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A filled stope is one in which the support for walls and men and, at times, for the back of ore, is furnished by waste rock or sand tailings. The filling may be rock sorted out in the stope or from the walls, develop-ent, or the surface. The orebody is mined in sections, each practically an open or timbered stope, filled wholly or in part before adjacent ground is attacked. As a rule, the filled-stope method is limited to overhand flat-back, stepped-face, or rill stopes. The examples given are Copper Range, Iron Cap, Verde district, Zaruma district, Lucky Tiger, and Silver King Coalition.

Jan 1, 1925

By H. C. Heard

The review by Professor J. C. Jaeger (Chapter 1) briefly summarizes and discusses a select group of papers by various workers dealing primarily with aspects of fracture in brittle rock materials. Professor Jaeger's treatment is primarily concerned with the correlation of phenomenological and theoretical failure criteria with empirical results from short duration tests at ambient temperatures and generally at low lithostatic and interstitial fluid pressures. As engineering rock mechanics becomes more concerned with new techniques of mineral exploration and production at increasingly greater depths in the crust, it is well to be aware of the effect of the environment -that of the superposed stress field upon the lithostatic and interstitial fluid pressure, the temperature and the duration of the loading upon the failure of rocks either by fracture or flow. All results to be discussed here are from laboratory tests on small homogeneous samples, thus caution should be used in the direct extrapolation of these results to large inhomogeneous rock masses having quite different boundary conditions in the earth. The purpose of this supplement is to briefly point out the major effects of these parameters as examined singly, with all others held constant, and to cite some recent results which apply to the main theme on the brittle failure of rocks. The total stress field imposed upon a small volume of porous and permeable rock in the earth's crust may be thought of as the sum of an applied differential stress, plus a lithostatic pressure, plus an interstitial fluid pressure. The differential stress portion may be completely specified by nine components, six shear and three normal. If the small volume element is in rotational equilibrium, by suitably choosing our coordinate axes we may resolve these nine components into the three principal com-

Jan 1, 1967

By J. B. DILWORTA

Ix estimating the investment-value of a mining-property or plant, the value of which decreases with operation, it is often necessary to know the sum which must be set aside periodically from earnings either to renew the plant at the end off its life, or to return the capital involved when the earning-power of the investment has ceased. In such cases it is manifestly incorrect simply to divide the total amount to be retired by the number of periods (usually years) during which the investment shall be active, as the sums periodically withdrawn have a certain interest-earning power varying with the length of time they are held and with the opportunities afforded for their investment. But though the interest may be considered to accumulate regularly year by year, yet the rules and tables for compound interest do not apply, owing to the addition of a fixed amount of new money to the total at the beginning of each period. Briefly stated, the problem of sinking-funds is, to find the amount of money which must be periodically set aside at a certain rate of interest, regularly compounded, to yield a certain sum in a given, length of time. In most practical cases the interest is compounded and the fresh amount added at the same time-usually once a year-and on this basis the problem may be solved as follows

Nov 1, 1909

Aamot, Olav Crone, Chem. Engr., Norsk Elektrokemisk, Kongensgt. 18, Olso. Norway. '29 Abadilla.-Quirico A., Dir., Bureau of Mines Manila, P. I. '38 Abbott, Clarence E., V.P., Charge of Raw Materials, Tennessee Coal, Iron & R.R. Co., 1212 Brown-Marx Bldg., Birmingham, Ala. '04 Abel, Raymond L., Prof., Dept. of Pet. Refin., Univ. of Pittsburgh Pittsburgh, Pa. '29 Abel. Walter D., Cons. Engr 1839 Holmby Ave., W. Los Angeles. Calif. '32 Abele, Louis T R. F. D. 5. Susquehanna Trail, N., York. Pa. '31 Abell, Leo M., Ore Dressing Investigator, School of Mines Adelaide, S. Australia. '31 Abenius. Hakan V., Mine Supt., Bolidens Gruvaktiebolag Boliden, Sweden. '37 Aborn, Robert H., Asst Met., Research Lab., U. S. Steel Corp. Lincoln Highway, Kearny, N. J. '19 Abraham, W. E. V., East India United Service-Club, 16 St. James' Sq., London, S. W. 1, England. '28 Abrams. Charles Jackson 1624 17th St., Denver, Colo. '36 Abstein, Henry T., Engr. & Mgr., Profile-Tamarack Mines Co Yellow Pine, Idaho. '27

