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By AIME AIME

A new Index of the Transactions, Volumes I. to XXXV., is now being prepared, and will probably be ready for distribution during the coming summer. The Index will be about the size of the average volume of the Transactions, and will be bound in cloth and in half morocco. The price of the cloth-bound copy is $5, expressage prepaid. Half morocco binding will cost $1 extra. It is very desirable that all who wish to purchase this Index will notify the Secretary's office promptly, sending a check, money-order or draft, made payable to the American Institute of Mining Engineers.

May 1, 1907

By E. C. Wright, P. W. Mumma

This paper describes some properties of steels in the composition range 0.10 to 0.30 per cent carbon and 1 to 7 per cent chromium. It is well known that some steels of this type develop high tensile strengths upon receiving comparatively simple heat treatments, such as ordinary air cooling from appropriate temperatures, with or without subsequent tempering treatments. These high strengths are frequently associated with unusual toughness as measured by the Izod or Charpy impact test. The chromium content, in addition to imparting the above properties, enhances the resistance to corrosion and improves the strength and oxidation resistance at elevated temperatures. Moreover, these steels have good forging and fabricating properties, as evidenced by the fact that several thousand tons of seamless tubing have been made during the past five years from steels containing 0.10 to 0.25 per cent carbon and 5 per cent chromium. Composition and Properties of Materials Tested Twelve 15-lb. induction furnace heats of the compositions shown in Table 1 were prepared, using low-carbon open-hearth steel base melts

Jan 1, 1933

By D. E. Thomas, C. E. Birchenall

ALTHOUGH Eoltzmann gave a mathematical solution for the diffusion equation (for planar diffusion in infinite 01. semi-infinite systems only) in 1894 allowing for variation of the diffusion coefficient with a change in concentration, it was not until 1933 that this solution was applied to an experimentally investigated metallic system. The calculation was carried out by Matano' on the data obtained by Grube and Jedele3 for the Cu-Ni system. Since that time concentration dependence of the diffusion coefficient has been demonstrated for many pairs of metals. However, the nature of this dependence has never been fully elucidated. Many investigators have suspected that these variations could be related to the thermodynamic properties of the solutions, one of the earliest explicit statements being contained in a discussion of irreversible transport processes by Onsager' in 1931. Development along these lines has been greatly retarded by the lack of reliable data on the variation of tliffusivity with concentration, the paucity of the thermodynamic data for the same systems at the same temperatures and compositions, and an incomplete understanding of the relation of the thermodynamic properties of the activated state for diffusion to the bulk thermodynamic properties. The last factor has been discussed by Fisher, Hollomon, and Turnbull.5 In many instances where data exist, it is difficult to know which are acceptable. This problem probably applies more strongly to diffusion data than to activity measurements. For instance, four sets of observers"-" have reported self-diffusion coefficients for copper. The average spread between extreme results is a factor of about four, though the individual sets of data are self-consistent to about 20 pct. Thus one or more factors are out of control, at least in these experiments, making estimates of internal error unreliable. The most reliable diffusion data in most systems have resulted from the use of welded couples with a plane interface from which layers for analysis are machined parallel to the interface after diffusion. The layers are analyzed, and the result is a graphical relation between distance and concentration, usually called the penetration curve. Given the same set of analytical data and distances and following the same procedure in computation, different observers will generally produce diffusion coefficients which vary appreciably, especially at the extremes of the concentration range. Experiments must be carefully designed so that the precision is good enough to answer a particular question unequivocally. In the first calculation of the dependence of the diffusion coefficient on concentration in the metallic solid solution Cu-Ni, Matano found that the coefficient was insensitive to concentration from 0 to 70 pct Cu, after which it rose more and more steeply to some undetermined value as pure copper was approached.' The same behavior was reported for Au-Ni, Au-Pd, and Au-Pt.* The data used were those of Grube and Jedele which were very good at the time, but are not considered particularly good by present standards. Furthermore, the method of calculation makes the ends of the diffusion coefficient-concentration curve unreliable. For better reliability, the high copper end of the curve has been checked by incremental couples, where the concentration spread is 67.7 to 100 atomic pct Cu. The implication of the curves calculated by Matano was that diffusion is very concentration sensitive in one dilute range of this completely isomorphous system and hardly at all in the other. Matano's result is confirmed. Later Wells and Mehll0 published data on diffusion in Fe-Ni at 1300°C, which represent a thorough test of the shape of the concentration dependence curve. They ran couples with the following ranges of nickel concentration: 0-25 pct, 1.9-20.1 pct, 0-20.1 pct, 20.1-41.8 pct, 0-99.4 pct, and 79.3-99.4 pct. Although the trend of the data indicates an S-shaped concentration dependence, their curve was drawn to the pattern set by Matano. Their original data have been recalculated for the 0-99.4 and 79.3-99.4 pct couples. Wells and Mehl's points and two independent recalculations from the raw data are plotted in Fig. 1. What appears to be the best curve is drawn through them. This curve shows little sensitivity to composition in both dilute ranges with a strong dependence at intermediate composi-tions.? Similar experiments on the Cu-Pd system are reported here at temperatures where solubility is unlimited. These lead to the same type of concentration dependence for the diffusion coefficients as was found upon recalculation of the data for the Fe-Ni system. Experimental Procedure Cu-Pd: The concentration dependence of the diffusion coefficient may be determined by the use of

