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By C. E. Sims, C. A. Zapffe

AN investigation of the behavior of inclusions in steel several years ago1 led to the conclusion that some of the commonly occurring inclusions in steel have appreciable solubilities, particularly in liquid steel. In the belief that further study and clarification of this matter was warranted, a laboratory study of oxides in liquid steel was started. These oxides are generally the result of deoxidation treatment, and the basis of an understanding of their behavior must be, therefore, the behavior of the deoxidizer in liquid iron. The Fe-Si-O system was selected for the first study, and the apparatus used and experiments conducted are described herein. APPARATUS The apparatus is shown in Fig. I and the system is shown by diagram in Fig. 2. Furnace Atmosphere Commercial hydrogen (1) passes through an orifice (2) into a manometric system that measures the tankside pressure (3) and the back pressure (4) in the system. A water trap (5) guards against excess tankside pressure. A by-pass with stopcocks (6 and 7) is provided, so that the hydrogen can be routed directly from the tank to the furnace if desired. When stopcock 7 is closed and stopcock 6 is open, the gas proceeds through the conditioning train, of which the first unit is a furnace (8) that contains platinized asbestos at 350°C. The temperature is measured by a thermocouple and potentiometer (9) and is controlled by a slidewire resistance (10). In [ ] this furnace free oxygen is converted to water vapor. The exiting gas passes over a water bath (11) kept slightly below boiling temperature by an auxiliary heating unit (12). This unit also heats a surrounding copper coil (13) containing water, and the heated water rises through a collar (14)

Jan 1, 1942

By H. A. Schwartz, Wolfram Ruff

The spheroidal form of the temper carbon nodules in malleable cast iron and of the graphite mottles of "mottled" cast iron suggests that in both all the graphite in a given mottle or nodule grew from a single center of crystallization or nucleus. $ There is, however, a distinct metallo-graphic difference between the mottle and the nodule; the area of mother metal impoverished in combined carbon by the crystallization of graphite in a mottle is practically coextensive with the ramifications of the graphite, while the impoverished zone of metal corresponding to a given nodule is always larger, and usually much larger, than the approximately spherical mass of graphite crystals forming the nodules. Furthermore, the mottle probably is formed during freezing and the nodule almost always at a considerably lower temperature. Assuming that the nodules or mottles can be used as a measure of the existing nuclei (capable of germination) we propose to record certain observations as to the graphitizing reaction in the light of the number and habits of growth of these nuclei. The present authors, in cooperation with others'-', have reported upon various cognate aspects of the problem. The fact that temper carbon is a mass of flakes and not a solid granule has become well recognized since the introduction of an improved polishing technique8, 9, 10 for cast iron. The problem of deriving from the circular planar intercepts of a mass of spheres of varying sizes their number and size distribution in space has also been satisfactorily solved12, 13 Growth of Nuclei in White Cast Iron It has already been shown1, 3 that the progress of graphitization with time is usual1y consistent with the assumption that nodules grow in size

Jan 1, 1936

By Wolfram Ruff, H. A. Schwartz

The spheroidal form of the temper carbon nodules in malleable cast iron and of the graphite mottles of "mottled" cast iron suggests that in both all the graphite in a given mottle or nodule grew from a single center of crystallization or nucleus. $ There is, however, a distinct metallo-graphic difference between the mottle and the nodule; the area of mother metal impoverished in combined carbon by the crystallization of graphite in a mottle is practically coextensive with the ramifications of the graphite, while the impoverished zone of metal corresponding to a given nodule is always larger, and usually much larger, than the approximately spherical mass of graphite crystals forming the nodules. Furthermore, the mottle probably is formed during freezing and the nodule almost always at a considerably lower temperature. Assuming that the nodules or mottles can be used as a measure of the existing nuclei (capable of germination) we propose to record certain observations as to the graphitizing reaction in the light of the number and habits of growth of these nuclei. The present authors, in cooperation with others'-', have reported upon various cognate aspects of the problem. The fact that temper carbon is a mass of flakes and not a solid granule has become well recognized since the introduction of an improved polishing technique8, 9, 10 for cast iron. The problem of deriving from the circular planar intercepts of a mass of spheres of varying sizes their number and size distribution in space has also been satisfactorily solved12, 13 Growth of Nuclei in White Cast Iron It has already been shown1, 3 that the progress of graphitization with time is usual1y consistent with the assumption that nodules grow in size

