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WHAT DOES "MAGNETIC" MEAN? The word magnetic has several meanings. When used, as it usually is, without qualification one is often unable to tell which meaning is intended. 1. A body is magnetic which has power to attract iron magnetically. Such is a lodestone or magnet, either permanent or not. This is an active sense or meaning in that the body itself does the attracting or is .magnetic. 2. A body is magnetic which may be made to attract iron magnetically, as the iron core of an electro-magnet when not magnetized by the current. This is a potentially active meaning, the body being capable of becoming a magnet. 3. A body is magnetic which has the property of being. attracted by a magnet magnetically. Such are iron, cobalt, nickel, magnetic oxide of iron, magnetic alloys, etc. This is a passive meaning, the attracting being done by the actively magnetic body. With these three meanings to choose from, one must usually make a guess based on previous knowledge as to which is the right one. Would it

Jan 5, 1914

POSITIONS VACANT (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons.) Opening for man as head of laboratory of large brass manufacturing plant in Ohio; must also be competent to manage foundry making brass castings, following practice of malleable iron castings and insulating materials. Good opportunity for right man. No. 36. Professorship in Mining at a Western university; requires man competent to give instruction in ore dressing, in metal and coal mining, and in zinc smelting, and capable of gaining confidence of mining interests. Salary $2,200 to $3,000. No. 37. ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of - the Institute by members or other persons introduced by members.) Member, graduate engineer, aged 44, with over 20 years' experience in connection with large coal and coke operations in different parts of the country, desires position as general superintendent of large coal company, or will take an interest with the management in a smaller company. No. 206.

Jan 6, 1915

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

By Charles E. Wait

The old laboratory at the School of Mines was among the notoriously bad ones, being situated in apartments of the main collegebuildings not originally intended, and conspicuously unfit, for the use to which they were put; while, as in many of our schools and colleges, the assaying was done in the basement of the college. Prominent among the disadvantages of such an arrangement are insufficient light, poor ventilation, and little or no provision to carry off offensive gases. It is not my intention now to present a complete description of this building. I wish merely to call attention to a few points in its construction and equipment, which may prove of interest to those who contemplate erecting buildings for snch work, and who may be, as we were in this instance, limited as to funds. In this laboratory every room is well lighted; all rooms used by students are well ventilated, and are provided with closed hoods for

Jan 1, 1887

By F. F. Aplan

Pollution control will be of utmost importance in the 1970's. In this area, the mineral process engineer has a special competence to understand and remedy many pollution situations. There is an old adage that goes, "Build a better mouse- trap and the world will beat a path to your door." Would that it were so, but the reality of the situation is such that, just as a supplier must sell his machine, a professional man must sell his competence. It is a sad but true fact that mineral processing engineers have not done a very good job in selling their extensive competence in the control of a broad range of pollution problems. Recently one of our students visited a paper pulp mill where he was shown a foam fractionator used to remove paper pulp fibers from plant discharge waters. "Foam fractionator hell, that's a flotation cell!'' was his comment. Ah so, it would appear that large numbers of technical people consider themselves experts on "foam fractionation" Or is it that we have been very remiss in demonstrating the usefulness of our equipment and processes and our professional competence to solve, these pollution problems?

Jan 1, 1970

By Edwin B. Johnson

The success of self-fluxed sinter in enhancing the operation of the blast furnace during the past few years has reasonably led to the assumption that the use of self-fluxed pellets might result in even greater furnace efficiencies. A great share of development work in agglomeration has been directed towards techniques related to the production of self-fluxed pellets, but no appreciable tonnage of self-fluxed pellets had been produced on a commercial scale until this past year when The Cleveland-Cliffs Iron Co. produced 35,000 tons of such pellets by the grate kiln system at the Republic mine during the period May 21-June 5, 1962.

Jan 3, 1963

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 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. HARRISON W. CRAVER, Director.

Jan 4, 1919

By E. M. MacKevett

The only source of uranium ore in Alaska that has been mined commercially is the Ross-Adams de- posit, a gently inclined, fusiform orebody in alkali granite in which uranothorite and uranoan thorianlte are the chief ore minerals. In mode of occurrence, apparent genetic association with the granite, and to a lesser extent in mineralogy, this type of deposit is uncommon. The mine is in the southern part of Prince of Wales Island (Fig. 1) at an altitude of about 950 ft on the southeast flank of Bokan Mountain. A steep unpaved road 1 ¾ miles long leads to the dock on the West Arm of Kendrick Bay, which can be reached by boat or seaplane from Ketchikan, some 35 miles to the northeast.