Jan 1, 1938

THOSE MARKED THUS * ARE MEMBERS, MARKED THUS ?ARE ASSOCIATES. THESE SIGNS DOUBLED INDICATE LIFE MEMBERS AND ASSOCIATES RESPECTIVELY. THE FIGURES AT THE END OF THE ADDRESS INDICATE THE YEAR OF ELECTION. HEAVY-FACED TYPE SIGNIFIES HONORARY MEMBERSHIP. *AARONS, J. BOYD, Vivian Gold Mining Co., Ltd., Harris, West. Australia. '05 *ABADIE, EMILE R., Cons. and Min. Engr., 214 Union Savings Bank Bldg., Oakland, Cal. '76 ?ABBÉ, MAX F., Prest., Abbé Engineering Co, 220 Broadway, New York, N.Y. '07 ? ABBÉ, PAULO., Secy.,Abbé Engineering Co., 220 Broadway, New York, N.Y. '07 *ABBOTT, AI ARTHUR Morococlia, Peru, So. America. '95 *ABBOTT, CLARENCE Chief EDgr., Iron Mines, Dic Tennessee Caol, Iron & R. R. Co., Bessemer, Ala. '04 *ABBOTT, JAMES W., Min. Engr: Ploche, Lincoln Co., Nev. '94 *ABE, MASAYOSHI, Prof. of Mining, Imperial University Kyoto, Japan. '05

Jan 1, 1910

By R. W. Hertzberg, F. D. Lemkey, J. A. Ford

The technique of unidirectional solidification has been applied to the A1-AI3Ni and A1-CuAl2 ezltectic alloy systems; the controlled microstructure of A1-A3Ni consists of parallel A13Ni whiskers emhedded in an aluminum matrix while the Al-CuAl2, system solidifies as parallel alternate lamellae of aluminm and CuAl2. Mechanical tests (tension and flexure) have shown that the particle-matrix interface bond formed during unidirectional solidification allowes for efficient load transfer from the matrix to the reinforcing phase. Strength and fracture characterstics of the alloys were studied as a function of phase orientation; the tensile strength of controlled Al-Al3Ni samples was 43,000 psi (three times greater than that of as-cast specime~s). The strength of the Al-CIA2, cutectic was studied as a function of lamellae-flexure stress-axis orientation using a microbend apparatus. A twofold increase in outer fiber stress was observed as the lamellae were rotated from a position of no reinforcing (perpendicular to the stress axis) to one of maximum reinforcing (parallel to the stress axis), The brittle reinforcing constituent in each alloy (A13Ni and CuAl2) was observed to he the nucleating phase for fracture. It is to be concluded from this investigation that unidirectionally solidified eutectic alloys have a potential use as reinforcing coniposite) materials. In a recent review article, Chadwick1 has described the work of many investigators in the area of controlled solidification of binary eutectic alloys. Thus far, more than twenty eutectic alloys have been unidirectionally solidified to produce structures consisting of two phases in the form of alternating lamellae or as whiskers embedded within a continuous matrix; in either case, the phases are aligned parallel to the growth direction. In particular, Kraft and Albright2 have shown that the Al-CuA1, eutectic alloy exhibits a lamellar microstruc- ture as a result of unidirectional solidification while Lemkey, Hertzberg, and Ford3 have studied the A13Ni whisker-aluminum matrix morphology in the A1-A13Ni system. Whether these alloys could exhibit reinforcing behavior would have to depend upon the strength and volume fraction of the reinforcing phase (AI3Ni and CuA12) and the nature of the bond between the reinforcing phase and the matrix. Hertzberg and Kraft4 have shown that the interface bond between chromium whiskers and a copper matrix in unidirectionally solidified Cu-Cr is particularly good while Lemkey and Kraft5 have reported chromium-whisker tensile strengths in excess of 1,000,000 psi. However, with the chromium volume fraction being less than 2 pct, no reinforcing behavior was displayed by the Cu-Cr alloy.6 In view of the encouraging results concerning the good interfacial bond and high strength of the reinforcing phase in the Cu-Cr system and preliminary mechanical test data reported by Lemkey et al.3 for the A1-A13Ni system, the A1-CuA1, and A1-A13Ni eutectic alloys containing 50 and 10 vol pct, respectively, of the reinforcing phase give promise of possessing mechanical reinforcing behavior. Based on this premise, the objective of the investigation was to study the strength and fracture behavior exhibited by these anisotropic microstructures. EXPERIMENTAL PROCEDURE Controlled Solidification Procedure. An extensive description of the technique of unidirectional solidification has been presented elsewhere.' However, the pertinent details for each eutectic system studied are discussed below. Al-A13Ni System. Several master heats of this alloy were prepared by vacuum-induction melting in an A12O3crucible and casting in SiO2 mold or by induction melting in alumina crucibles under argon. The initial heats were prepared from 99.99 pct A1 and 99.99+ pct Ni, while later heats used 99.999+ pct A1 and 99.99+ pct Ni. Specimens of these master heats were unidirectionally solidified using induction and resistance heating sources and argon atmospheres at growth rates from 1.1 to 28.7 cm per hr. The thermal gradients in the liquid were controlled in the range of 26" to 36°C per cm for these runs. Al-CuA12 System. The master heat and controlled