Jan 1, 1936

By J. Leslie Goodier

The International Law of the Continental Shelf, so far ratified by 35 nations, extends the national boundary of any coastal nation to the edge of the continental shelf, this normally being at a continuous water depth of 200 m. The Law further extends this boundary to include the floor of the deep ocean to any depth that can be mined by advanced mining technology. In effect, proof of mining can constitute proof of ownership of the subaqueous land and the minerals on or below the sea floor. Irrespective of the fact that present technology is too limited to permit mineral exploitation in the high seas-and the law regarding the right to mine appears hazy-the U. S. Treasury Department's Bureau of Customs, has a ruling that would further deter mining operations on the high seas. This law contends that minerals mined on the continental shelf of the United States are actually mined within the continental United States and are free of tariff, but mined products or other articles obtained from the ocean or the sea floor beyond the continental shelf, if brought into this nation, must be considered as imported and are subject to such customs duties as are applicable under the tariff schedules of the United States.

Jan 7, 1968

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Jan 1, 1938

By Wm. R. Dotson

Forty years ago the atom was split and the Age of Fission dawned. Uranium was the element used in this earth-shaking accomplishment. Thitherto almost unknown to the man in the street, uranium soon became widely and persistently sought. And the quest for this unique material is not likely to diminish during this century. To find is one thing; to own is another. Who owns uranium in the ground? Where no mineral rights in the land have been severed by devise, grant, reservation or lease, the uranium belongs to the fee simple owner of the land. But where there has been a conveyance or reservation of all or part of the "minerals", determining WHAT a substance is has been the traditional way of determining WHO owns it. What, then, is this element called uranium? The 1907 edition of Watts Dictionary of Chemistry calls it "a lustrous, hard, silver-white metal". Of nature's three prime divisions it falls within the embrace of the mineral kingdom - substances neither animal nor vegetable. In its natural state uranium always is combined with other elements or substances in the form of an ore mineral. May we, then, put to rest any doubt or question as to the nature of uranium and classify it for all purposes, including that of ownership, as mineral? Not quite! That self-same logic would find oil and gas primly ensconced in the animal or vegetable kingdom. Technically, oil and gas are not minerals but legally they have been classified as such. Why? The Supreme Court of Tennessee sought the answer in 1897 in the case of Murray v. Allard, 43 S.W. 355. After citing authorities pro and con, and while admitting their origin to be "decomposition of marine or vegetable organises" that court firmly concluded that since they were obtained by a form of mining, oil and gas were minerals. From the above example two elementary truths emerge. First, for purposes of ownership, uranium is and will be whatever the courts say it is. Secondly, the courts historically and currently favor a practical rather than technical test to determine the "mineral" character of a substance. So now we turn to the jurisprudence for enlightenment and definition. EARLY CASES ALLOT URANIUM TO MINERAL OWNERS Two early cases involving the ownership of uranium followed what had been well-settled mineral within the meaning of the conveyances involved, confirming ownership in the mineral owners. In 1956 the U. S. District Court for New Mexico in the case of New Mexico and Arizona Land Company v. Elkins, 137 F. Supp. 767, appeal dism'd 239 F.2d 645 (10th Cir. 1956), found that a 1946 deed reservation of "all oil, gas and minerals underlying or appurtenant to said lands" included uranium and thorium. The court reasoned that uranium and thorium, being minerals within the scientific, geological and practical meaning of the term, would certainly constitute minerals within the purview of the reservation. While agreeing that uranium and thorium were "minerals", defendants argued that at the tine of execution of the conveyance it could not have been the intention of the parties to reserve them because they had no commercial value in the locality and were, in fact, not known to there exist until their later discovery in 1950. The court re¬jected, as a matter of law, this "lack of knowledge" theory citing the Supreme Court of Kentucky holding in Maynard v. McHenry, 113 S.W. 2d 13, that: "The mere fact that a particular mineral has not been discovered in the vicinity of the land conveyed or is unknown at the time the deed is executed rules of construction and held that uranium was a does not alter the rule . . ." that a grant or exception of "mineral" in a deed includes all mineral substances which can be taken from the land unless restrictive language is used indicating that the parties contemplated something less general than all substances legally cognizable as minerals. Further, argued the defendants, the only feasible mining procedure for such substances was open pit or strip mining, which would destroy the value of the land for grazing or agriculture. Finding that the language of the reservation was clear and unambiguous, the court would not permit the admission of extrinsic evidence as to mining procedures required. Elkins is the first uranium case construing the granting clause involved. In 1958 the Texas Court of Civil Appeals at San Antonio, in Cain v. Neuman, 316 S.W. 2d 915, no writ, held that a 1918 lease conveying "all of the oil, gas, coal and other minerals in and under" the land involved covered uranium. The lease provided a royalty of 1/10th on "other minerals." "We find no Texas precedent which discusses uranium," said the court, "but the usual arguments that uranium is not embraced within a lease are that the ejusden generis rule excludes uranium from the meaning of the lease