Jan 1, 1953

By Jack C. Jones, Hemendra N. Kalia

This paper is partially based on a comprehensive ground control investigation that was conducted by Harza Engineering Company under a contract from the Bureau of Mines. This investigation required in- stalling several types of ground movement indicating devices on the surface and in the mine. The major instrumentation systems consisted of hydraulic borehole pressure cells, multi-point extensometers, in- clinometers, convergence indicators, Jack pressure recorders time domain reflectometers, and a 200 station subsidence network. The investigation demonstrated the versatility of the system. We were able to install pressure cell s to a depth of over 200 feet in the coal bed and we were successful in installing 10 pen mechanical recorders to monitor differential strata movement. In this paper, we have briefly discussed data from 18 borehole pres- sure cells, two time domain reflectometer cables and four subsidence lines. The data collected showed that the front and rear abutment pressures were approximate1 y 1000 feet (304.81~1) to 1200 feet (356.76111) from the active face. The peak pressure was about 4 times the over- burden pressure.

Jan 1, 1983

By L. S. Darken, H. A. Wriedt

The equilibria at 1 atm total pressure and 600° to 1300°C (1112° to 2372°F) between gas mixtures with various partial pressures of the reactive constituents (principally sulfur dioxide, carbon dioxide, water vapor, oxygen or carbon monoxide, and hydrogen) and coexisting solid phases (groups variously including calcium oxide, calcium carbonate, calcium sulfide, calcium sulfate, iron, ferrous sulfide, and the iron oxides) are examined. Tables and charts show the combinations of temperature, oxygen activity, and carbon dioxide partial pressure under which the various groups of the solid phases coexist and the corresponding sulfur dioxide pressures. In the presence of calcium sulfide, calcium sulfate, and calcium oxide, the partial pressure of sulfur dioxide has a peak value at each temperature which increases from 101 atm at about 800°C (1472°F) to 1 atm at about 1200°C (2192°F). With water vapor present, hydrogen sulfide may predominate among gaseous sulfur compounds, particularly at low temperatures and oxygen activities; under all other circumstances considered, sulfur dioxide is the dominant gaseous sulfur-bearing species.

Jan 1, 1974

By Charles Morgan

AN increased demand for brown iron ore in the Birmingham district during the past 18 months has caused renewed activity both in prospecting and mining these ores. In recent years the production in Alabama has ranged from 41,559 tons in 1932 to 639,351 tons in 1928. During the last 9 years about 83 per cent of the total brown ore produced in the United States has come from Alabama (Tables 1 and 2). PROSPECTING Two methods of prospecting are used in this district: (1) test pits, (2) churn-drilling. Usually there is certain quite definite information on an area to be prospected; some of the indications are float ore such as small gravel or small and large boulders known as "dornicks" scattered over the surface, and ore exposed by erosion in gulleys and ravines, which have cut or eroded through the overburden. Often these natural erosions furnish an indication of the thickness of the ore and to some extent of the area of the ore body.