Jan 1, 1965

By Herbert J. French

ALLOY steels have become essential to industry in meeting the rigid requirements on materials imposed by our, advanced technology. In comparison with the total ingot capacity of the steel industry, the volume of alloy steels is relatively small although for many years annual alloy-ingot tonnage has, been in seven figures. However, the monetary value of the alloy-steel production is exceedingly high and the benefits derived from the products are relatively great. The trend in total ingot production since 1932 has been generally upward with only two major interruptions. That of the year 1938 was due to a decrease in general business activity whereas that of 1946 resulted largely from work stoppages. Traditionally, the tonnage of alloy-steel ingots produced was in the neighborhood of 5 to

Jan 1, 1948

[JOSEPHSON, W. G.: The Argonaut Mine of Today, M88, 475 JOUET, C. H., biography, M29, 258 Joule-Thompson effect, 98, 381 JOWETT, J. H., biography, M83, 276 JUDSON, S. A.: Operations in the Gulf Coast of Texas and Louisiana for 1926, G26, 659 JUDSON, S. A., EASTON, H. D. JR. AND SCHAEFFER. W. A. JR.: Estimation of Petroleum Reserves in Prorated Fields 114, 11. Abs., YB35, 50 JULIHN, C. E.: Copper---An Example of Advancing Technology and the Utilization of Low-grade Ores. Brookings Lecture, in Mineral Economics (1931 volume, B. W. Mudd Fund)]

