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By Alexander Knoll, Dwight L. Baker

THE work herein reported shows that galena in certain organic solutions of fatty acids becomes coated with lead soaps, and that this coating is not only highly water-repellent but is also repellent to certain organic liquids, particularly those [ ] of high surface tension; i.e., nitrobenzene, diphenylmethane. WETTING PROPERTIES OF GALENA IN NONAQUEOUS FATTY ACID SOLUTIONS When a "captive bubble"' is withdrawn from a polished, plane galena surface under a nitrobenzene solution of stearic acid, the air bubble shows a decided tendency to "cling" to the mineral surface. The contact angle, therefore, was greater than zero, although it was not large enough to be measured quantitatively by the captive-bubble method.* [ ] When pure nitrobenzene was substituted for the nitrobenzene-stearic acid solution, no clinging of the bubble was observed; viz., contact angle = zero. Although the contact angle developed in air-galena-nitrobenzene-fatty acid solution was small, the organic solvent repellency of the galena surface was great enough to enable good recovery in a laboratory flotation cell.2 In Table I are given the results of flotation experiments using several different fatty acids dissolved in nitrobenzene.

Jan 1, 1941

By J. J. Brown

The ore-hearth was the earliest type of furnace used in smelting Mississippi Valley lead-ores, which are very pure, and low in silver-content. The first smelters made no attempts to recover lead from the smoke; and since about 15 per cent. of the lead in the charge escaped in this manner, early practice with the hearth was decidedly wasteful. At most of the large smelting-plants blast-furnaces with auxiliary roasters were substituted for the hearths long ago. But, upon the introduction of the Lewis and Bartlett bag-process for collecting fume, the ore-hearth was used by companies engaged in the manufacture of pigments, simply on account of the large percentage of fume made by it. In fact, the extraction of lead mas kept down by the use of hot blast and other devices. During recent years, however, several smelting companies have realized that the preliminary roasting of galena for the blast-furnace is not economical, and have, therefore, replaced the roasting-furnace with a modification of the old Scotch hearth, in which a large percentage of the lead in a charge is

Jan 1, 1912

There is no simple answer to the question, "What is the meaning of life?" The expressions of life are so multiple that life has different meanings for different spheres of thought, such as art, science, or philosophy; and it conveys a different significance to different persons, according to their individual development and interests. Life is complex from a philosophical point of view. The meaning of life is superficially positive and unmistakable only when approached from a mechanistic view- point; namely, that of biology or biochemistry, since these deal with the physicochemical basis of life processes. However, such a purely mechanistic or biochemical approach to the significance of life and the interpretation of man's behavior on the basis of purely physical laws is certain to run into trouble. Similarly, a concentration of effort upon materialistic advances in world progress is extremely dangerous. The possible consequences of splitting the atom, development of guided missiles, and possible bacterial warfare are timely examples. Man becomes more self-reliant as he extends his scientific and technologic discoveries and learns how to shape natural conditions to his own desires. When man will be able to travel to other planets in atomically propelled space ships and destroy whole worlds by pushing a button, a possibility which now seems to be within the realm of the predictable future, he will need the strong-

Jan 1, 1950

By R. C. Kadyk, C. J. Bise

High-voltage cable couplers are convenient and widely used accessories in modern coal-mine power distribution systems to help extend and retract power-feeder cables throughout a mine. Coupler design has tried to keep pace with the industry's desire to move to higher distribution levels, but the increase in recorded failures of 15-kV class couplers, which serve the 12.47-kV and above distribution levels, has inhibited this transition. Problems associated with the effects of partial discharge on high-voltage cable couplers are analyzed. The phenomenon of partial discharge is discussed, a testing standard is developed, and various coupler designs are subjected to its requirements. An analysis of test results and results based on field applications are provided.

Jan 1, 1985

By H. A. Hamza, N. E. Andersen

Emulsions have long occupied an important position in many industries. In the petroleum industry, where enhanced oil recovery techniques such as steam stimulation, flooding, etc. are being increasingly practiced, emulsions are very frequently produced. Characterization of these emulsions are an important prerequisite for monitoring and evaluation of the recovery processes. Emulsion properties will also determine the type of treatment required to separate and recover the oil phase. A variety of laboratory, pilot-scale and field-generated emulsions were characterized. Coulter technique results for size analysis are compared with microscopy (image analysis) and laser light scattering methods; Coulter determined oil contents are compared with gravimetric and volumetric methods of analysis.

Jan 1, 1980

By R. L. Stephenson

A sampling technique has been developed for procuring a sample of sinter representative of the entire depth of the sintering bed. The sampling method involves the use of an open-bottom metal basket that rides on the grate of the sintering machine and when removed contains a sample of the sintered product. Additional data have been obtained to indicate that the tumbler test is a suitable means of measuring sinter strength.

