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FRIENDS of the late Charles F. Rand presented in 1930 a sum of money from which the income is available to support various phases of the work of the Institute in which Mr. Rand was so deeply interested. At present the fund amounts to $10,400. The specific terms of the deed of gift are as follows: "The fund collected to establish a memorial to the late Charles F. Rand shall be placed in the custody of the Board of Directors of the American Institute of Mining and Metallurgical Engineers, to be set up as a trust to be known as the `Charles F. Rand Foundation,' the income of which shall each year be applied to a distinct purpose to be decided upon in that year by vote of the Board of Directors. This purpose shall be such as to promote the general welfare of the Institute and to constitute a permanent memorial of the usefulness of Mr. Rand, who for many years gave unstintingly of his time and talents in its service. "It shall be within the discretion of the Board of Directors to establish a medal to be known as the Charles F. Rand Memorial Medal to be awarded at such a time and under such rules as may be determined by the Board of Directors, for Distinguished Achievement in Mining Administration." The establishment of this medal was announced at the annual meeting in February, 1932, the term "mining" being defined in its broad sense to include metallurgy and petroleum. Robert Linton is chairman of the Charles F. Rand Foundation Award Committee.

Jan 1, 1943

By W. E. Gaby

INTRODUCTION SINCE the time of their discovery, the genesis of the ores at Mount Morgan, and the nature of the changes which have affected the surrounding rocks, have been the subject of investigation and speculation by geologists and mining engineers. Developments at this mine, for a long period the greatest gold producer of the world, show that with depth the orebody grades into copper, of which metal it now furnishes a large output, exceeding in value the gold. In earlier times, the purity of the gold and the first extremely heterogeneous character of the ore made it an interesting problem. Now, the probable depth of the copper enrichment, genesis, and true relations of the neighboring rocks furnish equally profitable material for investigation, and the present somewhat detailed description of these ores and rocks, from microscopic study, may prove of interest. The mine occupies a highly silicified portion of a belt of quartz-porphyry, which is believed to be the oldest rock of the region. This belt of quartz-porphyry and allied rocks runs north and south between two areas of a later intrusive granite, as shown on the geologic map,1 Fig. 1. Near the orebody the quartz-porphyry has been intruded by a dense basaltic mass called the "Old Basic." Cutting all three of these igneous masses are two sets of basaltic dikes, one running northwest-southeast, and the other, cross dikes, northeast-southwest. These dikes may be contemporaneous with, instead of later than, the ore. Their number has caused peculiar difficulties in extracting it, as the clay selvage of decomposed material affords no adhesion between dike and ore, causing great blocks to loosen and come down.

Jan 9, 1916

By Edgar Kidwell

To any one acquainted with the practical conditions surrounding the mining engineer and mine-manager, especially in this country, the presentation to the American Institute of Mining Engineers of a paper on the above subject will need no explanation. The members of this profession are continually called upon to design and erect, both above and underground, structures which involve the use of beams. Not to mention the various buildings connected with large mining operations, I need only refer, in support of this statement, to trestles, derricks, headworks, etc., on the surface, and to timbered stations and other spaces of large span in the mine-workings. Notwithstanding the rapidity with which iron and steel are replacing wood in the construction of large buildings, there will always be cases in which the use of metal will be unadvisable. Especially will this be true in districts remote from large cities. Works of temporary character will continue to use timber. High freight-charges, the liability of delays in delivering iron, and the temporary character of many of the structures, will for many years to come make it advantageous for the mines west of the Mississippi and on Lake Superior to construct their buildings almost exclusively of wood. The timber-resources of the country are decreasing so rapidly that already the engineer finds difficulty at times in obtaining beams of large size. This difficulty will steadily increase, and will force the constructor to resort more frequently to built-up beams, such as have long been used in Europe, owing to the difficulty of obtaining there such large sizes of timber as have

Jan 1, 1898

By Archer Wheeler

The Boston & Montana Reduction Works at Great Falls, Mont., was formerly the reduction works of the Boston & Montana Consolidated Copper & Silver Mining Co., and continued as the reduction plant for the independent company until .June 1., 1910, when the consolidation of a large number of the operating companies of Butte was effected. It then became merged in the Anaconda Copper Mining Co. as the Boston Montana Reduction Department of the Anaconda Copper Mining Co. The history of copper converting at this plant, while not covering the entire period of the commercial use of the process in this country, does cover by far the larger part of it, and as the operations and appliances of the process have undergone many changes during the time, it may, perhaps, be of some interest to put the record of these changes into permanent form. The plan followed in the preparation of this paper has been to give first a brief chronological record of the principal events and changes and then, even at the risk of some repetitions, to give more detailed account, of some of these changes under separate headings. The headings for the complete paper are as follows: 1. General Chronological Review. 10. Development of Different Classes 2. Mechanical Manipulation of Converters After Class I. 3. Casting of Finished Copper. 11. Basic Lining. 4. Tamping of Linings. 12. Number and Size of Tuyeres. 5. Early Acid Linings. 13. Cast Copper Tuyeres. 6. Acid Linings With the Use of Ore. 14. Efficiency of Air. 7. Introduction of Flux Through the 15. Size of Converter Mouth. Tuyeres 16. Height of Converter. 8. Bottom Blast. 17. Summary. 9. Disposal of Converter Slag.