Jan 1, 1936

By E. W. Henderson

Oil and gas development in Utah in 1936 added nothing of importance to the commercial possibilities of the state and consisted principally of efforts to reach objectives in wildcat wells started prior to 1936. Leasing activity on structures having oil and gas possibilities in beds of Pennsylvanian age or older followed announcement by the Standard Oil Company of California that a test of beds of Mississippian age would be made on the San Rafael structure. DRilling Clay Basin, Dagget County.—The Mountain Fuel Supply Co. completed a third well, sec. 16, T. 3 N., R. 24 E., on a flank of this structure. Total developed open flow of the field is approximately 50 million cubic feet and sufficient reserve has been established to warrant construction in 1937 of a pipe line connecting with the Salt Lake City-Ogden line. San Rafael, Emery County.—The Standard Oil Company of California started a wildcat test in sec. 22, T. 23 S., R. 11 E. Circulation was lost in a water-filled cavity, in dolomitic limestone, below 2185 ft. and the hole conditioned as a water supply for drilling a second test in sec. 27, T. 23 S., R. 11 E. The Carter Oil Co. in 1921 drilled a well in sec. 24, T. 23 S., R. 11 E., which was abandoned at a depth of 3035 ft. after testing at least a part of the Pennsylvanian section. Czsco, Grand County.—Drilling operations at the Utah Sout.hern Oil Company's test in sec. 33, T. 22 S., R. 22 E., continued throughout the year. Information obtained by means of a seismographic survey of the area indicated that beds of Pennsylvanian age would be found at approximately 2500 ft. The bottom of the hole at 6300 ft. is believed to be in beds of Pennsylvanian age but positive determination has not been made froin the drill cuttings. Green River, Grand County.—Test of Glen Ruby et al., sec. 34, T. 21 S., R. 16 E., was abandoned at 2627 ft. as a dry hole after drilling into Permian Kaibab limestone. Shows of oil and gas were reported and a flow of carbon dioxide gas under low pressure encountered.

Jan 1, 1937

BARBOUR, PERCY E., Deputy Supt., (Captain), New York State Troopers; Captain, 22nd Regiment, N. Y. N. G. BARLING, 1i. B., 1st Lieutenant, Engineer Officers' Reserve Corps. CHAPMAN, R. H., Major, Engineer Officers' Reserve Corps. DUNN, THEODORE S., 1st Lieutenant, Engineer Officers' Reserve Corps. DWIGHT; ARTHUR S., Major, Engineer Officers' Reserve Corps. FORBES, CARROLL R., Captain, Engineer Officers' Reserve Corps. GOODSPEED,. G. E., JR., 1st Lieutenant, Engineer Officers' Reserve Corps.

Jan 7, 1917

By ERJIINICI FERRARIS

1. HISTORICAL REVIEW AND INTRODUCTION. THE development of the mining industry in Sardinia dates from the application of the minim law of 1859, which, following the example of the French mining law of 1810, declared prospecting to be free, and suppressed the liens which had previously attached the mine to surface ownership. The first ore-dressing plants were installed by German engineers upon the classic models of the Harz and of Freiberg; but in 1880 Sardinia commenced to open a new path in that industry, utilizing the refuse from the mining of rich, selected minerals, of poor deposits, and of mixed ores. The first experiments were attempts to adapt the existing apparatus to local conditions, but progress was rapid, as was demonstrated already in 1887 by the calamine-dressing-mill of Monteponi, which exhibited a large plant designed in accordance with the experience gained, and constructed entirely in the machine-shops of the country, after new models and designs.1 This example was followed two years later by the Société Malfidano, with a large plant of the same sort, and with the reconstruction of the old-fashioned-dressing-mill, built in 1880 by the Austro-Belgian Company. In 1900, almost all the mines of Sardinia had adopted the new designs, and the island contained 32 concentrating-works, employing 2,000 h.p. and 1,924 workmen. Since that time, there have been added a large dressing-mill for blende at Gennamari, and two for calamine, at San Giovanni and at Masua, while the establishments at other mines have been enlarged and perfected. For the treatment of intimately mixed ores, a large establishment has been built upon the new

