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THE twelfth annual meeting of the American Asso-ciation of Petroleum Geologists will be held in Tulsa, Okla., on March 24 to 26, at the Mayo Hotel. The per-sonnel of the committee on arrangements for this meet-ing is as follows : Chairman, M. M. Valerius ; finance, J. H. Gardner; program, Sidney Powers,; publicity, Luther H. White; reception, L. G. Welsh; registration, Frank A. Herald; exhibits, Frank C. Greene; entertain¬ment, Harry H. Nowlan ; ladies' entertainment, T. E. Weirich; golf tournament, A. L. Beekly; hotels, G. C. Potter; transportation, A. W. Duston; banquet, R. Hughes; decoration, V. H. Hughes.

Jan 2, 1927

By H. F. Dunlap, R. R. Hawthorne

A method of calculating formation water resistivities from chemical analyses is presented which is somewhat faster and more accurate than previously described methods. For 26 formation water samples taken from wells in the Texas Gulf Coast, the average deviation of calculated from measured water resistivities was 3.3 per cent, with an average bias of + l.l per cent in the calculated values. This compares with average deviations of 4.6 per cent and 7.8 per cent, with corresponding average biases of +3.2 per cent and -6.3 per cent, for the two methods previously described in the litera-

Jan 1, 1951

By R. R. Hawthorne, H. F. Dunlap

A method of calculating formation water resistivities from chemical analyses is presented which is somewhat faster and more accurate than previously described methods. For 26 formation water samples taken from wells in the Texas Gulf Coast, the average deviation of calculated from measured water resistivities was 3.3 per cent, with an average bias of + l.l per cent in the calculated values. This compares with average deviations of 4.6 per cent and 7.8 per cent, with corresponding average biases of +3.2 per cent and -6.3 per cent, for the two methods previously described in the litera-

Jan 1, 1951

By S. A. Falconer

The benefication of non-sulfide or non-metallic minerals by froth flotation has been practiced commercially for at least 30 years. In the pioneer stages of development of this flotation art, most of the promoters investigated were fatty acids or soaps that had been found to float sulfide minerals. When commercial application of froth flotation started to assume importance in the late 1920' s and 1930's, a great deal of fundamental research work was done in the laboratory (11-14, 19, 22, 23, 26, 29, 32). Among other subjects, this work included studies of the relative effectiveness of the different fatty acids and their salts on the flotability of various non-sulfide and non-metallic minerals. The successful present-day use of fatty acid and petroleum sulfonate type promoters results from better understanding of the principles of non-sulfide flotation plus the developnent of effective selectivity modifying agents. Many investigators have contributed to a greater appreciation of the numerous interrelated factors involved in fatty acid and soap flotation of non-sulfide minerals. Of these, mention should be made of recent fundamental studies by Tagart and Arbiter (31); Wolstenholme and Schulman (35); Schulman and Smith (28); Wark and his co-workers(3,4) Du FIietz(l5); and J. Leja(24). According to J. Rogers, K. L. Sutherland and E. E. and I. W. Wark(27), "the basic requirements for a 'collector' in flotation are that it shall form a film over the surface of the mineral to be floated and that this film should be oriented so that hydrocarbon (non-polar) groups form the effective surface." When modified in that way, the mineral surface possesses some degree of air avidity. All investigators would agree with Taggart, Taylor and Ince (33)that such a film can be produced only if the collector compound contains an active (polar) group to be attracted to the mineral surface, as well as the non-polar group. The commonly used anionic-type promoters for non-sulfide, non-metallic and metallic oxide ores include: 1. Fatty acids, and their soaps and emulsions. 2. Fatty acids residues — "pitches" and "foots." 3. Sulfonated and sulfated fatty acids and so-called "petroleum sulfonates." 4. Paraffin chain salts — sulfonated and sulfated higher alcohols. 5. Cyclic organic acids or salts, such as naph-thenic acid and naphthenates. Certain fatty acids are more effective than others as promoters for particular minerals under certain specified conditions. Some of the more costly fatty acids or collectors of the paraffin chain salt type may give improved selectivity in some instances and are being used commercially in a limited number of operations. Local availability may dictate the choice of the fatty acid used — for example, the use of palmoil fatty acid for flotation of copper carbonate ores in the Belgian Congo. Coconut oil fatty acids have also found limited use.