Jan 1, 1979

REJUVENATED is an apt word to apply to Chino, Kennecott's big open-pit mine at Santa Rita, New Mexico. Back in 1923 Chino was merged with Ray by an exchange of shares, and in 1926 the Ray-Chino combination was taken over by Nevada Consolidated through an issue of bonds that were traded for the Ray and Chino assets. Subsequently, of course, the whole package was acquired by the Kennecott Copper Corporation. On the basis of the terms of the Ray-Chino-Nevada exchanges, Chino was rated third in value, something less than thirty per cent of the total. In 1955 the appraisal would doubtless be forty per cent or more. But it is not only vis-a-vis Ray and Nevada that Chino has blossomed out. At the end of 1931, Chino ranked seventh among the Porphyries in point of output; whereas by the end of 1954 it was fifth,. having passed both Inspiration and Nevada Consolidated. Sharp curtailment in production in 1932-33-34 and total suspension in the two years following (see Fig. 21) found the property in a somewhat parlous position. However, the engineers had not been idle; they had been planning for the future, and in 1937 a far-reaching program of rejuvenation was launched. During the ensuing five years, capital expenditures totaled more than $8,500,000. Among the projects undertaken were the following: (1) Mine-Purchase of larger and better equipment for drilling, loading, and transporting the ore. (2) Mine-Beginning of the first systematic project to leach and recover copper in the waste dumps at the mine.

Jan 1, 1957

By Alexandre Pourcel

The phenomena of liquation in steel or iron ingots of all sizes, but naturally to greatest extent in the heaviest ingots, have been noticed ever since the commencement on a large scale of the Besse mer and open-hearth manufactures; but they have been studied with care during the last few years only. The English and the Ameri cans were the first to publish the results of investigation upon phe nomena of this clam, to which they have given the name of segregation. Historical. Passing by that which has been written concerning the segregation observed in gray pig-iron, of which instances were given by Karsten, we shall confine ourselves here to that which is known of this subject with exclusive reference to ingot steel and iron. Mr. H. M. Howe, of Boston, in his Metallurgy of Steel, the most complete and well-arranged treatise upon steel, gives a resume of observations, with the results of numerous analyses, bearing upon the phenomena of segregation. According to Tchernoff (with whom we discussed this question at length in 1878, in connection with the cast-steel plates of large dimensions designed for the Italian fleet, which we showed him at Terre-Noire), Kalakoutsky called attention in 1866 to the lack of homogeneity in Bessemer ingots, especially when cast in sand. Our own attention had been called to the phenomena of liquation in 1868 by a somewhat surprising fact which appeared in almost every one of a number of steel-rail ingots coming from the works of Messrs. Pierre and Emile Martin at Sireuil, to be rolled at TerreNoire. In the heating or in the first groove of the rolls, a slice of from 6 to 10 centimeters (2.4 to 3.9 inches) separated itself from the head of each ingot. As a general consequence, the section of

