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Servicing School Opening of a special factory training course in servicing earthmoving equipment is announced by the Euclid Road Machinery Co. Four [ ] beginning and four advanced one week training courses will be offered to representatives of distributors and customers. Circle No. 1 Core Drill The new Acker "Teredo" core drill, is named after the "boringest little animal in the world" to underline its function as a light, compact, portable core drill capable of depths to 600 ft. While light enough to be truck or jeep-mounted, it offers the combination of a three-speed totally enclosed transmission with either hydraulic or screw feed drill heads. Full 24-in. travel gives maximum footage per shift, 360° rotation permits freedom of hole location, a transmission mounted cathead winch is used in pulling rods and casings, and a power take-off is provided for a pump. Circle No. 2 Plastic Pipe Planned production of both flexible and semi-rigid plastic pipe is announced by Triangle Conduit & Cable Co. Rigid and high-impact pipe will be added to the line later. Three types: non-toxic, industrial, and suction, are being made and in sizes from 1/2 to 6 in. Circle No. 3

Jan 1, 1952

Harrison W. Craver, Director The Library of the above-named Societies is open from 9 A.M. to 10 P.M., except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 5, 1917

By Samuel S. Wyer

Magnitude and Econonmic Importance THE magnitude and economic importance of the problem of correctly valuing natural-gas leaseholds become evident when we consider that: (a) Natural gas is handled in 55 per cent. of the gas distributing plants in the United States. (b) Present known natural-gas acreage forms 47 per cent. of the total known mineral-land acreage in the United States. (c) Five acres of land are now required to protect and maintain continuous service to each of the 2,000,000 domestic natural-gas consumers in the United States. (d) The cost of acquiring and maintaining this acreage of an expendible resource represents a substantial part of the cost of the natural-gas service to the consumer. (e) "The right of a citizen by means of his ownership of or his mining leases on land to draw gas from beneath its surface is property and sometimes valuable property."1 A large number of other court decisions have established the basic legal principle that the right to drill for gas within a given area constitutes an interest in the land itself, and is necessarily an exclusive property right.

Jan 4, 1916

By A. B. Kinzel

ALTHOUGH calcium carbide and other compounds of calcium, as well as a number of calcium alloys, are well known and are the basis of important industries in the of United States, calcium metal has been thought of as something of a rarity and has received comparatively little attention from industrial metallurgists. The metal may he made in a number of ways, but the electrolytic deposition of calcium from a molten calcium chloride bath was the first process to be used for its commercial production and is still the standard procedure. Calcium metal has elicited little interest among nonferrous metal producers, as the demand has been relatively small and its production restricted to only a few plants, exclusively in France and Germany.