Jan 1, 1961

By Charles Jones

IN the winter of 1902, while occupying the position of mining and examining engineer for the Mountain Copper Co., Ltd., of Keswick, Cal., I had occasion to discuss with the General Manager, among other things, the question of the enormous waste of sulphur in smelting cupriferous, pyrite ore, and to cast about for means to utilize this waste or to render the fumes innocuous to vegetation. The decreasing rate of production of California farms, the consequent need of fertilizers, and the opportunity thus offered to utilize large quantities of sulphuric acid in the manufacture of superphosphates naturally brought the subject to the practical and commercial side of phosphates. I was informed that the company had made efforts to find phosphates in the West, without success. I advised as a start placing inquiries for phosphate deposits on the Pacific coast in the current mining ,journals. This was done, with the result that in January, 1903, from an advertisement in the Mining and Scientific Press we got track of a deposit in Rich county, Utah, through T.J . Wilson, of the Southern Pacific railroad in San Francisco. As soon as snow in the mountains would permit, in May, 1903, I undertook an examination of the property, with the result of recognizing the importance of the find, in spite of its lack of facilities for transportation at a commercial figure. On June 15, 1903, I concluded my report by saying, "This may be one of the world's deposits of phosphates." On Nov. 17, 1903, I concluded my report for the season in the following words : " I have now no hesitation in saying that I believe the Carboniferous formation so largely developed in the Wasatch mountains of Utah and the mountains of the Great Basin will prove to be one of the greatest storehouses of phosphoric acid in the world."

Jan 10, 1913

By John Johnston

ONLY two of the Institute's 26 Local Sections were unrepresented at the delegates' three sessions, held on Monday morning and afternoon and Thursday afternoon of the annual meeting. The Philadelphia and Wyoming Sections alone sent no delegates. In all, seven hours were spent most profitably in reviewing the work done by the Institute at headquarters and in the field, comparing ideas and practices in varied activities, and in establishing personal contacts. Cordiality and the co¬operative spirit marked the meeting and apparently no one had any serious grievances to air. Four motions were introduced and unanimously passed. The first, which was introduced by B. L. Sackett, was a recommendation by the delegates that a national committee be appointed to cooperate with Local Sections in the matter of student activities, to promote Institute welfare. It was agreed that this recommendation be made simultaneously to the Board of Directors and to the Mineral Industry Education Division. A subsequent resolution by A. M. Smith was passed asking that a part of the duties of this committee be to secure the opinions of Local Sections as to the most desirable methods of interesting students in the preparation of technical papers, by giving prizes or otherwise, and to report their findings at the Section Delegates' meeting next year.

Jan 1, 1933

By D. A. Elgillani, M. C. Fuerstenau, J. D. Miller

Adsorption of lead and ferric iron on quartz and alumina is presented as a function of pH. Only the hydrolyzed species of these metal ions, FeOH++ and PbOH+, adsorb significantly on each of these minerals. Zeta potentials of quartz were measured as a function of pH in the presence of various additions of aluminum, lead, and magnesium salts. Sign reversal occurs at the pH values where significant concentrations of hydroxy complexes are formed. Models of adsorption are presented in the absence and presence of collector. The mechanism of adsorption of metal and collector species in the activation of nonmetallic minerals is still the center of considerable discussion in spite of the extensive study given this system. Until recently, the view was widely held that hydrated metal ions were responsible for this phenomenon. This fact is surprising, since it had been shown that the pH range in which flotation is effected corresponds to that in which metal ion hydrolysis occurs.' Additional support of this concept was pro vided by the work of Wolstenholme and Schulman in another system.' Later work has shown that hydroxy complexes of metal ions are the active species. These studies have also indicated that basic aqueous complexes of metal-collector may be necessary for flotation.3-7 Depending on the molecular weight of the collector, formation of these complexes may occur before or after precipitation of the metal-collector salt has occurred. Ion pair formation can occur when low molecular weight collectors are involved because relatively high concentrations of metal hydroxy complex and collector can be present in solution before precipitation occurs. This is not the case when high molecular weight collectors are used. A model of aqueous complex adsorption has been presented6,7 in which it has been assumed that adsorption occurs by the formation of water from adsorbed hydroxyl and hydrogen of the hydroxyl contained in the complex. Other authors8 have suggested that hy-droxy complexes are involved in these systems but that collector adsorption occurs by replacement of the hydroxyl of the adsorbed metal hydroxy complex with a fatty acid anion. All of these investigations have involved mineral surfaces that were negatively charged so that it is not possible to state with certainty whether hydrated metal ions or hydroxy complexes are the active species in this system. Use of a positively charged mineral should be helpful, however, since the hydrated metal ion will be repelled from this surface. On the other hand, if the hydroxy complex adsorbs by splitting out water, surface charge should have no effect because of the free energy decrease that the system will experience when water is formed. In this regard, sapphire is well-suited for study, since its surface is positively charged until approximately pH 9. Electrokinetic studies of quartz in the presence of various metal ions should also be useful in establishing the mechanisms of adsorption in these systems. That is, if the hydroxy complexes adsorb by water formation, drastic changes in the zeta potential should occur in the pH range in which hydrolysis occurs. In this view, adsorption of ions of widely different hydrolysis characteristics on both sapphire and quartz was measured. In addition, zeta potentials of quartz were measured as a function of pH in the presence of various metal ions and compared with flotation responses obtained under similar conditions. Experimental Materials and Techniques Reagent-grade aluminum, ferric and magnesium chlorides, and lead nitrate were used in this investigation. Adjustments in pH were made with reagent-grade HCl or KOH. Conductivity water, made by passing distilled water through an ion exchange column, was used in all of the experiments.