Jan 3, 1953

By Joseph W. Leonard

Partition (Tromp) curves, as used in diagnosing problems in coal cleaning equipment, are discussed and classified using five arbitrarily chosen types to represent, on a scale from one to five, system performance. Causes of unsatisfactory Tromp curves for various cleaning units, ranging from operational inadequacies to problems best corrected by the equipment builder, are analyzed.

Jan 1, 1982

By W. H. Reck

Increasing use of flotation in modern beneficiation has resulted in a variety of froth handling methods. Froth must be handled mechanically to maintain common floor elevation, because pure gravity flow, stage to stage, makes for multiple level machine installations with higher first cost and less convenient operation. Bucket Elevator--Froth is collected by launder and goes to the feed entry of the elevator, below the floor. The bucket goes to the next treatment stage by gravity flow. The outstanding advantage is high efficiency of conveyance.

Jan 5, 1955

By Ferid Kromer

This paper is the first in a series which will describe geology, mining methods, and production costs of some of Turkey's more important minerals. In this paper the economically significant minerals-chromite, meerschaum, and magnesite-of the Tastepe district are described. The cost data presented are believed by the author to be the first made public on Turkish chromite mining.

Jan 1, 1950

Jan 1, 1945

By Harlowe Hardinge, R. C. Ferguson

Laboratory and plant data covering 12 different operations show that lower than "standard" ball mill speeds increase grinding efficiency. In the case of high pulp-level mills, the gain is so great that the increase in capital cost of the larger lower speed mill will pay for itself in less than a year's time.

Jan 11, 1950

The Howe Memorial Lecture, in memory of Henry Marion Howe, Past President of the Institute, was authorized in April, 1923, as an annual address to be delivered by invitation under the auspices of the Institute by an individual of recognized and out- standing attainment in the science and practice of iron and steel metallurgy or metallography, chosen by the Board of Directors upon recommendation of the Iron and Steel Division. The follow- ing were the Howe lectures and lecturers for the years indicated: 1924 What is Steel? By Albert Sauveur. 1926 Austenite and Austenitic Steels. By John A. Mathews.

Jan 1, 1932

Many of those who attended the meeting at Chicago spent the first part of the following week in Pittsburgh, when the Experiment Station of the Bureau of Mines was dedicated and the fourth annual First Aid and Mine Rescue Contests were, held. The Bureau buildings were open for inspection during the three days, Monday, Tuesday, and Wednesday. The dedicatory ceremonies were held in the Bureau of Mines main building, Monday morning, Sept. 29, Mr. T. J. Gillespie, representing the Pittsburgh Chamber of Commerce, presiding. In his address of welcome, Hon. E. V. Babcock, Mayor of Pittsburgh, said: "The reclamation work already done stands out conspicuously beneficial to industry and populace alike all over the United States. It has demonstrated methods of preservation of life and reclaiming of injured persons which are new and greatly beneficial to modern civiliza-tion. The establishment of this institution in Pittsburgh was greatly desired, and now it is here it is greatly appreciated." The response was given by First-Assistant Secretary of the Interior Vogelsang, who represented Secretary Franklin K. Lane. He said that the Bureau of Mines did more during the war for the triumph of American arms than any other institution.

Jan 11, 1919

E. E. BACH, Ellsworth, Pa.-A personal interview with a man is one factor in reducing labor turnover; his working conditions is another, while the conditions under which lie brings up his family is still another; all have much to do with the reduction of labor turnover. A man well placed, happy in his work and happy in his home, will stay put and incidentally decrease the labor turnover in any industry. C. R. HOOK, Middletown, Ohio.-I am so deeply and sincerely interested in the employment problem, that it is very difficult for me, once I get started, to know when to, stop. In the first place, I want you to understand that I realize that what may be a possible accomplishment in the plant with which I happen to be connected, may not be possible of accomplishment in the same way in your plant. Our problems might be quite different; our location might be quite different, and therefore our employment problem would be very much affected by the community conditions. Two of our plants happen to be located in a town of about

Jan 4, 1918

Roof Bolts An expansion shell and plug Westinghouse roof bolting assembly made for use with threaded steel rods and large flat washers or steel channel employs a plug larger in diameter than those for trolley wire service. The notched plug helps prevent shell and plug from turning. The unit is shipped complete. Circle No. 1 Fan The Jeffrey Mfg. Co. Aerodyne Midget fan is a self contained blower or exhauster for auxiliary ventilation through tubing. Operating rating with 5 hp motor is 6.5 in. maximum static pressure, and 6200 cfm free delivery volume. Weight is 340 to 475 lb and it may be furnished in open or permissible form. Circle No. 2 Heavy-Density Initial installation in the Mesabi Range country of the Wilmot-Daniels heavy-density concentrating system was a 175 ton per hour plant at the [ ] Skubic Bros. Virginia, Minn., operation. This Wilmot Engineering Co. unit has a separatory vessel providing unidirectional medium flow and as the only moving part uses a standard drag-line conveyor for lifting sink out of the bath. Circle No. 3 Portable pH Meter A low priced battery-operated portable pH meter of utmost simplicity announced by the Photovolt Corp. uses only 3 ordinary radio batteries which give over 2000 hours of service. Accuracy of 0.03 pH is claimed by the manufacturer for the model 125, and AC power line supply is available. Circle No. 4