Jan 5, 1908

Discussion of the paper Of JAMES JOHNSTON, presented at the New York meeting, February, 1914, and printed in Bulletin No. 85, January, 1914, pp. 107 to 133. CHAIRMAN E. GIBBON SPILSBURY.-I would like to call attention to the fact shown in this paper that less than five years or perhaps seven years ago nobody had thought it possible to cyanide with success silver ores. The cyaniding of silver and gold ores was first of all started in Mexico, and gradually extended to this country in the case of the silver ores alone. The average extraction, I think, for the metals in Mexico, in the case of the silver ore, is less than 85 per cent., whereas here, in the case of a very complex ore, carrying a high percentage of sulphur and arsenic, and other objectionable elements, the ore has been treated so as to extract an average of 95 per cent. of the silver contents of the ore. It is really a phenomenal revolution in the metallurgy of silver ores which has been demonstrated and worked out at the Nipissing mines. GEORGE A. PACKARD, Boston, Mass.-I would like to suggest a slight modification, perhaps, of the statement which is made that no one considered cyaniding of silver ores up to five, or perhaps seven years ago, because in 1897, when I was at Mercur, Utah, one mill near there was operating on silver ores. It did not operate very successfully from a commercial standpoint, because they did not have a great deal of ore, but the extraction, I was told, was very satisfactory, and I am quite confident that it was, because, as suggested by the name, Chloride Point, the ores were silver chloride ores, and of course very easily soluble. Some years before that, in 1892, I made some tests myself. I spent three months making tests on more or less complex silver sulphide ores at Virginia City, Mont., and while our tests on the plain sulphide ores, finely ground, were quite successful, on account of the presence of a small amount of copper we did not work out a satisfactory solution of the problem at that time; although since then a cyanide plant has been erected and for at least eight years these ores have been treated by cyaniding at Virginia City, and the mill is still in operation. The period of five to seven years should, therefore, be modified considerably, in justice to the pioneers in the cyanide processes. REGINALD E. HORE, Toronto, Ont., Canada.-I hoped that there would be metallurgists from Cobalt here to present and discuss Mr. Johnston's paper. In their absence a few remarks from me may help to make clearer to you what they have accomplished.

Jan 6, 1914

William Kent, New York City: I regret that I have not had the time since the Cincinnati meeting to make as complete a study of Mr. Salom's paper as I wished. I regard it as one of the most important papers that have been presented on this subject, and worthy of complete study. I started out, on the limited time I had, on a system of study which I would recommend to any one else who has leisure to complete the investigation. I took the original report presented at the Cincinnati meeting, and selected from it' such tests as had the analyses reported along with the physical tests, giving the amounts of carbon, phosphorus, manganese, etc., taking only those in which all these elements are given.

Jan 1, 1885

By E. M. Wise

THOUGH known as the platinum-group metal- the sextuplet, platinum, palladium, iridium. rhodium, osmium, ruthenium, might well be called the American metals or perhaps Pan-American metals, as the ore containing them eras first discovered in South America, and in recent years the largest production has come from North America. The South American alluvial deposits, which also, contain gold, are in active production, as are the alluvial platinum deposits of Alaska, but the main production is from the copper-nickel ores of Sudbury, Ontario. The Russian deposits in the Urals were the source of most of the worlds platinum for about 100 years, but since 1934 have assumed second place. For a time considerable amounts of platinum came from several rather rich deposits in South Africa but these were exhausted quickly. However, a tremendous reserve of lower-grade ore exists there, which could be worked profitably if the price of platinum were considerably higher.

Jan 1, 1942

By Ionel Gardescu

IN connection with some of the experiments carried out by the writer on the behavior of gas and oil in a sand reservoir,1 an interesting phenomenon was observed which may throw some new light on the problem of recovery of oil from a natural reservoir. The experiments are intended to show the effect of the surface area of the occluded gas masses, originally present in a reservoir, on the further evolution of gas from the oil and its consequent effect upon the rate of production of oil. The apparatus used in the experimental work is shown in Fig. 1. It consists primarily of a sand reservoir R and a displacement chamber D, which is used to induce small variations in volume. The reservoir and displacement chamber form a unit, and a lowering of the plunger D is equivalent to increasing the volume occupied by the oil and gas in the reservoir. The reservoir was first filled with dead oil and maintained under pressure until it was ascertained that most of the free gas had gone into solution. The volume of free gas present in the reservoir was computed from the coefficient of compressibility of the fluids by means of the dis-placement chamber D, reading to 0.005 c.c. and a special gage J reading to 0.02 lb. per sq. in. The oil was saturated with gas under pressure in reservoir S by circulating the oil for a long period of time through the gear pump B. Subsequently, the saturated oil was circulated through the sand reservoir following the circuit S6, B, S5, R4, the sand reservoir R, R1, R2, F4, F1, back to reservoir S. In the following experiments the sand reservoir R was filled with gas-saturated oil at a pressure of 415 lb. per sq. in. with no free gas present. This was ascertained by. closing off all the outlet valves, and determining the coefficient of compressibility of the system by means of the dis-placement chamber D.