Jan 1, 1937

By David J. Mack, Chin Bea Kim

The decomposition of the Ni-Zn eutectoid at 56 wt pct Zn was studied by isothermal transformation. Its progress was followed by metallographic, hardness, and X-ray diffraction methods. Three transformation products were found: lamellar pearlite at high temperatures; an intermediate temperature structure; and martensite at the lower temperaCures. No transition structu,ves were found. THE decomposition of the Ni-Zn eutectoid at 56 wt pct Zn was stuadied as part of a long-range program of study on the eutectoid transformation in alloy systems which do not have one or more components which exhibit allotropy. Available information on the Ni-Zn eutectoid transformation is limited to that presented in connection with the determination of the phase dilagram. No systematic studies of the eutectoid were found in the literature, alkhough the microstructures of the Ni-Zn eutectoid were reported by Tamuru.3 X-ray diffraction data exist for the ß, ß1, y , and y1 phases.' EXPERIMENTAL PROCEDURE The eutectoid alloy was prepared from "A" nickel shot and Bunker Hill super-purity zinc (99.998 pct).

Jan 1, 1962

By Robert F. Calman

OUTLINE FIVE EXAMPLES OF GOLD-LINKED FINANCINGS 1. Financing the Lupin Mine • Sale of Cdn $40.0 million of 12% preferred shares and Cdn $40.0 million of Gold Purchase Warrants @ $595 per ounce. 2. Financing the Copper Range acquisition • Borrowing 100,000 ounces from a Canadian chartered bank @ US$307 for five years. 3. Financing the Round Mountain expansion • Borrowing up to US $80.0 million in dollars, convertible into gold, repayable over five years from a group of North American banks. 4. Financing the Tenneco Precious Metals Division acquisition •Sale of SFr 110.0 million of ten year 3-718% bonds with warrants to buy 132,000 ounces of gold at US $560. 5. On Forward Sales, Puts and Calls • Gold, Silver, Canadian Dollars, Swiss Francs THE FINANCIAL RULES AT ECHO BAY 1. Never bet the company 2. Equity is the primary form of capital for a gold mining company 3. On debt 4. The Yardsticks for Corporate Decisions 5. Financial Community Relationships 6. Dividend Policy No Text Available Tables Follow

