into the data stream for LINTERP. When the project geologists were satisfied that they had obtained

Jan 1, 1980

By Robert E. Thurmond, E. D. Spaulding, Walter E. Heinrichs

DISCOVERY of a commercial ore deposit has resulted from a program emphasizing geophysical techniques and concentrating upon exploration of alluvial-covered areas. United Geophysical Co. selected these areas as offering the best possibility of success, for here the surface evidence of ore deposits has been hidden from the eyes of prospector and geologist alike. Pima mining district, Pima County, Arizona, was selected for initial exploration. The project was successful in that a commercial ore deposit was discovered and proved through drilling and extensive underground development.

Jan 2, 1954

By F. V. Lenel, G. S. Ansell

The creep behavior of an aluminum -aluminum oxide alloy, A T 400, fabricated by compacting an atomized aluminum powder, extruding the compact, cold working, and recrystallizing the extrusion, was investigated. This alloy has a dispersion spacing of 1 . Previously Ansell and Weertman determined the steady-state creep rate of a recrystallized aluminum-aluminum oxide SAP-type alloy, MD 2100, with a 0.48-p dispersion. This alloy was found to have a steady-state creep rate of less than 10-6 min-1, too small to be measured accurately. By employing a more sensitive method of measuring creep rate, it was possible to determine the steady-state creep rate of AT 400 alloy, which is somewhat faster than that of MD 2100, at a series of temperature and applied stresses. Above a stress of Burger's vector, A = dispersion spacing, u = is a shear modulus) the rate follms an equation of the type: Steady-state creep rate K = A exp. where A is a constant, Q is the activation energy for sey-diffusion, and is the applied stress. At stresses lower than the steady-state creep rate drops off sharply and is no longer in agreement with this equation. This behavior is in good agreement with that predicted by the model for dispersion strengthened alloys in the stress and temperature range investigated. The absolute value of the creep rate is, however, four orders of magnitude lower than that predicted if the normal number of active dislocation sources are assumed to be present. It is concluded that in this SAP-type alloy the usual three-dimensional dislocation network is not present. Instead, short dislocation segments extending from one dispersed particle and terminating at a neighboring particle may act as dislocation sources. With this provision the creep model proposed by Ansell and Weertman reasonably accounts for the creep behavior which was observed. RECENTLY, Ansell and Weertman1 proposed a dislocation model from which they derived creep equations to describe the steady-state creep behavior of dispersion - strengthened alloys. Following Schoeck,2 they assumed that the rate controlling process for steady-state creep is the climb of dislocations over the dispersed particles. In order to verify their creep model, Ansell and Weertman determined the steady-state creep behavior of an aluminum-aluminum oxide SAP-type alloy, MD-2100, in both the fine-grained as-extruded, and coarse-grained recrystallized conditions. Since the grain size was the order of the dispersion-spacing, their model was not applicable for the as-ex- truded alloy. It should, however, be applicable to the coarse-grained recrystallized alloy. The results they obtained were rather unexpected. No meas-ureable steady-state creep was observed for the recrystallized MD-2100 alloy. If their model is correct, and if the second-phase particles act solely to hinder dislocation motion, then some measureable steady-state creep would have been expected. On this basis, they postulated that, in this SAP-type alloy, the main effect of the fine dispersion was to inactivate dislocation sources rather than to hinder the movement of dislocations. In order to understand more fully this unusual creep behavior, and to determine the validity of the model proposed,' the steady-state creep behavior of an aluminum-aluminum oxide recrystallized SAP-type alloy, with a somewhat coarser dispersion spacing, was investigated. The results of this study are presented in this paper.