Jan 1, 1971

By AIME AIME

WILBER JUDSON is one of that fairly large group of mining engineers that graduated at an Eastern college, worked his way up in various jobs in the West and in the Latin-American countries, and finally came to New York as an administrative officer of a large mining company. Since coming to New York he has been a loyal friend and counselor of the A.I.M.E., and is now serving a second term as one of its Directors, his first term covering the period 1935-1938. Mr. Judson was born in the capital city of Michigan on July 26, 1880. Probably it was his roving spirit rather than professorial urging that was responsible for the fact that four colleges were responsible for his education: Northwestern, University of Michigan, Harvard (S.B., 1901), and the Michigan College of Mines (graduate study). In his first ten years of professional work he might have been found serving as mine foreman at Catamarca in the Argentine, as superintendent of the Inter Ocean mine at Sunshine, Colo.. as foreman for the Cerro Prieto, Magdalena, Sonora, as superintendent of the Hudson Iron Co. in New York, or as manager of the Dolores mine in Chihuahua for the Mines Co. of America, or in Spain, or in Panama.

Jan 1, 1942

By WILLETT G. MILLERS

GENERAL RECEPTION COMMITTEE.-Willett G. Miller, Chairman; F. G. B. Alan, Hon. Frank Cochrane, Eugene Coste, Thomas W. Gibson, Cyril W. Knight, J. C. Murray, 0. N. Scott, Alan Sullivan, J. B. Tyrrell, J. W. Wells, A. B. Willis. COBALT RECEPTION COMMITTEE.-Arthur A. Cole, Chairman; Will. Ask with, R. W. Brigstocke, Robt. Bryce, Fred Coombs, M. I. Culbert, I. R. Drummond, J. W. Evans, A. Ferland, F. N. Flynn, E. L. Fraleck, S. R. Heakes, Joseph Houston, D. L. Jemmett, I. R. Jones, Major Leckie, Capt. Jack Leckie, R. W. Leonard, W. H. Linney, Alexander Longwell, Frank Loring, Murdock McLeod, John Martin, D. B. Rochester, W. E. Running. COBALT RECEPTION COMMITTEE (Ladies).-Mrs. A. A. Cole, Mrs. A. Edwards, Mrs. R. Jennings, Mrs. S. H. Logan, Mrs. A. Longwell, Mrs. H. F. Marsh, Mrs. J. Smith. SUDBURY LOCAL COMMITTEE.-Mayor L. O'Connor, Chairman; S. Fournier, Secretary; A. H. Beath, W. J. Bell, F. B. Bennett, D. M. Brodie, J. S. Buchanan, F. C. Busby, Wm. Chalmers, R. Dorsett, W. A. Evans, John Frawley, J. S. Gill, A. B. Gordon, J. G. Henry, T. N. Kilpatrick, Major Leckie, Chas. McCrea, John McLeod, Wm. McVittie, R. Martin, R. S. Mitchell, J. H. Morin, J. A. Orr, James Purvis (President Board of Trade), C. R. Reid, Major Smith, W. W. Stull, J. F. Templeton, S. E. Wright. The first session, held in the Banquet Hall of the King Edward Hotel, was called to order Tuesday, July 23, 1907, at 2.30 p.m., President John Hays Hammond presiding. Prof. Willett G. Miller, chairman of the General Committee, introduced Alderman J. J. Graham, who, in behalf of the City of Toronto, extended a hearty welcome to the members and guests of the Institute. To this welcome, President Hammond replied in a few well-chosen and hearty remarks. In the hall in which the session was held there was exhibited a fine, full-length, life-size portrait of Dr. Rossiter W. Raymond, in 1871 Vice-President and acting President, in 1872, 1873 and 1874 the elected President, in 1876 and 1877 Vice-President, in 1883, by appointment of the Council, and for the last 24 years by annual election, Secretary, of the Institute. Dr. James Douglas, of New York, N. Y., on behalf of numer-

