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By Darwin Soler

This chapter will outline the operating procedures at Freeport Kaolin Co.5 kaolin mining operations in Georgia, with emphasis on explaining new techniques recently introduced to reclaim mined-out areas for reforestation. Kaolin is found in the central Georgia area (See Fig. 1) in lenticular, sedimentary deposits of high purity. The beds are Cretaceous in age and vary from 4 to 60 ft in thickness, under a cover of sedimentary overburden ranging from 5 to 150 ft. The kaolin beds contain the mineral kaolinite (a hydrous aluminum silicate) and have a particle-size distribution ranging from about 20µ to the submicron level and averaging about 60% below 2µ. The only contaminants in the deposits are coarse mica, quartz particles, and minor amounts of iron and titanium oxides. These kaolin deposits vary widely in quality from deposit to deposit and also vary within individual deposits. Some of the controlling quality specifications which are determined during exploration are viscosity in water suspension, optical brightness index as measured by reflectance, amenability to bleaching, and particle-size distribution. For this reason, only a small portion of the total kaolin reserves in the Georgia belt are suitable for wet processing for the present markets being served. Kaolin clays are selectively mined by different mechanical methods and are beneficiated by both wet and dry processing to produce a number of products used as fillers and coatings in the paper industry; fillers or additives in the paint, plastic, and rubber industries; and as basic raw materials for the ceramic industry. The State of Georgia is the largest kaolin producer in the United States, with 3,206,454 tons produced in 1966, according to U.S. Bureau of Mines statistics. Freeport Kaolin Co’s processing plant is located in Gordon, Ga., about 20 miles east of Macon, Ga.

Jan 1, 1969

By M. D. Hassialis

THE claim is made in a number of patents1,2,3,4 that some compounds of the class known as aryl sulphides have collector properties. One of these patents generalizes the claim to include all aryl sulphides, whose generic formula is R-S¬R[=]-R’ (where x = r,2, . . . ), with the restriction that if the aromatic radicals R, R' contain substituent groups these groups may not contain nitrogen or oxygen. Moses, Hess, and Perkins cite as evidence for their claims the results of flotation tests on Anaconda and Miami copper ores using Biphenyl sulphide, ditolyl disulphide and dinapthyl disulphide as collectors. The use of alkyl sulphides as collectors has also been reported5 with the conclusion that the alkyl sulphides are better collectors than the corresponding aryl sulphides. The experimental work cited appears to confirm this contention. In order to test these claims with respect to diphenyl sulphide, a sample, purchased from the Eastman Kodak Co., was tested against Anaconda ore. The procedure followed was that of Moses, Hess, and Perkins. A sample of ore weighing 500 grams was placed in a laboratory ball mill. To this was added 220 grams of water, 0.06 grams of commercial diphenyl sulphide (1/4 lb. per ton of ore), and 0.8 grams of lime (3 lb. per ton of ore). The material was ground until 93 per cent passed a 65mesh screen. This pulp was diluted to 16 per cent solids. A sample of the diluted pulp was placed in a Minerals Separation type of laboratory flotation cell. After a 2-min. agitation period, pine oil was added and the froth collected for a period of 15 min. This test recovered 68 per cent of the copper, with a ratio of concentration of 6.8: 1. The tailing assay was 0.3 per cent Cu. Moses, Hess and Perkins attained a recovery of 75 per cent, with a ratio concentration of 12: 1. Although these results do not compare too well with those of Moses, Hess and Perkins, subsequent tests showed an improvement, as judged by vanning of the tails. It is concluded, therefore, that the patent results are confirmed. CONTACT-ANGLE TESTS In order to study the response of the various minerals, found in Anaconda ore, to commercial diphenyl sulphide, some contact-angle tests were made. Polished particles of bornite, chalcocite, chalcopyrite, pyrite and quartz were conditioned for 15 min. in a suspension of diphenyl sulphide in water. The concentration of this suspension was 0.284 grams per liter, this being the concentration of this reagent in the ball mill. The conditioned particles were rinsed with water (not rubbed with filter paper or boiled linen) and then tested against an air bubble in the bubble machine, with the following results: born-

Jan 1, 1943

By Cornelius F. Kelley

SEVENTY-FIVE years ago, in Wilkes-Barre, Pennsylvania, 22 men of vision banded together to initiate this great organization. Ideals and emotions mingled and united in the declaration of a twofold purpose: first, the more economic production of minerals and metals, and second, the promotion of greater safety and welfare for each man so employed-tacit recognition of the inseparability of humanitarian and utilitarian concepts of world progress. The members and honorary members then, as now, were mining engineers and associates from allied walks of life. Under the able guidance of David Thomas, our first president and outstanding ironmaster of the time, there were elected 46 members and associates, and the foundations of the Institute were laid. Conceived in a turbulent postwar era, the problems then faced had some similarity to those we face in this time of war-bashed uncertainty. With a Civil War behind them and once again dedicated to a spirit of national endeavor, they surveyed the landscape, then surged ahead toward a beckoning industrial horizon. That effort has never been relaxed. Poised upon the threshold of a new century, rancher, banker, engineer and businessman paused to contemplate and evaluate his natural endowments. Surrounded by immeasurable God-given wealth, necessity inspired