Jan 1, 1932

By Brahm Prakash, R. Schuhmann

Chemical conditions for flotation and nonflotation of quartz with oleic acid as collector and barium, calcium, aluminum, iron, and tin as activators were studied using a simple vacuum-flotation technique in glass-stoppered graduates. The detailed study of barium activation led to an interpretation based on ideal Langmuirian chemisorption.

Jan 1, 1950

Jan 1, 1968

By John A. Emery

The Pea Ridge iron ore deposit near Sullivan, Missouri, is a dike-like mass of magnetite enclosed in Precambrian porphyries. The ore body tops at the Precambrian surface at a depth of 1300 feet below the present surface and extends to an unknown depth. It dips nearly vertically, intersecting the dip and strike of the enclosing porphyries at an extremely sharp angle. Faulting, both pre- and post-ore, appears to be of minor consequence, and present knowledge indicates that no preferred structural conditions existed prior to emplacement. The ore body is composed of magnetite with specular hematite, quartz, apatite, and pyrite occurring as accessory primary minerals. Specular hematite in appreciable quantities occurs on parts of the cap and the footwall of the ore body. Fresh porphyry breccia is enclosed in the magnetite along the hanging wall and in the western portion of the ore body. Hanging-wall quartz-amphibole and footwall quartz-hematite occur as replacements of certain porphyries. Further alteration has caused sericitization of parts of these zones. The ore deposit is interpreted as having been formed essentially by a single injection of a magmatic differentiate with hydrothermal end phases forming the quartz-amphibole and quartz-hematite portions of the deposit.

Jan 1, 1968

[A Aalseth, Earl P. (M 51) Geol, Amerada Petr. Corp., Box 1498, Billings, Mont. Abadie, Henry G. (M 43) Asst to Supvr of Oper, Long Beach Oil Dev. Co., 255 S. Santa Clara, Long Beach 7, Calif. Abbe, T. Waldo (A 56) Ass't Dist Oper Supt, Sun Oil Co., Beaumont, Tex. Abbott, J. L. (M 56) Partner, Pritchard & Abbott, 501, Century Bldg, Fort Worth, Tex. Abbott, Richard H. (J 51) Owner, Abbott & Howard, 422 W. Hermosa, San Antonio, Tex. Abbott, Seth J., Jr. (M 51) Tekoil Corp., .2;A6 Mercantile Nat'l. Bank. Dallas, Tex. Abbott,. William G. (M 50) Div Mgr, Rice Eng. & Op. Inc., Box 1142, Hobbs, N. M. Abderhalden, R. R. (J,59) Box 100, Carmi, Ill. Abel, Malcolm D., Gen Mgr, Bakke Oil Co., Midland, Tex. Abel, Raymond L. (M 28) Prof of Chem Engr, Univ. of Pittsburgh, Pittsburgh 13, Pa. Abel, Wayne K. (M 57) 1513 Patton Drive, Odessa, Tex.]

Jan 1, 1961

APPROXIMATELY 26 percent of the total ore production to date from the largest single deposit of copper-bearing material in the world was mined during the war years, 1942 to 1945, at Chile Exporation Company's great open-pit mine at Chuquicamata, Chile. About 18 percent of the total waste removed during the life of the mine was handled in the same period. The total of ore and waste represents approximately 24 percent of the total material that has been excavated from the pit. This is more than was removed in the first fourteen years of operation from 1914 through 1927. The pit at Chuquicamata is 17/8 miles long, 1/2 mile wide, and has a present vertical extent of 817 ft between the top of the highest bench and the lowest bench being worked. However, when

Jan 1, 1948