Jan 9, 1959

By B. I. Routh

A STUDY of the effects of temperature on the gel strength of drilling muds is a natural outgrowth of the present era of deep drilling. The control of the gel solids' is now considered important because it affects the wall-building qualities; the suspension of weighting material; the removal and release of sand, cuttings, and gas; and the control of cav-ing formations. With regard to the effect of temperature on gel strengths Herrick2 states: "Temperature variation within ordinary limits does not have much effect on yield points." Lewis, Squires and Thompson3 investi-gated one clay and found no marked change with temperature in either yield point or mobility. Reed4 found that potassium bentonite showed a great increase of gelation with increase in temperature and qualitatively there occurred a marked increase in viscosity upon heating. The apparatus used in these experiments consisted of a Stormer viscosimeter, Marsh funnel viscosimeter, rectangular and cylindrical shearometers, Mudwate hydrometer, and other minor laboratory equip-ment. The various methods of measuring viscosity and gel strength have been extensively described by Evans and Reid.5

Jan 1, 1938

By Arthur F. L. Bell

Discussion of the paper of ARTHUR F. L. BELL, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 105, September, 1915, pp. 1769 to 1799. WILLIAM A. WILLIAMS, San Francisco, Cal.-Is the Union Avila plant run as a topping plant or as a dehydrating plant? A. F. L. BELL, San Francisco, Cal.-Both. It takes off an average of 20 per cent. water besides topping the oil. Part of the crude oil is run through an electrical separator before running to the topping plant, but the entire crude averages about 20 per cent. when it enters the topping plant. DAVID T. DAY, Washington, D. C.-I suppose most of the work contemplated in these large topping plants is simply to deal with topping the oils with only a small percentage of water in them. A. F. L. BELL.-Not more than 2 per cent. of water can be handled in ordinary stills without causing trouble. At our Gavotte refinery, where the oil runs from 15 to 30 per cent. water, we carry 20 lb., pressure oil our stills to hold the framing down, we can do that with small stills, with large one's it would not be safe; but with a retort, the quantity of water contained in the oil does not affect its working. It simply means additional fuel to evaporate the water.

Jan 12, 1915

J. B. MCGRAW, New York, N. Y. (written discussion*).-In Mr. Burke Baker's description of the process of the American Briquet Co., he speaks only of the attractive features, but every process which uses a compound or emulsified binder has certain undesirable features which must be considered. In making an emulsion, the success of which depends upon the introduction of the various ingredients at certain fixed temperatures and the complete intermixing of a soluble solution with an oil which has absolutely no affinity for it, considerable difficulty is found in keeping the various factors in strict accordance with the formula. To serve its purpose properly or, in other words, to be right for easy mixing with the coal, it should be of a certain predetermined density. Among the controlling factors of this ate the proportion of moisture contained and the temperature of the oil when introduced. If the latter is higher than intended, a greater proportion of moisture will be evaporated than is proper, and if the oil is not sufficiently hot the process of emulsification is retarded. These various factors can be controlled with more or less certainty where working in a laboratory or in a small experimental way, but when it is attempted on a large commercial scale, certain obstacles not otherwise apparent are likely to be encountered.

Jan 5, 1918

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and guests who called at Institute headquarters during the period Apr. 10, 1916; to May 10, 1916: Philip P. Baily, New York, N. Y. George W. Otterson Seattle, Wash. John M. Brooks, Jr., Knoxville, Tenn. C. Q. Payne, New York, N. Y. C. A. Burdick, New York, N. Y. Charles F. Potter, Los Angeles, Cal. W. N. Crafts, Oberlin, Ohio. Albert E. Rhoads, Harrisburg, Pa. Andrew B. Crichton, Johnstown, Pa. M. F. Sayre, Schenectady, N. Y. 0. P. Hood, Pittsburgh, Pa. H. V. Smythe, Northpines, Ont., Canada. W. McA. Johnson, Tulsa Okla. W. 0. Snelling, Long Island City, N. Y. G. H. Morgan, New York, N. Y. W. H. Staver, Ophir, Colo. E. G. Norton, Chicago Ill., A. W. Tucker, Salisbury, N. C. M. L. O'Neale, Coal City, Ala. Andrew Weisenburg, Philadelphia, Pa. Arthur H. Brown has resigned his position with the Dome Lake Mining & Milling Co., South Porcupine, Ont., Canada. Robert Sterling has resigned his position as chief engineer of the Goldfield Consolidated Mines Co., Goldfield, Nev., to accept the position of assistant manager of the vanadium mines of the Primos Chemical Co., Vanadium, Colo.