Jan 8, 1913

By W Lindlief, Cyril Stanley Smith

Several investigators, mainly concerned with the mechanical properties of the alloys, have studied the so-called aluminum bronzes after various quenching and reheating treatments. Of these works, perhaps the most complete is that of Bouldoires, who studied changes of length, electrical conductivity, thermoelectric force, hardness and micro-structure on tempering quenched alloys containing 5 to 20 per cent of aluminum, although the work of Carpenter and Edwards,² Curry13 Greenwood,4 Braesco,5 Matsuda,67 Grard8 and others has added much to our knowledge of the changes occurring during tempering. The so-called acicular ß decomposes on tempering at temperatures between 350" C. and the eutectoid, giving rise to a Widmanstätten structure of a needles in a matrix of 6 or fine a + 6, associated with an increase in hardness and almost complete loss of ductility. Matsuda studied the eutectoid transformation by means of dilatation and electrical conductivity measurements during cooling at different rates. He found that on cooling at the rate of 10" C. per minute there was a decrease in electrical resistance and in length instead of the usual increase which occurred with slow rates of cooling. On tempering the rapidly cooled samples, the increase commenced at about 400" C. and at 520" C. the resistance and length had reached the equilibrium values. These peculiarities he accounted for as being due to a transitional phase ß' being formed, ß' having an electrical resistance and volume less than either ß or a + 6. Obinata9 published some electrical conductivity curves for copper-aluminum alloys showing a double break at the eutectoid temperature,

Jan 1, 1933

MINING and Metallurgy closed the year 1928 showing a small profit, the receipts, exclusive of the charge against members, dues for subscriptions, having been $43,067.81, and expenditures $40,925.58. In accord with the policy of the Board the budget is made each year with the purpose of balancing the accounts rather than the maximum of profit from the undertaking since it is the service the journal performs for members that justifies its existence. This service is being constantly increased. Within the year a number of changes have been made in the dress of the magazine, a new cover adopted, color more frequently used, and illustrations more generally employed. These changes seem to have been appreciated both by readers and advertisers. More space has been devoted to papers read before local sections and to the news of their activities. It is believed that this has helped materially in sustaining and increasing the interest in such meetings. The general, regional, and division meetings have also been fully reported and news of Board meetings, of the work of the various committees, of the employment service and other activities of the Institute has been spread before its members month by month. The 570 pages of reading matter printed in the course of the year constitute not only a record of what the Institute was doing but of what the most representative sections possible of the members of the mining and metallurgical professions were thinking. With 9000 members scattered around the world, occupying key positions in the industry, the Institute affords through its own journal an unsurpassed medium for broad contact and enables the readers with the minimum of expenditure of time and at no extra money expense to keep a general contact with the whole range of subjects touched by miners and metallurgists. In these days of intense specialization but rapid change such contact is particularly valuable. The more formal papers presented to the Institute are published in the Transactions, Technical Publications and the special volumes. Mining and Metallurgy carries abstracts of all papers published ,by the Institute and prints in full the shorter, less detailed papers and those which reflect work in progress rather than finished. Such papers have a news value which is supplemented by editorial comment, discussion by members and others, and the actual news of the organization itself. Without therefore attempting to fill the place of a general news sheet, it has a timeliness that gives it an immediate value much appreciated by the readers. In accord with the general policy of the Board every effort will be made constantly to improve the quality of the magazine to the full extent that its revenue will permit. Your Committee feels that, through the intelligent cooperation of the official staff in the office, Mining and Metallurgy has been improved in

Jan 1, 1929

By P. Campbell, E. M. Gardy, L. Hachkowski

Introduction The efficient process control of a uranium mill and its associated mining operation requires a nearly continuous knowledge of the uranium concentration in the ore. Generally, the approach is to use laboratory assays of grab samples from the mill feed belt. In some cases, elaborate and expensive systems have been used to ensure random sampling, but even with these systems, mass-balance discrepancies still exist. There is a requirement for an on-line instrument that can give a prompt, accurate analysis of a large portion of the feed stock. The authors have recently evaluated a laboratory system that achieves these goals using neutron activation and delayed neutron counting. The development of the on-line uranium ore analyzer is a consequence of previous work done at the Whiteshell Nuclear Research Establishment (WNRE) (Campbell et al., 1978 and 1981), and is based on the emission of delayed neutrons after the neutron irradiation of fissionable materials. The mechanism of delayed neutron emission has been described (Keepin, 1965), but briefly is as follows. The fission fragments resulting from irradiation are in an excited state. Certain of these delayed fission products, precursors, decay to a more stable state by the emission of a delayed neutron. The delayed neutrons can be divided into six groups with effective half-lives ranging from 0.2-55 sec. It is important to note that more than 50% of the delayed neutrons are emitted within the first 6 sec after irradiation; this has an influence on the design of the analysis instrument. Measurement Cycle The measurement cycle involves a neutron irradiation, a delay time, and a counting period. The laboratory demonstration model of the ore analyzer comprises a californium-252 neutron source, a source chamber, a pneumatic transfer facility, and a neutron irradiation and counting module [(Fig. 1)]. The ore sample is placed in the irradiation chamber. The neutron source is transferred to the center of the chamber for a 5-sec irradiation while the helium-3 thermal neutron detectors are switched off. As the source returns to the storage chamber, the detectors are switched on and the delayed neutrons counted. The total assay cycle is 16 sec. The current instrument design calls for the ore to be cut from the main belt every 16 sec by a mechanical arm and dropped into the analyzer directly, or via another belt. The cycle starts when there is a sufficient mass of ore in the irradiation chamber to depress a switch and stops when the delayed neutron count is finished. The ore is then dropped through the bottom of the analyzer chamber and returned to the main belt. The counts from each cycle are accumulated and the data reduced to give the desired information.