Jan 1, 1962

By E. C. Houston, H. S. Rankin

Olivine is considered a valuable potential source of metallic magnesium in the chloride electrolytic process. Treatment of olivine with hydrochloric acid can be carried out under conditions that prevent the formation of gelatinous silicic acid, which would inhibit the reaction by forming a covering around the ore particles. It is our hypothesis that the formation of gelatinous silicic acid is avoided by the dehydrating action of the magnesium chloride, which takes up water to form a series of hydrates and leaves the silicic acid in granular condition. Leaching serves to separate the magnesium chloride from the silicic acid and unattacked ore, which can be treated with fresh acid in successive steps until extraction is essentially complete. The leach solution can be i purified by the addition of caustic magnesia and the precipitated impurities removed by decantation or filtration. The resulting magnesium chloride contains: Fe, less than 0.001 Per cent; Mn, 0.012 ; per cent; Ni, none. Chlorination† of olivine has two major defects: (1) a large part of the chlorine goes to form silicon and iron chlorides, (2) the anhydrous magnesium chloride is held by absorption in the finely divided silica. SupplY It is well known that olivine, a silicate of magnesium and iron, is present in large amounts in several localities in the United States. The largest deposits occur in the southeast and on the Pacific Coast.' The southeastern deposits were surveyed by Lewis2 in 1896 and by Hunter3 in the period 1933-1940 It is estimated that high-grade olivine, conveniently located with regard to transportation and power, is present in excess of 230 million tons above local drainage level in western North Carolina and north Georgia. Previous Technical Work In the past few years, olivine has attracted considerable attention in the refractory field. In the chemical processing industry, however, it has long been thought axiomatic that the cost of processing silicates is an economic barrier to their utilization, especially where more reactive minerals, such as carbonates, oxides or salts, are available. This attitude is not entirely justified in connection with olivine. unlike most silicates, olivine is readily attacked by acids, chlorine and other reagents without resorting to fusion to break down the silicate structure. Olivine has been suggested as a raw material for making epsom salt by roasting with pyrites.4 Other processes include acid treatment6 and digestion with calcium chloride.6 Recently a small plant was built near Webster, N. C., for making epsom salt from olivine by treatment with sulphuric acid. This plant is now in commercial operation, producing approximately two tons per day. Olivine is also receiving attention from the fertilizer industry as an inexpensive source of soluble magnesium.

Jan 1, 1942

By H. S. Rankin, E. C. Houston

Olivine is considered a valuable potential source of metallic magnesium in the chloride electrolytic process. Treatment of olivine with hydrochloric acid can be carried out under conditions that prevent the formation of gelatinous silicic acid, which would inhibit the reaction by forming a covering around the ore particles. It is our hypothesis that the formation of gelatinous silicic acid is avoided by the dehydrating action of the magnesium chloride, which takes up water to form a series of hydrates and leaves the silicic acid in granular condition. Leaching serves to separate the magnesium chloride from the silicic acid and unattacked ore, which can be treated with fresh acid in successive steps until extraction is essentially complete. The leach solution can be i purified by the addition of caustic magnesia and the precipitated impurities removed by decantation or filtration. The resulting magnesium chloride contains: Fe, less than 0.001 Per cent; Mn, 0.012 ; per cent; Ni, none. Chlorination† of olivine has two major defects: (1) a large part of the chlorine goes to form silicon and iron chlorides, (2) the anhydrous magnesium chloride is held by absorption in the finely divided silica. SupplY It is well known that olivine, a silicate of magnesium and iron, is present in large amounts in several localities in the United States. The largest deposits occur in the southeast and on the Pacific Coast.' The southeastern deposits were surveyed by Lewis2 in 1896 and by Hunter3 in the period 1933-1940 It is estimated that high-grade olivine, conveniently located with regard to transportation and power, is present in excess of 230 million tons above local drainage level in western North Carolina and north Georgia. Previous Technical Work In the past few years, olivine has attracted considerable attention in the refractory field. In the chemical processing industry, however, it has long been thought axiomatic that the cost of processing silicates is an economic barrier to their utilization, especially where more reactive minerals, such as carbonates, oxides or salts, are available. This attitude is not entirely justified in connection with olivine. unlike most silicates, olivine is readily attacked by acids, chlorine and other reagents without resorting to fusion to break down the silicate structure. Olivine has been suggested as a raw material for making epsom salt by roasting with pyrites.4 Other processes include acid treatment6 and digestion with calcium chloride.6 Recently a small plant was built near Webster, N. C., for making epsom salt from olivine by treatment with sulphuric acid. This plant is now in commercial operation, producing approximately two tons per day. Olivine is also receiving attention from the fertilizer industry as an inexpensive source of soluble magnesium.