Jan 1, 1941

By E. W. Filer, L. S. Darker

ONE of the primary purposes of this investigation was to determine how far blast-furnace metal and slag depart from equilibrium, particularly with respect to sulphur distribution. In studying the equilibrium between blast-furnace metal and slag, there are two approaches that can be used. One method is to use synthetic slags, as was done by Hatch and Chipman;' the other is to equilibrate the metal and slag from the blast furnace by remelting in the laboratory. In the set of experiments here reported, metal and slag tapped simultaneously from the same blast furnace were used for all the runs. The experiments were divided into two groups: 1—a time series at each of three different temperatures to determine the t.ime required for metal and slag to equilibrate in various respects under the experimental conditions of remelting, and 2—an addition series to determine the effect of additions to the slag on the equilibrium between the metal and slag. An atmosphere of carbon monoxide was used to simulate blastfurnace conditions. The furnace used for this investigation was a vertically mounted tubular Globar type with two concentric porcelain tubes inside the heating element. The control couple was located between the two porcelain tubes. The carbon monoxide atmosphere was introduced through a mercury seal at the bottom of the inner tube. On top, a glass head (with ground joint) provided access for samples and a long outlet tube prevented air from sucking back into the furnace. The charge used was iron 6 g, slag 5 g for the time series, or iron 9 g, slag 7 % g for the addition series. This slag-to-metal ratio of 0.83 approximates the average for blast-furnace practice, which commonly ranges from about 0.6 to 1.1. A crucible of AUC graphite containing the above charge was suspended by a molybdenum wire in the head and, after flush, was lowered to the center of the furnace as shown in Fig. 1. The cylindrical crucible was 2 in. long x % in. OD. The furnace was held within &3"C of the desired temperature for all the runs. The temperature was checked after the end of each run by flushing the inner tube with air and placing a platinum-platinum-10 pct rhodium thermocouple in the position previously occupied by the crucible; the temperature of the majority of the runs was much closer than the deviation specified above. The couple was checked against a standard couple which had been calibrated at the gold and palladium points, and against a Bureau of Standards couple. The carbon monoxide atmosphere was prepared by passing COz over granular graphite at about 1200°C. It was purified by bubbling through a 30 pct aqueous solution of potassium hydroxide and passing through ascarite and phosphorus pentoxide. The train and connections were all glass except for a few butt joints where rubber tubing was used for flexibility. The rate of gas flow was 25 to 40 cc per min. As atmospheric pressure prevailed in the furnace, the pressure of carbon monoxide was only slightly higher than the partial pressure thereof in the bosh and hearth zones of a blast furnace—by virtue of the elevated total pressure therein. Simultaneous samples of blast-furnace metal and slag were taken for these remelting experiments. The composition of each is given in the first line of Table I. There is considerable uncertainty as to the significant temperature in a blast furnace at which to compare experimental results. This uncertainty arises not only from lack of temperature measurements in the furnace, but also from lack of knowledge of the zone where the slag-metal reactions occur. (Do they occur principally at the slag-metal interface in the crucible, or as the metal is descending through the slag, or even higher as slag and metal are splashing over the coke?) The known temperatures are those of the metal at cast, which averages about 2600°F, and of the cast or flush slag, which is usually about 100°F hotter. To bridge this uncertainty, remelting temperatures were chosen as 1400°, 1500" (2732°F), and 1600°C. For the time series the duration of remelt was 1, 2, 4, 8, 17, or 66 hr; crucible and contents were quenched in brine. The addition series were quenched by rapidly transferring the crucible and contents from the furnace to a close-fitting copper "mold." Of incidental interest here is the fact that the slag wet the crucible

Jan 1, 1953

By C. R. Hayward, H. O. Hofman

I. INTRODUCTION. THE aim of instruction in a metallurgical laboratory is to make real the principles on which metallurgical processes and operations are based, and to foster the spirit of investigation: The materials with which experiments are carried out are ores, metals, and metallic compounds. The method varies with the end sought. A class may work as a whole, each member contributing his share to the solution of a problem, or the students may carry on investigations independently; the former exemplifies class-research; the latter, individual research. It is with a branch of the former, with special reference to ore-treatment that the present paper intends to deal. In smelting an ore by a well-established process, the result is shown by analyzing the products to see whether their compositions correspond to those calculated in making up the charge; by taking account of stock to show the distribution of metal in the different products made and the losses from dust and volatilization, by casting a thermal balance to find the ,distribution and losses of heat; and by making a cost-sheet to ascertain, as far as possible, the necessary outlay of money. In, lixiviation and amalgamation, the mode of operating has to be varied to adapt a process to the individual ore. Here a number of tests become necessary. Each will consist of a series of experiments with one variable, in order to find the conditions under which the variable gives the best result; a. summary of several tests will give the best method of operating.. Working a number of charges with the best method will furnish the data desired for ascertaining the recovery of metal,

