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By Nathaniel Arbiter

THE separation of minerals by flotation can be regarded as a rate process, with the extraction of any one mineral determined by its flotation rate, and the grade of concentrate by the relative rates for all the minerals. So regarded, the significant variables for the process are those that control the rates. These variables are of two types, the first describing the ore and its physical and chemical treatment prior to flotation and the second characterizing the separation process in the cells. This paper will examine the variation in rates for a group of separations, will show that a simple rate law appears to govern, and will consider the relation of the control variables to the rates. The use of rate constants for evaluation of performance and efficiency will be discussed.

Jan 9, 1951

GENTLEMEN Herewith are transmitted reports from the Treasurer and of the principal standing committees of the Institute. To these special reports members are referred for details as to the year's work. Despite the unfavorable business conditions obtaining throughout the year, the Institute was able to carry on its various activities without curtailment and without drawing on the surplus accumulated through previous years. In fact, small additions were made to the Life, Member¬ship and various other funds. It is highly desirable that such additions should continue to be made, especially to the Life Membership fund, for reasons reported last year. At present, money must be used from current receipts in order to enable the Institute to fulfill its obligations to those who on joining the organization commuted their dues by a single payment. In addition, with the passage of years the number increases of those who have paid dues forty years or more and who, by reason of age or dis¬ability, are unable longer to practise their profession. These men have supported the Institute through their active professional life and it would be a pity to lose them as members through resignation or for failure to keep up their dues. In accordance with the By-laws the Board has authority to advance such members, on application, to the Honor Roll of Senior Members and to relieve them from further payment of dues. It has been the policy of the Board to do this liberally, but to keep up this, as well as to meet other obligations, it is necessary for money to be provided. It has been estimated by the Treasurer that nearly $50,000 additional should be placed in the Life Membership fund as soon as possi¬ble to meet these obligations without using current income and to that end it is necessary, not only to avoid running behind currently but to earn, if possible, some surplus each year. The small amount transferred to the Life Membership fund from surplus this year was, as a matter of fact, made possible by certain members paying personally bills that were properly chargeable to the Treasury. Such generosity is common among those active in Institute work and probably no year would have closed with a surplus except for it.

Jan 1, 1923

By R. W. Raymond

THE absence of a convenient glossary of terms connected with mining and metallurgy has long been felt by the general public. It is to meet this want, not to furnish a technical manual for experts, that the following glossary has been prepared. It originated in an attempt on my part to revise for publication the manuscript of a compilation prepared from the appendix of Yale's work on Mining Titles and one or two other sources, to serve as an appendix to a new work on mining law, about to be published by Mr. H. N. Copp, of Washington, D. C. This revision soon assumed, contrary to my original intention, the proportions of a reconstruction; and with the consent of Mr. Copp, and for the purpose of receiving from my fellow-members valuable aid, I presented my still incomplete work as a paper at the Lake Superior meeting of the Institute, inviting from any quarter suggestions of new terms or better definitions to be incorporated in the glossary before its final publication. This invitation was so widely and generously responded to, that I cannot undertake to make in this place individual acknowledgments to those members of the Institute, and professional colleagues outside of it, who have favored me with assistance and advice. The labor bestowed upon this paper since its presentation at the Lake Superior meeting has considerably exceeded that of its first preparation, as may be inferred from its great increase in length, as well as the numerous alterations which it has undergone. It could certainly be still further enlarged and improved; but I think a comparison of it with any of the glossaries of the same class now in print will show, at least, that it is an advance upon what has hitherto been accomplished. 1 shall be grateful, however, for further criticisms and suggestions; and I purpose at some future time to incorporate in a supplementary paper the results of such additional collections or corrections as I may obtain. To avoid too great prolixity, I adopted at the outset the following general principles: 1. To include the most important technical words and phrases used by American miners and metallurgists, or occurring in English books and periodicals.