Jan 1, 1947

By I. Stapf

Systematic investigations on silver-rare earth metal systems have been extended on the Ag-Ce system in order to clarify the discrepancies reported in literature. The phase diagram has been reinvestigated on the base of thermal analyses and of microstructure examination on cast and annealed specimen. All intermetallic phases Ag4Ce, Ag3Ce, Ag2Ce and AgCe show no extended range of homogeneity, they melt congruently fm), or decompose peritectically (d) at 815 °C (d), 1030 °C (m), 855 °C (d) and 855 °C (m), respectively. The system shows eutectics at 793 °C/10 at.%, 780 °C/42 at.%, and about 505 °C/81 at.% Ce. d-Ce dissolves up to 2 at .% Ag and decomposes metatectically at 710 °C. Furthermore, the phase transformation of the intermetallics would be clarified. The phases Ag5Ce and Ag51Ce14 reported in literature could not be verified.

Jan 1, 1984

SOUTHERN CALIFORNIA SECTION Executive Committee SEELEY W. MUDD, Chairman. C. COLCOCK JONES, Vice-Chairman. FREDERICK J. H. MERRILL, Secretary-Treasurer, 631 Higgins. Bldg., Los Angeles, Cal. RALPH ARNOLD A. B. CARPENTER A. B. W. HODGES WILLIAM F. STAUNTON The third meeting of this winter season tool: place in a private dining room of the Sierra Madre Club in Los Angeles on Feb. 1, 1916, at 6:30 p.m., 22 members and guests being present. In the absence of the Chairman, S. W. Mudd, the Vice-Chairman, C. Colcock Jones, presided. After an enjoyable dinner the meeting was called to order, and the first paper by Ralph Arnold on Conservation of Oil and Gas in the Americas was read by the Secretary. W. F. Staunton then read an important paper on The Influence of California Oil on the Mining Industry of the West. In this he touched upon the uses of oil as a fuel for generating power, especially in connection with the Diesel engine. This paper was discussed it some length by J. F. Mitchell-Roberts, R. B. Moran, F. H. Asbury and L. D. Godshall. The Chair then introduced Robert B. Moran of the California State Mining Bureau, Deputy Supervisor of Gas and Oil, for the' Los Angeles . District, who addressed the meeting on the work of his department. The meeting concluded with A. B. Carpenter's reading of a paper on The California Gasoline Industry by W. R.. Hamilton, Manager of the Ventura Refining Co. F. J. H. MERRILL, Secretary. ,

Jan 4, 1916

Plans for the Petroleum Division during the ensuing year are in process of development, in contemplation of the usual fall meetings in the Mid-Continent and California areas, as well as the annual meeting to be held in New York in February, 1936. Houston, Texas has been suggested as the place for the Mid-Continent fall meeting, the exact date to be announced shortly. During the past year, the Division's technical programs, as in former years, have emphasized the wide fields of engineering endeavor in the petroleum industry yet remaining for more thorough investigation and discussion. An effort has been made to bring an international interest into the proceedings of the Division by inviting the participation of prominent foreign technologists. This viewpoint should promote a continuation in 1935 of past high standards, afford a more thorough understanding of problems throughout the membership, and maintain the Institute's position among the various technical organizations functioning particularly in the oil-producing and refining areas. In the list of subjects proposed for the fall meetings is the problem of estimating petroleum reserves. Various factors requiring study will include productive sand volume, porosity, average permeability, saturation, and types of recovery. Research papers are proposed dealing with energy consumption per unit of oil recovered, reservoir pressure or energy loss relationship to the usual volumetric method of estimation, and the study of oil and gas segregation within the reservoir. Other subjects tentatively suggested include new casing practice in relationship to wells producing from several productive zones, progress in lifting methods, repressuring, advanced methods in drilling economies, and the economics of conservation. Although the threat of overproduction yet remains, to a lesser degree than during the past few years, intensive activity is now being directed towards the discovery of new petroleum reserves. This situation undoubtedly will influence, in some considerable degree, the channels through which technical activities will be directed. A continuation of the commendable work on production statistics for the various oil-producing states and foreign countries has been effected. The usual papers dealing with the general economics of the industry will be reserved for the annual New York Meeting. The Stabilization Committee maintains its membership of nationwide authorities, and interest is manifest in new developments to meet the changing requirements of the industry.

Jan 1, 1935

By H. G. Schneider

The Smackover oil and gas field lies in Ouachita and Union Counties, Ark., in the south-central part of the state, in T.15 and 16S., R.15, 16, and 17W. It is 10 miles north of El Dorado, the principal business and railroad center in the south-central part of the state, and extends from the town of Smackover in all directions. Productive territory having an aggregate area of nearly 55 sq. mi. has been developed. It extends 6 miles from north to south and 12 miles from east to west. The field may be divided into two parts: the east district, which includes the area east of the town of Smackover, and the west district, which includes the area west of the town of Smackover. In relation to the neighboring productive fields of Arkansas, the Smackover field is 9 miles north of the El Dorado oil and gas field, 8 miles slightly west of north of the East El Dorado oil and gas field, and 16 miles east of the Stephens oil field. Smackover was discovered in May, 1922, when the Oil Operators Tnist drilled well No. 1 on the J. T. Murphy farm, in the southeast quarter of sec. 8, T.16S., R.15W. This well is located almost on the top of the Norphlet dome and was drilled to the Nacatoch sand. It had an initial open flow volume of 30,000,000 cu. ft. of dry gas per day, and a rock pressure of 950 lb. per sq. in. In July, 1922, the V. K. F. Co. completed the first oil well in sec. 29, T.l5S., R.l5W., on the north side of the Norphlet dome, and 3 miles north of the first gas well. This well started the active development of the north and northwest sides of the dome.] The field was extended westwards, when oil was discovered in the Nacatoch sand, during October, 1922, in sec. 4, T.l6S., R.l6W., 51/2 miles west of the original gas well. This opened up the so-called "light oil district," which is located on a structural terrace, for which the name