Jun 1, 1909

By J. L. Tomlinson, B. D. Lichter

Electrical resistivities 01 liquid Cd-Bi, Cd-Sn, Cd-Pb, In-Bi, and Sn-Bi alloys were measured using an electrodeless technique. The resistivities ranged from 50 to 160 microhm -cm, temperature dependences were positive, and no sharp peaks in the composition dependence of the resistivity were observed. On the basis of these observations, it was concluded that the alloys are typical metallic liquids. The electron con-cent9,ation was calculated from the measured resis-tizlity and available thermodynamic data using a model which attributes electrical resistivity to scattering by density and composition flzcctuations. A correla-tion was shown between the departure of the electron concentration from a linear combination of the pure component valences and the value of the excess integral molar free energy. Calculation of the temperature dependence of the electrical resistivity showed a need for more detailed thermodynamic data in these systems and led to suggestions for improvement in the concept of residual resistivity in the fluctuation scattering model. THE electrical resistivity of liquid metals provides information regarding interatomic interactions and their effects upon structure. In this experiment an electrodeless technique was used to measure the electrical resistivities of liquid alloys of Cd-Bi, Cd-Sn, Cd-Pb, In-Bi, and Sn-Bi, and the results were used with thermodynamic data to calculate a parameter which reflects the tendency toward localization of electrons due to compositional ordering. It was found that the resistivities of these alloys are generally metallic in magnitude and temperature dependence. The electrical and thermodynamic properties are discussed in terms of the fluctuation scattering model'22 which supposes that the electrical resistivity arises from scattering due to a static average structure and departures from the average due to fluctuations in density and composition. Further, this model is compared with the pseudopotential scattering model of Ziman et al.3-5 EXPERIMENTAL PROCEDURES Alloy samples were prepared from 99.999 pct pure elements obtained from American Smelting and Refining Company (except tin which was obtained from Consolidated Smelting and Refining Company.) J. L. TOMLINSON, Member AIME, formerly Research Assistant Division of Metallurgical Engineering, University of Washington, Seattle, Wash., is now Physicist, Naval Weapons Center, Corona Laboratories, Corona, Calif. 0. D. LICHTER, Member AIME, is Associate Professor of Materials Science, Department of Materials Science and Engineering, Vanderbilt University, Nashville, Tenn. This work is based on a portion of a thesis submitted by J. L. TOMLINSON to the University of Washington in partial fulfillment of the requirements for the Ph.D. in Metallurgy, 1967. Manuscript submitted May 31, 1968. EMD Weighed portions were sealed inside evacuated silica capsules, melted, and homogenized before the resistivity was measured. The resistivity of a liquid alloy was measured by placing the sample inside a solenoid and noting the change in Q. According to the method of Nyburg and ~ur~ess,~ the resistivity of a cylindrical sample may be determined from the change in resistance of a solenoid measured with a Q meter as T7--5--W =R7JT^ ='Kc-lm(Y) [1] where L, R, and Q = wL/R are the inductance, series resistance, and Q of the solenoid. The subscript s refers to the solenoid with the sample inside; the subscript 0 refers to the empty solenoid. Kc is the ratio of the sample volume to coil volume and y = 2 [bei'0(br)-j ber'o(br)~\ br\_bero(br) +j bei0 (br) expressed with Kelvin functions which are the real and imaginary parts of Bessel functions of the first kind with arguments multiplied by (j)3'2. The argument of the function Y is hr where r is the sample radius and b2 = po~/p, i.e., the permeability of free space times 271 times the frequency divided by the resistivity in rationalized MKS units. Since Eq. [I] cannot be solved explicitly for p, values of Kc. lm(Y) were tabulated at increments of 0.1 in the argument by. A measurement of Q, and Q, determined a value of Kc . lm (Y) and the corresponding value of br could be read from the table. From the known r, uo,, and w, the resistivity, p, was determined. The change in Q was measured after letting the encapsulated Sample reach equilibrium inside a copper wire solenoid. The solenoid was contained in an evacuated vycor tube in order to retard oxidation of the copper while operating at high temperatures and heated inside a 5-sec-tion nichrome tube furnace capable of obtaining 900°C. Temperature was determined with two chromel-alumel thermocouples, one in contact with the solenoid 30 mm above the top of the sample and the other inserted in an axial well at the other end of the solenoid and secured with cement so that the junction was 2 mm below the bottom of the sample. Temperature readings were taken with respect to an ice water bath junction, and the voltage could be estimated to the nearest thousandth of a millivolt. The lower thermocouple was calibrated by observing its voltage and the Q of the coil as the temperature passed through the melting points of samples of indium and tellurium. The upper thermocouple reading was systematically different from the lower thermocouple reflecting the temperature difference due to a displacement of 60 mm axially and 6 mm radially. Calculations show that the gradient over the sample was less than 2 deg. Q was measured by reading a voltage related to Q from a Boonton 260A Q meter with a Hewlett Packard