Sep 1, 1907

Jan 1, 1967

By C. E. Van Orstrand

An intrusive body is a mass of igneous rock that has migrated upward, presumably from great depths. Great variations in form, composition and depth of burial occur. It is not proposed in this paper to go into all of the details of the problem. Instead, it mill be assumed here that the intrusive has the form and characteristics represented in Fig. I. According to W. 11. Emmons minerals are not deposited in appreciable quantities below the "dead line." Important amounts of ores of virtually all metals may be found around summit cupolas, but only gold, copper and zinc (in limited quantities) are usually associated with trough cupolas. Most students of ore deposits agree that temperature changes are largely instrumental in precipitating many ores in the "hood" and that the difference in temperature between the intrusive and that of the country rock may be the chief factor in determining the mineralogy of a deposit. A problem then of some interest is to correlate the principal physical features of the intrusive with the phenomena of heat conduction as evidenced by the cooling curves and the isothermal surfaces. Mathematical Theory In order to show the possible application of heat conduction to the interpretation of the processes of metalliferous deposition associated with intrusives, it will be as- sumed that the intrusive is a large par-allelopiped of dimensions, 2l, 2m, 2n. The equation that represents the flow of heat from the parallelopiped into country rock (v = o, 1 = o), which has the same thermal properties as the intrusive, is2,3 l-x v I FT 2 [2 2 — l-x m — y — m — y n — z In this equation, the origin, x = o, y = o, z = o, is at the center of the parallelopiped. v = temperature at point x, y, z, time 1. v, = initial temperature throughout the intrusive, 1 = o. k = coefficient of thermal diffusivity. a, ß, y are variables of integration. Put n = m in Eq. I, and we have v I [2/5 [2I-x 2 — l-x m — y 2 2 2 kt 2 20xt e-a2da ebrdß

Jan 1, 1946

By C. E. Van Orstrand

An intrusive body is a mass of igneous rock that has migrated upward, presumably from great depths. Great variations in form, composition and depth of burial occur. It is not proposed in this paper to go into all of the details of the problem. Instead, it mill be assumed here that the intrusive has the form and characteristics represented in Fig. I. According to W. 11. Emmons minerals are not deposited in appreciable quantities below the "dead line." Important amounts of ores of virtually all metals may be found around summit cupolas, but only gold, copper and zinc (in limited quantities) are usually associated with trough cupolas. Most students of ore deposits agree that temperature changes are largely instrumental in precipitating many ores in the "hood" and that the difference in temperature between the intrusive and that of the country rock may be the chief factor in determining the mineralogy of a deposit. A problem then of some interest is to correlate the principal physical features of the intrusive with the phenomena of heat conduction as evidenced by the cooling curves and the isothermal surfaces. Mathematical Theory In order to show the possible application of heat conduction to the interpretation of the processes of metalliferous deposition associated with intrusives, it will be as- sumed that the intrusive is a large par-allelopiped of dimensions, 2l, 2m, 2n. The equation that represents the flow of heat from the parallelopiped into country rock (v = o, 1 = o), which has the same thermal properties as the intrusive, is2,3 l-x v I FT 2 [2 2 — l-x m — y — m — y n — z In this equation, the origin, x = o, y = o, z = o, is at the center of the parallelopiped. v = temperature at point x, y, z, time 1. v, = initial temperature throughout the intrusive, 1 = o. k = coefficient of thermal diffusivity. a, ß, y are variables of integration. Put n = m in Eq. I, and we have v I [2/5 [2I-x 2 — l-x m — y 2 2 2 kt 2 20xt e-a2da ebrdß