Jan 1, 1924

[59H1-Water Law and Its Significance to the Mining Industry by Wells A Hutchins 59H2-Relation of Land Subsidence to Groundwater Withdrawals in the Upper Gulf Coast Region, Texas by Leonard A Wood and A G Winslow 59F3-Hydraulic Mining of Gilsonite and Its Application to Coal Mining by J H Baker 59H4-Recovery of Phosphates by In Situ Fluid Mining by Sylvain J Pirson 59F5-Coal Cleaning Plant Design for Minimum Operating Labor by Wm M Bertholf and John D Price 59F6-Coke Combustibility A Neglected Characteristic by J D Price 59B7-Union Carbide's Uranium Operation at Maybell, Colorado by K W Lentz and F T Temple 59H8-A Rapid Method for Estimating Alumina in Feldspathic Sands by Hugh H Bein 59H9-Water Laws as Related to Dredging in Idaho by Robert A Lothrop, Richard B Porter, and Robert P Porter 58B19-Separation and Washing of Alumina Process Residue by Morton Handelman 59B11-Feed Preparation and Froth Modification for Fatty Acid Flotation by Carl C Martin and Burt C Mariacher 59B12-Design Requirements for Tailing Disposal in the Southwest by E Vern Given 59B13-Semi-Dome Shaped Buildings for Bulk Storage by Edward E Ives and William L Payne]

Jan 1, 1961

By R. D. Young, E. A. Harre

Nitrogen exists in two broad categories commonly designated as elemental nitrogen and fixed nitrogen. Elemental nitrogen is found in nature as a diatomic molecule and constitutes about 78%, by volume, of the earth's atmosphere. Fixed nitrogen is a common term used for nitrogen that is chemically bound to other elements. Although elemental nitrogen is very abundant, nonleguminous plants cannot utilize nitrogen unless it is in the chemically combined form. The content of this chapter is confined to fixed nitrogen since the uses and properties of elemental nitrogen and the fixed nitrogen compounds are different. Certain bacteria associated with legumes are able to fix atmospheric nitrogen, but not to the extent required by succeeding nonleguminous crops. The need to use fertilizers containing fixed nitrogen compounds to grow food crops has been recognized for hundreds of years, and from antiquity farmers have used organic wastes such as animal manures, vegetable wastes, sewage sludge, fish scraps, etc., containing these compounds for fertilizers. These organic materials have a low nitrogen content, however, and cannot support large-scale food production. Known commercial-size deposits of natural nitrates containing much higher nitrogen content exist only in Chile, and the possibility of the discovery of other significant deposits is remote. The Chilean deposits were the major source of nitrogenous fertilizers until the Haber-Bosch process for the production of synthetic ammonia was developed. In the Haber-Bosch process, nitrogen reacts with hydrogen at high temperatures and pressures and in the presence of a catalyst to form ammonia. Modern plants use air, water, and natural gas or other hydrogen sources to produce the ammonia that is now the key building block of the fixed nitrogen industry. Several major problems that developed in the 1970s continue with the nitrogen industry into the 1980s. These are (1) the continuing sharp escalation in the cost of feedstocks for ammonia production as well as all energy sources, and (2) the very steep increase in the investment cost of production facilities. More than 75% of the fixed nitrogen produced domestically is consumed as fertilizers. The types of materials used as fertilizers have changed significantly during the past years. There has been a trend from the use of low-analysis fertilizers to types which contain high percentages of plant nutrients. The average plant nutrient content (N + P2O5 + K2O) of fertilizers used in the United States has increased from 18% in 1930 to 32% in 1960 and today approaches an average of 44%. In the case of nitrogen fertilizers, the low analysis natural nitrates (16% N) gave way to ammonium sulfate (20% N) after about 1920. After World War II, ammonium nitrate (33.5% N) previously used in munitions, became established as the leading nitrogen fertilizer. Urea use as a fertilizer (46% N) began in the 1960s, and in the past 10 years has become the world's leading solid nitrogen fertilizer. Nitrogen Materials Anhydrous Ammonia-Anhydrous ammonia is a colorless gas at ambient temperatures and pressures and has a sharp pungent odor. Anhydrous ammonia is stored and transported as a liquid in high-pressure cylinders and tanks at ambient temperature, and in low-pressure tanks, barges, and ships at -28°F. Anhydrous ammonia is applied directly at 4 to 7-in. depths in the soil as a high-pressure liquid by special applicators, after which it expands to a gas that dissolves in the soil moisture or is absorbed on soil colloids. In other systems ammonia is metered into irrigation water and is thereby introduced into the soil.