Jan 1, 1985

By R. Schuhmann

PROBLEMS in expressing, interpreting, and using size-distribution data recur in many phases of mineral dressing; therefore it is desirable that size analyses be expressed in such a form, either numerically or graphically, that comparisons can be made readily. The size distribution of comminuted material is a result of a specific physical operation on the material and therefore should be governed by some definite physical principle, or cause-effect relation. Although this principle has not been discovered, it has been found that the size distribution of comminuted, homogeneous solids may be expressed by relatively simple mathematical equations. Two equations in particular, proposed by Gaudin1 and by Rosin and Rammler,2 respectively, have stood out, both having wide demonstrated ranges of application. The form and the method of application of the two appear almost irreconcilably different on the surface, but, as will be shown, they are asymptotic in the fine sizes when expressed in the same units. This paper gives the results of a further study of the Gaudin and Rosin-Rammler relations, made with the object of developing a form of size-distribution equation that will be more usable and more significant-particularly in comminution studies, both for interpreting the nature of size distribution and for evaluating surface. The work is summarized in the following: I. An equation relating cumulative per cent finer to particle size in the fine sizes is derived from Gaudin's original equation. That equation relates weight per cent retained on one size and through the next larger size in a geometric series of sizes to size (of the retaining screen, for example). 2. Comparisons with Gaudin's equation and with the Rosin-Rammler equation show that the cumulative equation applies to the fine sizes of all size distributions that fit either of these earlier relations, and, furthermore, has some advantages over each. 3. A simple graphical method of surface calculation based on the cumulative-equation plot is evolved and illustrated. 4. Additional confirmation of the cumulative equation was obtained in the more severe test of sizing down to the limit of a sedimentation balance a sample of jaw-crushed quartz. The equation was closely followed over a 20o-fold range in size, from approximately 0.4 mm. (35 mesh) down to 0.0023 mm. (2.3 microns), the lower limit of the size analysis made. There is no indication that the equation will not hold further to well below 2.3 microns. 5. Calculations of the surface produced in the jaw-crushing test mentioned above showed that at least 8o per cent of the total new surface was on particles finer than 35 mesh (about ½ 5 of the crusher setting). The minus 35-mesh portion was only

Jan 1, 1940

By Willard Ide Pierce

THE native methods of mining and milling gold-ores in Korea may not present any specially new features, but are chiefly interesting as primitive practices, still followed at the present day. In mining where the rock is hard, wood is piled up near the face of the tunnel or drift and then set on fire. The fire bums for twenty-four hours, after which, three or four days are given for the rocks to cool, before the miners go in and extract the loosened material. The only tools in use are a hammer, a steel gad about five inches long, and a flat spoon-shaped basket. The pay-streak or chute is closely followed, and in places the workings are very small and intricate. Rock not yielding more than $6 per ton is not extracted. The manner of opening a mine is to begin on the outcrop, where the rock pays, sink a shaft or run a tunnel on the vein, and follow the pay-streak and more easily worked ore. When this is exhausted, or the influx of water interferes, the opening is abandoned and operations are begun again at a new spot on the outcrop. The place usually selected is as high up on the mountain as possible, and in no instance is advantage taken of the topography by running a cross-tunnel to tap the vein. The ore is brought in baskets to the surface, and there placed in sacks, holding about 150 1bs. each, and taken to be crushed. The rock is first crushed between two stones, as shown in Fig. 1. The upper stone is oval and rounded on the bottom, so that it can be readily rocked on the under stone. Two pieces of wood, used for handles, are placed, one on each side, in grooves in the upper stone, and held in position by means of straw rope. The lower stone is not smooth on top, but exhibits three elevations running lengthwise, with shallow depressions between them. The middle elevation acts as a fulcrum on which the upper stone may be rocked. From two to ten men, according to the weight and size of the stone used, are employed in rocking. With four men, from 300 to 350 lbs. of rock can be crushed per day, the stone making 50 complete oscillations per minute. The men squat on each side of the stone and move it to and fro by means of the wooden handles. The ore is fed, in pieces up to the size of an egg or even larger, by one of the men. During the crushing one man on each side, as the stone rocks from