Jan 1, 1881

By Paul Averitt

The U. S. Geological Survey has been actively engaged in work on coal for more than 50 years. During this long period we have released more than 300 publications containing information about coal and coal reserves, including details on the thickness, distribution, and quality of coal, and the structure and stratigraphy of the coal-bearing rocks. We have also cooperated with state surveys on many similar publications. For many areas these reports are the only reliable published data on our resources of coal. During the last several years we have substantially increased our activities above the wartime low. We now have field work in progress, or reports in preparation, on 13 detailed mapping projects distributed as follows: 1. Pennsylvania anthracite field 2. Casselrnan Basin, Md. 3. Leslie County, Ky. 4. Deep River field, N. C. 5. Coosa field, Ala. 6. Powder River field, Mont. 7. Spotted Horse field, Wyo. 8. Yampa field, Colo. 9. Paonia field, Colo. 10. Trinidad field, Colo. 11. Durango field, Colo.

Jan 1, 1949

By Theodore Simons

The rapid and comparatively recent development of flotation has opened so fascinating a field for study and research that the older processes of gravity concentration no longer receive the attention they deserve. The early work of Munroe1 and Richards,2 and the more recent contributions by Clevenger and Coe,3 Laist and Wiggin,4 Ammon,5 Bardwell,6 Crowfoot,7 and Hayden8 to mention only some which have appeared in our own Transactions-and by Schulz,9 have furnished so much data that to offer something new seems a difficult task. It is still possible, however, to present known facts from a different point of view, and, with this in mind, the writer has undertaken to express basic principles of gravity concentration in terms of simple mathematics and mechanics; the conclusions thus reached will be found to correspond, in general, with those obtained by experimental methods. Rittinger, in his classic Aufbereitungskunde (1867), reached analogous conclusions by way of intricate higher mathematics, for which reason his interesting investigations have remained a sealed book to most of us. The writer hopes that a more elementary treatment of the subject, based in part on Rittinger's methods, may, arouse new interest in the study of basic principles.

Jan 7, 1922

By Heinrich Ries

Fullers' earth is a clay-like substance, which has the property of decolorizing or clarifying oils. An ultimate chemical analysis shows it to differ from most ordinary clays in having usually a high percentage of combined water and a low amount of alumina. There is probably a large amount of hydrous silica present. Fullers' earth possesses little or no plasticity, and in order to work properly has to be ground very fine. A chemical analysis is of little value at present in determining its quality; only a practical test suffices. Up to about two years ago all of the fullers' earth used in this country was imported from England; but about that time deposits were discovered in Florida, "† and since then rumors of its occurrence have been coming from all parts of the country. Next to the Florida deposits of fullers' earth, those of South Dakota are the most extensive thus far discovered in this country. The earth was first discovered near Fairburn, Custer county, and other deposits have since been prospected at Argyle, Minnekahta and other localities. Fairburn.—One of the first deposits located and opened up is five miles southeast of Fairburn, Custer county. The mine is a mile from the Fremont, Elkhorn and Missouri Valley Railroad, and the section exposed shows, beginning at the top: Feet. Micaceous sandy clay,......... 6 Fullers' earth,..........9 Micaceous sandstone,......... The fullers' earth passes upwards into the sandy clay, but in its purer portions it is a yellowish, gritty clay, with a somewhat

Jan 1, 1898

By Hugh P. Tiemann

The desirability of employing the centigrade scale for the measurement of temperatures is becoming more and more recognized in this country, particularly in view of the fact that this scale is used almost exclusively in technical papers and publications—exclusively in those published in French or German. There are, however, a large number of factories and laboratories which still employ the Fahrenheit scale. It therefore frequently becomes necessary to convert one into the other and the accompanying chart (Fig. I) has been found very convenient for this purpose. The formulas for conversion follow: (1) °F. = 9o /5+ 32 (2) oC = 5 (oF - 32 ) (1) 100° C X 9 900/5 =180 .'. 180 + 32 = 212° F. 5 (2) 5 (212° F - 32) = 5 X 180 =100o C 9 9

Jan 1, 1916

[PRESIDENT AND DIRECTOR * R. R. McNAUGHTON, '63, Trail, B. C., Canada PAST-PRESIDENT AND DIRECTOR * JOSEPH L. GILLSON, '62, Wilmington, Delaware PRESIDENT-ELECT AND DIRECTOR * LLOYD E. ELKINS, '64, Tulsa, Oklahoma VICE-PRESIDENTS AND DIRECTORS * JOHN S. BELL, '62, Houston, Texas * A. B. CUMMINS, '62, Bound Brook, New Jersey * WAYNE E. GLENN, '62, Houston, Texas * C. C. LONG, '62, Monaca, Pennsylvania * J. S. SMART, JR., '63, New York, New York * J. W. WOOMER, '62, Pittsburgh, Pennsylvania]

