Search Documents

By A. B. Cox, L. W. Wark

In the paper on the development of the flotation process at Broken Hill (Australia) prepared by the Broken Hill Branch of the Australasian Institute of Mining and Metallurgy and published in its Proceedings for 1930 (N. S. 80), it is stated that the concentration of ores by flotation has been established on a commercial basis in Australia since 1904 and that differential flotation was practised at Broken Hill in 1912. Since then, progress in flotation practice throughout the world has been rapid, and during recent years the knowledge of the reactions between comparatively modern so-called chemical promoters or collecting agents and the mineral surfaces has been broadened by the published accounts of many investigators, particularly those working in American universities. Because of the benefits the Australian mining industry has derived from the flotation process, it was felt that the industry should take some part in the efforts that are being made to extend the knowledge of the principles on which the flotation process is based. Accordingly, early in 1930, three Broken Hill mining companies—the Broken Hill South, the North Broken Hill, and the Zinc Corporation—together with the Electrolytic Zinc Co. of Australasia, Ltd., and the Mount Lyell Mining & Railway Co., established a laboratory in the chemistry department of the University of Melbourne for the purpose of investigating the principles underlying flotation. Subsequently, the Burma Corporation, Ltd., expressed a desire to cooperate. The two authors are directly employed and controlled by these six organizations, and the cost of the investigation is divided equally among them. The research has been carried out under the general direction and in close cooperation with Harry Hey, chief metallurgist for the Electrolytic Zinc Co. of Australasia, Ltd., and the authors desire to place on record their indebtedness to him for his ever willing help and constructive criticism. After an extensive search of the literature, it was decided to determine in a preliminary investigation whether the effect of chemical collectors could be evaluated quantitatively by the "contact-angle" method. This preliminary investigation showed that with the bubble machine of

Jan 1, 1935

By Henry S. Rawdon

Any laboratory corrosion test, as judged from the practical point of view, is valuable only to the extent that it foretells what will, in all probability, occur in service. Such a test is most properly to be considered as a "pilot test," that is, a test which indicates the direction along which action may be expected to occur rather than as a truly quantitative test which would be expected to tell just how and to what extent the action would proceed. It is generally recognized that laboratory corrosion tests should be chosen with particular reference to the character of service expected for any particular type of metal, so far as it can be foreseen. Even when this requirement has been fulfilled, however, the question whether the actual service behavior of the material is in accordance and general agreement with predictions based upon such laboratory tests is always a pertinent one. The information available in the technical literature bearing on the correlation between the service behavior of metals from the corrosion standpoint, and the results obtained with the same metals in laboratory corrosion tests is very meager, indeed. The results which have been obtained in weather-exposure tests of sheet duralumin which form the body of this discussion are presented here for their bearing on this particular phase of the problem of the corrosion resistance of duralumin. Although the exposure tests described have not been completed, in the sense that all of the tests, in the series initially laid down, have been accomplished, still the general trend shown by the results is so clear that a number of definite conclusions at this stage (subject, of course, to possible modification in the light of later results) are believed to be warranted. The tests reported upon here form one phase of the much broader study of this subject which has been under way for several years in which the National Advisory Committee for Aeronautics, the Bureau of Aeronautics of the Navy Department, the Army Air Corps and the Bureau of Standards have cooperated. Without the very helpful cooperation of the manufacturers in furnishing the

Jan 1, 1929

By Henry S. Rawdon

Any laboratory corrosion test, as judged from the practical point of view, is valuable only to the extent that it foretells what will, in all probability, occur in service. Such a test is most properly to be considered as a "pilot test," that is, a test which indicates the direction along which action may be expected to occur rather than as a truly quantitative test which would be expected to tell just how and to what extent the action would proceed. It is generally recognized that laboratory corrosion tests should be chosen with particular reference to the character of service expected for any particular type of metal, so far as it can be foreseen. Even when this requirement has been fulfilled, however, the question whether the actual service behavior of the material is in accordance and general agreement with predictions based upon such laboratory tests is always a pertinent one. The information available in the technical literature bearing on the correlation between the service behavior of metals from the corrosion standpoint, and the results obtained with the same metals in laboratory corrosion tests is very meager, indeed. The results which have been obtained in weather-exposure tests of sheet duralumin which form the body of this discussion are presented here for their bearing on this particular phase of the problem of the corrosion resistance of duralumin. Although the exposure tests described have not been completed, in the sense that all of the tests, in the series initially laid down, have been accomplished, still the general trend shown by the results is so clear that a number of definite conclusions at this stage (subject, of course, to possible modification in the light of later results) are believed to be warranted. The tests reported upon here form one phase of the much broader study of this subject which has been under way for several years in which the National Advisory Committee for Aeronautics, the Bureau of Aeronautics of the Navy Department, the Army Air Corps and the Bureau of Standards have cooperated. Without the very helpful cooperation of the manufacturers in furnishing the