Jan 1, 1990

By A. M. Skov, L. F. Elkins

First response to large-scale water flooding in the fractured very low permeability Spraberry sand has led to a new unique cyclic operation. Capacity water injection is used to restore reservoir pressure. This is followed by marly months production without water irzjection and the cycle repeated. Expansion of the oil, rock and water during pressure decline expels part of the fluids but capillary forces hold much of the injected water in the rock. At least with reservoir pressure restored and with partial water flood development, field performance has proved this cyclic operation is capable of producing oil from the nzatrix rock at least 50 per cent faster and with lower water percentage than is imbibition of water at stable reservoir pressure. INTRODUCTION The Spraberry Field of West Texas presents unusual problems for both primary production and water flooding. Extensive interconnected vertical fractures in the fractional-md sandstone permitted recovery of oil on 160-acre well spacing, but they made capillary end effects dominant. Primary recovery by solution gas drive is less than 10 per cent of oil in place. The concept of displacement of oil from the sand matrix by capillary irnbibition of water has led to field techniques which promise greatly increased oil recovery. Free exchange of laboratory research, reservoir information and results of field pilot tests among the various companies has been very important in development of this technology. Five units covering a total of 170,000 acres have been formed for water flooding, and 10 other areas covering an additional 175,500 acres are in various stages of unitization. Part of the Driver Unit reaching fillup first has demonstrated very unusual waterflood behavior and indicated numerous operating problems that will develop within and among the various units. SPRABERRY ROCK AND PRIMARY PERFORMANCE The Spraberry, discovered in February, 1949, is a 1,000-ft section of sandstones, shales and limestones with two main oil productive members: a 10-15 ft sand near the top and a 10-15 ft sand near the base. In part of the field some thinner intermediate sands are oil productive, and others are water bearing. All sands have permeabilities of 1 md or less and porosities of 8-15 per cent. Ordinary core analysis and electric and radiation logs are ineffective in differentiating between oil productive and nonprcductive sands. Sands capable of containing producible oil are best identified by mercury injection capillary pressure measurement and, in some cases, by core water saturation. About 3,500 wells have been drilled in the 500,000-acre trend. Vertical fractures were observed in practically all Spraberry cores. Continuity and interconnection of fractures were confirmed by pressure interference among wells during early development.' Major fractures trend northeast-southwest as indicated by oriented cores and confirmed by five fluid injection tests, by analysis of the pressure transients observed during development,''' and by three interference tests in the Driver Unit Water Flood reported herein. Fracture spac- ing probably averages inches to a few feet. Spraberry wells typically produced 100-400 BOPD initially after hydrauLic fracture treatments. By 1962 oil production had declined to an average of 12 bbl/well/day, near the economic Limits of operation. Reservoir pressure had declined from 2,300 psi initially in the Upper Spraberry and 2,500 psi in the Lower Spraberry to 500-1,000 psi. Partial closing of the fractures with declining reservoir pressure is believed to be the cause of such low oil production rates at these relatively high reservoir pressures. Cumulative recovery of 208 million bbl of oil is 80 to 90 per cent of that recoverable by primary means. Performance of the entire reservoir is summarized in Fig. 1. IMBIBITION WATER FLOODING By 1952 reservoir performance indicated low primary recoveries. Most engineers, expecting serious channeling of injected fluids through the fractures, held little hope for secondary recovery. With its extensive background of research on the fundamentals of fluid flow within reservoir rocks, Atlantic's Research and Development Division on short notice in 1952 conceived that displacement of oil by capillary imbibition of water into the rock might significantly increase Spraberry recovery. Laboratory data reported by Brownscombe and Dyes scaled to probable reservoir conditions showed potential waterflood recovery equal to or greater than primary recovery with a 10-15 year flood life.= A pilot test using three 40-acre injection wells, one central producing well and 18 surrounding observation wells demonstrated technical feasibility of the process. Injection of 1.5 million bbl of water from November 1952 to August 1955 proved water entered the rock and displaced oil

By J. B. Dilworth

Outcrops of coal have been discovered in many localities in the Philippine archipelago, and practically all of the larger islands contain deposits of this mineral. Very little prospecting has been done to determine the value of the various cod-bearing areas, but so far as known, the largest and most promising fields are found: (1) in northern Cebu; (2) in the small island of Batan, a part of the province of Albay in southeastern Luzon; (3) in the somewhat larger island of Polillo, off the east coast of Luzon, and (4) in southern Mindoro, near the small coast town of Bulalacao. Northern Panny, south-central Cebu, and various localities in southern Luzon, Masbate, Negros, and Mindanao also afford evidences of the existence of coal-beds, the extent and value of which have not yet been proved. The general position of these islands and districts is shown on the map of a portion of the Philippine Islands, Fig. 1. Some of these coal-fields have been known for many years (coal was discovered in Cebu in 1827 and in Batan in 1842),'

Jan 1, 1909

Transit A light weight, totally enclosed theodolite, especially designed for mining, has been placed on the market by Askania Werke, A. G. The instrument weighs only 41/4 lb and measures 51/8 x 71/2 in. without tripod and in a waterproof aluminum hood. It may be mounted on tripod or bracket without removing the protective hood. [ ] Standard equipment includes diagonal eyepiece rotating in all directions which eliminates need to be in line with scope for sighting and makes an auxiliary scope unnecessary for steep sights. The transit reads direct to 1 minute and may be estimated to 6 seconds by means of optical micrometer on both horizontal and vertical circles. The telescope in vertical position serves as optical plummet, sighting through an opening in the base. The instrument is shown above mounted for attaching to a pin driven in timber or rock, eliminating tripod or set-up bar in cramped quarters. The chain clamp in the lower picture is used on timber or steel ground supports. Complete with carrying case and set-up brackets, ready for use in a raise, it weighs less than 6 lb, and the protective hood remains on until the instrument is securely mounted. [ ] Accessories for increasing versatility of this mining theodolite are: tripod, electric illumination for optical micrometer and reticule, close range objective lens, and objective lens prism for sighting vertically in front of the instrument. Circle No. 1