Jan 1, 1942

By R. W. Gurry

THERMODYNAMIC calculations indicate that boron is a better deoxidizer than silicon but probably is not quite as effective as aluminum. Boron should, therefore, be readily oxidized out of the open-hearth bath, which implies that it is not recovered in significant concentration from any scrap charged; also that, if added in the ladle, it tends to oxidize out during teeming unless protected by the presence of a. better deoxidizing agent. These conclusions do not apply to liquid cast iron, in which the oxygen content is much lower than in liquid steel. The possibility of conserving certain strategic alloying elements widely used in steelmaking, notably manganeie, chromium and molybdenum, by the use of boron, which in small concentration appears to be extraordinarily effective in promoting hardenability, raises a question as to what extent any boron present in the scrap charged into the open hearth is oxidized out during melting and subsequent refining. This question is significant because the optimum concentration of boron in the finished steel, which is fairly critical, would be very difficult to attain if the boron in the charge were largely retained in the metal. Moreover, unless boron is substantially eliminated in the open-hearth process its use on a large scale would eventually make it impossible to produce boron-free steel except by restricting the charge to virgin material. There is at present, unfortunately, virtually no satisfactory direct evidence to provide an answer to this question; but there are indications from practice that boron is oxidized out in the open hearth in the production of medium or low-carbon steel, although it may be retained if the carbon content remains fairly high; that is, if the oxygen is kept fairly low. In the absence of direct data, it is necessary to rely upon the indications of indirect evidence, the best approach now available being a thermodynamic calculation of the deoxidizing power of boron in liquid steel by the general method used so successfully by Chipman1 in his study of the reactions in the open-hearth process. The thermal data for boron, upon which such a calculation must be based, are reasonably satisfactory; the only quantities not directly determined are the entropy of melting of boron, the activity coefficient of boron in liquid steel, and the activity coefficient of B203 in an open-hearth slag; but these values may be estimated with ample accuracy. The results of this calculation, which is presented later, are given in Table I, together with corresponding data for other deoxidizing elements. This table shows the calculated residual content of oxygen in equilibrium with different residual concentrations of the deoxidizer in the metal;

Jan 1, 1943

By E. W. Hough, G. L. Stegemeier

Empirical equations for surface tension of propane and normal butane as functions of reduced temperature are obtained from experimental data. Another correlation relating surface tension to enthalpy of vaporization is given for these two compounds. In addition, new paracbor numbers are calculated for the normal paraffin hydrocarbons. These numbers are utilized for the calculation of interfacial tension of two-component systems as functions of pressure and temperature, using a modified form of Weinaug-Katz equation. The experimental data for two binary systems are approximated by the correlation. From these results it is found that the interfacial tension in the high-pressure region remains extremely low at large pressure decrements below the critical pressure. Thus, it appears that condensate systems may have flow characteristics almost like single-phase conditions even though the pressure is within the two-phase region. Experimental data have shown that interfacial tension divided by density difference approaches zero as the critical pressure is approached. A calculation of wetting-phase saturations indicates that the saturation gradient at the two-phase contact becomes increasingly abrupt as the critical pressure is approached. DISCUSSION Prediction of the surface and interfacial tension of the light hydrocarbons and of two-component hydrocarbon mixtures at various temperatures and pressures may be made if other physical properties are known. Extensive experimental work on single-component and binary systemsl is the basis for the correlations outlined in this paper. Interfacial tension is defined as the specific surface-free energy between two phases of unlike fractional composition, while surface tension is defined as the specific surface-free energy between two phase:; of the same fractional composition. The usual definitions relating interfacial tension to a liquid-liquid interface and surface tension to a gas-liquid interface are not clearly defined when the critical region is included, and there is no sharp distinction between a gas and a liquid phase. Interfacial tension is probably the most important single force that makes one-half to one-third of the total oil actually in place in a reservoir rock unrecoverable by conventional gas-drive or waterflood methods. A rough estimate of this figure for the United States is 100 billion bbl. Interfacial tension presently is used by petroleum engineers in the estimation of saturation gradients at the gas-oil contact and at the oil-water contact. The data in this paper should prove useful for estimates of reserves involving gas-oil contacts. Relative permeability undoubtedly is influenced by interfacial tension, for sufficiently small values. These data should be useful in determining how small the values are In addition, these data should eventually add to our fundamental knowledge of surfaces. At the critical point, all surface excesses approach zero and the thickness becomes very large. SINGLE-COMPONENT SYSTEMS It has been observed1 that the following relationships are good approximations to the physical properties of propane and n-butane.