Jan 1, 1961

By AIME AIME

MORE than thirty members of the Coal Division attended the Coal Land Valuations Round Table on Monday morning. Chairman Dilworth stated that the Committee had been appointed to take up the question and, after reading the list of members of the Committee, pointed out that the object of the meeting was to formulate a plan of action rather than to discuss any phases of valuation, per se. To this end he presented a tentative outline of points to be considered in the future by the Committee. After a lively discussion on the desirability of inclusion of some questions in the agenda of the Committee, the following outline was adopted :

Jan 1, 1931

By P. A. E. Armstrong

For hardening, the steel should be heated just above the critical temperature, as a properly forged steel quenched from this heat has some toughness, with maximum hardness and density. The quenching bath should be kept at approximately a constant temperature. In drawing or tempering, longer time periods at lower temperatures are better than the shorter periods at higher temperatures. A recent questionnaire brought out the following facts: The double-arc, double-taper bit and cross bit give the best service; resharpening of the drill steels most frequently was caused by wear of gage; chipping of bit was, with one exception, the second cause; breakage of shank was with one exception, the third cause; upsetting of bit, upsetting of shank, and breakage of body were the fourth cause. The direct cause of the necessity of resharpening given was poor heat treatment first, and faulty steel and severe rock conditions second. Rock-drill Steel By N. B. Hoffman Much of the drill steel produced in America is manufactured into hollow rods. After all forging has been finished the entire bar should be thoroughly annealed and heat trcated before the point is hardened and tempered, at least where the drill has heavy duty, such as working in deep holes and hard rock. A large number of tools of like character and doing work requiring similar properties are now being made of alloy steels; for instance a steel with a carbon content of 0.75 to 0.85 per cent., manganese 0.25 to 0.35, phosphorus under 0.020, sulfur under 0.030 and vanadium 0.18 to 0.23 has proved very satisfactory for chisels. A steel of this type properly manufactured will be far superior to the ordinary carbon steels, while at the same time is one whose price range should not prove prohibitive. Much of the cutting efficiency of a drill depends on proper heat treatment. This vanadium steel has a far greater safe hardening and forging range than ordinary carbon steels, making it more nearly foolproof. It will harden nicely at 1400" I?. but will also harden well and satisfactorily at 1550" F. retaining its quality of hardness and toughness in either case. Drill Steel from Hollow Ingots BY P. A. E. ARmstrong Hollow drill steel is made from a drilled billet with a sand-filled core or the drilled, pierced, or the drilled and pierced billet, not sand-filled, is rolled down over a projectile or ball much the same as in ordinary pipe manufacture. The first is the method generally used in this country; the second is used largely in Sweden. Swedish hollow drill steel has a

Jan 1, 1922

By Fred W. Gordon

It is my purpose to call attention to the close approximate correctness of certain coefficients and formulas concerning the flow of gases, and their applicability to the practical construction of flues and

Jan 1, 1886

By M. A. Mahtab, T. M. Yegulalp

This paper presents the development and application of an approach for clustering fracture orientation data. Data are projected on the surface of the unit upper hemisphere and the clustering approach is applied in three steps: (1) randomness test and identification of dense clusters, (2) estimation of cluster statistics, using Bingham distribution, and (3) rejection of extremal data based on Chauvenet's criterion.

