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By Harold Margalin, Elmars Ence

M. H. Mueller, M. V. Nevitt, and H. W. Knott (Argonne National Laboratory)—We have reported1 the crystal structure of Ti2CU as body centered tetragonal with a. = 2.944A and co = 10.786A, six atoms per unit cell, and space groupl4/mmm(MoSi2 type). This cell is larger but definitely related to the unit cell reported by the authors. It permits definite positions for the titanium and copper atoms in the cell located as follows: 2 Cu (a) 0 0 0; 1/2 1/2 1/2 4 Ti (e) 0 0 z; 1/2 1/2 1/2 + z; 0 0z; 1/2 1/2 1/2- z where z = 0.341 The face centered tetragonal cell reported by the authors can be transformed to a small body centered tetragonal cell with flo (small bet) = ao(fct)v2 Both unit cells have the same CO. Neither the face centered tetragonal cell with four atoms per unit cell nor the small body centered tetragonal cell with its two atoms per unit cell lend themselves conveniently to an orderly arrangment of the 2 to 1 ratio of titanium to copper atoms. When the co of this small body centered cell is tripled, however, a large body centered tetragonal cell results with six atoms per unit cell as described above. We had also noted that the X-ray patterns of Ti2Cu indicated that the structure could be approximately described by the face centered tetragonal cell as reported by the authors; how- ever, there was evidence for a few additional very weak lines whose positions indicated a larger unit cell. Since the X-ray scattering amplitudes of titanium and copper are nearly equal, it is evident that it is difficult to distinguish their positions especially from X-ray powder patterns. It was therefore decided to look at a powder pattern obtained by neutron diffraction since the scattering amplitudes of the two elements are considerably different in magnitude and opposite in sign. The sample used for neutron diffraction was selected from a group of three alloys prepared by arc melting using crystal bar titanium of 99.92 pet nominal purity and 99.999 pet pure Cu. The alloys designated as A, B, and C had the following respective compositions: Ti-32.8 at. pet Cu, Ti-33.3 at. pet Cu, and Ti-33.8 at. pet Cu. On the basis of the melting losses incurred, it was established that the actual concentration of either component in any of the alloys probably did not deviate from the intended value by as much as 0.1 at. pet. The alloys were annealed for 5 days at 700°C in evacuated Vycor capsules and quenched in tap water. The metallographic structures of these alloys are shown in Fig. 1. None of the alloys contained sufficient second phase to permit its positive identification. Since alloy B contained the least amount of second phase and since its composition placed it closest to the ideal stoichiometry, it was chosen for the neutron diffraction study. The oxygen content of alloy B was found by chemical analysis to be 0.06 at. pet. This particular intermetallic compound is especially suitable for investigation with neutron diffraction since if the titanium and copper atoms have a random statistical distribution, a near null-matrix would result in which there would be practically no coherent scattering of neutrons, and hence no Bragg diffraction peaks. Such a condition could come

Jan 1, 1962

Jan 1, 1910

By D. C. Sisti

A technical evaluation of actual performance of the preparation facilities at Beaver Consolidated Coal Co.'s Stinson plant is presented, with special emphasis on sulfur reduction in 1-1/2 x 3/8 in., 3/8 in. x 28 mesh, and 28 mesh x 0 size fractions. Evaluation of the heavy medium section of the plant and the treatment of the 28 mesh x 0 coal is included. Design criteria considered for sizing and selection of equipment required to process 1-3/4 million tpy of raw coal on coals of divergent washability characteristics are summarized.