Jan 1, 1929

By George W. Powel

IN the nation's effort to raise its magnesium metal supply to meet the ever increasing demand, the Government is relying not only on standard established practice but has extended its support to developments not so well proved-at least, not commercially proved. Within the past few months considerable progress has been made, not only in the definite output of metal but in the exploitation of new processes, the successful adaptation of which should, in a reasonably short time, assure an adequate supply of magnesium. Recent months have also witnessed a reshuffling of the favored methods as well as of the likely raw materials, with the mineral dolomite gaining in interest over its richer but less abundant competitor, magnesite, while the lowly sea water appears to be losing ground to the higher magnesian brines of Michigan and western Texas. Every month sees a new alignment and there are signs that still newer methods or raw materials will be in use before the industry finally stabilizes itself.

Jan 1, 1942

By A. B. Parsons

NOT every organization on reaching the relatively ripe age of three score and fifteen can say with truth that its purpose and objects remain precisely the same as prescribed by its founding fathers. Of course, constancy of purpose may be something else than unalloyed virtue. It could merely reflect slavish worship of tradition, intellectual stagnation, or sheer inertia. On the other hand, it could establish the fact that the founders were men possessed of broad outlook, of prophetic vision, and of an acute sense of direction. In addition to charting the course with precision, the founders of the A.I.M.E. surely showed a flair for expressing clearly in a few words what others might say obscurely in many words. To quote verbatim from the "call" for the meeting, in 1871, the proposed organization was to have: "two great objectives: "First, the more economical production of the useful minerals and metals. "Second, the greater safety and welfare of those employed in these industries." This text underwent some refining on several subsequent occasions but today the ultimate product, as set forth in the Constitution reads: "to promote the arts and sciences connected with the economic production of the useful minerals and metals and the welfare of those employed in these industries by all lawful means." The original call was dated "Wilkes-Barre, Pa., April, 1871," and was signed by Eckley B. Coxe, of Jeddo, and by R. P. Rothwell and Martin Coryell, both of Wilkes-Barre, each of the three subscribing himself as "mining engineer." The authors proceeded to explain briefly just how it was proposed to achieve these objectives: "In European countries, where the arts of mining and metallurgy have long been the subject of the most careful study, no means have been found so effectual in attaining the end above proposed, as the free interchange of experience among those actually engaged in these industries; and this object has been accomplished mainly through the medium of `Institutes,' `Associations,' or `Societies,' composed of those engaged in these occupations, and by the periodical publication of `essays' or `papers' communicated to such societies by their members. "It must be evident to all practical men that the interchange of the varied experience

Jan 1, 1947

By Henry Rawdon

ANY laboratory corrosion test, as judged from the practical point of view, is valuable only to the extent that it foretells what will, in all probability, occur in service. Such a test is most properly to be considered as a "pilot test, " that is, a test which indicates the direction along which action may be expected to occur rather than as a truly quantitative test which would be expected to tell just how and to what extent the action would proceed. It is generally recognized that laboratory corrosion tests should be chosen with particular reference to the character of service expected for any particular type of metal, so far as it can be foreseen. Even when this requirement has been fulfilled, however, the question whether the actual service behavior of the material is in accordance and general agreement with predictions based upon such laboratory tests is always a pertinent one. The information available in the technical literature bearing on the correlation between the service behavior of metals from the corrosion standpoint, and the results obtained with the same metals in laboratory corrosion tests is very meager, indeed. The results which have been obtained in weather-exposure tests of sheet duralumin which form the body of this discussion are presented here for their bearing on this particular phase of the problem of the corrosion resistance of duralumin. Although the exposure tests described have not been completed, in the sense that all of the tests, in the series initially laid down, have been accomplished, still the general trend shown by the results is so clear that a number of definite conclusions at this stage (subject, of course, to possible modification in the light of later results) are believed to be warranted. The tests reported upon here form one phase of the much broader study of this subject which has been under way for several years in which the National Advisory Committee for Aeronautics, the Bureau of Aeronautics of the Navy Department, the Army Air Corps and the Bureau of Standards have cooperated. Without the very helpful cooperation of the manufacturers in furnishing the

