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By Charles M. Cooley

In these troubled times free enterprise is maintaining vital molybdenum output, while expanding plant, and bringing in new low grade ore reserves, at Climax, the world's largest known molybdenum deposit. Climax Molybdenum Co. is putting $25 million into additional surface plant facilities and other millions into underground development. The expansion program to be operating by 1954 includes a new mining level, crushing plant, 4000-ft conveyor, milling units, by-products plant, and housing for 198 families. Completion of this program and low grade plant will add 10,000 tons per day to present capacity and several million tons to ore reserves.

Jan 1, 1953

By J. T. Price

The study was undertaken to investigate the effect in the charge to a blast furnace of zinc and alkali contents, which tend to form accretions and scaffolds in the upper sections of the furnace. Commercial iron oxide pellets were reduced in a CO:N2, 40:60 gas mixture in a 5-cm by 5-m counter-current reactor (Rist-type apparatus) designed to simulate blast-furnace conditions. Pellets from a commercial magnetite concentrate were prepared in the laboratory with zinc (1% ZnO) and alkali (1% KOH) additions to the concentrate. Reducibility, crushing strength and swelling tests were carried out and the results compared with test data from pellets prepared without additions. The results indicated normal behaviour for those pellets containing zinc, whereas those containing alkali swelled catastrophically under the same reducing conditions.

Jan 1, 1977

By A. J. Lynch, W. J. Whiten

Extensive research, ,development and plant application work has been done on automatic control systems for wet grinding and sulphide flotation circuits during the past twenty years. The result is that there is a good understanding of the process mechanisms, the effects which changes in different variables have on these processes, the procedure for design of control systems to satisfy particular objectives and the problems in the implementation of control systems. There is also an appreciation of the problems which are still to be solved. These are reviewed briefly in this paper. Other processes used for the beneficiation of fine particles have been studied in lesser detail. The control of dry grinding, coal flotation and gravity separation are mentioned briefly in this paper.

Jan 1, 1980

By A. H. Dierker

Next to the metal itself, molding sand is the most important raw material used in the manufacture of steel castings. There are no accurate figures available but probably it would be safe to say that the average steel foundry uses approximately 1000 lb. of new molding sand per ton of castings produced. With untreated sands costing from two to four dollars (in some extreme cases it may run as high as eight or ten dollars) per ton delivered at the foundry siding, molding sand is an important item in the cost of making castings, and any information that may help to reduce this sand consumption should be of interest to the industry. Fundamental Considerations In a general way, molding sand in the average steel foundry passes through the cycle shown in Fig. 1. This diagram indicates that if all of the sand could be returned from the shakeout floor to the mixer no new sand would be required from the stock pile and molding costs would be reduced accordingly. Unfortunately, for reasons to be discussed later, it has heretofore been necessary to dilute the used sand constantly with new raw sand in order to maintain the properties that are essential to the production of satisfactory molds.

Jan 1, 1930

By C. Schlumberger

LAST year the authors presented a paper that discussed the various electrical measurements they perform in drill holes, which they name "electrical coring."' The object of the present paper is to give a brief account of the points of scientific interest that have been elucidated by further field work and laboratory research, as well as the economic, results that have been attained recently. The practical examples given in this paper are drawn, for the most part, from the field work performed in Russian oil fields during the years 1931 and 1932. This is due to the fact that, thanks to the comprehensive cooperation of the Russian geologists and scientists, the authors are allowed to make public a large amount of recent information. In other countries in which the authors are engaged in similar work, the competi¬tion between private companies makes it imperative, for a considerable lapse of time, to avoid publication of the results obtained. The following points will be discussed successively, under sepa-rate headings: 1. Electrochemical phenomena in drill holes. 2. Stratigraphic correlations and tectonic studies. 3. Relations between the productivity of oil horizons and their electrical resistivity. 4. Location of coal seams. 5. Summary and conclusions.