Jan 1, 1982

By M. J. Spendlove, H. W. St. Clair

An automatic surface-follower mechanism was used to measure the surface temperature and the rate of evaporation of molten zinc while undergoing distillation at low pressure. At pressures of 50 to 100 microns Hg, the rate of evaporation may be 60 to 80 pct of the theoretical maximum corresponding to the measured temperature. The rate decreases rapidly at pressures above 100 microns Hg, to only 7 pct of the theoretical maximum at 2000 microns Hg. Measured temperature gradients at the surface are in agreement with theoretical gradients calculated from the heat of vaporization, rate of evaporation, and thermal conductivity of molten zinc. THIS paper covers a series of careful measurements of the rate of evaporation of molten zinc at low pressures, undertaken as a part of a general investigation on the separation of metals by distillation.' Preliminary results on the rate of evaporation of zinc were described in a previous publication.' The results of the preliminary study are as follows: 1—The observed rates of evaporation of zinc were as high as 0.60 g per sq cm per min, corresponding to 75 pct of the maximum rate as determined by the temperature of the metal. 2—The evaporation rate was decreased from 0.30 g per sq cm per min at a pressure of 25 microns to only 0.09 g per sq cm per min when the pressure was increased to 5 mm. 3—The temperature of the surface during rapid evaporation may be 35" to 100°C less than the main mass of metal. Observed temperature gradients at the surface are consistent with those calculated from the heat of vaporization and the thermal conductivity of liquid zinc. In the preliminary experiments, the rate of evaporation was determined from the loss in weight of the metal in the crucible during the test. This was compared with the weight of the condensate. Obviously, this method was subject to error because of some uncertainty as to the period of evaporation that should correspond to the loss in weight. Furthermore, this method did not permit taking into account probable variations in the rate of evaporation during the test. A more serious shortcoming was that the temperature at the evaporating surface was not known, so the maximum theoretical rate of evaporation could not be calculated accurately. To improve the precision of rate measurements and to allow accurate measurements of the surface temperature, a refined experimental technique was developed whereby the temperature and position of the surface could be measured accurately. This was done by an automatic surface-follower mechanism that gave a continuous record of the surface temperature and the amount of zinc evaporated. These data permitted an instantaneous determination of the actual rate of evaporation and the surface temperature throughout the test. Pure zinc (99.99 pct Zn) was used in all experiments. Description of Distillation Furnace The details of construction of the distillation furnace are shown in Fig. l. The furnace is enclosed in a large quartz tube open at one end. The open end of the quartz tube is sealed by means of a water-cooled head. The entire enclosure is vacuum tight. The connection between the water-cooled head and the quartz tube is sealed by means of a rubber gasket which fits tightly against the smooth end of the tube. The metal is heated by induced current set up in the molten zinc and the walls of the graphite crucible by means of a water-cooled induction coil outside the quartz tube. High frequency current is passed through the induction coil from a 6 kw mer-

Jan 1, 1952

By Eugene Coste

Although some of the observers who first paid especial attention to the occurrences of oil and gas in the strata (such as Hunt in 1859, Andrews in 1861; Winchell in 1865, Mendelejeff in 1876, Höfer in 1876, Minshall in 1881, and I. C. White in 1883) seem to have been impressed with the fact that oil and gas deposits were connected with the disturbances in the rocks caused by their upheavalll yet, with the exception of Mendelejeff, and possibly Andrews, these observers do not appear to have understood what is really the one essential factor in the occurrence of oil and gas in the strata: viz., the faulting, uplifting, fracturing, fis-suring, and jointing always accompanying even slight rock disturbances, and in certain districts (petroliferous provinces)2 allowing solfataric hydrocarbon emanations to force their way up from the interior and to reach and impregnate the porous portions of sediments subjected to the disturbances. Instead of this simple explanation to account -for the observed connection between petroleum deposits and rock disturbances, most of the observers mentioned above, and many others who have foliowed them on the same lines since, have entirely reversed the problem. To them, instead of the dissemination of gases from fissures into the sediments, it presented the accumulation and concentration, according to anticlinal or other geologic structures, of oil and gas originally present throughout the whole mass of the strata where they were produced by the decomposition or distillation of organic remains. Whether this important problem involves accumulation from sources within the strata themselves, or infiltration and dissemination from outside sources, may be easily determined if all preconceived ideas are put aside and the established facts only are considered. Physical Facts Sedimentary strata are composed of alternate beds of shales, sandstones, and limestones, most of which are sufficiently close-grained to

Jan 1, 1915

By F. J. Escandon V.