Jan 1, 1976

By A. J. Sedriks

ALTHOUGH the occurrence of a readily visible tarnish on the stress-corrosion fracture surfaces of titanium alloys tested in oxygenated nitrogen tetrox-ide solutions has been reported,' the possibility that the formation of this tarnish is a requirement for cracking to proceed does not appear to have been considered. It has been proposed that failure occurs in this system as a result of some electrochemical-mechanical process.2 However, recent studies3-6 of the stress-corrosion cracking of a brass in certain ammoniacal solutions, which also cause visible tarnishing, have led to the view that failure occurs by the repeated formation and fracture of a brittle surface film of cuprous oxide. The purpose of this note is to point out the similarities which exist between the tarnish which forms on a brass and that found on titanium alloys failed in nitrogen tetroxide, and to suggest, by analogy, that a similar tarnish-rupture mechanism may be operative in the latter case. The titanium alloy selected for the present study contained 5.2 pct Al, 2.5 pct Sn, 0.025 pct C, 0.16 pct Fe, 0.014 pct N, 0.012 pct H, 0.07 pct 0, and 0.002 pct Mn by weight. Vacuum-annealed alloy strips measuring 4 by 0.25 by 0.04 in. were used to prepare self-stressed test specimens. Each specimen was made from two strips by bending the end portions and spot welding them together to produce curved sections of uniform bending stress. (The exact details of preparing such specimens have been described by Lisagor el al.7) The curvature in the strips determines the ma-magnitude of the outer fiber stress, which in the present specimens was 100,000 psi (yield stress = 120,000 psi). The specimen surface in the spot-welded end regions was shot-peened to induce compressive stresses and thereby eliminate the possibility of stress-corrosion cracking in these regions. The test environment was nitrogen tetroxide, initially containing 99.5 pct N2O4, 0.1 pct H2O, and 0.08 pct C1, through which oxygen had been bubbled for 30 min. During testing the tetroxide was subject to an oxygen pressure of 250 psi. The duration of the test was 96 hr, and during this time stress-corrosion cracks propagated through some 50 pct of the thickness of the specimens. After testing, the tarnish was liberated from the fracture surface by immersion in a methanol-5 pct bromine solution, and then examined by electron dif- fraction and transmission electron microscopy using a JEM-7 electron microscope. The possibility that the bromine solution had affected the structure of the tarnish was investigated by an "in silu" examination of the stress-corrosion fracture surface using a reflection electron diffraction attachment designed for handling bulk specimens. Typical areas of the tarnish liberated by the me-thanol-bromine solution are shown in Fig. 1. Fig. l(a) reveals that the tarnish consists of individual platelets, and from Fig. l(b) it can be seen that the platelets are joined together to form a semicontinuous film, the boundaries of the titanium substrate grains being retained in the tarnish. Electron-diffraction patterns taken from these areas exhibited diffraction spots typical of a monocrystal. The diffraction pattern shown in Fig. 2 was taken from the central area in Fig. l(n). Monocrystal patterns obtained from areas containing numerous individual platelets can only be explained by assuming that their growth is governed by the titanium substrate (i.e., their growth is epitaxial). In other areas, the tarnish had folded over or became mechanically damaged, and these areas gave diffraction patterns consisting of "spotted" rings, enabling interplanar spacings of the tarnish lattice to be determined. These spacings, measured using a

Jan 1, 1968

By Kittitep Fuenkajorn

Ring tension tests, permeability tests, and microscopic fracture studies have been performed to investigate the damaged zone induced by drilling (diamond, percussion, and rotary) in the borehole walls. Specimens are drilled with three different hole sizes (38, 76 and 102 mm diameter) in Pomona basalt and Grande basaltic andesite. The thickness of the damaged zone ranges from 0.0 to 1.7 mm. A larger drill bit induces more wall damage than a smaller one. Different drilling techniques show different damage characteristics (intensity and distribution). Damage characteristics are governed not only by drilling parameters (bit size, weight on bit, rotational speed, diamond radius, and energy), but also by properties of the rock. The weaker rock tends to show more intense damage than does the stronger one. Cracks within grains or cleavage fractures are predominant in coarse grained rock (larger than 0.5 mm grain size) while intergranular cracks are predominant in fine grained rock (smaller than 0.01 mm grain size). The influence of the damaged zone on the permeability of the rock around the hole is investigated by permeability tests.

Jan 1, 1984

By Robert F. Calman

OUTLINE FIVE EXAMPLES OF GOLD-LINKED FINANCINGS 1. Financing the Lupin Mine • Sale of Cdn $40.0 million of 12% preferred shares and Cdn $40.0 million of Gold Purchase Warrants @ $595 per ounce. 2. Financing the Copper Range acquisition • Borrowing 100,000 ounces from a Canadian chartered bank @ US$307 for five years. 3. Financing the Round Mountain expansion • Borrowing up to US $80.0 million in dollars, convertible into gold, repayable over five years from a group of North American banks. 4. Financing the Tenneco Precious Metals Division acquisition •Sale of SFr 110.0 million of ten year 3-718% bonds with warrants to buy 132,000 ounces of gold at US $560. 5. On Forward Sales, Puts and Calls • Gold, Silver, Canadian Dollars, Swiss Francs THE FINANCIAL RULES AT ECHO BAY 1. Never bet the company 2. Equity is the primary form of capital for a gold mining company 3. On debt 4. The Yardsticks for Corporate Decisions 5. Financial Community Relationships 6. Dividend Policy No Text Available Tables Follow