Jan 1, 1946

By L. F. Bishop

THE ore bodies of the Butte district1 are found in many different vein systems having many different structural characteristics; some are narrow with self-supporting ore but with weak walls; some are wide with weak or strong ore and weak walls; some of the veins dip steeply and others do not; some have well defined walls, and others, in the "horsetail" area, are mined to sample limits. Consequently, many types of stoping methods are used in mining these ores. The stoping methods used in the Anaconda Copper Mining Company's properties are the square-set and cut-and-fill. The square-set method is the principal stoping method used because, generally speaking, the ore and walls are weak, the ore is high grade, and good extraction is required. These square-set stopes may be classified as conventional, vertical slice, slot, timber rill, and Mitchell slice types. The conventional type square-sets are those of various shapes and sizes, mined by horizontal slicing to the boundaries of the stopes. The rock is slid to the chute and the filling is moved by gravity. The ore and waste may be handled with a scraper when local conditions require it. The vertical-slice square-set system is the type used in narrow veins that are mined in vertical panels. The slot stopes are stopes in wide veins that employ a slot across the vein instead of a con- ventional chute to handle the ore. The timber rill fs a type of square set in which the ore is mined as in inclined cut and fill but the square-set timber is used. The Mitchell slice is the type used for some broken or heavy ore blocks, or for pillar extraction between two converging slot stopes. The cut-and-fill method is used where the ore will stand without much support although the walls may be weak. The principal type of this method is the horizontal cut-and-fill, with mechanical scraping. The inclined cut-and-fill, or rill, stopes are used in some veins too narrow for scraping. The production from the various meth: ods in use for the second six months of 1944 are shown in Table I. [ ] This paper deals mainly with the vertical slice and slot types of square-set stoping, because of their effect on production locally and their potential possibilities here and in other districts, with sufficient reference to conventional square-setting for comparison.

Jan 1, 1945

By R. G. Turner, M. G. Hubbard, A. E. Dukler

Gas phase hydrocarbons produced from underground reservoirs will, in many instances, have liquid phase material associated with them, the presence of which can affect the flowing characteristics of the well. Liquids can come from condensation of hydrocarbon gas (condensate) or from interstitial water in the reservoir matrix. In either case, the higher density liquid phase, being essentially discontinuous, must be transported to the surface by the gas. In the event the gas phase does not provide sufficient transport energy to lift the liquids out of the well, the liquids will accumulate in the wellbore. The accumulation of the liquid will impose an additional back pressure on the formation that can significantly affect the production capacity of the well. In low pressure wells the liquid may completely kill the well; and in the higher pressure wells there can occur a variable degree of slugging or churning of the liquids, which can affect calculations used in routine well tests. Specifically, the calculated bottom-hole pressures used in multirate backpressure tests will be erroneous if the well is not removing liquids on a continuous basis, and gas:liquid ratios observed during such a test may not be correct. Several authors1,3,8,14 have suggested methods to determine if the flow rate of a well is sufficient to remove liquid phase material. Vitter14 and Duggan' proposed that wellhead velocities observed in the field would be adequate for keeping wells unloaded. Jones8 and Dukler3 presented analytical treatments resulting in equations for calculating, from physical properties, the minimum necessary flow rate. An analysis of these studies indicates the existence of two proposed physical models for the removal of gas well liquids: (1) liquid film movement along the walls of the pipe and (2) liquid droplets entrained in the high velocity gas core. Although there probably is a continuous exchange of liquid between the gas core and the film, they will be treated separately for the purposes of this study. The development and comparison of these separate models with experimental data will permit the determination of which, if either, is the controlling mechanism for the removal of liquids from gas wells. The Continuous Film Model Liquid phase accumulation on the walls of a conduit during two-phase gas/liquid flow is inevitable due to the impingement of entrained liquid drops and the condensation of vapors. The movement of the liquid on the wall is therefore of interest in the analysis of liquid removal from gas wells. If the annular liquid film must be moved upward along the walls in order to keep a gas well from loading up, then the minimum gas flow rate necessary to accomplish this is of primary interest. The analysis technique used follows Dukler2 and Hewitt5 and involves describing the profile of the velocity of a liquid film moving upward on the inside of a tube. The minimum rate of gas flow required to move the film upward is then calculated.