Jan 1, 1970

By AIME AIME

THE petroleum economics session," held on Wednesday morning, Feb. 20, 1929, presided over by Campbell Osborn, chairman, proved to be of un- usual interest and resulted in serious and constructive discussion of the papers presented. The first paper on the program, "Gasoline Economics and Refinery Operation," was by H. J. Struth, petroleum economist of the Gulf Publishing Co., Houston, Tex. While this paper was intended to cover the re- finery situation, it also presented the author's reasons for believing that the oil producer should give cognizance to gasoline demand as a most reliable barometer by which to parallel the production of crude petroleum. The discussion which followed brought out some interesting points in connection with the immediate outlook for the industry as a whole during the present year. Some advanced the opinion that, regardless of the out- come of proration efforts, the refiner is in a position to conduct his operations on a reasonably profitable basis, provided that he exercises control over them. This would mean running less crude and resorting to wider utilization of cracking to produce the gasoline demand. Thus, if the refiner uses diligent care in scheduling his still runs, the producer will be obliged to carry over a large stock of crude this year, unless he is able to keep production below the limits prescribed by the demand for gasoline.

Jan 1, 1929

By Emery R. Hayhurst

SILICOSIS has been described in a report of the American Public Health Association as a disease due to breathing air containing silica, characterized anatomically by generalized fibrotic changes and the development of miliary nodulations in both lungs, and clinically by shortness of breath, decreased chest expansion, lessened capacity for work, absence of fever, increased susceptibility to tuberculosis (some or all of which symptoms may be present), and by characteristic X-ray findings. ... The disease is divided arbitrarily into first, second, and third stages for convenience of description and possible compensation purposes. At least two distinct types of silicosis are recognized, acute and chronic. The acute form was reported as early as 1713, when a British patent for grinding flint by wet methods was granted because the dry powdered material "proved very destructive to mankind, so much that any person, ever so healthful, working in that business cannot possibly survive over two years."

Jan 1, 1936

By Edward Keller

(Canal Zone Meeting, November, 1910.) UNDER the title, Labor-Saving Appliances in the Works-Laboratory, I published a paper1 in which was described how multi-manipulations, in a works-laboratory, and in the furnace-room of an assay-laboratory, can be condensed into single manipulations by applying the proper mechanical devices. For example, I now deposit in, or withdraw from, a muffle a set of 48 cupels as one unit. The front row. (8) of these. are blanks or heaters; the other 40, when they have attained the proper temperature in the muffle, are charged simultaneously with the 40 lead-buttons. Three manipulations here accomplish an operation which by the generally customary method requires 136, and this number is only limited by the size of muffle and cupels. This operation is an enlargement of what I have already described in my former paper, and Fig. I shows the improved implements. In the paper referred to I described a gold-silver bead parting-bath, which is the last of the devices used in regular sequence in practice. This bath was designated as being convenient, but was not a labor-saver properly. Fig. 2 of the present paper shows a new device. Instead of the original tray, there are now sectional holders for the test-tubes, each having a wooden handle on either end, so that the holders may be removed from the boiling bath, and the acid or water poured off from each set of tubes (in this case, 7) without waiting to cool. The tubes, held in place by clutches, as shown in Fig. 3, rest in holes in the base-strip, having a smaller diameter than the tubes. Each holder is stamped at either end with a number, so that the bath becomes further useful by permitting several men to use it at the same time without interference. Apart from the handles, the holders are made of sheet-copper. ' Trans., xxxvi., 3 to 18 (1906).