By Raymond Mancha

A TEST of any fan requires the determination of such data as fan pressure, air volume handled by the fan, and power input to the fan shaft. When testing operating mine fans of the centrifugal type, test methods have been employed, for the sake of convenience, that permit great latitude in detail of procedure resulting in wide variance in results by different investigators. Some controversial aspects of field fan testing are the result of past failure to define dearly the various forms of fan pressure and to a lack of understanding of the accurate procedure for the measurement thereof. Also, the anemometer for air-volume measurement, although convenient, if carelessly used and maintained is subject to a wide error range with variation in method of application and in instrument accuracy. The appearance of the axial-flow type of mine fan offers the possibility of refinements in field testing that were impractical with the centrifugal fan. First of all, the fan inlet and outlet are more sharply defined, giving loser agreement as to just where the fan begins and ends; thus there is less disagreement as to the proper location for measurements of fan pressure. The area of passage into the inlet of an axial-flow mine fan usually constricts, causing high air velocities with accompanying steadiness of flow. Thus the fan inlet offers an ideal location for accurate air-volume measurements with the Pitot tube, the proper use of which is well established by code. Thereby the controversial aspects of such measurements are eliminated. Use of the Pitot tube also facilitates a more accurate measure of fan pressure, since the individual pressures measured can be properly weighted, as will be explained later. Determination of power input to the axial-flow mine fan operating in the field is subject to the same inaccuracies as with the centrifugal fan if the axial-flow fan is also belt driven. However, because of the higher rates of rotation usual with axial-flow fans, direct-driven units are more numerous and it is unnecessary to assume a drive efficiency, thus eliminating one possible source of error. It is the purpose of this paper to define and explain the various types of pressure measurements involved in a field test of an axial-flow mine fan, and to further explain the proper use of the Pitot tube when measuring pressures and volumes. DEFINITION OF FAN PRESSURES The two fan pressures most commonly discussed are fan total and fan static pressure, each of which has the same meaning regardless of whether the fan is blowing, exhausting, or blowing and exhausting, as in the case of a fan with ducts connected to both outlet and inlet. Fan total pressure is the amount by which the total pressure of the air delivered by the fan exceeds the total pressure of the air received by the fan. This pressure is a measure of the maximum amount of the work done on the air by the fan that is available for external use.

Jan 1, 1942

By R. J. Weege, A. W. Schillinger

Conventional underground mapping methods and diamond drilling are being applied in a study to determine the nature of the copper ore occurrences near the footwall of the Osceola lava flow top, commonly referred to as the Osceola Amygdaloid. The work to date suggests that structures formed by relatively impermeable barriers, created by flowage and injection of still-molten lava from the interior of the flow into the solidified, brecciated crust, acted as the ore receptacles. Ascending hydrothermal fluids traveling near the footwall contact were trapped and confined in these barriers which retarded the direct upward movement of the ore fluids and caused deposition of copper. Oreshoots located near the footwall appear to have been formed spatially independently from the hanging-wall oreshoots by fluids traveling simultaneously, but along different channelways. The barrier concept, as advanced by earlier writers to explain the concentration of the ore-bearing fluids into broad shoots constituting entire ore bodies, is found to be equally as applicable for the localization of smaller oreshoots within the Osceola ore body. Recently, the Calumet Division of Calumet and Hecla, Inc. completed the unwatering of the old mine workings on the Osceola amygdaloid. Two shafts were subsequently reactivated and mining commenced on the Osceola lode after an idle period of over 20 years. Early in 1961, the Calumet and Hecla Geological Dept. was assigned the task of locating additional reserves. Accordingly, an intensive mapping and underground diamond drilling program was initiated. Except for a very few years following the first mining on the amygdaloid, the Osceola lode had never been a high grade producer. It was, therefore, recognized from the onset that a concentrated effort would have to be made by the mining, milling, and geological departments to insure success of the project. Company reports contained many references to ore that had been located near the footwall of the Osceola amygdaloid. Information concerning the grade of this ore was meager, but it was known that at least some was very rich. In contrast to ore that occurred near the hanging-wall, however, the footwall copper did not appear to have a systematic distribution and a large amount of poor rock had to be removed in developing this ore. This, of course, resulted in high development costs and discouraged any extensive mining of footwall ore. The possibility of more continuity than had previously been suspected was recognized by other workers, in particular Dr. T. M. Broderick, formerly Chief Geologist of Calumet and Hecla, who suggested attempts be made on a trial basis to follow the footwall contact with the main development drift. As most mining was done on the Osceola lode before a geological department had been established by the company, and almost all of these openings are now caved, very little information concerning the geology of footwall ore was available. It was, therefore, decided that the first step in the exploration program would be to become familiar with footwall ore occurrences by mapping the geology as the openings were driven. It was possible that a mapping program would reveal the features that controlled the localization of the ore. Furthermore, if it could be shown that footwall ore was more continuous, or if its distribution was more systematic than generally believed, it would be possible to produce a high grade ore that could be blended with the lower grade hanging-wall ore. In connection with the geological program, the Michigan College of Mining and Technology Geophysical Dept. under the direction of Professor Lloyal Bacon, is making a geophysical study of the problems of locating footwall ore by electrical methods. GENERAL GEOLOGY OF MICHIGAN NATIVE COPPER DEPOSITS The native copper deposits of Michigan are located in Keweenaw, Houghton, and Ontonagon Counties. The host rocks are Keweenawan in age and are comprised of interbedded sediments and lava flows which form a belt two to four miles wide and over one hundred miles long. These rocks form part of the south limb