Jan 1, 1890

By C. Fairhurst, A. M. Starfield

As a practicing mining engineer, I face many rock mechanics' problems daily and would like to mention one or two examples to illustrate the current gap between laboratory investigations and actual field problems. I would like to endorse Dr. Obert's suggestion that more field measurements and observations should be undertaken. There is an ever-increasing body of data beginning with Hast's results in Sweden,l then measurements at Elliot Lake, Canada, and so on, including our own measurements at White Pine, which clearly indicate that the horizontal stresses underground are often at least as large as the vertical stresses. Visual obsenation of the deformation of roof and pillars (including failure due to horizontal compression) also demonstrates that the horizontal stresses are often most important. Yet almost every laboratory investigation begins with the assumption that the only stresses acting are vertical. Roof spans in layered formations. for example, are calculated on the assumption that the rock behaves as a gravity loaded beam. This is all too often unrealistic. Roof bolts are also often considered to be simply means of suspending the gravity loaded beams. As Dr. Reed has mentioned they are probably, in fact, acting to restrain a beam which is attempting to buckle due to lateral pressure. The fact that moisture can reduce the strengths of some rocks as much as 50 percent has been known for many years. In the mine me are almost always faced with wet rock, yet no one has investigated ways in which this wakening effect can be overcome. as, for example, by waterproofing the rock. C. Fairhurst, University of Minnesota I would like to mention that we have found,2 from stress-relief determinations, that appreciable (over 1000 lb per sq in.) horizontal pressures occur also at the surface in granites quarried in central Minnesota. Whilst I agree that more field measurements are desirable, it is important to point out that most university research is undertaken by graduate students who must attend classes daily. Their research is therefore restricted to the laboratory. A.M. Starfield, University of Minnesota No one denies the importance of obtaining: data from field measurements. It is equally important, however, that field measurements be guided by theory. Much time and money can be wasted by indiscriminate measurement. An example of the value of theory in interpreting measurements is given in Dr. Obert's comments on the time dependent strain observed in a salt mine. He anticipated that the stress at the wall of the opening would change with time because salt is viscoelastic rather than elastic. It can be shown from theory that if an excavation in a viscoelastic medium is unsupported, then the stress at the wall does

Jan 1, 1967

By P. A. Beck

ACCORDING to a recent hypothesis of Sully,' xY. binary CT phases are characterized by 1.7 bonding 3d electrons per atom, which completely fill the first Brillouin zone. This hypothesis appears to imply that there are no empty 3d orbitals in the u phase, and that, correspondingly, this phase must be dia-magnetic, or at most weakly paramagnetic. On the other hand, Bowen and Hoar' reported that a u phase extracted electrolytically from an alloy steel became ferromagnetic when cooled to about —113°C. In view of the fundamental interest of the problem from the point of view of the electron structure of the u phase, it seemed worthwhile to study the magnetic properties of massive u phase specimens of various known compositions. Sigma specimens of the following compositions were tested: 1—40 atomic pct Fe, 40 atomic pct Cr, and 20 atomic pct Mo 2—35 atomic pct Fe, 35 atomic pct Cr, and 30 atomic pct Mo 3—48.7 atomic pct Fe, 50.2 atomic pct Cr, and 1.1 atomic pct W 4—40.7 atomic pct Co and 59.3 atomic pct Cr All specimens were found to be strongly paramagnetic at room temperature, particularly alloy No. 1. At liquid nitrogen temperature, alloy No. 1 be- came ferromagnetic; the other u alloys remained paramagnetic. Even though apparently not all u alloys become ferromagnetic at liquid nitrogen temperature, in view of their strong paramagnetism it is probable that the electron structure proposed by Sully is not correct. Similar qualitative studies were made with the p, P, and 8 phases." A p phase specimen of 57.2 atomic pct Co and 42.8 atomic pct Mo; a P specimen of 19.9 atomic pct Cr, 37.8 atomic pct Ni, and 42.3 atomic pct Mo; and a 8 specimen of 50.4 atomic pct Ni and 49.6 atomic pct Mo were tested at room temperature, and all were found to be paramagnetic, although considerably weaker than the u phase specimens described above. A test at liquid nitrogen temperature gave similar results for all specimens; none became ferromagnetic. Thanks are due to D. K. Das for preparing several of the alloys and to Pol Duwez of California Institute of Technology for kindly loaning four specimens of cr alloys. References 1 A. H. Sully: The Sigma Phase in Binary Alloys of the Transition Elements. Journal Inst. Metals (1951) 80, p. 173. - K. W. J. Bowen and T. P. Hoar: Low Temperature Ferromagnetism of Sigma Phase in an Alloy Steel. Research (1950) 3, p. 484. 3 S. Rideout, W. D. Manly, E. L. Kamen, B. S. Lement, and P. A. Beck: Intermediate Phases in Ternary Alloy Systems of Transition Elements. Trans. AIME (1951) 191, p. 872; Journal of Metals (October 1951).