Aug 1, 1910

By E. B. REESER

EFFICIENCY is the foundation on which the prosperity of this Nation must be built. Your organization and the members thereof are constantly thinking of Gays and means whereby greater efficiency may be developed. It is often said that this Nation has become great because of its almost up limited supply of raw materials at low production 'costs. This was undoubtedly true in the earlier years but today we face an entirely different situation. We have learned that nature has been very generous in supplying all parts of the world with ample resources of various kinds to meet the demands. This applies to practically all commodities but for the purposes of this discussion, we will limit our remarks to petroleum.

Jan 1, 1931

By Paul F. Kerr

The insufficiencies of our mineral resources are becoming well known, and the national political conscience seems to be troubled at last by our dependence upon mineral commodities which must come from other lands. This realization places increased responsibility upon the industrial, educational, and governmental groups whose task it will be to solve the problems of mineral supply. As we all know, from the time that man first sought mineral deposits until recent years, prospectors have been largely responsible for mineral discoveries. Today the era of the prospector is almost over. The human ants that have literally examined all accessible outcrops and have tested the gravels of nearly all stream beds in the United States have left undiscovered few worthwhile mineral deposits within the scope of their recognition. The pages in the history of mineral exploration are now being turned from the era of the surface prospect to the era of the hidden de- posit.

Jan 1, 1949

By Luther M. Krupp

A 3 ½ -mile asphalt mixed mat haulage road joins American Smelting & Refining Co.'s El Tiro copper pit northwest of Tucson and its Silver Bell mill. Two-axle trucks operate continuously over the road- way but the asphalt top shows none of the wash- board wear usually seen on dirt haulage roads during use by heavy vehicles. The following data cover construction of this road, and results of its use by Asarco and Isbell Construction Co., the road's builder.

Jan 11, 1958

By Charles Mitke

EXCLUDING top-slicing, and sublevel caving, large production caving methods may be divided into two general classes, the branch raise, or undercut caving method, and the combined shrinkage and caving method, each of which has a number of variations, the result of continual efforts towards obtaining lower costs and better extraction, by the introduction and substitution of minor improvements and modifications. EARLY CAVING METHODS Present caving methods are the cumulative result of developments covering a period of many years, with the most rapid growth during the past 15 years. They originated, presumably, from early English stoping methods, and, as far as is generally known, were first introduced in the Michigan iron district. They have had their greatest expansion and application in the large low-grade porphyry coppers. In their present form, they are probably a development and combination of sublevel caving and shrinkage (back-stoping on ore) with gravity handling of broken material. Sublevel caving, as practiced in the Michigan district today, is a combination of drift, or crosscut, mining, with top-slicing, and caving, supplemented by later refinements in the shape of mechanized handling of broken ore. A height of anywhere from 16 to 20 ft. is generally taken, and the ore is drilled and blasted along the drift or crosscut for half this height (say 8 to 10 ft.), after which the upper 8 to 10 ft. caves and breaks of its own weight, with comparatively little assistance from drilling. This

Jan 1, 1928

By Robert Burrows

IN preparing this paper the object has been to set forth facts relating to illumination problems, which, judging from the results realized in the iron and steel and other industries somewhat similar to mining, will tend toward furthering safety, production, and contentment of employees, as well as economy of operation in mines. By applying the principles of illumination with the assistance of modern appliances, the full benefits in efficiency may be derived from improvements already made in other details of mine operation. The lighting of a typical coal mine may be divided into four distinct parts: 1, The lighting of the buildings about the top; 2, the lighting of the working faces; 3, general illumination at the bottom; and 4, special applications of lighting. The lighting of buildings about the top may be treated in the same manner as that of any other industrial plant, for we have a boiler room, an engine and generator room, a forge, a machine shop, and a hoist room. These can be well and efficiently lighted by the use of 100-watt tungsten-filament multiple lamps with proper reflectors so spaced and suspended that a power consumption of from ¼ watt per square foot in the boiler room to 1 watt per square foot in the machine shop is obtained. The methods that apply to this kind of lighting have been ably treated by a number of authors,1 and for this reason a detailed discussion is unnecessary.