Jan 1, 1962

In 1934 the Southern Experiment Station of the U.S. Bureau of Mines in. cooperation with the University of Alabama began an investiga-tion of the availability of kyanite ores as a source of raw material for the manufacture of refractories. Under this program, gravity concentration and flotation tests have been made on two varieties of Georgia kyanite ore, mica schist and massive. Most of the attention has been directed to the mica schist ores, as they are more widely distributed and seem to offer greater economic possibilities than the massive ores. It is evident that the preparation of kyanite for use as a refractory material involves other considerations than the mere elimination of impurities. A concentration process that eliminates impurities satisfactorily may have to be followed by some additional treatment, since the final product must be of a coarse-ness and size ratio that will make it suitable for refractories manufacture. So far in the investigation at the Southern Experiment Station of the U.S. Bureau of Mines only the concentration problem has been considered, and this paper is intended as an interim report.

Jan 1, 1936

The Inspiration ore body was discovered in 1904, but a 50 -ton mill which was installed to treat the disseminated copper ore promptly failed. The original Inspiration Company then gave way to another, backed by W. B. Thompson, which found 40 million tons of ore. Control then passed to Anaconda and Dr. Louis Ricketts took charge as consulting engineer. He abandoned the mill which had been partially built (to the horror of the stockholders, according to Ira Joralemon) and spent a year and a million dollars experimenting with flotation. The first large copper flotation plant was then built and recovered 50% more copper than had previous gravity mills. It, of course, was highly successful and became the forerunner of modern flotation plants. Inspiration is distinctive as the first fully integrated copper operation in the United States. Three open pits supply sulfide ore to the concentrator and mixed oxide and sulfide ore to a vat leaching and electrowinning operation with leached ore also being sent to the concentrator. In addition, dump leaching supplies pregnant solution for scrap iron precipitation. Inspiration has recently constructed an electric furnace smelter and also operates a continuous casting and rod plant. The new primary 54 in. by 74 in. crusher was completed in May of 1972 and replaced an older unit which was in the way of the open pit development. It is of an unusual circular silo design, which permits dumping 0 from two positions at 90 from each other. One dumping position is in line with the spider, while the other one is at right angles to it. A box girder splitter bar hung from the dump pocket slopes downward from the second dump point, across the spider cap, and rests on the pocket bottom. This splitter was not installed to protect the spider but was to aid in distributing wet ore being dumped from that position to both sides of the spider. Any large amount of wet ore delivered to one side of the spider would pack in the crusher cavity. The round front wall of the 18 ft (5.5 m) deep pocket is unlined except for light steel protection at the top, while the straight back wall is lined with vertically positioned railroad rails. Water for dust suppression is sprayed into the pocket through a cluster of 3/8 in. (9.5 mm) nozzles at the back of the pocket. About 5 gpm (19 lpm) of water are mixed with 90 psi (620 kPa) air upstream of the nozzles to produce a fog which is effective in dust control. The 54 in. Allis -Chalmers gyratory is placed mostly within one quadrant of the circular enclosure to permit placement of the apron feeder on the lowest level in the proper position to transfer crushed ore to the

Jan 1, 1978