Jan 1, 1983

By T. Yamasaki, S. Usu

Adsorption of potassium dodecyl xanthate from aqueous solutions on artificial and natural zinc sul-fides was studied by means of infrared absorption spectroscopy. The adsorption species and their stabilities varied depending upon the conditions of the surfaces of the zinc sulfides. Adsorption products were analyzed after they had been removed from the surface with pyridine. Zinc dodecyl xanthate was confirmed for surfaces covered with oxidized products while dodecyl alcohol and carbon disulfide were detected on purified or weakly oxidized surfaces. It is of great significance to study the adsorbed species of collectors on the surface of sulfide minerals with a view of increasing our understanding of the mechanism of flotation. Compared with other methods, infrared spectroscopy promises to be of particular value in determining the nature of the species adsorbed at the mineral/solution interface since it gives direct identification of the adsorption products; and, furthermore, it has an advantage over the electron diffraction technique which has been employed in similar problems in that infrared spectroscopy utilizes radiation of very low energy so that the probability of changing the unstable surface films during examination should be correspondingly decreased. Infrared spectroscopic studies concerned with sulfide mineral flotation have already been reported by several investigators on zinc sulfide-hexanthi01' and lead sulfide-xanthate2,3 systems. The purpose of the present study was to investigate the adsorption of potassium dodecyl xanthate (KDX) at the zinc sulfide-aqueous solution interface by means of infrared spectroscopy. Rarely is the pure zinc sulfide-xanthate system encountered in practical flotation since zinc sulfide is usually activated with small amounts of certain metallic ions, such as copper ion. However, investigation of the pure zinc sulfide-xanthate system appeared promising for studying the fundamental mechanism of the adsorption of xanthate on the sulfide minerals. Although there are few cases where xanthates having an alkyl radical higher than hexyl are employed in practical operations, KDX was used in this study since it was reported that the adsorbability of xanthate on zinc sulfide was increased with an increasing number of carbon atoms of the alkyl radicals.4 EXPERIMENTAL Samples: Experiments were made on artificial zinc sulfide and natural sphalerite. The artificial zinc sulfide was obtained commercially from Dainihon Toryo Co. as a fluorescent pigment of the purest grade A. Considering the fact that there are often cases where the surface of sulfide minerals are apt to be oxidized so that the adsorption of xanthate at sulfide mineral/solution interfaces may be substantially affected, two different procedures were employed in preparing the samples of the artificial zinc sulfide. 1) The zinc sulfide was washed with hot concentrated ammonium chloride solution (300 g per liter) to remove surface oxidation products and followed by washing with deoxygenated hot distilled water by centrifugation until the constant electric conductivity of the solution was reached (Sample I) (specific conductivity of the solution = 8.6 x l0-5 ohm-' cm-'). 2) Sample I in a suspension of 5% by weight was oxidized with a 1.5% aqueous hydrogen peroxide solution for about one hour, and then was washed with distilled water as mentioned in the preparation of Sample I (Sample 11) (specific conductivity of the solution = 1.0 x 10"4 ohm-' cm-'). Both Samples I and II were dried under vacuum and stored in a vacuum desiccator. The specific surface areas of the samples determined by the BET method using carbon dioxide gas were 19 x l04 cm2 per g for Sample I and 35 x l04 cm2 per g for Sample 11. In addition, a sample which was derived from Sample I was also prepared. In 40 ml of 3 x 10-2 M zinc sulfate solution was placed 2 g of Sample I for 2 hours, washed with distilled water by successive centrifugation until no sulfate ion could be detected and dried under vacuum (Sample 111). The purpose of this treatment will be described later. Natural sphalerite was carefully selected by hand, ground in a mechanical agate mortar for about 40