Jan 1, 1952

By R. W. Balluffi, R. Resnick

NUMEROUS investigations of chemical diffusion in a brass have been made and the results are collected in several places.1-3 This work has been mainly concerned with the determination of the chemical diffusivity as a function of composition and temperature. In 1947 Smigelskas and Kirken-dall&apos; showed that zinc and copper diffuse at different rates in face-centered-cubic brass, and since then, a number of efforts have been made to determine the intrinsic diffusivities of zinc and copper in this alloy.1, 5-9 Horne and Mehl8 in particular have recently determined the intrinsic diffusivities as functions of temperature and composition using sandwich-type couples and inert markers. Inman et al." also have determined the intrinsic diffusivities in homogeneous alloys using tracer techniques. When the present work was started, no information of this type was available. Consequently, measurements of the intrinsic diffusivities were made as a function of temperature at a constant composition of 28 atomic pct Zn with vapor-solid diffusion couples where the zinc was diffused into the diffusion couple from the vapor phase. The application of these couples to the study of diffusion in a: brass has been described previously.0,7 The temperature dependence of the intrinsic diffusivities was found to follow the relation D, = A, exp(-Hi/RT) and the values of Hzn, and Hcu, were found to be closely the same. It is emphasized, however, that the chemical dif-fusivity (D = N1D2 + N2D1) is a composite diffusivity and does not necessarily follow this exponential form. It is usually found to do so within experimental error for substitutional alloys because the heats of activation of the intrinsic diffusivities generally are not greatly different.&apos;" Also, at the onset of this work, there was no information available concerning possible unequal diffusion rates of individual components and the existence of a Kirkendall effect in alloys with other than face-centered-cubic structures. Since then, two reports indicating a Kirkendall effect in body-centered-cubic ß brass have appeared. Landergren and Mehl" have published a note describing Kirkendall diffusion experiments with sandwich-type couples. Inman et a1.9 also find a Kirkendall effect in this alloy using the tracer technique. In the present work, several aspects of the Kirkendall effect in ß brass were further investigated using vapor-solid couples. Two different couples were used, one in which the zinc was diffused into the specimen from the vapor phase and the other in which the zinc was diffused out of the specimen into the vapor phase. Briefly, the existence of a Kirkendall effect is confirmed and it is found that Dzn/Dcu = 3 at about the 46 atomic pct composition in this alloy at 600°, 700°, and 800°C. As a result of the unequal diffusion rates of zinc and copper, volume changes occur and subgrain formation is observed in the diffusion zone. In addition, significant porosity is produced by the precipitation of supersaturated vacancies. Diffusion in this alloy is therefore outwardly similar to diffusion in a brass where these effects are also observed, a Brass Experimental Methods—The use of vapor-solid couples in studying diffusion in a brass has been described in previous articles.6,7 The method briefly consists of sealing a copper specimen with Kirkendall markers initially placed on its surface in an evacuated quartz capsule along with a large zinc source of fine a brass chips and then diffusing the zinc into the specimen through the vapor phase. The zinc concentration at the specimen surface rises rapidly enough to a value near that of the a brass source so that the surface concentration may be regarded as constant during diffusion. Under these boundary conditions, values of the chemical diffu-sivity may be obtained by applying the Boltzmann-Matano analysis to the concentration penetration curve, and the intrinsic diffusivities may be obtained from Darken&apos;s5 equations when the velocity of marker movement is known. The diffusion specimens were made from OFHC copper in the form of disks 3.2 cm diam and 0.5 cm thick with faces surface-ground parallel to within +0.001 cm. Markers in the form of fine alumina particles <0.0002 cm diam were placed on the specimen surface. These specimens were then sealed in quartz capsules along with enough a brass chips of a 30.0 atomic pct Zn composition to keep the source concentration from decreasing by more than 0.3 atomic pct Zn as a result of the loss of zinc to the specimen during diffusion. The quartz capsules which were initially evacuated to a pressure of