Jan 1, 1953

By M. D. Hassiallis

The claim is made in a number of patents1'2'3'4 that some compounds of the class known as aryl sulphides have collector properties. One of these patents generalizes the claim to include all aryl sulphides, whose generic formula is R-S2-R' (where x = 1,2, . . . ), with the restriction that if the aromatic radicals R, R' contain substituent groups these groups may not contain nitrogen or oxygen. Moses, Hess, and Perkins cite as evidence for their claims the results of flotation tests on Anaconda and Miami copper ores using diphenyl sulphide, ditolyl disulphide and dinapthyl disul-phide as collectors. The use of alkyl sulphides as collectors has also been reported5 with the conclusion that the alkyl sulphides are better collectors than the corresponding aryl sulphides. The experimental work cited appears to confirm this contention. In order to test these claims with respect to diphenyl sulphide, a sample, purchased from the Eastman Kodak Co., was tested against Anaconda ore. The procedure followed. was that of Moses, Hess, and Perkins. A sample of ore weighing 500 • grams was placed in a laboratory ball mill. To this was added 220 grams of water, 0.06 grams of commercial diphenyl sulphide (1/4 lb. per ton of ore), and 0.8 grams of lime (3 lb. per ton of ore). The material was ground until 93 per cent passed a 65-mesh screen. This pulp was diluted to 16 per cent solids. A sample of the diluted pulp was placed in a Minerals Separation type of laboratory flotation cell. After a a-min. agitation period, pine oil was added and the froth collected for a period of 15 min. This test recovered 68 per cent of the copper, with a ratio of concentration of 6.8:I. The tailing assay was 0.3 per cent Cu. Moses, Hess and Perkins attained a recovery of 75 per cent, with a ratio concentration of I2:I. Although these results do not compare too well with those of Moses, Hess and Perkins, subsequent tests showed an improvement, as judged by vanning of the tails. It is concluded, therefore, that the patent results are confirmed. Contact-angle Tests In order to study the response of the various minerals, found in Anaconda ore, to commercial diphenyl sulphide, some contact-angle tests were made. Polished particles of bornite, chalcodte, chalco-pyrite, pyrite and quartz were conditioned for 15 min. in a suspension of diphenyl sulphide in water. The concentration of this suspension was 0.284 grams per liter, this being the concentration of this reagent in the ball mill. The conditioned particles were rinsed with water (not rubbed with filter paper or boiled linen) and then tested against an air bubble in the bubble machine, with the following results: born-

Jan 1, 1943

By Terkel Rosenqvist

Few subjects in iron metallurgy and steelmaking have caused so much discussion and have resulted in so many divergent and partly contradictory statements as the theory of the distribution of sulphur between molten iron and slag. An interesting survey of the different points of view is given by Grant and Chipman.1 Grant and Chipman themselves conclude in their paper that, at least in the open hearth and electric steel furnaces, the governing reaction is a simple distribution like: FeS steel ? FeS alas [Ia] and MnS steel ? MnS alas [Ib] They conclude that no significant reaction takes place according to the more classical scheme: FeS steel + CaO slag ? FeOslag + CaS slag [2a] This is the reaction which is regarded by most investigators as the primary sulphur reaction in the blast furnaces, where it is accompanied by the reaction with carbon: FeO slag + C ? Fe + CO [2b] The writer suggests an alternative to the reactions mentioned above. It is the opinion of the writer that the a priori assumption of defined molecular compounds being present in molten steel as well as in molten slag, has retarded rather than promoted a solution of the sulphur problem. As for the constituents of molten steel, it is taking too much for granted to mention the presence of FeS and MnS. If this infers that the melt contains diatomic molecules, the statement must be made that at least such molecules do not exist in the solid state at room temperature. Solid FeS crystallizes in the nickel-arsenide structure, and MnS (high temperature form) in the sodium-chloride structure. In these structures the sulphur is surrounded by six metal neighbors, and no molecular groups can be isolated. When sulphur is dissolved in molten steel, it is expected to maintain the same coordination number as in the solid state. We know that sulphur in steel has a certain chemical potential and a chemical activity which can be expressed by the reaction: S steel + H2 ? H2S where the activity A. is proportional to the ratio PH2S/Ph2. We know also that this activity is influenced by the presence of other constituents. For instance, there is reason to assume that carbon and silicon increase the sulphur activity and manganese decreases it. However, the exact relationship here is scarcely known, and further investigations are needed. Concerning the molten slags, if anything should be assumed a priori it would be that they are composed of ionic rather than molecular parts. There are indications of this in that solid silicates form ionic structures, and molten slags show high electric conductivity and can be electrolyzed.2 It has been claimed by Taylor and Chipman3 that their activity investigations