Jan 1, 1894

By Paul Averitt

require both time and money. Any attempt to secure a quick answer will yield a figure that very likely cannot be substantiated, and certainly will not yield information in the detailed form now desired. It will be about 10 years before a completely new estimate can be prepared for the coal reserves of the United States at our present rate of progress, though of course, much information will be available in the interim. We would like to present such information as we obtain in the form most acceptable to the industry, and to that end we are working closely with coal resource committees of the AIME, the National Bituminous Coal Advisory Council, and the Bureau of Mines. DISCUSSION G. H. Cady*—Mr. Averitt's description of the nature of the coal resources investigations of the United States Geological Survey and the progress of this work is very timely in view of the general interest in the subject of coal resources. The Federal Survey is obviously taking the "long view" with respect to the appraisal of the coal resources as part of the preparation of the general geological map of the country and the attendant determination of the quantity of all mineral and fuel resources. It is apparently for regional surveys of the conventional type that the detailed procedures employed by the Federal Survey are applicable. Even if so it is somewhat unexpected to find the same criteria for evaluation will be applied to the country as a whole. The work on coal resources appraisal has been proceeding at various rates in a number of coal producing states for various periods. Undoubtedly since there has been no common practice in the method of appraisal the states each have worked independently and independently of the Federal Survey, and each has adopted certain practices to meet local conditions. I do not know how much consideration has been given by the U. S. Geological Survey to these practices. It seems probable that such consideration might result in important modifications of the standards which apparently have been set up by the Federal group in line with local requirements. It is the practice in some state surveys to present the facts in regard to the occurrence and distribution of coal beds and their variations in thickness down to thicknesses of 1 to 1 1/2 ft in relatively narrow stages up to maximum thickness. It is then possible for any one using such figures to compile quantitative estimates of workable coal at various minimum thickness limits. This is a desirable objective where surveys are detailed and information correspondingIy good. However, vast quantities of coal lie in beds that are relatively thin about which little information is available and the quantity of such coal might affect the final appraisal to the extent of several thousand million, depending upon the minimum limitation observed. Thus in the case of Illinois a difference of 1 ft in average thickness of coal in the coal field would make a difference of approximately 35 billion tons in the estimated quantity present. One is dealing with a very large area and small differences in thicknesses are very irnportant in the overall picture. The estimate of 10 years to accomplish the sort of detailed appraisal outlined by Mr. Averitt is viewed somewhat skeptically and certainly would require many more trained geologists than seem to be available. The requisite detailed mapping and study are very time consuming not only because of the geological field work required, which is difficult in certain seasons, but also in order to assemble data from company and personal files, and to study drill records and cores, and to sample and analyze the coal. Unless the staff of geologists could be increased in the order of several hundred per cent the prospects are that the appraisal of the type suggested will require many decades not just one. The permanent value of such appraisal, however, is not questioned and it should be expedited as rapidly as means allow. Satisfactory appraisal is not easily achieved and will vary from time to time. The main function of a geological survey is to collect and present the facts that will make possible appraisal in terms of existing conditions by individuals, particularly engineers, qualified by training and expcrience for making such estimates. Thickness and character of the coal bed, nature of the overlying and underlying strata, position, thickness, and character of "partings," relationship to other coal beds, and a variety of other factors must be assembled by the geologist in order to present a complete picture of the geological setting. The economic and engineering factors are in general outside the field of geological experience. The geologist should see to it that the pertinent geological facts are available; much more information than simply thickness and depth of the coal beds is essential to meet all the requirements of appraisal in the future as well as at present. With respect to the present demand by engineers and coal mine operators and others for a rapid re-appraisal of the available coal resources, in the light of existing practices and those in immediate prospect, the Federal procedure of systematic mapping and appraisal is scarcely in line. It will be necessary for those particularly interested in having such an estimate made to establish standards with respect to the various factors involved so that the scope of the geological work can be definitely restricted for the various coal fields. There is little use in setting up general standards since no such standards will be applicable to all fields. Thus it is folly to establish a standard minimum thickness to be generally applicable which is one-half to one-third the minimum minable thickness in some fields. The greatest difficulty in appraisal of the presently actually workable coal bed lies in the variation in the importance placed on roof, floor, structural conditions, bedded impurities. sulphur content and other factors that affect judgment relative to the value of a coal bed. It is doubtful whether any appraisal will have universal approval in view of the variable factors involved. For this reason if none other, the facts should be carefully and painstakingly assembled after the manner of a systematic geological survey such as that advocated by Mr. Averitt. Only upon the basis of sucb information can reliable estimates be made in line with selected conditions. Paul AveRitt (author's repty)— In this paper I discussed, but did not define as such, two major phases of our activities on coal, which are closely related, and which normally we in the U. S. Geological Survey see as an integrated whole. It is understandable, therefore, that Dr. Cady should assume that my remarks applied only to the current work on coal reserves with which I am directly concerned. In view of Dr. Cady's discussion, however, I think a brief summary of the two phases of U. S. Geological Survey activities on coal will be appropriate. The long-term function of the U. S. Geological Survey on coal investigations is to make detailed geologic studies, involving the preparation of detailed geologic maps showing the outcrops and correlations of coal beds, direction and dip of coal-bearing rocks, nature and thickness of overburden, location of faults and fold axes, and similar features. Such studies also yield many measured sections of coal and associated strata, which show variations in the thickness of the beds, and the intervals between coal beds. Taken as a whole, detailed geologic studies provide much useful information for mine operators and engineers. As Dr. Cady points out, this type of geologic work is arduous and time consuming, but it provides the basic data that are necessary both in the development of our coal fields, and also in the preparation of coal-reserve estimates, which are discussed in the next paragraph. The U. S.