Jan 1, 1970

By H. T. Kennedy, S. M. Avasthi

An equation developed for gaseous hydrocarbon mixtures predicts molal volumes with an average absolute deviation of 0.73 percent when applied to 264 natural gas and condensate systems including 2,043 PVT points. Another equation developed for liquid hydrocarbon mixtures predicts molal volumes with an average absolute deviation of 1.12 percent when applied to 346 crude oil systems including 1,759 PVT points. Both equations require composition of the mixture to be expressed as mole fraction of methane through heptanes-plus, hydrogen sulfide, nitrogen and carbon dioxide, together with the characteristics of the heptanes-plus fraction in addition to the temperature and pressure. The equations cover wide ranges of the variables involved, and their accuracy is considerably better than that of other available methods. The equations were differentiated to allow calculation of the coefficients of isothermal compressibility and isobaric thermal expansion. (In this paper the coefficient of isothermal com-pressibility and the coefficient of isobaric thermal expansion will be expressed as compressibility and thermal expansion coefficient, respectively.) Equations to calculate these quantities are presented. INTRODUCTION Calculations of reservoir performance for petroleum reservoirs require accurate knowledge of the volumetric behavior of hydrocarbon mixtures, both liquid and gaseous. Compressibilities are required in transient fluid flow problems, and thermal expansion coefficients are important in thermal methods of production. An accurate laboratory investigation of the PVT behavior of each reservoir fluid encountered would be costly and time consuming. For this reason various correlations for predicting fluid properties have been developed and recorded in recent literature. Correlations have been presented in the form of graphs, tables and equations. Since an increasing number of studies are being conducted with the aid of electronic computers, recent efforts have been directed toward development of correla-tions suitable for computer programming. Application of computers permits the use of more complex correlations which otherwise are not feasible. Moreover, methods for predicting reservoir performance, particularly those based on the compositional material balance, depend upon the capability of accurately expressing the molal volumes and other fluid properties as functions of pressure, temperature and composition. The coefficient of isothermal compressibility c is defined by

Jan 1, 1969

By B. E. Warren

Jan 1, 1965

By C. F. Lucks, W. D. Wood, H. W. Deem

Electrical ad thermal-conductivity measurements have been made on titanium and 6 titanium alloys. The following expression was derived for calculating thermal conductivity from electrical conductivity: K = 0.626 s T x 10-8 + 0.00497 where K = thermal conductivity, cal sec-1 cm-2 cm0C-1 s = electrical conductivity, ohm-]cm-1 T = temperature, deg Kelvin This expression gives calculated thermal conductivities that are not in error by more than 10 pct from the experimental values for A-55 titanium and the 6 alloys measured; namely, A-110AT, C-110M, C-130AM, Ti-6A1-4V, Ti-140A, and Ti-155A, which are representative of the presently available commercial a and a-ß titanium alloys. THERMAL conduction in a gas, liquid, or amorphous solid is accomplished by energy diffusion from molecule to molecule, a relatively slow process. For this reason, such materials have a low thermal conductivity. When a material is crystalline, there is in addition a heat transfer by a vibratory motion of the crystal lattice. It is the contribution of this lattice conduction that makes a crystal a much better conductor than a gas, liquid, or amorphous solid. Lattice conduction, however, does not account for the relatively enormous thermal conductivity of a metal. This is explained by the freedom of movement of valence electrons. These valence electrons drift in a metal in a direction toward a drop in electrical potential and, to a lesser degree, in the direction of a temperature drop in the metal. Since both the electrical and thermal conductivities of a metal depend upon the presence of free electrons, there should be some relatively simple relation between the two. Wiedemann and Franz in 1653 first discovered an approximate empirical relation between the electrical and thermal conductivities of metals at the same temperature. This ratio varies appreciably with temperature, and Lorenz later showed that by adding a temperature factor to the Wiedemann-Franz ratio the value of K/(s T) is constant, where K is the thermal conductivity, a the electrical conductivity, and T the absolute temperature. This Lorenz constant shows a greater variation for alloys than it does for pure metals, the ratio increasing slightly as the proportion of alloying elements increases. It has been found that a closer correlation between electrical conductivity and thermal conductivity can be obtained by means of an equation of the form K - A s T + B [1] where A and B are constants. In this equation the term AsT is the contribution of electronic conduction and B is the contribution of lattice conduction to the total thermal conductivity. EXPERIMENTAL MEASUREMENTS Electrical-resistivity and thermal-conductivity measurements on titanium and 6 titanium alloys serve as the basis for determining an equation of the K = AsT + B type for titanium alloys. Specimens—Table I shows nominal compositions of the 7 metals on which electrical and thermal conductivities were measured. The electrical and thermal-conductivity specimens for each alloy were taken from stock of the same heat and usually from adjacent sections of the same bar. All of the metals measured were in a mill-annealed condition. Methods—Electrical-resistivity measurements