Jan 1, 1949

By M. D. Hassialis

THE claim is made in a number of patents1,2,3,4 that some compounds of the class known as aryl sulphides have collector properties. One of these patents generalizes the claim to include all aryl sulphides, whose generic formula is R-S¬R[=]-R’ (where x = r,2, . . . ), with the restriction that if the aromatic radicals R, R' contain substituent groups these groups may not contain nitrogen or oxygen. Moses, Hess, and Perkins cite as evidence for their claims the results of flotation tests on Anaconda and Miami copper ores using Biphenyl sulphide, ditolyl disulphide and dinapthyl disulphide as collectors. The use of alkyl sulphides as collectors has also been reported5 with the conclusion that the alkyl sulphides are better collectors than the corresponding aryl sulphides. The experimental work cited appears to confirm this contention. In order to test these claims with respect to diphenyl sulphide, a sample, purchased from the Eastman Kodak Co., was tested against Anaconda ore. The procedure followed was that of Moses, Hess, and Perkins. A sample of ore weighing 500 grams was placed in a laboratory ball mill. To this was added 220 grams of water, 0.06 grams of commercial diphenyl sulphide (1/4 lb. per ton of ore), and 0.8 grams of lime (3 lb. per ton of ore). The material was ground until 93 per cent passed a 65mesh screen. This pulp was diluted to 16 per cent solids. A sample of the diluted pulp was placed in a Minerals Separation type of laboratory flotation cell. After a 2-min. agitation period, pine oil was added and the froth collected for a period of 15 min. This test recovered 68 per cent of the copper, with a ratio of concentration of 6.8: 1. The tailing assay was 0.3 per cent Cu. Moses, Hess and Perkins attained a recovery of 75 per cent, with a ratio concentration of 12: 1. Although these results do not compare too well with those of Moses, Hess and Perkins, subsequent tests showed an improvement, as judged by vanning of the tails. It is concluded, therefore, that the patent results are confirmed. CONTACT-ANGLE TESTS In order to study the response of the various minerals, found in Anaconda ore, to commercial diphenyl sulphide, some contact-angle tests were made. Polished particles of bornite, chalcocite, chalcopyrite, pyrite and quartz were conditioned for 15 min. in a suspension of diphenyl sulphide in water. The concentration of this suspension was 0.284 grams per liter, this being the concentration of this reagent in the ball mill. The conditioned particles were rinsed with water (not rubbed with filter paper or boiled linen) and then tested against an air bubble in the bubble machine, with the following results: born-

Jan 1, 1943

By M. D. Hassiallis

The claim is made in a number of patents1'2'3'4 that some compounds of the class known as aryl sulphides have collector properties. One of these patents generalizes the claim to include all aryl sulphides, whose generic formula is R-S2-R' (where x = 1,2, . . . ), with the restriction that if the aromatic radicals R, R' contain substituent groups these groups may not contain nitrogen or oxygen. Moses, Hess, and Perkins cite as evidence for their claims the results of flotation tests on Anaconda and Miami copper ores using diphenyl sulphide, ditolyl disulphide and dinapthyl disul-phide as collectors. The use of alkyl sulphides as collectors has also been reported5 with the conclusion that the alkyl sulphides are better collectors than the corresponding aryl sulphides. The experimental work cited appears to confirm this contention. In order to test these claims with respect to diphenyl sulphide, a sample, purchased from the Eastman Kodak Co., was tested against Anaconda ore. The procedure followed. was that of Moses, Hess, and Perkins. A sample of ore weighing 500 • grams was placed in a laboratory ball mill. To this was added 220 grams of water, 0.06 grams of commercial diphenyl sulphide (1/4 lb. per ton of ore), and 0.8 grams of lime (3 lb. per ton of ore). The material was ground until 93 per cent passed a 65-mesh screen. This pulp was diluted to 16 per cent solids. A sample of the diluted pulp was placed in a Minerals Separation type of laboratory flotation cell. After a a-min. agitation period, pine oil was added and the froth collected for a period of 15 min. This test recovered 68 per cent of the copper, with a ratio of concentration of 6.8:I. The tailing assay was 0.3 per cent Cu. Moses, Hess and Perkins attained a recovery of 75 per cent, with a ratio concentration of I2:I. Although these results do not compare too well with those of Moses, Hess and Perkins, subsequent tests showed an improvement, as judged by vanning of the tails. It is concluded, therefore, that the patent results are confirmed. Contact-angle Tests In order to study the response of the various minerals, found in Anaconda ore, to commercial diphenyl sulphide, some contact-angle tests were made. Polished particles of bornite, chalcodte, chalco-pyrite, pyrite and quartz were conditioned for 15 min. in a suspension of diphenyl sulphide in water. The concentration of this suspension was 0.284 grams per liter, this being the concentration of this reagent in the ball mill. The conditioned particles were rinsed with water (not rubbed with filter paper or boiled linen) and then tested against an air bubble in the bubble machine, with the following results: born-