Jan 1, 1952

By Sidney W. Poole

THE control of deoxidation, together with other factors involved in electric-furnace melting practice, to consistently produce heats of high-quality alloy steel to stringent specifications as to nonmetallic inclusion content is a problem of considerable magnitude. Steel melting as an industrial process is subject to many variables that can influence the quality of the product made. In order to modify the size, amount and distribution of inclusions and to promote their elimination, deoxidation, among other practices, plays a major part. The primary purpose of deoxidation in the production of electric-furnace alloy steels is the removal of dissolved oxygen present as FeO in the bath, which is produced as a result of prior oxidizing conditions. The elements usually added to effect this removal of soluble oxygen are those that will, upon addition, cause the formation of an oxide compound insoluble in the molten steel bath as silica, alumina or silicate combinations.

Jan 1, 1947

By Bernard Lallement

INTRODUCTION Geostatistics have been used for five years at the B. R. G. M. to compute the ore reserve estimation. At present this technic is also used at the beginning of the exploration project to determine the best way to prove the orebody. The best way is a compromise between the cost of the exploration and the precision of the estimation. It is clear that geostatistics cannot be used without any data, but very often an exploration project is decided on an orebody which has already been drilled. Old data can therefore be used. This was the case this year for two orebodies: an iron deposit and a lead deposit. The iron deposit was explored by drifts and has now to be proved. We used geostatistics to determine the best drilling pattern. The variograms computed with these old data showed that an anisotropy existed between the two directions of the orebody, which meant that the drill pattern had to be rectangular. The lead deposit was explored by drill holes and a short drift in part of the orebcdy. The problem was to choose between a regular pattern of drill holes or a long drift and some added drill holes. The case of this study will be exposed afterwards. On the other hand, if the orebody is completely unknown, the exploration project generally forecasts two exploration steps (the first step

Jan 1, 1977

By Heinrich Siemes, Christa Hennig-Michaeli

The effect of temperature and orientation on the plastic behaviour of an impure titaniferous magnetite from Palabora (South Africa) has been investigated. Prismatic specimens were axially compressed along [001], [110] and [111]. The strain rate was about 3.10-6 s-1. Trace analyses of glide lines revealed a plastic anisotropy due to glide on several non-equivalent crystallographic planes. At 200 °C {111}<112> twinning, {111}<110> slip and {100}<011> slip have been operative. At 400 °C {111}<110> slip and {100}<011> slip are primary glide modes. {110}<110> slip seems to be a secondary glide mode in the [001] specimens at 400 °C. {III}<112> twin glide generates isolated sharp lamellae. {111}<110> slip produces smooth surface striae. {100}<011> slip is characterized by coarse and partially wavy slip bands. {I10}<110> slip displays faint remarkably equidistant glide lines. The critical resolved shear stresses (CRSS) decrease with rise of temperature. The CRSS ratio of slip on [100) to slip on {lll} increases from 1.1 at 200 °C to 1.4 at 400 °C giving rise to a distinct flow anisotropy of the magnetite at 400 °C.

Jan 1, 1982

By Charles Catlett

Much has been done of late years to facilitate preliminary stratigraphical investigations, and for examination at considerable depths and in a certain character of material the diamonddrill, in its general forms, certainly stands pre-eminent among the tools for such work. But there are large classes of deposits —indeed, I may say the larger proportion in which ordinary. prospecting is done—which lie near the surface and are interbedded with soft and fine material. The method usually employed for prospecting these is by means of small shafts. These are sunk with considerable slowness and at considerable expense, depending largely upon the character of the material encountered, and are greatly interfered with by water. In this region the smallest are 3 by 4 feet, but they are usually considerably larger. Having had occasion during the past year to do a large amount of prospecting work, I have found the use of a hand-auger and drill of immense value in this respect, and in my practice it has largely superseded, and always preceded, the other forms of investigation. I believe that the information desired mas

Jan 1, 1898

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

In 1947 a large low grade deposit of uranium was located in the northwest corner of Saskatchewan, in the Beaverlodge property of Eldorado Mining & Refining Ltd. Most of the values occur as thin seams and as coatings on other minerals, and the ore, which is light and friable, is not amenable to the usual gravity methods of concentration. The acid leaching process developed to retreat the company&apos;s Port Radium tailings was also impractical, as the percentage of carbonates is high and the percentage of sulphides relatively low. Construction of the mill building and installation of equipment, both scheduled for 1952, awaited selection of a satisfactory ore dressing process on or before Oct. 1, 1951. An extensive research program on dressing of ores from the Ace mine therefore was undertaken by the Mines Branch in Ottawa, a research team at the University of British Columbia and an ore dressing group at the company&apos;s Port Hope refinery.

Jun 1, 1955