Jan 1, 1929

By Myron Read

DURING the past 25 years, mining engineers have seen the development of a multitude of specialized engineering curricula in the mineral industry field. Bachelor degrees are now !ranted in the fields of mineral dressing petroleum engineering, geological engineering, fuel technology, and many others. These fields were all, previously considered to be part of a mining enginieer's work and elementary phases of them were included in mining engineering curricula. Their emergence has left some mining engineers with the fear that nothing will he left for a purely mining engineer to teach, or that mining engineering graduates will be unable to complete in any of these fields with the more specialized students and thus will have neatly restricted employment opportunies. A secondary reaction has been that if students who began to say that the pining engineering curriculum taught everything but mining, since so many of :he subjects that had always been udedAuded in the mining engineering curriculum now were fields in their own right.

Jan 1, 1946

By David B. Brooks

INTRODUCTION Resources are not; they become (Zimmermann 100) . The companion concepts of reserves and resources appear, one way or another, in almost all considerations of mineral supply. Yet, no other concepts in the economics of the mineral industries have occasioned so much confusion. Whereas everyone agrees that in general the terms refer to the amounts of material that-depending upon technology, market conditions, and institutions-will become available for production in the near or more distant future, the apparent agreement disappears when we come to more specific definitions or to application of the definitions. Some definitions emphasize the physical aspects of reserves and resources, while others emphasize the economic. Some treat reserves and resources as fixed quantities, while others regard them as continually varying. Some consider that reserve and resource estimates have validity only for individual deposits, while others insist that they can be measured with sufficient accuracy for regional or national planning. This confusion in concepts that lies at the very heart of mineral economics is both strange and not so strange. It is common in the social sciences to find concepts that have been adopted into scientific jargon from popular usage and given rather special meanings -at the same time that they continue to be widely used without such qualifications. Psychologists have the same trouble with personality and sociologists, with community. Nevertheless, an attempt must be made to straighten out the various meanings of reserves and resources, or at least to clarify the conditions under which different meanings are applicable, before much progress in analysis of mineral problems can be expected. That is the objective of this chapter. Throughout the chapter, an attempt has been made to provide enough references to guide the interested reader to the most pertinent works on the concepts under study. However, even in a review article, it is no longer feasible to provide a comprehensive set of citations; there are simply too many. In many instances the works cited will themselves include the bibliographies needed to complete a literature search; those that are particularly useful in this respect are so noted. Also, because of the limited availability of foreign periodicals, some important works -originating largely in Canada, France, the

Jan 1, 1976

By T. W. Atkins

ATHOUGH the magnesium industry in this country is about thirty years old, not until American industry began to amaze the rest of the world and confound our enemies with the extent and variety of our war production did the industry begin to come into its own. At the outset of the war, only three companies were producing and fabricating magnesium in this country. Today, about sixty companies are producing, casting, forging, extruding, rolling, and stamping this lightweight champion of metals. Experience in alloying, processing. and fabricating the metal gained during the war years is now being translated into hundreds of civilian peacetime applications. In no sense should magnesium be considered as a substitute for other metals. It has come into popular favor because If many unique properties in addition to is being the lightest known structural metal. These attributes are toughness, igidity, corrosion-resistance, and the ease with which it can be machined and worked. Magnesium is the third most abundant element in nature. Sea water, magnesite,

Jan 1, 1946

By H. B. Kinnear

THE first copper stool used under an ingot mold to receive molten steel has recently been taken out of service after it had received ingots amounting to 6012 gross tons. This stool, weighing 8330 lb. had been in continuous service for 1822 heats since its installation. From this modest beginning the use of copper for ingot-mold stools grew to 425,000 lb. in 1934, with an additional 50,000 lb. of copper used in the form of inserts in cast-iron stools. During 1935 the quantity of copper used for stools increased by about 350,000 lb., making a total of 775,000 lb. now in use for that purpose. Copper used for inserts has increased during this time 180,000 lb., or over 350 per cent, to a total of 230,000 lb. The total of copper, therefore, in use at present under ingot molds is slightly over 1.000,000 lb.