Jan 6, 1916

By Thomas J. O’Neil

During the past five years, the mining industry has been subjected to new operating constraints that are unprecedented in number, scope, and urgency. The industry must operate in a safer, cleaner manner, yet produce more without large price increases. Compliance with any new sweeping legislation is always difficult-and particularly so in today's adverse economic climate, which is being aggravated by the steady stream of environmental control and tax-reform programs. In effect, while government is unwittingly but surely undercutting the country's productive capabilities, it blames industry for the resulting failure to meet consumer demand. Any such real or alleged failure then brings heightened bitterness from Congress. During the recent energy shortage, for instance, threats of nationalization were ventilated in public along with proposals to abolish the mineral depletion allowance.

Jan 11, 1974

By Donald W. Gentry

The recently established SME-AIME Education Board has completed its first full year of operation, and its six constituent committees-Accreditation, Career Guidance, Continuing Education, Educational Statistics, and Scholarship-have been extremely active in identifying and initiating programs to serve the educational needs of the Society of Mining Engineers and its members. The Continuing Education Committee-primarily concerned with the needs and problems associated with providing a continuing education program for SME members-is responsible for: (1) determining the need for short course offerings; (2) developing needed courses, along with new means and opportunities of presentation; and (3) scheduling and evaluating course presentation. In response to this charge, the committee has sponsored two short courses at the SME-AIME Fall Meeting in St. Louis and three short courses at the AIME Annual Meeting in Denver. Its major effort, however, has been directed toward the 1978 SME-AIME Fall Meeting to be held in Orlando, Fla., where 18 days of short-course instruction have been scheduled. A portion of these courses will be presented prior to the meeting, with the remainder to be presented in Nassau, Bahamas, immediately following the meeting.

Jan 7, 1978

ALLERTON S. CUSHMAN, Middletown, Ohio (written discussion*).¬ This subject is one to which I have given much thought and study and which I have frequently discussed informally with Mr. Cain and others. I have long been convinced that the gaseous elements, either combined or entrained (occluded), in steel play a much more important role than is ordinarily admitted. This is probably due to the difficulties encountered in the accurate quantitative estimation of gases, some of which Mr. Cain has referred to, as well as to the fact that, considered from the weight-percentage basis, gas content is measurable only in hundredths or even thousandths of 1 per cent. Volumetrically, however, the results ob-tained by modern research are startling, to say the least. Baraduc-Muller,1 as cited by Mr. Cain, pumped out of 1000-lb. ingots of basic Bessemer steel 2100 l. of gas. or about 75 cu. ft., at normal temperature and pressure, per ton of steel. In other words, we are to understand that Bessemer steel normally carries about fifteen times its own volume of gas. According to Baraduc-Müller's table of results, which is given here-with, carbon monoxide, nitrogen, and hydrogen are important consti-tuents of Bessemer steel, the latter gas being undoubtedly formed by the

Jan 11, 1919

By Thomas W. Healy

Particles present in mineral processing systems that are termed ultrafine are those that are small enough to be unaffected by gravity or the flow conditions imposed on the pulp. As such, their interaction with one another and with other larger particles are controlled by specific attractive and repulsive colloidal or surface interactions. Electrostatic repulsion between ultrafines is dominated by surface potential, double layer thickness and specific adsorption potential effects - controlled by pH, salt and complexing ion concentrations. Attraction due to van der Waals interactions must be assessed in terms of bulk and surface coating effects and of particle size and shape. The net effect of attraction and repulsion must finally be related to the average kinetic energy of particles in the real system.