Jan 1, 1933

By G. K. Burgess

§ 22. THe results published in Professor Howe's paper10 of our determinations on the Ac3 and Ar3 points for a series of commercial carbon steels " containing manganese in varying proportion, represent the average temperatures found by taking several (4 or 5) heating and cooling curves. The accompanying curves, Figs. 6 and 7, are, for each steel, the first heating and cooling curves as obtained by the inverse-rate method of Osmond, using a cylindrical chronograph sensitive to 0.1 sec. for recording time. Simultaneous observations were also taken by the differential method with a platinum neutral and plotted by Rosenhain's derived differential method and gave substantially the same results, the curves having sensibly the same contours in both cases.12 The observations were taken in vacuo on cylinders 5 by 1 in. in length bored to center with a 1/8-in. hole to receive porcelain insulated thermo-couple, and inclosed in an out- and in-glazed Berlin porcelain tube heated electrically by platinum foil wound on the tube. The vacuum was usually better than 0.1 mm. The heating and cooling of the furnace was automatically controlled by a salt-water rheostat with shaped electrodes, giving a uniform rate of heating and cooling.

Jan 1, 1914

Joseph HartshoRnE, Pottstown, Pa.: I have read Professor Akerman's valuable paper with great interest. Few of the present generation of American steel metallurgists are aware of the very important part taken by Swedish engineers in the successful development of the Bessemer proeess, and I am afraid some of the older ones have forgotten it. Certainly, I think, most of us would have said that Terre Noire was the first to introduce the use of metal direct from the blast-furnace. It is very well, therefore, that honor should be given to whom honor is due. I can speak from personal experience upon one part only of Prof. Akerman's paper; namely, the effect of the temperature at which the molten metal is cast upon the quality of the finished steel. In a general way I have, of course, known for a long time that the

Jan 1, 1894

WHEN Georgius Agricola, in 155o, dedicated his now famous De re Metallica to the rulers of Saxony, Thuringia, Meissen, and other, smaller principalities, he included in his review of previous works on similar subjects reference to two books written in German: one, an "anonymous, rather disorganized account of assaying for metallic content and of metals," which must be the Probierbüchlein, the other, "dealing - with veins, written by Calbus of Freiberg, a well-known physician."* Calbus is mentioned a second time-and cited-at the end of the Third Book of De re Metallica. Comparison of the citation with the Bergbüchlein leaves no doubt that Agricola considered Calbus of Freiberg the author of the latter work, although all the editions of the Bergbüchlein known now were published anonymously. It is generally accepted by those who have dealt with the bibliography of the Bergbüchleint that Calbus was Ulrich Rülein von Kalbe, who served the City of Freiberg, in Meissen, as health officer in 1497, as member of the City Council in 1509, and as mayor in 1514 and 1519. He died at Leipzig in 1523. In connection with the very garbled description of the mining compass toward the end of Chapter 3 of the Bergbüchlein it is of interest that von Kalbe is supposed to have been not only a physician of repute but a mathematician, astronomer, mine sur-

Jan 1, 1949

Jan 1, 1947

By Michael J. Fiannnaca, Michael M. Easdon

Disseminated epithermal gold metallization occurs within a breccia unit interpreted to be a submarine debris flow. Gold is associated with oxidized pyrite, fluorite, and jasperoidal silica. A minimum of 8 Mt (9 million st) of open-pittable mining reserves will be cyanide heap leached as run-of-mine ore at a rate of 0.9 Mt (1.0 million stpy 1. Careful evaluation of the combined results of successive sampling projects has established the pit plan, minable reserves, and process metallurgy of the operation. The sampling procedure utilized for a given test depended upon geological interpretation as well as the procedures, successes, and failures of previous tests. This paper summarizes the sampling and testing procedures of the development effort in light of the project goals and attendant problems in achieving them.

Jan 1, 1985

By Stuart McGill

This case-study of the financing of the Ok Tedi project illustrates the nature of project financing and outlines the arrangements made in the case of this project; it also demonstrates that the limitation of financial exposure is an important goal for Governments involved in developing the resources sector. The account includes a chronological description of the process by which the sponsors prepared for the financing of the project and the lenders became involved in it. The type of security arid loan documentation required for such financing is described, together with a broad analysis of their content and the manner in which the various risks involved in development are apportioned among the sponsors and lenders. The ability to apportion and limit financial liability is an important development for the owners of capital and resources.