Jan 1, 1959

By G. Gabra

The kinetics of acidified thiourea leaching of pyrite concentrate was investigated at temperature ranging form 20 °C to a 60 °C. The effect of various parameters on the dissolution rates are discussed. The gold extraction was found to be zero and first orders with respect to Fe (111) and thiourea concentration, respectively. The order of the reaction with respect to sulfuric acid was found to be zero. The activation energy was determined from the Arrhenius plot as 2,039 kcal mole -1 (for a freshly prepared acidic solution containing Fe (111) as the oxidant and at 800 rpm stirring speed. This relatively low activation energy value suggests that the gold extraction is controlled by a-physical phenomenon. Under optimum conditions, more than 90% of gold has been dissolved in about 30 min. and 95% in 60 min. Attempt to recover gold from thiourea solution using active carbon is also discussed.

Jan 1, 1984

By A. W. Ruff

The seismic wave produced by an explosive is very important in blasting. A true understanding of the wave is only important when considering possible structural damage to buildings located near the blast, but it is also of primary importance when considering rock fragmentation. Because of the importance of the seismic wave to fragmentation, a finda-mental study of the seismic wave and its effect was made at the Cananea Consolidated Copper Co.'s mine at Cananea, Sonora, Mexico. Strain gages were used to measure the strain in the rock when nearby explosive charges were detonated. The variance in the circuit voltage caused by changes in the resistance of the strain gage was measured with an oscilloscope and recorded with a Polaroid camera. CONFINED DRILLHOLE CHARGES To record the seismic wave from a confined drillhole explosive charge, a gage was cemented to the bottom of a 4-in diam drillhole. The horizontal gage hole and nine horizontal charge holes were drilled perpendicular to the center line of the 2-39 drift and 4 ft above the floor. The gage hole was 29 in. deep, and the charge holes were drilled so that each bottomed 1 in. deeper than the gage hole. The gage was installed with its axis horizontal and parallel to the 2-39 drift. The charge holes had the following horizontal distances from the gage: hole 3, 3 ft; hole 4, 4 ft; hole 5, 5 ft; hole 9, 9 ft; hole 10, 10 ft; hole 14, 14 ft; and hole 15, 15 ft. Figs. 1 and 2 show the relationships of the gage and the charge holes. Charges of 80 pct special gelatin, which weighed 50, 100, and 150 g were exploded in the charge holes and the seismic waves were recorded. All charges were stemmed with 200 g of mud and detonated with an electric blasting cap. Fig. 3 shows the recorded seismic waves. The reflected components of the waves were too weak to be objectional on these records. Table I shows the data taken from the wave forms. The approximate average velocity of a wave with a 9-ft travel distance was 12,900 fps. Since different charge weights were used, it was necessary to scale the data. The scaled maximum compress ion-strain data and the scaled maximum tens ion-strain data are shown in Figs. 4 and 5, respectively. Figs. 6 and 7 show the strain-distance data from Figs. 4 and 5 converted to a 1-lb charge. The results showed that the wave consisted of an initial compression pulse followed by a tension pulse. The amplitude of the tension pulse approached the amplitude of the compression pulse as the distance between the gage and the shot increased. The decay rate of the seismic wave is very important in the evaluation of the blasting characteristics of a rock. When high-amplitude stresses are produced, as in rock fragmentation, the rate of decay is much more rapid than when small amplitude stresses are produced. In underground mine blasting, the burdens are usually not greater than 6 ft and the decay is very rapid. The rapid seismic-wave decay rate in the fragmentation range means that in practice, if the minimum weight of powder is used to break a specified burden, only a very

Jan 1, 1961

By L. F. Reinartz

ANOTHER year has rolled by. We are twelve months further away from the start of the depression and. therefore that much nearer to recovery. The accumulated needs and wants 'of our lame, virile population are ready to burst their bonds as soon as confidence returns and credit is stabilized. The steel industry has been harassed by uncertainty of the Government's attitude toward organized labor's de¬mands, and irregularity in volume of production. Steel labor, if left to its own devices, would in most instances, march shoulder to shoulder with the management of steel plants in their effort to pull the industry nut of the ?red.? Cooperation between management and men has improved considerably during; the year.

Jan 1, 1935