Jan 1, 1950

By Terkel Rosenqvist

J. Chipman (Massachusetts Institute of Technology, Cambridge, Mass.)—The fact that the experimental work has been applied to copper rather than iron and that the paper is presented to the Iron and Steel Division, I regard as rather significant. It shows the unity of metallurgy and the fallacy of trying to cut it up by metals. This result for the solubility of sulphur in molten copper correlates with Professor Schuhmann's finding that the published data on the other side of the copper-sulphur miscibility gap are also in error. I should like to ask the author to say a little bit more about the sulphur capacity of the slag. T. Rosenqvist (author's reply)-—I hope that Dr. Chipman will find the derivation of the expression for sulphur capacity more clearly explained in the printed version of the paper than in the oral discussion at the meeting. I feel that this quantity, which actually is the ratio of two activities, can be measured more easily than the individual activities. Even if the ratio CaO/CaS is chosen as the standard state, the expression can be used for any slag, even for slags completely free of lime, and it represents a way to put the desulphurizing power of all slag constituents into one bag. Some doubt has been expressed as to whether oxygen ions really exist in calcium oxide and in molten slags. From a thermodynamic view point that question is of minor importance. The term oxygen ion activity, or any activity for that matter, is defined rigorously by the equation: activity = exp p/RT, where p is the change in free energy connected with the transfer of one mol of ions from the standard state into the slag. Whatever happens to the ion in the slag is of no concern to the thermodynamicist. Regardless of whether the ion is "free" in the slag or not, or whether it is present in a very small amount, its activity can always be expressed, and for a thermo- dynamic calculation that is all we need. However, ionic activities will only be of some real value if they are simple functions of the slag composition, or can be measured easily. Concerning the real nature of the oxygen in the slag, my feeling is that the oxygen atom has a rather multiplex nature depending on how strongly it is tied by covalent forces or polarized by the other atoms or ions present. The oxides of iron, cobalt, and nickel differ from calcium oxide and blast furnace slags as to the amount of free electrons that can give rise to electronic conductivity. In slags we know that the conductivity is mostly ionic. The fact that reversible emf's can be obtained with oxygen electrodes in certain salt melts, indicates a significant amount of oxygen ions in these melts. But extended work, e.g. polaragraphic studies and measurements of transference number; are needed to obtain quantitative information about the real structure of the slags. D. E. Babcock (Republic Steel Corp., Youngstown, Ohio)—-With reference to the ion, it might be well to remember Dr. Moses Gomberg. All of his life he had no use for the ionization theory and he contributed greatly to the field of chemistry on the assumption there was no such thing as ions. I do not think we have to worry about whether the oxygen is ionic or not. I think one thing specifically should be brought to your attention and this I think is one of the important contributions of Dr. Rosenqvist. He pointed out what we know as oxygen potentials or what is described as oxygen potentials. I have used this concept for a long period of time and I want to state that if this concept is properly applied, it vitiates much of what we have in the literature, or makes our usual ideas regarding oxidation seem primitive. That one thing is more valuable than almost all the rest of the discussion as a fundamental basis on which to build a reasonable in-

Jan 1, 1952

US 4,185,872-In the solution mining of uranium values from a subterranean uranium ore deposit, a lixiviant comprising sodium sulfate or other alkali metal sulfate and optionally minor proportions of an alkali metal carbonate or bicarbonate and an alkali metal hypochlorite is introduced into the ore to solubilize uranium therein. The pregnant lixiviant is recovered for processing. E.T. Habib, Jr., assigned to Mobil Oil Corp. Jan. 29, 1980. 5 pp (299-4). Filed- 8-18-78 (934,933).