Jan 1, 1985

By John P. Ashby

Mine production blasting is a process of destruction of rock masses in order that ore may be extracted. Many open pit operations are faced with the apparently conflicting requirements of providing large quantities of fragmented rock for the processing plant and of minimizing the damage inflicted upon the surrounding pit slopes. A reasonable compromise between these two conflicting demands may often be found by means of simple engineering of production blasts. Many operations tend to rely too heavily upon traditional wall control techniques to alleviate a problem already created by the production blasts. Various production trends including use of larger blastholes and patterns have tended to aggravate the situation. These practices only serve to emphasize the need for engineered improvements. Central to blasting engineering is the process of systematic trial and evaluation. Changes to the blasting system should be made singly, starting with the simplest. This paper discusses simple changes involving drill pattern control, effective use of blastholes and explosives, adequate delaying including use of down-the-hole sequential techniques, effective utilization of free faces, and avoidance of "choked" situations. By directing explosive effort where it is needed, such changes generally result in a significant improvement of slope conditions and of production blasting cost and performance.

Jan 1, 1983

By N. E. Rogen, N. J. Grant

AGE-hardening in nickel-chromium-titanium-aluminum alloys in the composition range characterized by the Nimonic alloys, is dependent upon the precipitation of the Ni3(AI,Ti) (y') phase.1 This phase is found to precipitate at about 700°C.1 Ni,Al is a face-centered-cubic ordered structure with a lattice parameter of 3.560 A. The atomic configuration is such that the aluminum atoms occupy the cube corners and nickel occupies the cube faces with titanium substituting for the aluminum preferentially. A maximum of three out of every five aluminum atoms can be replaced by titanium atoms in the -y 'phase.' When the solubility of the y'-phase is exceeded for titanium the T(Ni,Ti) phase is formed. The T-phase is an ordered close-packed hexagonal intermetallic structure which shows little solubility for the other elements in these alloys. The lattice parameter for T-phase is a - 2.5454 kr and c = 8.2900 kx units."

Jan 1, 1959

By B. B. Gottsberger

HAVE given considerable thought during the past year to the subject of licensing of engineers and par-ticularly to the position which the mining engineer should take on this question. I have found, however, that it is not a subject which yields much result for the thought expended on it. So far as any published record will show, mining engineers have been either ignorant of the extent to which the movement for the licensing of engineers has progressed or else indifferent to it. It is true that the Mining and Metallurgical Society of America, by a questionnaire sent out to its member-ship, did a great deal in calling this matter to the atten-tion of the mining profession, and so far as I know, the report of its committee, which analyzed the replies received, is the only published statement of the feelings and opinions of our branch of the engineering profes-sion. It is to be hoped that the conclusions shown by that report, namely, that mining engineers are almost unanimously opposed to the principle of licensing and consequently any legislation dealing with it, has received serious thought and that we are ready for an even more thorough consideration of the subject.

Jan 3, 1922

Jan 1, 1887

By Robert O. Davis, Phillip A. Abbott

The response of geologic materials subject to nuclear weapon effects is of considerable interest in the design of buried protective construction. Recently, more consideration has been given to placing such structures in rock rather than in soil. Although rock has the obvious advantages of high strength and low deformability, discontinuities such as joints and fault planes severely complicate any response analysis. Nevertheless, some knowledge of the effects of these discontinuities must be developed, even if that knowledge remains largely qualitative in nature. In this paper, we present a constitutive description of cracked rock subject to uniaxial shock loading. The constitutive equations are based on certain average response characteristics of a particular cracked rock model. Rather than attempt to represent each material discontinuity individually, we have incorporated the discontinuity effects into constitutive relationships for a continuous medium. The resulting equations are suitable for use in hydrodynamic computer codes presently used for ground motion calculations. APPROACH The continuum description which will be presented below is based on a detailed analysis of a particular cracked rock model. This model can be visualized as a sequence of plates (representing the intact rock) separated by gaps (representing the discontinuities). This so-called "plate-gap" model was first used by Thouvenin (1) in an effort to explain the behavior of porous materials at high