Jan 1, 1965

By F. H. Wilson, E. W. Palmer

The solid solubility of iron in 2 to 10 pct cupro-nickels increases with temperature and nickel content. Property changes accompanying various heat treatments indicate typical precipitation hardening behavior. Iron content also affects softening temperature and sub-scale formation. These factors, as well as impingement corrosion resistance, influence the optimum iron content of commercial alloys. FOR many years Cu-Ni alloys have been used extensively in the form of tubes, pipes, and plates for the construction of salt-water lines and surface condensers on shipboard and in tidewater power stations. The 30 pct Ni alloy has been considered more resistant to rapidly flowing sea water than alloys of lower nickel content, and has been standard on ships of the U. S. Navy. Some ten years ago, the still better corrosion resistance obtained by modifying the 30 pct Ni alloy with approximately 0.5 pct Fe was recognized, and the iron-bearing alloy rapidly superseded the plain alloy as the standard material for severe service. In 1945, Tracy and Hungerford1 published a study of the effect of iron on the corrosion of various cupro-nickels in sea-salt solutions, and their data indicated that the 10 pct Ni alloy containing about 0.75 pct Fe was equivalent to the 30 pct Ni alloy containing 0.5 pct Fe. This was confirmed by LaQue in discussion of the above paper, and by results in an experimental condenser set up at the Kure Beach marine test station of The International Nickel Co., reported by Freeman and Tracy.' The 10 pct Ni iron-bearing alloy is now being very widely used in applications where the 30 pct Ni iron-bearing alloy was formerly considered standard. While this "substitution" has undoubtedly been stimulated by the present extreme shortage of nickel, it must be emphasized that it involves no loss of service performance, and would have occurred anyway in the course of time, for economic reasons. In view of the increasing use of the 10 pct alloy, it seems desirable to make generally available the results of several investigations of Cu-Ni-Fe alloys carried out in the Metallurgical Research Laboratory of The American Brass Co. in recent years. The present paper, deals with the constitution of these alloys in the copper-rich corner of the system, and with the variations in hardness and tensile properties resulting from the heat treatment of alloys containing various amounts of iron. Most of this work is concerned with alloys containing 10 pct Ni. With over about 0.75 pct fe, the 10 pct Ni alloy is suscep- Alloys Several series of cupro-nickel alloys containing iron were used in these investigations. Most of them were prepared in the laboratory, but two samples of commercially fabricated alloys were included. Series A—Nominally 2 and 5 pct Ni, each with 0 to 1.5 pct Fe. Series B—Nominally 10 pct Ni with 0.1 to 0.4 pct Fe. Series C—Nominally 1.0 pct Ni with 0 to 2 pct Fe. Series D—Nominally 10 pct Ni with 3 to 5 pct Fe. Series E—Nominally 10 pct Ni with 1 and 1.5 pct Fe.

Jan 1, 1953

Members of the American Institute of Mining and Metallurgica Engineers can now secure copies of the Journal of the Institute of Metals of Great Britain at a special price of $5 for the two volumes issued during the year, postage extra amounting to approximately 25 cents. This Journal is one of the best books dealing with the subject of non-ferrous metals and alloys and this arrangement with the Institute of Metals permits our members to take advantage of this specially low price. Back numbers of the Journal can be purchased on the same basis. The Journal can be ordered directly through the office of the Institute of Metals, Great Britain 36 Victoria St., Westminster, S. W. I., London, England. The letter should be accompanied by an international money order and a copy sent to Secretary of the A. I. M. E. in order that the membership record may be checked.

Jan 9, 1919

By G. G. Brown

Enthalpy-entropy diagrams are presented for natural gases of 0.6, 0.7, 0.8, 0.9, and 1.0 gravity over the pressure range of 5 to 10,000 Ib. per sq. in. and temperature range of 32º to 700°F. The charts indicate directly the work requirement and temperature rise for adiabatic compression or temperature change for free emansion of natural eases. Computation and Uses of Charts The Mollier diagram (Fig. 4), in which the enthalpy (heat content) is plotted against the entropy with lines of constant temperature, pressure,, and in some cases volume, has been found most convenient when dealing with the compression, expansion, and flow of fluids. In dealing with the flow of fluids, the sum of the increase in the enthalpy, AH, plus the increase in kinetic energy, AM —, plus the increase in potential energy, ?MZ, representing the total increase in energy of the fluid in flow, is equal to the sum of the heat q, and work added, —w, to the fluid while flowing between the entrance and exit of the flow system. AH + AM— + ?MZ = q-w [1] In cases where there is no significant change in potential energy or in kinetic energy (velocity), it follows that the increase in enthalpy is equal to the total energy supplied to the fluid. Under such conditions' the changes in the property of the fluid as it flows through a throttling valve, choke, or any other similar arrangement, may be read directly from the enthalpy-entropy diagram by following a horizolltal line between the known pressures' When compressing Or expanding a gas by means of a Or or engine in which no heat is added to or subtracted from the gas, but only work done, the changes in the properties of the gas may be determined along a vertical line of constant entropy between the entering and exit pressures. The power required for the compression of the gas may be readily determined by converting the increase in enthalpy into the desired units. The enthalpy-entropy diagram for natural gases is to the gas engineer what the steam diagram is to the steam-power engineer. For this reason it would be extremely convenient if a reasonably satisfactory enthalpy-entropy diagram could be prepared as a function of the gravity of the gas. A careful study of the known properties of natural gas indicate that this is possible. The effect of temperature upon the enthalpy at constant pressure is expressed as the "heat capacity" or "specific heat" of the gas. The best available data for natural and petroleum refinery gases indicates the relationship shown in Fig. I. From this it is clear that the specific heat of natural gases is a function only of the gas gravity and the temperature at atmospheric pressure. The effect of pressure on the enthalpy of natural gases is dependent upon the pressure-volume-temperature relationships,