Jan 1, 1936

By AIME AIME

POSSIBILITY of a greatly increased manganese production from domestic source; is indicated by news that the Bureau of Mines has been successful in producing concentrates with high manganese content from the low-grade deposit, in the Las Vegas, Nev.) area. The first unit of the comprehensive group of pilot plants built by the Bureau of Mines at Boulder City, Nev., under a defense appropriation has started operations, demonstrating definitely the applicability of a process developed in the Bureau laboratories. About 12 1/2 lb. of manganese is needed for the production of every ton of steel, and substitution is difficult. The United States produces only about 3 per cent of its total needs of this ore. Only high-grade ore, such as the Russian ore, containing 18 per cent or more manganese, is generally used by American producers in making ferro¬manganese the form in which manganese is usually added in steel manu-

Jan 1, 1941

By Russell Webster

In having maintained production for more than 40 years Arizona's Magma mine is unique in a mineral district that includes several major copper mines. Other past and present producers in this area are Miami and Inspiration at Miami, the Old Dominion in Globe, the Ray mine in Ray, and to the south the new San Manuel mine near Tucson. Magma's production of copper, silver, gold, and some zinc has come from nearly parallel east-west striking mineralized faults, one called the Main or Magma vein and the other the Koerner vein, about 1100 ft to the south. This vein system has been prospected and partially mined for some 9000 ft horizontally and 4800 ft vertically. In ascending order from the deepest exploration level, the Main vein cuts Pre-Cambrian schist, Pre-Cambrian Apache Group, Post-Devonian diabase, and Devonian, Mississippian, and Pennsylvania limestones. Until 1950 very little ore was obtained from replacement mineralization.

Jan 10, 1958

By AIME AIME

AMONG the industrial motion pic¬tures released in the last year of possible interest to people in the mining industry are the following: "A New World Through Chemistry," made by the public relations department of E. I. du Pont de Nemours & Co., Wilmington, Del. This film, which is in sound and color, interprets in twenty minutes of narration and ingenious photography many of chemistry's newest developments. It may be borrowed either in 16-mm. size on an 800-ft. reel, or 35-mm. size on a 2000¬ft. reel, the only charge being the cost of returning the film. Douglas D. Rothacker, 729 Seventh Ave., New York City, is prepared to loan free of charge except for transportation each way several films prepared in the plants of the International Nickel Co., 16 mm. with sound. These include: "Nickel High Lights," 35 minutes; "Nickel Mining," 18 minutes; "Nickel Smelting," 18 minutes; "Nickel Refining," 9 minutes; and "Copper Refining," 6 minutes.

Jan 1, 1941

By Edward H. Robie

HOW have recent events affected the general trend in world mineral production? What effect has the World War, with its resultant boom and depression, had on the long-term trend of output? Have all of the principal metals and fuels been similarly affected, or have some boomed or slumped much more than others? The trend of world production of coal, iron, the principal nonferrous metals, and petroleum is shown in the accompanying chart, covering the period from 1882 to 1931 inclusive-the last fifty years. The curves are plotted logarithmically to show the comparative trends. In the lower left-hand corner of the chart is a slope diagram to aid in visually evaluating. the average yearly rate of increase in production; from this one can easily see, for example, that the petroleum production curve indicates an average annual increase of around 8 per cent, and that up to the period of the World War the average annual increase in copper production was about 6 per cent.

Jan 1, 1932

By V. T. BERNER

THIS apparatus was designed primarily to meet the demand for a quick, efficient stopping to seal off the burning area temporarily during a mine fire, but it can be used in any circumstance where an immediate brattice is required for ventilation control. In using the old style brattice, mine-rescue workers have found it difficult, in smoke-laden drifts and stopes, to erect an effective stopping with wooden frame and canvas. Stulls must first be cut to the proper length, the canvas tacked in place, and the numerous irregularities of the walls and back must be caulked. This operation requires the employment of axes, saws, and hammers, which cannot easily and safely be handled in dense smoke. The fire fighters have often been forced to abandon their brattice, unfinished, because of the rapid approach of the fire, or because of the exhausted sup- ply of oxygen in their breathing apparatus. It is neces-