Jan 1, 1990

By W. B. Plank

I HAVE been asked by the Chairman of the Engineering Education Committee to outline what the engineering colleges would like the mining companies to do with the young engineer just, out of college. It has been suggested that, because my own personal experience has been almost entirely within the coal industry, I handle this subject from that view- point. Many thoughtful engineering educators are today wondering what effect the present employment policies of many industrial companies are going to have on the young man just starting out in his profession. Since before the World War large industrial concerns, such as those in the electrical and mechanical industries, have gone to the colleges to interview 'likely graduates until today there has developed in most of our engineering colleges, especially in the eastern part of the country, what appears to be a lively competition on the part of these companies in bidding for the young graduate engineer. The employers of mining engineers, with one or two exceptions, have not yet begun to enter this competition. It remains to be seen how serious this situation will become, how it will affect the training of other engineers, and what effect, if any, it will have on the mind of the young man about to enter college who may be inclined to take up mining engineering, but who gains the impression from this well advertised employment service just mentioned that there is no opportunity for him in the mineral industry as com- pared with the opportunities offered in say civil, mechanical, and electrical engineering.

Jan 1, 1929

By Robert J. McKay, F. P. Huston, WILLIAM G. HUMPTON

THE manufacture of nickel-clad steel plate and the fabrication of articles from it has progressed far enough to permit a general description of the working methods used. The manufacture of sheets made up of layers of nickel and steel is not new as a sheet of this character was patented in Germany in 1893. Present development differs mainly in the size and finish of the product. The earlier light-gage highly finished products have been limited in their application due to their similarity, in certain respects, to electro-plated and highly finished alloy sheets. The new product is a relatively heavy plate 1/4 or 3/s in. thick and heavier, with one side coated with nickel, the weight of nickel being of the order of 10 per cent of the whole. The finish is that of hot-rolled steel plate.

Jan 1, 1931

By George M. Fowler

MINING geology is a progressive study, so we must look to the future for the solution of many of its most significant problems. These problems, world-wide in scope, offer ample opportunity for the exercise of the utmost skill and intelligence by all that attempt to solve theta, as it is generally recognized that many ore deposits of the future will he found only by months or years of combined intelligent effort by the several engineering groups. Renewed appraisals are continually being made to better understand the relationship of physical-chemical processes to ore deposition and other mineralization and to interpret the findings of the geophysicists and others in terms of economic results. A study of current geologic activi¬ties clearly reflects the growing tendency for cooperation between the different branches of geology in order to appraise their united efforts. In line with these activities arrangements have been made to transfer the geophysical section of the U. S. Bureau of Mines to the Geological Survey.

Jan 1, 1936

By Walter E. Mingramm

THE construction of rescue-apparatus on the principle of furnishing the wearer with air from a tank containing it under high pressure was given up by inventors about 20 years ago. Such an apparatus must supply continuously, for not less than two hours, nearly 50 liters of pure air at atmospheric pressure per minute, or a total of 6,000 liters (210 cu. ft.); and a cylinder containing this amount of air, under 2,000 lb. pressure, would weigh 180 lb. or more. Although apparatus has been recently constructed utilizing liquified air, no experiments have been made to determine the regularity with which the air is generated, nor has its chemical composition been determined. Moreover, the chief objection to such an apparatus is the' difficulty and cost of keeping on hand a large quantity of liquified air. The system of furnishing the wearer of a breathing-apparatus with air which has given the best results, and has found employment in all the devices now in practical use, is that in which the air contained in the human lungs at the beginning of the work is regenerated by the apparatus. By means of chemicals, such as caustic potash and caustic soda, the carbonic acid gas, CO., exhaled is absorbed, and the oxygen that has been consumed is replaced from a tank containing this gas under high pressure. The pressure of the oxygen (which is 1,875 lb. in the two cylinders at the beginning of the work) is automatically reduced to 75 lb., and is sufficient to keep the air inside of the apparatus in constant circulation, and to force it to pass through the chemicals provided for the absorption of the CO, gas. In the attempt to construct an apparatus which would (1) furnish the wearer with a sufficient supply of air; (2) replace the amount of oxygen used up by the lungs during the time of

Jan 7, 1908

By Dozier Fircley

SOME nonmetallic minerals and their products, such as portland cement, common brick and hollow tile, sand, gravel, crushed rock, vitrified salt-glaze clay pipe, and the like, are a necessity in every community. They are mineral in nature but the establishment of plants for their production is usually a local and elementary problem. Yet it is probable that an economic study of the problem in every locality will show that such nonmetallic mineral commodities are not always obtained in the most economical way, or in the best quality. Other nonmetallic minerals are of such value that they may be shipped for long distances and sold in sufficient quantities to establish prosperous commercial ventures. Among these are phosphates, barium compounds, borates, nitrogen compounds, magnesium compounds, sulfur, asbestos, and potash. Success in marketing such products depends on quality, production cost, transportation, and similar conditions.