Jan 1, 1982

By C. W. Hoffman, W. R. Hinken

Probability sizing, a fairly recent development in the field of particle separation, is now under investigation to determine its value to the mining industry. The method employed is probability sizing through a vibrating network of decreasing screen openings. While probability sizing is not new, the possibility of using it for coarse, highly abrasive ores at high tonnage rates has only recently appeared to merit practical consideration. The advantages of probability sizing vs. conventional screening methods are: (1) reduced space requirements for a high capacity unit, (2) fewer moving parts, (3) more versatile product sizing selection, (4) reduced maintenance requirements, and (5) lower power consumption. Screening is a necessary part of virtually every crushing circuit. At some stage in the process, particle separation becomes a controlling factor in the operation. The basic type of screen in use today is the vibrating unit, which usually employs a mechanical vibrator of one type or another to obtain sizing and material transportation across the screen surface. The vibrating screen has its limitations and inherent problems. Operators must live with: (1) high maintenance — worn rods, screen cloth, spacers, cross members, chutes, etc., (2) low capacity in relation to floor space requirements, (3) extreme noise levels, (4) high power consumption, and (5) structural problems in the screens and supporting steelwork. All plant operators have become tolerant of these drawbacks through the years, and little innovation has been developed in screening. The vibrating screens in use today incorporate improved metals, more efficient power sources, better lubricants, and increased manufacturing skill, but the basic machine itself remains unchanged. Screening is a relatively small part of most plants' operating expenditures and gets relatively little attention from research and development. The HiProb sizer is a new approach to the problem of particle separation on a high tonnage basis. Developed by Dr. Fredrik Mogensen (president of Fred-rik Mogensen, A. B. of Djursholn, Sweden), this unit has found its primary acceptance in the sizing of wet or dry materials in the fine ranges. Climax has been working cooperatively with Mine and Smelter Supply Company, the United States licensee, on the adaptation of the sizer to obtain consistent recovery at a high tonnage rate on a — 3/8-in. separation. This was a new application for the sizer and opened up a whole new field of problems. Dr. Mogensen's machine utilizes the control of normal probability of falling particles and is designed to eliminate some of the undesirable features of vibrating screens mentioned earlier. The machine is light, compact, consumes less power than conventional screens and has a low noise level. PRINCIPLES Probability sizing is a process designed to allow solid particles to segregate with a high ratio of the materials reporting into their respective size fractions with a minimum amount of misplaced particles. Sizing is defined in this paper as segregation of dry solid particles into fractions of comparable sizes. Probability is usually estimated as the ratio of the number of ways an event might occur vs. the total number of allowable ways. The probability process described depends upon the fact that particles falling through a network will segregate across the sizing surface even though all openings are larger than the particles. The degree of segregation is dependent upon the particle size and the trajectory applied by the sizing network to each falling particle. Specifically, the process utilizes a maze made up of screen cloth to control the path of a particle in free fall as illustrated in Fig. 1. The usefulness of this probability sizing process is dependent upon the degree of efficiency of an effective maze. Primarily, a maze must be extremely flexible to meet the multi-faceted nature of solid particles and, at the same time, the degree of control must be reproducible so that a desired separation is predictable. Dr. Fredrik Mogensen has formulated a maze that is not only flexible and easily controlled, but, mote importantly, easily adaptable to a working machine.

Jan 1, 1970

By M. G. Fowler

A GENERAL decline in copper production for most American producers occurred during the past year as a result of shortage in available labor. Few noteworthy technical developments have been reported; undoubtedly, many changes and improvements have been made but have not been reported because of lack of time. During the war years through 1944 the pressure for sustained high production has been of prime importance and during 1945, with slackening of production, many operators were faced with the problem of catching up on repairs and maintenance of plants, with inadequate labor supply. In hydrometallurgy there were some important developments that undoubtedly will be reported during 1946. Several operators in the Southwest have instituted experimental leaching programs to exploit low-grade oxidized and mixed ore bodies. The Bureau of Mines is conducting pilot-plant experimental work to determine the possibility of producing a satisfactory sponge iron at an attractive cost from deposits of iron ore and coal in Arizona. The sponge iron would be used for the production of cement cop¬per. The cell house of the Inspiration Consolidated Copper Co. at Inspiration,

Jan 1, 1946

Jan 1, 1985

By A. L. Mular. Discussion by G. A. Parks

G. A. Parks (Associate Professor, Dept. of Mineral Engineering, Stanford Univ., Stanford, Calif.) - Professor A. L. Mular in his paper Effect of Impurities on the Flotation Behavior of Zinc Oxide (T.P. 65B206) has made a most interesting and thought provoking contribution. In view of his recognized lack of measurements of the ZPC's of the doped samples and lack of direct evidence for participation of semi-conducting electrons in collector adsorption an alternate explanation should be considered. The alternate also