The Plomosas stratiform lead and zinc deposits are located in northeastern Chihuahua in a sequence of folded Paleozoic and Jurassic rocks. They consist mainly of channel or blanket-like bodies of ellipsoidal cross section restricted to a 60-in-thick shaly limestone and a 30-m-thick marble horizon of La Casita formation, with some reemplacement veins and shoots within the Plomosas formation. The mineralogy consists of iron-poor sphalerite, galena with a small silver content, and pyrite, in a gangue of calcite, barite, and minor quartz. The ore bodies present a lateral zoning with zinc-lead ratios increasing to the northwest. Vertical zoning shows marked changes in zinc-lead ratios and in the width and tenor of the ore which cannot be related to sedimentary or diagenetic features. Transgressive mineralization and some small fissure veins and breccia pipes also point to an epigenetic origin. Sulfur isotope analysis and geochemical data indicate hydrothermal solutions. Texture of the ores in the Mina Vieja marble is coarse, but in the Cuesta shale it is banded along bedding. The low iron and silver content of the sphalerite and galena and the weak hydrothermal alteration (only marbleization) of the wall rock suggest a telethermal stage of the solutions. There is no evidence of a possible intrusive rock mineralization.

Jan 1, 1976

By Janshi Sen

VERTICAL-INTENSITY magnetometers, such as the Hotchkiss Superdip and the Askania vertical field balance, are now [ ] widely used, because vertical-intensity charts give definite information for the location of upper pole, dip and strike, and approximate shape of the deposit. Again, a slow and steady increase of dip over a large area indicates a large deep-lying deposit, while a large dip limited to a small area and falling away rapidly suggests a small and shallow one. The complication comes more from the richness of the ore. A large body of lean ore near the surface might produce the same vertical-intensity chart as a rich ore at depth. This paper presents a method for calculating the maximum depth of a single-pole deposit and another for a two-pole mineral body, by utilizing data of both vertical and horizontal intensities as obtained by a Thalen-Tiberg magnetometer. As shown on the left side of Fig. 1, lean ore, rich ore and a single pole produce the same magnetic field. The depth of the pole, [ ] h, can be calculated from the following relation: [h=a=tan¢=G-F h=aXFy] where G is the vertical intensity at point A due to the pole; F, the horizontal intensity of the same; and a, the distance from the point of maximum vertical intensity or the vertical projection of the pole on the surface to the point of observation A. If an entirely covered deposit is indicated by magnetic measurements and boring cost estimated from the calculated depth is so reasonable as to encourage drilling, the ore should be struck somewhere within the limit of the calculated depth by the borehole. A number of such points as A should be taken for calculation, erratic results should be rejected and the average figure used for cost estimation.

Jan 1, 1944

By Thomas T., Read

TWO American students entered the Ecole des Mines in 1856, Joseph Lesley of Philadelphia and Thomas Egleston of New York. Lesley remained there only one year, but Egleston completed the whole 'curriculum and received, in 1860, the certificate given to foreign students .in lieu of the official appointment and degree. awarded French students. Returning home he received, in 1861, an appointment by Secretary Henry of the Smithsonian Institution to sort, label, and arrange the collections of mineralogical and geological specimens which had been brought to Washington by the various government exploring expeditions in the West. Thomas Egleston, born in New York City on Dec. 9, 1832, was the son of Thomas Jefferson Egleston, who came to New York from Massachusetts some time before 1829. The first American ancestor of the family had settled near Dorchester. in 1630. T. J. Egleston and Joseph Battell established an iron-merchandizing business* at 166 South St., New, York, which prospered exceedingly; so much so that when Thomas J. Egleston died, July 12, 1861, his estate had a book value of over $500,000. Since an older brother was expected eventually to take over this business, Thomas, who had a liking for science, went to Yale,, where he completed the regular four-year course in 1854, and then remained another year for advanced work in chemistry under Silliman. I One biographer says he went to Europe, . early in 1-856, on account of his health. It was the custom at that time for wealthy young men to make a tour of Europe after completing their academic education. Whatever the precise reason, he began scientific work at the Jardin des Plantes in Paris but soon trans* It still operating as Egleston Bros. Inc., though no direct descendants of its founder are now living.