Jan 1, 1932

By Wilfred P. Sykes

AT intervals in the course of history an event occurs which, though scarcely heeded at the moment, marks in retrospect the beginning of a new era in some one field of human activity. Such a happening is perhaps more readily spotted in the field of technology than in other realms of human endeavor. Here the span of years is relatively short and the records have been kept with some degree of precision. In the current scene of our social and economic drama the art and science of metallurgy is playing a major role. Off stage will be found the metallurgist in one guise or another aiding, he trusts, in the development of processes and products which will contribute to the happiness of his fellow men. The results of his efforts appear in the form of metallic substances known as alloys built up from any two or more of the wide variety of metals which have been extracted from the mineral deposits in the earth's crust. An alloy by virtue of its inherent physical properties may seem ideally suited for human use in a special way but until this material can be produced economically it will fail to attain a place of prominence as an article of commerce. In fact many commercial alloys are being continually replaced by new or modified compositions better suited to meet the increasingly severe demands of industrial service.

Jan 1, 1939

By W. P. Sykes

ThiS investigation was undertaken primarily to establish the relations existing between temperature and mechanical properties in molybdenum, nickel, and an aluminum-copper alloy. Mlolybdenutn (m.p. 2500" C.) was chosen because it is partly similar to tungsten and partly similar to the common ductile metals. Also it is known to furnish, by proper treatment, a desirable material to use in studying relation of grain size and physical properties. The molybdenum used was of the quality that is drawn into wire 0.003 in. in diameter for use as filament supports in incandescent lamps; Chemical analysis shows less than 0.1 per cent. of impurities. Nickel belongs to the same class as iron. Its melting point is 1450" C. and an allotropic change at about 370" C. results in a loss of magnetism above that temperature. This feature made nickel doubly valuable for the purposes of these tests. The nickel used was obtained from the Driver-Harris Co. as 0.090 in. (2.3-mm.) wire, annealed; analysis showed 99.8 per cent. nickel and 0.150 per ccnt. iron. Aluminum is one of the low melting-point metals. Some tensile tests at clevated temperatures have been reported by Bengough but the possibility of learning more with the low temperature and sensitive apparatus available rccommendcd this metal. The samples marked A1 arc an aluminum-copper alloy that contains 3 per cent. copper, 0.42 per cent. iron, and 0.21 per cent. silicon. The presence of the copper somewhat coniplicates the analysis of the results; but the action of copper in aluminum has been studied so that its influence might have been foretold, in part at least. The material and analyses were furnished by the Aluminum Castings Co. The nickel wire, which was deformed at 400" C., was drawn under a bath of molten lead and through a die, which also was immersed in the bath. A thermocouple was suspended in the molten metal to indicate the temperature. Hot oil was uscd as the heating bath for drawing the

Jan 1, 1921

By Robert L. Kidd

ONE time or another placer mining attracts the attention of a large number of people, because of the possible low initial investment, low operating cost, and quick returns. Much has been said about sampling and operating placer deposits but many are still inclined to jump at a property without giving much, if any, consideration to proper sampling. This statement does not apply to experienced mining engineers but I am hoping that readers will tear out this article and pass it along where it will do the most good and thus help to preserve the reputation of legitimate mining. It would appear that some people have an ability to sink test pits in high-grade gravel that is positively uncanny. One pit showing high-grade values proves to some property owners and promoters that the entire property will do the same. This is

Jan 1, 1937

By JAMES SCULLY

For the last 4 years political leaders have found a new subject on which they can safely generalize wihout creating opposition. That subject is commodity prices. Since the four-fold increase in OPEC crude oil prices, public attention has focussed as never before on the subject of commodity prices. To advocate stabilizing commodity prices is akin to supporting motherhood or peace or better schooling. Everyone gives lip service to the concept that stable commodity prices are desirable. It is easier to state the principle than to achieve it. Prices that are stable in terms of one currency may be clearly unstable in terms of a different currency. This has become a troublesome matter since 1971, when the world's leading trading currencies were set free to float in relation to each other. To illustrate: consider copper prices in the interval between the end of 1974 and the end of 1977. During those 3 years, the copper price in pounds sterling on the London Metal Exchange rose by 25 per cent. During that period, however, in terms of the USA dollar equivalent, the price was unchanged. And during that period, in terms of the German mark equivalent the price shrank by 13 per cent while the Japanese yen equivalent fell by 20 per cent. Thus a price that appears stable in dollars, rose in terms of pounds sterling and fell in terms of marks and yen. Had this result been achieved as a consequence of an international effort to stabilize prices, an American would have said the effort was successful. An Englishman would have said it had failed to prevent a price rise. And a German or a Japanese consumer would have been happy to have covered his copper needs at a lower cost in terms of his own currency.