Jan 1, 1930

By S. M. Shelton

SINCE the Saar started. the real progress in scrap-metal recover is in the change of point of view regarding secondary metals. The tendency had been to regard scrap as the normal outgrowth of obsolescence, fluctuating somewhat from periods of depression to periods of prosperity. but nevertheless an unwieldy economic factor more to be contended with than embraced. Now, metals above the ground are being looked upon as semi-permanent reserves or stock piles in various stages of repeated use or revolving life cycles. The change in point of view is due to the forced realization that domestic supplies of new metals are limited and many foreign sources are at least temporarily closed. The stock piles must be cultivated. The reserves must be made more nearly permanent. Steps are being taken : (1) develop methods for recovery of scrap metals heretofore not recovered, and (2) restrict strategic metals to uses ensuring a large percentage of re-use, which in turn means substitute materials in the dissipative uses.

Jan 1, 1942

By AIME AIME

OUR new Director from the 15th District is Robert W. Thomas; of Ray, Ariz., general manager of the Ray Mines division, Kennecott Copper Corp. In electing him to this office his fellow engineers pay tribute to his ability as an engineer and express appreciation for his service to the A.I.M.E. and its Arizona Section. ?Bob? Thomas was born April 1, 1886 at St. James Minn. received his early education in the public schools of Topeka Kans. and was graduted from Topeka High School in 1905. Already he had decided upon mining engineering as a profession. so he entered the mining school of the University of Kanas from which he was graduated with the degree of B.S. in hlining enginrering. While in college he became a Student Associate of the A.I.M.E. After graduation, lution and isolated mining camps wel-e not the most desirable places in w

Jan 1, 1944

The apparent small effect of skimming on desulphurization is somewhat misleading because the data was collected during the first months of use on the skimmer. During this period of time, the operators were, of course, just learning to use the equipment and, consequently, in many cases a so-called skimmed heat may have only been partially skimmed. In addition, during this period, the percentage of sulphur in the blast furnace slag was gradually increasing because of the increasing oil injection rates being employed at the blast furnace. An additional factor that cannot be disregarded is the apparent slower slag formation rate obtained in the BOF when the blast furnace slag is removed. This is evidenced at our shop by a much stronger tendency toward sparking and related lance skulling problems with deslagging, in spite of satisfactory manganese levels in the hot metal. Naturally, slower slag formation could account for poor desulphurization which would partially offset the beneficial effect of a lower sulphur input.

Jan 1, 1972

By Albert Sauveur

THE following experiments were conducted in order to study the influence of the rate of cooling through and below solidification on the dendritic structure (macrostructure) and microstructure of some hypoeutectoid steel. The steel selected was of commercial grade and had the following composition: C, 0.40 per cent.; Mn, 0.85; Si, 0.70; P, 0.099; S, 0.043. After melting in vacuum in an Arsem furnace, the various samples were allowed to solidify and to cool to room temperature as indicated in Fig. 1. Samples were thus obtained representing all possible combinations of slow and fast cooling through the various ranges of temperatures indicated, namely: (1), zone of solidification or primary crystallization, (2) zone of granulation, and (3) zone of secondary crystallization. The location of the different temperature zones in the iron-carbon equilibrium diagram is shown in Fig. 2. The authors adopted. Belaiew's notations. The designations of the various samples readily indicate their treatment, as will be apparent from Table 1.

Jan 1, 1930

POSITIONS VACANT (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons.) General manager .for a pyrite mine in Virginia, with experience in the mining and particularly in the washing of pyrite, required. Salary at start, $250 per month with perquisites. No. 28. Assayer and cyanide man for a Costa Rica plant. Salary $100. No. 29. Mine manager to develop gold-mining property in Witwatersrand, Transvaal. Salary £2,000 to £4,000, according to the experience and ability of the engineer. No. 31. Mine superintendent for a mine in Arizona containing copper, gold, silver ore. Will have entire charge of operation and development. Salary to start, $200 per month with perquisites. No. 32. .Mining engineer to make complete report and suggest necessary machinery for development and operation of a placer property; also to examine a copper property. Both properties in Peru, South America. No. 34.

Jan 4, 1915