Jan 1, 1967

By C. G. McLachlan

THIS paper outlines a series of tests carried out during the first six months of 1927, in the laboratory and mill of the Moctezuma Copper Co. The object of the tests was to determine whether the soluble salts present in the mill circuit water were having a detrimental effect on the recovery made by flotation. To accomplish this object a series of water analyses were made, followed by flotation experiments in which definite quantities of the salts found were added as addition agents. Before proceeding to describe the results obtained in the course of the investigation, reference will be made to five articles that have appeared during the last two years in which the action of such salts is discussed. Two of these are by A. T. Tye1,2 and describe flotation practice at Cananea and the way in which water high in ferrous and ferric salts is conditioned for differential flotation. Two, one by A. C. Munro and H. A. Pearse3 and the other by H. A. Pearse,4 outline Britannia milling methods, and the advantages that have been derived from ore washing; while in the fifth, A. W. Hahn5 summarizes the results of laboratory experiments in which ferrous, ferric and aluminum sulfates have been added in varying amounts. The mill of the Moctezuma Copper Co. has a daily capacity of 3000 tons, and is situated about 75 miles south of Douglas, Arizona, on the Rio de Nacozari, in the Mexican state of Sonora. The ore treated is mined from the company's mine at Pilares, about 5 miles southeast of the Concentrator. This ore contains about 2.5 per. cent. copper -- present almost entirely as chalcopyrite-and 10 per cent. iron, of which

Jan 1, 1928

By Robert Gilman Brown

The original power-plant of the Standard Company has been described* by Mr. T. H. Leggett, late president and manager of the company; but since the presentation of his paper considerable additions have been made, which will be found interesting because of the engineering features involved and of the attainment of a high degree of flexibility with the inflexible, two-wire, alternating system of electrical transmission. Although these additions have been completed during the last year, they constitute, to a large extent, only the carrying out of plans that belonged to the original conception of the installation. The regular operation of the water-power through the winter proved very difficult; there was a considerable length of ditch to be kept open, and, as the stream is small and any freezing night may stop the whole flow of water, there was the .additional trouble of having no reserve to draw upon. The rule for the winter is, that after a night of hard frost water begins to move in the canon before noon on all but the coldest days. To obviate the nuisance of the anchor-ice, and to make available all of the water, a dam of sufficient height to impound several days' run of water has been built across the canon, 3875 feet above the power-house, and provided with pressurepipe well below the surface. In place of the 1571 feet of pipeline from penstock to power-house, there has been substituted a line 3875 feet long to bring water direct from the dam. The dam is of logs, cribbed up in squares of about 12 feet, ballasted with earth and rock and sheathed on the water-face with 3-inch plank.

Jan 1, 1897

By Martti E. Maliniemi

The Svappavaara mine is located 47 km southeast of Kiruna C. The ore deposit now being worked, Leveäniemi, belongs to Luossavaara- Kiirunavaara AB (LKAB) and is the company's, and also Sweden's, third biggest mine after Kiirunavaara and Malmberget. The distance by rail to the Norwegian port of Narvik is 214 km and to Lulei on the Gulf of Bothnia 340 km (Fig. 1). The village of Svappavaara has about 800 inhabitants. The climate is arctic in character. The temperature during the months of December to February is about -20º to -35ºC, and the ground is covered by a blanket of snow for about eight months of the year. The brief, intensive summer often arrives with startling speed, bringing both sunshine and warmth. HISTORICAL BACKGROUND Mining operations took place in Svappavaara as far back as 300 years ago. During the period 1655-1684, copper ore was taken from the deposit called Gruvberget in the vicinity of the village. The total production of raw copper was probably about 1,045 tons. During the 18th and 19th centuries, several attempts were made to extract iron ore from the numerous deposits found within the district. These brave attempts, however, were foiled by the high phosphorus contents and the enormous transport difficulties. The present-day mine fields in Leveäniemi were discovered in 1897. At that time, it was difficult to determine the size and value of the deposit because of the thickness of the soil cover (3 to 15 m) and the