Jan 1, 1941

Univ of Alabama-University, Alabama-Mining and Metallurgical Society William L Mason, Faculty Sponsor, E C Wright, Dept Head Univ of Alaska-College, Alaska-Mining Society of the Univ of Alaska Douglas W Huber, Faculty Sponsor, E H Beistline, Mining & Metallurgy Dept Head, Troy L Pewe, Geology Dept Head, James Crawford, Chapter Counselor Univ of Arizona-Tucson, Arizona-Miners Society Willard C. Lacy, Faculty Sponsor, J D Forrester, Mining & Metallurgy Dept Head, F. W Galbraith, Geology Dept Head Univ of California-Berkeley, California-Mineral Technology Association H E Hawkes, Faculty Sponsor, Joseph A Pask, Dept Head Carnegie Inst. of Technology-Pittsburgh, Pa -The Metals Club William R Bitler, Faculty Sponsor, Robert F Mehl, Dept Head

Jan 1, 1960

By Don C. Blackmar

The production of non-ferrous secondary metals has become a large and important industry in the United States, and deals with practically cvery type of manufacturing concern. Its business is unique in that it generally buys frorn its customers as well as sells to them, whether they are individuals, cities, corporations, or the United States government. Its operations are of vital importance to the success and prosperity of nlany of the nation's most important manufacturers; yet there are few industries about which less is generally known by those outside it, whether concerning the rliagnitude of its operations or the details of its actual technique. The industry itself is to blame for this meager publicity, because its technical men have made few attempts to openly exchange ideas, in spite of the excellent examples set by the iron and steel or the copper and brass industries. Whether this is due to the ancient shroud of secrecy generally supposed to cover smelting operations, or because its technical men actually felt that the industry was too puny to be interesting, is hard to say. This paper will consider its subject in a general way, attenlpting to show something of the size and importance of the industry, as well as its fitness to do its work well. Attention will be called to the sound economic reasons for the handling of non-ferrous wastes by specialists, and to the often unseen losses of metals and labor which occur when manufacturc~rs rcclairn thrir own metallic wastes. Magnitude of the Modern Industry No particular thought is given to the kitchen accident whereby a ruined saucepan is sorrowfully tossed into the ash can, yet it is a fairly safe guess that within a month this saucepan, together with hundreds of its follows, will again be in service, perhaps in an autonlobile crankcase, or in an electric vacuum sweeper. It is by this conversion of the useless into the useful, whether from home or large manufacturer, that the secondary tonnage is built up.

By Arnulf Muan, R. E. Johnson

Equilibrium CO2 /CO ratios of a gas phase coexisting with selected oxide phase assemblages of the system CaO-"Fe0"-SiOz and vnetallic iron have been determined at 1080°C. The data obtained are used to calculate activity-conzposition relations for metasili-cute, orthosilicate, and CaO- "FeO" solid solutions, and to determine a new value for the free energy of formation of C&S&0,. The metasilicate solution is practically ideal, whereas large deviations from ideality exist in the othe,r two solid solutions. BECAUSE of the geochemical and metallurgical importance of the oxides CaO, "FeO", and SiOz, the system CaO-"FeO"-SiO2 has been the subject of several experimental studies during the past 30 years. Following the delineation of phase relations at liquidus temperatures by a group of investigators at the Geophysical Laboratory of the Carnegie Institution of Washington in 1933,1 Chipman and associates in the early forties2,3 determined activities of FeO in liquids of this system. Since that time, many attempts have been made to interpret the data of Chipman et al. in terms of the constitution of the silicate liquids and the interaction parameters among the various constituents of the system (see for instance papers by Richardson4 and by Flood and coworkers5). One of the assumptions made in some of these interpretations4 is that the binary silicate systems CaSiO3-FeSiO3 and CazSi04-Fe2SiO4 mix ideally in the solid state. The objective of the present study is to provide experimental data on activity-com position relations in solid solutions of the system CaO-"FeO"-SiO2. Such data will contribute toward an understanding of the thermodynamics of silicate solid-solution phases in general, and will serve specifically to confirm or refute some of the assumptions made in interpreting liquid slag behavior. PREVIOUS WORK Phase relations in the system CaO-"FeO"-SiO2 in contact with metallic iron were determined by Bowen, Schairer, and Posnjak,1 and additional phase-equilibrium data for this system have been presented by Allen and snow.' A reproduction of the most up-to-date phase diagram for this system is shown in Fig. 1.7'8 Of particular interest in the present investigation are the relations among the various crystalline phases slightly below the lowest solidus temperature in the system, as shown in Fig. 2. The present work will be concerned primarily with some of the composition

Jan 1, 1968