Jan 1, 1956

By T. E. Weirich

Although 1931 witnessed no new discoveries of oil or gas in Oklahoma, the year is especially outstanding because of price demoralization, political intervention, abandonment of marginal properties, a strict curbing of oil flow from wells in flush fields and an extension of proration into settled fields. In spite of a strict, adherence to proration agreements, the price per barrel of oil sank from 65c to $1.07 to a low level of 10c to 22c. Table 1 gives the price range for crude oil in Oklahoma during the year. Under a martial law order by the governor, a period intervened from Aug. 4 to Oct. 10, of complete shutting in of the flush fields. This condition created an abrupt decline in the production curve during the two months&apos; period. Oklahoma, as elsewhere, is passing through a "transition period" of relieving expensive above-ground storage by maintaining the more copious supplies of crude oil in the natural reservoirs. For many years the thousands of small, nearly depleted wells have been considered as being the "backbone of the industry." A large number of wells of this type are now idle or completely abandoned. More than 1100 abandonments were recorded by the state Corporation Commission during the year. The industry is becoming less interested in these small wells, replacing the former attitude by the curbed potentialities of flush pools. Many of the major companies are grouping these marginal properties with those of adjacent owners, operating the whole

Jan 1, 1932

The Institute maintains a dual relationship with students: (1) an indi¬vidual relationship with a Student Associate; and (2) a relationship with local organizations of students, known as Affiliated Student Societies or Stu¬dent Chapters. 1. The conditions of Student Associateship are set forth in Section 9, Article I, of the Bylaws of the Institute (see page 57 and following pages). During 1934, sundry amendments were made for the purpose of improving the student relationship. Post-graduate students are now eligible; and associateship can be maintained, with the payment of the regular dues of $2 per year, for 18 months following graduation in June. With his regular dues, each Student Associate is entitled to receive during the year his choice of Mining and Metallurgy, Metals Technology, Mining Technology, Petroleum Technology, or two "classes" of Technical Publications; and on payment of an additional fifty cents he can have both Mining and Metallurgy and any one of the others. He is accorded the privilege of getting special publications such as "The Porphyry Coppers" and "Ore Deposits of the Western States" at the reduced prices applicable to Members; he has the privileges of the Engineering Societies Employment Service and the Engineering Societies Library; and he is not only invited but urged to attend all meetings of the Institute, its Divisions and its Local Sections. The Institute wants to extend the hand of professional fellowship to students following mineral industries curricula.

Jan 1, 1938

By Donald F. Kennedy

During the past several years Climax Molybdenum Co. has been engaged in testing various types and sizes of hollow drill steel. The majority of tests have been on 7/8-in. hexagon st.ee1, inasmuch as it represents approximately 70% of total drill steel consumption at the Climax operation. Prior to December 1960, tests on 7/8-in. hexagon drill steel were conducted on steel with a forged collar and, in most cases, with a threaded bit connection. Through these tests and research, some improvement in steel life was achieved by making changes in heat treatment, design and alloying constituents. However, during that month, research and testing commenced on a rubber collar which was designed to replace the forged collar on 7/8-in. hexagon drill steel. Manufactured by the LeRoi Div. of Westinghouse Air Brake Co.. the collar. is very simple in design, consisting of a 1 ½ -in. diam steel cylindrical sleeve 2 in. long, containing a bonded rubber insert and attached to the steel with an epoxy cement

Jan 8, 1962

By Bruce W. Gonser, A. U. Seybolt

A few copper-zinc-hasp alloys mppt die-casting requirements reasonably well, although improvements are desired. Aluminum bronzes, high-tin bronzes and some copper-nickel-zinc alloys can be die-cast, according to Herb,&apos; but seldom are because of such factors as higher melting ranges and greater cost than certain of the brasses. Fox2 has summarized the copper-base die-casting alloys that were in commercial use in 1937 and has given the effects of different alloying constituents. Table 1 gives some of the properties of these alloys as reported by Fox. a Properties reported by Fox.2 b Trade name of Brastil, Doehler Die Casting Co., similar to Webert Alloy,34 American Brass Co., and Tombasil Alloy,5 Ajax Metal Co. e Trade name Tinicosil, Titan Metal Manufacturing Co. Melting point (liquidus) of the yellow brass is given by Herb1 as 1650" F., of the high-silicon Brastil (with 4.5 to 5 per cent Si) as 1600" F., and of the nickel silver as 1675" F. d Criterion not stated.