Jan 1, 1943

THE great development of the mines and metallurgical works of this country during the last few years, accompanied as it has been by the investment of enormous sums of money in purchasing lands, and in the erection of improvements, requires that advantage should be taken of the accumulated knowledge of engineers, superintendents, and' others, in mastering &he problems which are constantly presenting themselves for our action. Among those may be mentioned the consideration of more economical systems of mining in our coal and metal-liferous mines, improved methods of transportation above and below ground, unwatering and ventilating mines, the mechanical preparation of coal and other minerals, the various metallurgical processes, and, in fact, every question tending to the attainment of two great objects : 1st. The more economical production of the useful minerals and metals. 2d. The greater safety and welfare of those employed in these industries. 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. I t must be evident to all practical men that the interchange of the varied experience of those engaged in such occupation in this country could not fail to advance very materially the desired objects; it is, therefore, proposed to establish an American Institute of Mining Engineers, which will hold its meetings periodically in the great mining and metallurgical centers, where works of interest, such as mines, machine shops, furnaces, and other metallurgical works, can be inspected, and the members exchange their views, and consult for mutual advantage upon the difficulties encountered by each; these transactions or proceedings, when published, would form a most valuable and greatly-needed addition to our professional literature. I t is proposed that a meeting of those sympathizing with the object above mentioned shall be called for the purpose of organizing such an association, the place and time of meeting being Wilkes-Barre, Pa., and the month of April or May. Communications indicating the opinion and wishes of all, both as to these points, and also as to the organization and objects of the Institute, will be gladly received by any of the undersigned, and a notice of the date of meeting, which will be arranged to suit the greater number, will be duly communicated. Any

By Terkel Rosenqvist

Few subjects in iron metallurgy and steelmaking have caused so much discussion and have resulted in so many divergent and partly contradictory statements as the theory of the distribution of sulphur between molten iron and slag. An interesting survey of the different points of view is given by Grant and Chipman.1 Grant and Chipman themselves conclude in their paper that, at least in the open hearth and electric steel furnaces, the governing reaction is a simple distribution like: FeS steel ? FeS alas [Ia] and MnS steel ? MnS alas [Ib] They conclude that no significant reaction takes place according to the more classical scheme: FeS steel + CaO slag ? FeOslag + CaS slag [2a] This is the reaction which is regarded by most investigators as the primary sulphur reaction in the blast furnaces, where it is accompanied by the reaction with carbon: FeO slag + C ? Fe + CO [2b] The writer suggests an alternative to the reactions mentioned above. It is the opinion of the writer that the a priori assumption of defined molecular compounds being present in molten steel as well as in molten slag, has retarded rather than promoted a solution of the sulphur problem. As for the constituents of molten steel, it is taking too much for granted to mention the presence of FeS and MnS. If this infers that the melt contains diatomic molecules, the statement must be made that at least such molecules do not exist in the solid state at room temperature. Solid FeS crystallizes in the nickel-arsenide structure, and MnS (high temperature form) in the sodium-chloride structure. In these structures the sulphur is surrounded by six metal neighbors, and no molecular groups can be isolated. When sulphur is dissolved in molten steel, it is expected to maintain the same coordination number as in the solid state. We know that sulphur in steel has a certain chemical potential and a chemical activity which can be expressed by the reaction: S steel + H2 ? H2S where the activity A. is proportional to the ratio PH2S/Ph2. We know also that this activity is influenced by the presence of other constituents. For instance, there is reason to assume that carbon and silicon increase the sulphur activity and manganese decreases it. However, the exact relationship here is scarcely known, and further investigations are needed. Concerning the molten slags, if anything should be assumed a priori it would be that they are composed of ionic rather than molecular parts. There are indications of this in that solid silicates form ionic structures, and molten slags show high electric conductivity and can be electrolyzed.2 It has been claimed by Taylor and Chipman3 that their activity investigations

Jan 1, 1949

The Inspiration ore body was discovered in 1904, but a 50 -ton mill which was installed to treat the disseminated copper ore promptly failed. The original Inspiration Company then gave way to another, backed by W. B. Thompson, which found 40 million tons of ore. Control then passed to Anaconda and Dr. Louis Ricketts took charge as consulting engineer. He abandoned the mill which had been partially built (to the horror of the stockholders, according to Ira Joralemon) and spent a year and a million dollars experimenting with flotation. The first large copper flotation plant was then built and recovered 50% more copper than had previous gravity mills. It, of course, was highly successful and became the forerunner of modern flotation plants. Inspiration is distinctive as the first fully integrated copper operation in the United States. Three open pits supply sulfide ore to the concentrator and mixed oxide and sulfide ore to a vat leaching and electrowinning operation with leached ore also being sent to the concentrator. In addition, dump leaching supplies pregnant solution for scrap iron precipitation. Inspiration has recently constructed an electric furnace smelter and also operates a continuous casting and rod plant. The new primary 54 in. by 74 in. crusher was completed in May of 1972 and replaced an older unit which was in the way of the open pit development. It is of an unusual circular silo design, which permits dumping 0 from two positions at 90 from each other. One dumping position is in line with the spider, while the other one is at right angles to it. A box girder splitter bar hung from the dump pocket slopes downward from the second dump point, across the spider cap, and rests on the pocket bottom. This splitter was not installed to protect the spider but was to aid in distributing wet ore being dumped from that position to both sides of the spider. Any large amount of wet ore delivered to one side of the spider would pack in the crusher cavity. The round front wall of the 18 ft (5.5 m) deep pocket is unlined except for light steel protection at the top, while the straight back wall is lined with vertically positioned railroad rails. Water for dust suppression is sprayed into the pocket through a cluster of 3/8 in. (9.5 mm) nozzles at the back of the pocket. About 5 gpm (19 lpm) of water are mixed with 90 psi (620 kPa) air upstream of the nozzles to produce a fog which is effective in dust control. The 54 in. Allis -Chalmers gyratory is placed mostly within one quadrant of the circular enclosure to permit placement of the apron feeder on the lowest level in the proper position to transfer crushed ore to the