Jan 11, 1915

By Charles A. Mitke

Excluding top-slicing and sublevel caving, large production caving methods may be divided into two general classes, the branch raise, or undercut caving method, and the combined shrinkage and caving method, each of which has a number of variations, the result of continual efforts towards obtaining lower costs and better extraction, by the introduction and substitution of minor improvements and modifications. Early Caving Methods Present caving methods are the cumulative result of developments covering a period of many years, with the most rapid growth during the past 15 years. They originated, presumably, from early English stoping methods, and, as far as is generally known, were first introduced in the Michigan iron district. They have had their greatest expansion and application in the large low-grade porphyry coppers. In their present form, they are probably a development and combination of sublevel caving and shrinkage (back stoping on ore) with gravity handling of broken material. Sublevel caving, as practiced in the Michigan district today, is a combination of drift, or crosscut, mining, with top-slicing, and caving, supplemented by later refinements in the shape of mechanized handling of broken ore. A height of anywhere from 16 to 20 ft. is generally taken, and the ore is drilled and blasted along the drift or crosscut for half this height (say 8 to 10 ft.), after which the upper 8 to 10 ft. caves and breaks of its own weight, with comparatively little assistance from drilling. This

Jan 1, 1928

By E. J. Roberts, E. B. Fitch

THE mechanism of classification by settling pools is most simply shown in the case of batch sedimentation such as was analyzed by Oden.1 The batch model will be considered, therefore, and it will be shown that the same mechanism applies to continuous operation. Classification in Batch Settling Pools: Consider a beaker or tank of slurry containing particles so dispersed that they can settle independently of one another under the influence of gravity. Originally all particle sizes are uniformly distributed throughout the suspension. All particles start immediately to settle towards the bottom at rates determined by their size, shape, and density—among other factors. Particles reaching the bottom settle out of suspension. After some given time the slurry above the deposited solids is siphoned off or otherwise removed, leaving the deposited solids behind. The deposited solids, together with entrained and any unremoved supernatant slurry, represent the underflow of a classifier. The slurry removed represents the overflow. There is a certain separation, size of particle which during the sedimentation has just time to settle from the top surface of the slurry to the level at which underflow and overflow are parted. All particles with a faster settling rate will have dropped to below this level, no matter where in the beaker they started from originally, and therefore will be absent from the overflow. Particles with a slower settling rate will not reach this level if they started from the top of the slurry, but a portion of them,

Jan 1, 1957

By Clarence M. Haight

The general practice in drill sharpening shops, of which descriptions have been written, is about as follows: The bit is heated to 1600" to 1900°F. Then when forged to the proper shape and size in the sharpening machine, the steel is allowed to cool; it is then passed to a hardening furnace where only the end is heated to about 1450" F., and then quenched in cold water, brine, or in brine with oil on top.

Jan 1, 1922

By AIME AIME

ONE hundred and eighty-three A.I.M.E. members, W. S. Morris with an excellent technical program, John Suman, "oil" President of the Institute, and a Texas norther blew into Dallas for the fall meeting of the Petroleum Division at the Adolphus Hotel, Oct. 16-18. and the most successful result will give future meeting committees a high mark to equal. People were still talking of the terrific heat the week before and it was quite noticeable that with the lowered temperatures, the members were in fine fettle for the technical sessions. The total attendance on Friday noon was

Jan 1, 1941

By ARCHIBALD DOUGLAS

BY this time almost everyone knows, in a general way, the corporate income distribution policies of the 1936 Revenue Act, and many of the practical problems arising there under. This article is not intended to be a technical discussion of that act by title, subtitle, section, or supplement, nor an analysis of inter- dependent sections of the various acts over many years woven on the fiscal loom f our Congressional machine. Such a discussion would require the spinning of a web of words too long for patience. Yet ,a general statement of the underlying plan of the 1936 Act, so far as it affects dividend policies, is perhaps useful.

Jan 1, 1937