Jan 1, 1969

By Joseph Chalmers, J. S. Desmond, R. Van A. Mills

[Because of the limited space in this volume and the fact that a description covering the oil recovery buildings and equipment (see page 4, Technical Publication No. 144) will be given in a forthcomnig U. S. Bureau of Mines publication, and because the paper was published in detail as Technical Publication No. 144, and is available as a separate at the Institute, it is impossible to include here more than the following brief extract.] Problems Being Studied The selection of the first problems to be studied was based largely upon the following very practical questions asked by several of the largest operators in the Mid-Continent field. 1. What are the causes for the formation of excessive amounts of bad thick oil on properties that are being repressured with compressed air and how can this trouble be prevented? 2. Why, in some areas, does the oxygen in the air injected into an oil sand during repressuring operations apparently change to carbon dioxide? Is carbon dioxide formed by the oxidation of some of the oil in the sand'? How can the formation of inert or low B.t.u. casinghead gas, loaded with nitrogen, carbon dioxide and oxygen, be prevented? 3. What percentage of the oil originally present in an oil sand can be recovered by the ordinary methods of operation when the gas originally dissolved in the oil is the main propulsive agent? 4. What percentage of the amount of oil produced by ordinary methods can be recovered under average conditions by repressuring a so-called depleted oil sand? 5. What are the relative propulsive efficiencies of compressed air and natural gas in repressuring operations? 6. What are the practical advantages of pressure maintenance and early repressuring as compared with late repressuring?

Jan 1, 1929

By F. D. Rosi

The plastic properties of extended silver and copper crystals of varying purity were studied as a function of crystal orientation in the early stages of flow. Variations in the gross shape of the shear stress-shear diagram and in the properties of critical Variationsshear stress and shear-hardening coefficient were correlated with changes in slip-band developments. The phenomenon of work hardening is discussed in terms of the existing dislocation theory. IT appears certain from the early studies on the deformation characteristics in metal crystals1-3 that plastic flow takes place in a preferred crystallo-graphic slip system which is determined by the geometry of the crystal (law of maximum shear stress), and that the value of shear stress for this system is independent of crystal orientation (law of critical shear stress). Experimentally, it has been demonstrated further that the law of critical shear stress can be extended to include extensive plastic flow.&apos; Thus, the shear-hardening coefficient, which is defined as the slope of the shear stress-shear curve, also is considered to be independent of orientation. It is noteworthy that deviations from this empirical shear-hardening law have been reported in cubic crystals whose initial orientation favors slip on more than two systems.&apos; Moreover, this law appears to have been derived from stress-strain data relating to relatively high values of shear strain (0.5 to 4), where widespread slip and complex distortions can be expected, regardless of crystal orientation. Since existing data indicate that the strain inhomogeneity in a crystal is manifested particularly in the early stages of flow, it would appear that a more exacting test as to the fundamental nature of the shear-hardening law would be to investigate systematically the shape of the stress-strain curve as a function of crystal orientation in the earlier stages of deformation. With regard to the general form of the shear stress-shear curve for cubic crystals, early studies show a parabolic hardening law, where the shear 1 stress is proportional to the square root of the shear-strain. Since this law was predicted theoretically by Taylor" in his original dislocation model for hard- ening, it has been accepted widely as a fundamental flow characteristic of cubic metals. However, it was recently pointed out by Masing6 hat the parabolic law is not the elementary form of hardening in cubic crystals, but instead is a consequence of complexities in the flow process (e. g., deformation bands and unpredicted secondary slip). Thus, in the very early stages of deformation (< 2 pct extension) where the occurrence of such complexities is unlikely, a different strain-hardening behavior might be anticipated. This view is supported by the recent work of Rosi and Mathewson7 on high purity aluminum where a linear law was obtained for extensions up to 2 pct. A linear hardening over a wider range of deformation also was reported by Rohm and Kochendorfer8 ho deformed aluminum crystals under conditions approximating pure shear. Even more pertinent is the recent evidence of Masing and Raffelsieper9 on high purity aluminum crystals. It was found that for crystals having initial orientations near a <l00> or <1ll> axis, a high hardening was obtained, whereas crystals with a <110> orientation exhibited a low and linear hardening curve followed by a region of more rapid hardening. Since much still remains obscure concerning the details of strain hardening as well as slip-band formation in face-centered-cubic crystals in the early stages of deformation, the present study was undertaken to evaluate the effect of crystal orientation on these two important manifestations of glide. It is important to note here that at the time of this study, Lucke and Lange11 presented information on the orientation-dependence of the shape of the strain-hardening curve in aluminum of various purities. Their work, which essentially represents an extension of that of Masing and Raffelsieper, in many respects is parallel to that of the present study. Experimental Procedure Production of Single Crystals: Single crystals of silver and copper of varying purity were used in

Jan 1, 1955