Jan 1, 1940

By A. U. Seybolt, Bruce W. Gonser

A few copper-zinc-hasp alloys mppt die-casting requirements reasonably well, although improvements are desired. Aluminum bronzes, high-tin bronzes and some copper-nickel-zinc alloys can be die-cast, according to Herb,&apos; but seldom are because of such factors as higher melting ranges and greater cost than certain of the brasses. Fox2 has summarized the copper-base die-casting alloys that were in commercial use in 1937 and has given the effects of different alloying constituents. Table 1 gives some of the properties of these alloys as reported by Fox. a Properties reported by Fox.2 b Trade name of Brastil, Doehler Die Casting Co., similar to Webert Alloy,34 American Brass Co., and Tombasil Alloy,5 Ajax Metal Co. e Trade name Tinicosil, Titan Metal Manufacturing Co. Melting point (liquidus) of the yellow brass is given by Herb1 as 1650" F., of the high-silicon Brastil (with 4.5 to 5 per cent Si) as 1600" F., and of the nickel silver as 1675" F. d Criterion not stated.

Jan 1, 1940

The Institute maintains a dual relationship with students (1) an individual relationship with a Student Associate, and (2) a relationship with local organizations of students, known as Affiliated Student Societies or Student Chapters 1 The conditions of Student Associate¬ship are set forth in Section 9, Article I, of the Bylaws of the Institute (see page 74 and following pages) During 1934, sundry amendments were made for the purpose of improving the student relationship Post-graduate students are now eligible, and associateship can be maintained, with the payment of the regular dues of $2 per year, for 18 months following graduation in June With his regular dues, each Student Associate is entitled to receive during the year his choice of MINING AND METALLURGY, METALS TECHNOLOGY, MINING TECHNOLOGY, PETROLEUM TECHNOLOGY, or COAL TECHNOLOGY, and on payment of an additional fifty cents he can have both MINING AND METALLURGY and any one of the others He is accorded the privilege of getting special publications such as "The Porphyry Coppers" and "Elements of the Petroleum Industry" at the reduced prices applicable to Members, he has the privileges of the Engineering Societies Personnel Service and the Engineering Societies Library, and he is not only invited but urged to attend all meet¬ings of the Institute, its Divisions and its Local Sections The Institute wants to extend the hand of professional fellowship to students following mineral industries curricula

Jan 1, 1952

The following rules, upon approval by the Board of Directors, shall serve as guides in the practical applications of the Bylaws for the operation of the Institute and have the full power and effect of Bylaws, however, these rules may be changed, modified, re¬pealed or amended when deemed necessary by the Board of Directors Any change or alteration of these Rules shall be published in the Journals of the Institute within three months after such alteration is adopted ARTICLE I-ORGANIZATIONS OF THE INSTITUTE Section 1-Societies Rule 1-Governing Body Each Society shall form its own governing body composed of an Executive Committee, or similarly designated executive body, duly elected officers, and a Nominating Committee for the nomination of Institute officers as provided by the Bylaws of AIME and of each Society approved by the Board In all correspondence and printed matter the Society Boards of Directors shall be specifically identified For ex¬ample, the Mining Board of Directors or the Board of Directors of the Society of Mining Engineers Using simply the "Board of Directors" could cause confusion

Jan 1, 1960

By D. F. Stoneburner, G. Derge, Ling Yang

PREVIOUS investigations in this laboratory have shown the existence of electronic conduction in several molten metal sulfides and the specific conductance of a number of these has been measured as a function of temperature.&apos; In order to better understand the electronic nature of these melts, the thermoelectric power of a molten FeS-solid tungsten thermocouple was measured and a value of approximately 55 µv per "C was obtained in the temperature range from 1200" to 1400c2 These studies have been continued and the thermoelectric power of several other molten metal sulfide-solid tungsten thermocouples have been obtained. The experimental arrangement is shown in Fig. 1. A Kanthal furnace was used, doubly wound to prevent any undesirable effects of an external field. A 1/2-in. McDanel tube was fitted with two vertical 5/8-in. McDanel tubes as shown. These tubes were about 2 in. apart. A graphite boat was used to hold a re-crystallized alumina boat in which the prefused sulfide was placed. Two probes were made using

Jan 1, 1960