Jan 1, 1971

By Morris Muskat

In preparing a well for pumping, observations are often made of the fluid level in the well bore or bottom-hole pressures at various times before equilibrium has set in. From a qualitative point of view one may immediately infer that if the rise in the bottom-hole pressure or fluid level is rapid the permeability of the sand about the well bore is large, and converse conclusions may be drawn if the rise is slow. However, a more quantitative estimate will give additional information of value, as will be shown in this paper. To derive such an estimate we may proceed as follows. Let h be the fluid height, above the sand face, at time t, and let yo be the average density of the fluid that enters the bore. The bottom-hole pressure, for a fluid height h will therefore be p = rogh, neglecting, of course, the friction drop in the well bore, while the fluid is rising, as may be justifiably done for most pumping wells. If a is the free area of the open-flow string—assumed to be uniform— the rate of production from the sand during the rise of fluid will be: where the last part of the equation merely indicates that, in general, the production rate Q must be considered as a function of the back pressure, and is determined by it alone. In fact, equation 1 shows that if the rate of rise of the pressure or fluid level is determined as a function of the height of rise, or p, for a number of values of the latter, this functional relation between Q and p will be immediately given. Conversely, if we know this functional relation, the rate of increase of p or h may be predicted, or, by observing the rate of rise of p or h some of the constants of the sand may be determined. Thus we may approximate the production from a well in a pumping state by that of a dead

Jan 1, 1937

By William G. Brissenden

Gaspe Copper Mines Ltd., a subsidiary of Noranda Mines Ltd., operates a completely integrated copper mining, milling and smelting plant at Murdochville, on the Gaspe Peninsula of Quebec. Operating six days a week, the mine produces 8000 tpd of ore. The mill runs continuously and capacity is rated at 6500 tpd of ore. Treating Gaspe concentrate output plus a certain amount of custom concentrate, the smelter produces between 3700 and 4000 tons of copper anodes per month.

Jan 9, 1959

By E. B. Burwell, R. H. Nesbitt

A NEW milestone in the progress of photography and subsurface exploration was reached when the Chief of Army Engineers announced the development of the NX borehole camera. In obtaining continuous undistorted cylindrical color pictures of dry or water-filled borings the device surpasses all other cameras designed for photographing interior surfaces of pipes, wells, and conduits. The usefulness of the camera and the unique projector that comes with it are at once apparent. To the geological, mining, and civil engineer alike it signifies the end of guesswork with respect to underground conditions that have eluded identification by conventional core-drilling methods. To the medical profession it may well signal new progress in photo optics which could result in cylindrical color photographs supplementing the X-ray and existing photographic methods used in exploratory surgery.

Jan 8, 1954

By Philip Drinker

IN THE mining and metallurgical industries, numerous problems arise requiring determinations of solid and of liquid particles suspended in air. Frequently, these problems are of local interest and involve purely economic or operating difficulties; on the other hand, toxic effects from the inhalation or the ingestion of substances suspended in air may be a matter of concern. For checking up process improvements or for determining ventilation efficiencies in problems of this general nature, various methods have been proposed. Although simpler methods are often satisfactory, precipitation combines several desirable features that other methods lack. This paper is, therefore, devoted to a discussion of portable alternating-current precipitators applicable to the quantitative determination and microscopy of dusts, fumes, and smokes in air. Small particles suspended in gases, such as air, are referred to in the literature as aerosols or suspensoids. Of these terms, suspensoids appears to be preferable as being more nearly in keeping with words in everyday use. In problems involving air pollution by small, particles-by suspensoids-it is convenient to distinguish three broad classes based on the size, the degree of dispersion, and the method by which the particles become suspended in the air. Dusts.-Particles or aggregates of particles, 150 to 1 micron in diameter, that are thrown into the air by mechanical agencies are termed dusts. Examples are silica, talc, cement, organic dusts such as hard rubber, starch, and cocoa; flocculated fume and smoke products. Fumes.-Particles, 0.2 to 1 micron in diameter, formed from chemical or physicochemical reactions are known as fumes. Examples are ammonium chloride, lead and mercury, zinc and magnesium oxides, fogs, and acid mists.

Jan 3, 1925