Jan 1, 1945

By Nicholas J. Grant, Yoichi Ishida, Arthur W. Mullendore

An inert particle -marker technique was developed to provide a direct measurement of grain boundary sliding during creep in tile interior of aluminum specimens. Groin boundary sliding in the interior as measured by this technique was found to be nearly the same or slightly lower than that measured on the surface. These data disagree with those obtained by the grain-counting technique developed by W. A. Rachinger. In tests where both techniques were used, the grain-counting technique gave large and variable values of grain boundary sliding. It is shown that the grain-counting technique gines erroneozcs results because of a preferred direction of grain growth during creep. A question which has long plagued those who study grain boundary creep is whether or not surface measurements yield a true representation of the deformation in the interior of a specimen. The first attempt to measure grain boundary sliding in the interior of a creep specimen was made by Rachinger.1 His technique is based on the measurement of average grain diameters, both parallel and perpendicular to the tension axis, followed by a calculation of the grain elongation from these measurements. The difference between total elongation, Et, and the calculated grain elongation, Eg, is considered to be the result of grain boundary sliding, Egb. Surprisingly large values of Egb/ Et (90 pct) came out of creep tests of pure aluminum at temperatures above 250°C (480°F), utilizing the Rachinger technique. This value is very much larger than the values of 8 to 15 pct measured by numerous investigators on the surface of a specimen. Values obtained on the surface by Rachinger, however, were consistent with those measured by the displacement of reference scratches. Chaudhuri and Grant2 repeated the Rachinger method for A1-10 pct Zn, and found the same large values of Egb/Et inside the specimen. However, from purely geometrical considerations, grain boundaries cannot slide without grain deformation; therefore, they questioned the validity of Rachinger's grain-counting method. Several authors2,3 have suggested that grain boundary migration during high-temperature deforma- tion may tend to restore the equiaxed grain shape in order to minimize interfacial energy. Rachinger4 tested this hypothesis and found that it did not hold. Grains elongated by rapid extension retained their elongated shape during a subsequent slow creep test. It appears that some other factor was responsible for the abnormally high values of .Egb/El. McLean and Gifkins5 made a survey of the effect of grain size on the ratio Egb/ Et, and proposed that the high values were the consequence of a small grain size. They failed to explain the low value of Egb/Et which Rachinger observed on the surface of the small grain size specimens, and suggested that the surface effect on the value of Egb/Et does not always occur. Many of the disagreements arising from Rachinger' s work stem from the fact that there was only one method of estimating grain boundary sliding in the interior of a specimen, and that method was of an indirect nature. If a marker line of some sort could be introduced inside of the specimen, one could make measurements just as clearly as on the surface. In the present investigation, the technique utilizes a layer of finely dispersed oxide particles inside the specimen introduced by hot press-bonding of two pieces of aluminum. Rachinger attempted a similar technique but with the oxide distribution he obtained there was so much interference with grain boundary motion that quantitative measurements were not attempted. MATERIALS AND EXPERIMENTAL PROCEDURE A) Materials Preparation. Two pure aluminum rods (impurity content in percent: Si, 0.002; Cu, 0.004; Fe, 0.002; Mg, 0.000: Zn, 0.000; V. 0.001) 1 in. diameter by 2 in. high were jacketed end to end in a 4-in.-diam cylinder of commercial-purity aluminum, 4 in, high, which had a l-in.-diam hole. The l-in.-diam mating surfaces of the two pure aluminum rods had been electropolished initially. This interface provided the oxide-film internal -marker plane after the hot press-bonding process, see Fig. 2. The composite was annealed for 1 hr at 900 F and hot upset more than 50 pct reduction in height in one step. The resulting slab was then rolled to 1/2 in. thickness; the pure aluminum test material was cut out and annealed at 900°F for 1 hr and cold cross-rolled to 1/8 in. thickness. The sheet was machined into specimens with a 1/8-in.-square cross section and a 1/2-in. gage length. The following heat treatment was given the specimens: Specimen 5A series: annealed at 1000°F for 5 min for grain-size control and then cooled to 700°F and held for 15 hr for stabilization.

Jan 1, 1965

By Y. Nakada, E. J. Fasiska, A. S. Keh, L. Zwell

DURING an investigation of solid-solution hardening of nickel by carbon,' we found that there were no reliable data on the dilating effect of dissolved carbon on the unit cell of nickel. Bernier2 reported an increase in lattice parameter of nickel (3.523A) when an unknown amount of carbon was introduced into solid solution (3.536A). Similarly KG, Tsien, and Misek3 found an increase from 3.523 to 3.531A when nickel was carburized. strong4 studied the variation of nickel lattice constant as a function of dissolved carbon. However, in his case carbon was introduced into nickel by solidifying the melt at 65 kbar. Therefore, his carbon concentrations were much above the highest equilibrium solubility limit5 (2.7 at. pct C at 1 atm). Knowledge of the lattice mismatch between solute and solvent is essential in understanding the mechanism of solid-solution hardening. Therefore, we decided to determine the dilation of the nickel lattice by carbon under the more usual conditions of atmospheric pressure. The material used was Inco Electrolytic Nickel of 99.95 pct purity, as specified by the supplier. The impurity contents in wt pct were: Fe, 0.01; Cu, 0.01; Co, 0.03; 0, 0.005; C, Si, S, N, trace. To this base material various amounts of AUC-grade high-purity carbon were added during vacuum induction casting. Ingots, 2 in. in diam, were heated in a muffle furnace at 1000°C for i hr., hot-rolled to 1/2-in. thickness, and quenched into brine. All ingots with carbon concentration greater than 0.98 at. pct were enclosed in a cast iron box during the heating to minimize decar-burization. Small pieces were then either swaged down to 0.028-in.-diam wire or cold-rolled to 0.010-in.-thick sheets. After the final cold reduction in area of 50 pct, the specimens were recrystallized by heating in evacuated capsules at 1100°C for 60 to 80 sec and then quenched into brine. The final grain size was 50 to 100 µ. The carbon contents of the alloys, Table I, were determined by a combustion method