Jan 1, 1978

By C. E. Shoenfelt

The most important development in an otherwise colorless year in Colorado oil fields was the completion, late in 1933, of a well on Iles dome on the western slope of Colorado, with an initial production of 1100 bbl. of oil. No great amount of activity beyond the drilling of necessary offset wells is to be expected as a result of the completion of a well of this size because the acreage on Iles dome is closely held; there is no pipe line outlet other than to the Texas Company's small refinery at Craig, 24 miles distant; and the market for the oil is limited to the demands of sparsely settled communities in the high mountains. The Iles field is located on a large dome developed in Mancos shale of Cretaceous age, and having a closure of approximately 400 ft. The structure is highly faulted on the southern end. The first commercial oil well on this dome was completed by the Midwest Refining Co. on the south side of sec. 22-4N.-92W. Oil of 37" gravity was developed in Nancos shale at 2560 ft. and water in the Dakota sandstone at 2630 ft., but a considerable amount of additional oil was found in the shale immediately overlying the Dakota. From 2630 ft., the well produced in 16 hr. 750 bbl. of fluid, 33 per cent of which was water. Production in the Sundance sand of Jurassic age was found in the Midwest Refining Company's No. 4 Parkinson, in the NE.-SW.-SE. of sec. 22-4N.-92W., and completed on the last day of the year 1926, for an initial production of 450 bbl. of oil at a total depth of 3242 ft. The well completed in 1933 is also a Sundance sand producer and was finished at a depth of 3447 ft. It extends the productive area of the field about a quarter of a mile cast. The Iles field is said to have a potential production of 5000 bbl. of oil a day from its present wells, but for the past year has been held at about 600 bbl. a day. The most important test, stratigraphically, ever drilled on the western slope of Colorado is the California Company's No. 1 Raven, NW.-SE. of sec. 30-2N.-102W., which had an initial production of 138 bbl. of oil of 32" gravity, in the Weber formation (Pennsylvanian) between 5750 to 6315 ft. It mas drilled to 7137 ft., probably near the base of the Weber, and then plugged back to 6315 ft. It was shot quite heavily with nitro-glycerin, but failed to respond. While the well can hardly be classified

Jan 1, 1934

By E. S. Machlin

THE function of this paper is to present certain results based on the fact that the strain energy arising from the solution of out-of-size solute atoms into the solid matrix is free energy and not internal energy, and that this strain energy is almost wholly shear strain energy as Zener1 pointed out. One natural consequence of this fact is an expression for the excess entropy of mixing due to the strain energy. Also, a derivation of the integral molar free energy of mixing partitioned to strain energy will be made using the model of Lawson2 and thermodynamics. This derivation has the advantage of showing in a simple way the assumptions involved in Lawson's treatment. The excess entropy of mixing partitioned to strain energy can be derived in two ways. The first way makes use of the fact that the strain energy is almost wholly in the form of shear strain energy. In this case, as Zener1 pointed out, the change in entropy due to the addition of shear strain energy is to a first approximation given by ?S/?? p,T = - ?lnµ/?T p,? Hence, the excess entropy of mixing partitioned to strain energy will be given by Sx ? = ?S/?? p,T Gx ? = - ?lnµ/?T p,? Gx ? where, Gx ? is the relative integral molar free en- ergy partitioned to strain energy; S is the entropy; is the shear strain energy; µ is the shear modulus; T is the absolute temperature; p is the pressure; and ? is the shear strain. Zener,1 as well as others, has pointed out that the shear strain energy stored in a compressible isotropic solid due to the insertion of an off-size incompres-sible sphere into a spherical hole in the solid, is approximately given by 2/3 µ/O (O°I - O)2 where a is the volume of spherical hole and no , is the volume of sphere. If we now consider the introduction of one mol of such spheres into an infinite volume of solid, then the relative partial molar free energy excess due to strain energy alone is GM ? = 2/3 µ/v (v ° 1 - v)2 where v is the molar volume of solvent and v°1, is the molar volume of pure solute type 1. Let us consider that these spheres are the two types of atoms in a binary solution, then there will be a similar relation for solute 2. The total relative integral molar free energy excess due to strain is then, to the approximations stated above GM ? = GM ? x1 + GM2 ? x2 = 2/3 µ/v [(v ° 1 - v)2 x1 + (v ° 1 - v)2 x2]. Lawson's relation for the strain energy can be de-

Jan 1, 1955