Jan 1, 1979

By H. Foster Bain

In the preparation of this series of books it was considered particularly appropriate to include this work. Gunther was one of the younger men who was associated with Colonel Mudd in the finding and development of ore deposits. Supported by Mudd, Gunther undertook a systematic survey of the sources of copper of ancient Europe. This survey resulted in the rediscovery of the deposits now worked by the Cyprus Mines Corporation for which Gunther was, until shortly before his death, the resident manager. In finding and developing these mines, Gunther applied the methods and data embodied in this book and proved their usefulness. It is believed that other young engineers may profit similarly. In presenting a new edition, the form and substance of this work have been preserved and no changes have been made in any direct statement of the original author. Individual illustrations, paragraphs and mine descriptions appearing in the first edition have been omitted in order to permit introduction of new material. The latter has been chosen so as to present a somewhat more balanced picture of the mining industry as it now exists. The new material relates largely to the so-called porphyry coppers, to mines in Canada, Rhodesia, Alaska, and a number in the United States that have become important since the book was first written. The new material was prepared by Mr. Russell C. Fleming, using the best that had been published and items of which he had personal knowledge or had obtained by correspondence with men familiar with the deposit described. Whenever possible the description used has been submitted to the original author for correction. In a number of instances

Jan 1, 1932

The Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties. United Engineering Trustees, Inc. When Mr. Carnegie made his gift which made possible a home for the engineering societies, a separate corporation was organized to act as a holding company and to manage the common property. This was long known as the United Engineering Society, but the name has now been changed. to one which more nearly reflects the real function of the corporation. It holds title to the Engineering Societies Building and to various funds placed in its charge and is managed by a Board of Trustees, of which three are chosen by each of the four societies, American Institute of Mining and Metallurgical Engineers, American Society of Mechanical Engineers, American Institute of Electrical Engineers and American Society of Civil Engineers, which have equal and undivided interests in the property. The land and building cost two million dollars. During the gear 1934, the constitution and By-laws of The United Engineering Trustees, Inc., were thoroughly revised and a better organization of its functions was affected: The Engineering Foundation and the Engineering Societies Library were made "departments? of the United

Jan 1, 1936

By Thomas L. Kesler

THE Cartersville mining district, 35 miles northwest of Atlanta, Ga., has been of varying but continuous importance in the southern mineral industry during the past century. Noted chiefly for its production of brown iron ore, manganese oxide ores, barite, sienna, and magnesian limestone, the district and its environs have produced brick and tile clays, slate, gold, bauxite, and graphitic schist. Minor deposits of serpentine, sericite schist, copper ore, and red iron oxide have been prospected. The obvious deposits of brown iron ore, together with some associated specular hematite, were mined out years ago, although a little ore was left in the workings. Moderately steady production of sienna reached a peak about 1930, then declined rapidly. Manganese mining passed through a relatively active period from the World War to 1931, but has subsided to a small but rather constant output for the Birmingham market. However, the White Manganese Corporation has prepared for possible increased production by constructing a new washer capable of handling about 300 tons of ore per day. Principal activity in the district proper has centered for some years in the production of barite and magnesian limestone. GENERAL GEOLOGY Geologic relations of the ore deposits of this district are more or less similar to those of many Appalachian districts. The lowermost Cambrian formation, heretofore called Weisner1 in this region, supposedly partly or wholly equivalent to the Erwin and Hesse quartzites as recognized to the northeast, is overlain conformably by the Shady [+] formation, also of Lower Cambrian age. In the Cartersville district, the sedimentary rocks of these formations were folded with increasing intensity eastward, and were recrystallized.

Jan 1, 1940

A. L. FIELD, Cleveland, Ohio (written discussion*.-)In equation 2, B is used to denote the ratio of bases (lime plus magnesia ) to acids (alumina plus silica) it being stated that this ratio gives more concordant results than the ratio either of bases to silica, or of lime to silica. I find, however, that, by making use of the ratio between true CaO (CaO by analysis minus sulfur calculated to CaS) to acids, equation 2 may he modified to agree with the observed facts within an average error of 0.0041 per cent. sulfur instead of 0.0045 per cent. The revised equation is s = 0.072 + 0.01835 - 0.00061 (t - 1400) - 0.0403B where B is the ratio of true CaO to Al2O3 Plus Si02, and the other symbols have the same significance as before. I would not appear to stress too much this slightly better agreement of the revised equation with the observed sulfur. Yet I believe that the use of this ratio of true CaO to acids is to be preferred, if for no other reason than the fact that it is more in harmony with the previous findings of the Bureau of Mines with regard to the effect of magnesia and other impurities on slag viscosity.1

Jan 12, 1919