Jan 1, 1969

By R. W. Coughlin, W. U. Ault

Experiments in laboratory and mine have clearly demonstrated the usefulness of radioactivity detection for directly measuring the potassium content of potash ore as mined. This paper presents the results of these tests and documents the design of a system for automatically grading and sorting potash ore on the basis of radiation detection. It is shown how the experimental results in the subject mine lead directly to the design of this kind of an automatic control system. The system is capable of grading the ore with an accuracy of approximately ±2% K20 content or better. Due to the usual stratification of the ore body, mining potash seldom presents an extreme problem of gangue separation. Nevertheless, it is frequently necessary to transport within a potash mine and even hoist to the surface considerable quantities of halite and other valueless materials. Up to recent times it has been customary to recognize and route these materials by simple visual and manual techniques. However, the work reported here clearly demonstrates that it is now practical and economical to improve upon these techniques by continuous measurement1 of the naturally occurring radioactive isotope, potassium-40. It was the purpose of the work reported here to investigate this technique and assess its applicability. LOCALE OF EXPERIMENTS The work described here was carried out in a potash mine in Carlsbad, N.M. At the working face of this mine the potash ore is freed by blasting; it is then transported a short distance by shuttle car to a moving-belt system which conveys it to the main shaft where it is hoisted to the surface. Quantities of gangue which are also produced in the mining operation are disposed of in mined-out sections of the mine where possible. Otherwise, this material which contains only a small percentage of potassium (as K2O) must also be transported by the conveyor-belt system to the main shaft and then hoisted to the surface and discarded. With this situation, any measuring device for automatic control purposes must be capable of clearly distinguishing between gangue containing insignificant amounts of K2O and ore containing larger percentages of the same mineral. The conveyor-belt system transports the material from the mine face to a rotary crusher and then to temporary storage pits at the main shaft. This is shown in Fig. 1. Upon leaving the conveyor belt the material enters either one of the two storage pits according to the position of a manually operated gate. It was decided that all experiments should be carried out at the conveyor belt between the crusher and gate with a view to the possibility of providing a signal which could operate the gate automatically. THEORETICAL BASIS AND LABORATORY EXPERIMENTS In principle it is possible to grade potassium-bearing ore on the basis of radioactivity. Natural potassium contains 0.012% K40, which is radioactive with a half-life of 1.3 x 10' years. Although about 89% of the K40 disintegrates to Ca40 by beta decay, the other 11% changes to Ar40 by electron capture and the emission of gamma rays. Unlike the ß-rays which are readily absorbed in the first few millimeters of ore surrounding the disintegrating nucleus, the y-ray photons will escape from an ore sample several inches in size. A detector rigidly mounted under a conveyor belt loaded with potash ore will intercept some constant fraction of all the photons emitted from the ore within its field of view. Under these

Jan 1, 1968

Abel, Charles Edwin, Student, Univ. of California Los Angeles, Cal. '81 Ames, Marshall B., Blaine-Republic Co Republic, Wash. "81 Anderson, Norman John, Student, South Dakota School of Mines Rapid City, S. D. '82 Angst, Robert A., Jr., Student, Michigan College of Min. & Tech Houghton, Mich. '82 Apgar, James William, Student, Lafayette College Easton, Pa. '83 Armstrong, John R. Box 274, Neosho, Mo. '81 Armstrong, Robert H., Student, Lafayette College Easton, Pa. '81 Arnot, Paul H. 608 S. Acacia St., Compton, Cal. '81 Asel, Philip R., Student, Colorado. School of Mines Golden, Colo. '82 Atkins, William Robert, Student, Michigan College of Min. & Tech Houghton, Mich. '82 Augenthaler, Robert L., Student, New Mexico School of Mines Socorro, N. M. '82 Augustine, Robert W., Student, Alaska School of Mines College, Alaska. '82. Avery, Eugene A., Student, Montana School of Mines Butte, Mont. '82 Babcock, Norwood N., Student, South Dakota School of Mines Rapid City, S. D. '82 Baer, Jerome S., Student, Michigan College of Min. & Tech Houghton, Mich. '81 Baker, Robert C., Student, Pennsylvania State College.. 112 E. Beaver Ave., State College, Pa. '82 Baldwin, William C., Student, Univ. of Illinois Urban, III. '81