Jan 1, 1978

By AIME AIME

WEDNESDAY night, by long tradition, is al- ways set aside for the annual dinner, even when, as it was this year, it is Ash Wednesday. Whether the somewhat smaller attendance than last year is attributable to that cause, the unexpectedly long persistence of business depression, or whatever may have been the reason, it was a joyous occasion, and the grand ball-room of the Commodore Hotel was as completely filled With diners as * was consistent with com- fort. In the half hour before the dinner was actually served the guests assembled in an adjoining room and not only exchanged greetings but proceeded along the receiving line to greet the guests of honor. The number present was so large that hardly more than half of them had been able to do this before the summons to the dining room sounded and a hearty and immediate response was made to it. Toy balloons at each plate, inflated and directed at the heads of companions or nearby friends, but which were just as likely to carom from the nose of a hurrying waiter, successfully broke the ice as well as not a few plates. It would be interesting to know whether the pleasure the guests derive from these de- vices is in part based on the all-too evident annoyance of the waiters, and what the relative quantitative relationships are.

Jan 1, 1931

By Harold W. Aldrich, Walter G. Scott

The leaching process of the Inspiration Consolidated Copper Co. is based upon the solubility of oxidized copper in sulfuric acid and the solubility of sulfide copper, largely in the form of chalcocite, in ferric sulfate solution. This necessitates the carrying of a rather large amount of iron in solution. The ferric sulfate is regenerated from ferrous sulfate by the oxygen given off at the anode during electrolytic precipitation of the copper. In September, 1924, excavation was started at Inspiration, Arizona, for the construction of a plant to treat 7500 tons of ore per day. When the plant was begun, the fact developed that by a minor change in the height of the overflow on the leaching tanks, 9000 tons could be charged into each tank and treated satisfactorily. This determined the maximum capacity of the plant as 9000 tons per day. The first ore was charged in October, 1926, and there are now available the records of five complete years of operation; namely, 1927 to 1931, inclusive. The original estimate of copper content of the ore to be mined for this plant was 1.19 per cent, of which 0.77 per cent was as oxide and 0.42 per cent as sulfide. From the metallurgical results obtained at the 35-ton pilot plant, it was estimated that a 90.0 per cent extraction of the oxide copper and a 75.0 per cent extraction of the sulfide copper could be made. It was estimated that the tailing would carry 0.182 per cent total copper, resulting in a

Jan 1, 1934

By W. E. STOKES

SOME extension of flying service to the mining industry occurred in 1938, particularly in Canada, where freighting activity radiated from Edmonton into the new northern mining districts. Again the airplane demonstrated its usefulness in getting new equipment rapidly into the field and in decreasing shutdown time while waiting for repairs. An 18-ton Caterpillar tractor with shovel attachment was disassembled, brought in by plane, and placed in operation at Berens River, Ont., within seven days after its de- livery at Winnipeg. At Central Patricia a mill breakdown required the replacement of a full mill head and trunnion with ball bearings, weighing 2700 lb. The Canadian Airways Junkers, termed the "flying boxcar," was called in from Yellowknife, 1300 mi. away, and the new installation was completed three days later.

Jan 1, 1939

Jan 1, 1971

By Oliver Bowles

DELICATE PLANTS are now put to bed for the winter under glass-wool or rock-wool blankets. Thus arise new and unexpected uses for non-metallic materials and rocks and, at the same time, certain unique uses are fading out; for instance, the Italians have taken steps to bar the use of salt for money in Ethiopia. Novel sources of supply find a place in the record of recent achievements as exemplified in the migration of the frontiers of industrial mineral exploitation beyond the land area of the earth to include the ocean. Salt, of course, has been recovered from the sea for years but the treatment of enormous quantities of sea water for bromine has lately added to the importance of the ocean as a reservoir of mineral wealth. Increased use of non-metallic minerals in the commercial and economic life of the country is reflected in the wide scope and activity of the Industrial Minerals Division of the Institute. The outstanding recent achievement of the Division is the publication of a 955-page volume on industrial minerals and rocks, comprising 48 commodity chapters each written by an authority on the subject.

Jan 1, 1938