Jan 1, 1932

By R. W. Mancantelli, J. R. Woodward

IN 1947 a large low grade deposit of uranium was located in the northwest corner of Saskatchewan, in the Beaverlodge property of Eldorado Mining & Refining Ltd. Most of the values occur as thin seams and as coatings on other minerals, and the ore, which is light and friable, is not amenable to the usual gravity methods of concentration. The acid leaching process developed to retreat the company's Port Radium tailings was also impractical, as the percentage of carbonates is high and the percentage of sulphides relatively low. Construction of the mill building and installation of equipment, both scheduled for 1952, awaited selection of a satisfactory ore dressing process on or before Oct. 1, 1951. An extensive research program on dressing of ores from the Ace mine therefore was undertaken by the Mines Branch in Ottawa, a research team at the University of British Columbia, and an ore dressing group at the company's Port Hope refinery. Pilot plant operations were conducted at the Ottawa plant of Sherritt Gordon Mines Ltd. under the general direction of C. S. Parsons, consultant on metallurgy and ore dressing for Eldorado. In mid-September, having compared results of the several research programs, Dr. Parsons recommended a process employing a carbonate or basic leach. He reported that, while the chemistry of the process had been proved, engineering of the flowsheet was incomplete, and he suggested that under normal conditions further pilot plant work at the Ace mine might be profitable. However, since this would involve a delay of 12 to 18 months in bringing the property into operation, he recommended that design of the concentrator proceed immediately. Concentrator capacity was determined by two considerations: 1) the amount of ore then available and 2) the expectation that continued improvements would be made in the ore dressing process as a result of the intensive research being carried out by the Mines Branch of the Department of Mines and Technical Surveys. As these improvements could affect both the chemistry and the en-

Jan 1, 1956

By Robert M. Yerkes

The following is a brief account of the methods of measuring intelligence especially prepared for use in the U. S. Army, of typical results, and of some of their immediately practical applications. It has been prepared for the assistance of army examiners and for the information of all who are interested in the relations of scientific placement to military efficiency. Purpose of the Intelligence Tests Under the direction of the Division of Psychology, Medical Department, and in accordance with provisions of War Department General Order No. 74, mental tests are given recruits during the 2-wk. detention period. These tests provide an immediate and reasonably dependable classification of the men according to general intelligence. Their specific purposes are to aid: 1. In the discovery of men whose superior intelligence suggests their consideration for advancement; 2. In the prompt selection and assignment to development battalions of men who are so inferior mentally that they are suited only for selected assignments; 3. In forming organizations of uniform mental strength where such uniformity is desired; 4. In forming organizations of superior mental strength where such superiority is demanded by the nature of the work to be performed; 5. In selecting suitable men for various army duties or for special training in colleges or technical schools; 6. In the early formation of training groups within regiment' or battery in order that each man may receive instruction and drill according to his ability to profit thereby; 7. In the early recognition of the mentally slow as contrasted with the stubborn or disobedient; 8. In the discovery of men whose low-grade intelligence renders them either a burden or a menace to the service.

Jan 1, 1919

By J. J. Cosgrove, J. E. Warren

A general model which approximates the effect of cross- flow has been developed to give a practical method for predicting the waterflood behavior of a stratified reservoir. The model is based on a modification of Dietz's theory and allows for variations in both the permeability and hydrocarbon pore volume. In the particular cases considered, it is assumed that the permeability can be characterized by a log-normal distribution and the hydrocarbon pore volume by a normal distribution. A simple graphical method which enables the practicing engineer to predict the behavior of a stratified system is presented The results obtained by the proposed method are compared with those obtained by the Dykstra-Parsons method. As a result of this study the following conclusions have been drawn: (1) The effect of cross-flow in a stratified system can be appreciable, particularly at very favorable or very unfavorable mobility ratios; (2) Under normal conditions, the effect of variations in the hydrocarbon pore volume can be neglected; and (3) The failure to use all of the available permeability data can lead to large errors in the prediction of the behavior of a stratified reservoir. INTRODUCTION Various methodshavebeenproposedto characterize and to predict the waterflood behavior of a stratified reservoir. Most of the methods assume that the reservoir is composed of discrete homogeneous continuous layers. With this model, the degree of stratification can be measured by several parameters based on core-analysis data. Among these are the Lorenz coefficient1 and the variation of a log-normal permeability distribution? The behavior of stratified systems is usually predicted by the Stiles, Dykstra-Parsons method or some modification of these. In both of these methods the reservoir is divided into discrete homogeneous layers with no cross-flow between layers. In the Stiles method the mobility ratio is assumed to be equal to unity while in the Dykstra-Parsons method it is allowed to take on any value. Other predictive methods have been proposed; method allows for cross-flow between the beds and a method by Schmalz and Rahme6 correlate.s the recovery directly with the Lorenz coefficient. In this new approach, which is essentially a continuous analog of Hiatt's method, the effects of both mobility ratio and cross-flow between the beds have been included. It is assumed that the permeability can be represented by a log-normal distribution and the hydrocarbon pore volume or porosity by a normal distribution. These types of distributions have been observed by several authors, 1,2,4 and most field data seem to confirm their observations; e.g., if these distributions are assumed and there is a 1:l correspondence between porosity and permeability samples, the commonly encountered linear relationship between porosity and the log of permeability is obtained. Since, in many field cases the permeability and poro sity data are truncated or cut-off at predetermined upper and/or lower values, the effect of discarding part of the data was investigated with the proposed method. A better technique for truncating the data is suggested. THEORY In the derivation of the method to be described in this paper the following assumptions are made: 1. Capillary forces are negligible per se; their effects are only manifest in the relative permeability curves. 2. The fluids are immiscible, incompressible and homogeneous. 3. The reservoir is horizontal and uniformly thick; it is initially liquid saturated i.e., connate water and oil. 4. The reservoir is composed of discrete layers, each having its own permeability, porosity and connate water saturation; each layer is homogeneous,

Jan 1, 1965