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Members Dues Resignations, Suspensions and Expulsions Institute Meetings Board of Director?s Meetings Directors and Officers Duties of Officers Committees Nomination and Election of Officers Publications Divisions, Local Sections, Affiliated Societies Amendments [As REVISED FEBRUARY 21, 19281 ARTICLE I MEMBERS-QUALIFICATIONS AND ELECTION , SEC. 1. The membership of the Institute shall comprise six classes, namely: 1. Members; 2. Honorary Members; 3. Senior Members; 4. Associates; 5. Junior Associates; 6. Rocky Mountain Members. All shall be equally entitled to the privileges of membership, excepting that Junior Associates, and all Members and Associates whose residence shall be outside of the United States of America, Mexico and Canada shall not be entitled to vote. SEC. 2. Members: A person to be eligible for election or transfer into the class of Member must be at least 27 years of age and must have had at least six years' employment in the practice of engineering, mining, geology, metallurgy, or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. This shall not apply to Rocky Mountain members.

Jan 1, 1928

By F. P. Schwarz, A. J. Erickson, S. M. Weber

The Mount Hope stockwork molybdenum deposit, Eureka County, Nevada, occurs In a small igneous cauldron complex 32 to 38 mybp in age. The deposit is characterized by alteration zones and mineralized shells symmetrically distributed around multiple intrusive. For samples from the 25000 meters of 1981-82 drilling, an appraisal of error in in-house sample preparation and in commercial assaying has been made. After splitting, drill core is crushed and reduced in volume (8: 1 at 10-mesh, 8: 1 at 70-mesh, 6: 1 at 200-mesh) to supply 25 grams of 200-mesh pulp for replicate analyses. A 0.5 g portion of the pulp 1s used for dissolution and atomic absorption analyses. Factors which initially generated unacceptable data variances have been minimized by planning, repeat analyses, introduction of standards, and routine monitoring. Assuming that error between replicate assays defines a Gaussian distribution with its average ideally equal to zero, precision (from preparation including core splitting and analysis of 8400 pairs of molybdenum samples) is on the order of ± 25%. The error distribution is not based. Accuracy is approximately 4% lower than absolute as determined by replicate assays of commercially prepared samples.

Jan 1, 1984

By R. S. Burns, J. G. Erskine

The performance of the nine 5.5 m diameter x 6.4 m mills (18 x 21 ft) initially installed at Bougainville Copper Ltd. did not meet the laboratory and pilot plant derived design expectations as measured by Bond Work Index. During the post-commissioning period, inefficient grinding of coarse material resulted in a build-up of large circulating loads and led to reduced throughputs because of pump and cyclone overloading. Installation of larger pumps and cyclones and development of an improved circuit control philosophy alleviated materials handling problems and permitted higher tonnages to be attained. Since 1977, plant throughput has been increased by installation of three additional mills. These are 0.9 m (2.9 ft) longer than the other nine and have a higher capacity. Developments in classification and mill speed-up, together with a finer ball mill feed size and substantial improvements to mill availability (99% in 1982) have further increased plant capacity. There is a continuing emphasis on improving grinding circuit efficiency in terms of throughput/grind. Current development work includes trials of graded ball charges, different liner profiles, and assessment of scalping/regrind proposals.

Jan 1, 1985

By G. E. Agar, A. L. Mular

G. E. Agar (Manager, Minerals Processing Research, International Minerals & Chemical Corp., Skokie, III.) — The author notes a discrepancy between the parameters a and ß which are the slopes of the size distribution and energy-size modulus plots respectively. The reason for the discrepancy and the systematic decrease in the magnitude of a with grinding time is abundantly clear from the work of Fuerstenau8 on dry grinding. Fuerstenau shows very clearly in his Fig. 5 that at short retention times the parameter a is the same as that obtained by sizing over the complete size range. From this figure, it is obvious that sizing to only 400 mesh gave distribution curves similar to Mular's - that is, the slope apparently decreased systematically with increased grinding. As a consequence of the improper determination of a, the magnitude of ß given by Mular must be larger than the true value. In order to demonstrate this, the following Fig. 6 was taken from Mular's paper (his Fig. 1). Fuer-stenau's results show that we can approximate the correct value of K by drawing lines parallel to the short retention time curves through the 400-mesh

Jan 1, 1963

At a special inaugural ceremony in Blue Hill, Maine on August 3rd, Governor John H. Reed detonated the first blast to signify the beginning of development work on a new copper-zinc mining venture that seems destined to focus increased interest in the mineral potential of that State. The property which is the first new base metal mine to be discovered in the northern Appalachians in 30 years, is owned by Black Hawk Mining Co., a subsidiary of Denison Mines Ltd. of Toronto. When it goes on-stream in 1966, it will join Ducktown, Tenn., as the only active copper producing region, east of the Mississippi River. According to official reports submitted by the Company to Robert G. Doyle, Maine's State Geologist, Black Hawk has found ore reserves totalling 4.5 million tons. Assays show 2.8 million tons of 2.0'; copper and 0.4 oz. of silver per ton; 1.2 million tons of 16.75% zinc and 0.58% copper; and 0.5 million tons of 6.75% lead with 4.25 oz. of silver per toil and some zinc.

Jan 9, 1964

By C. E. McWhorter

IN underground mining recent trends toward mining large tonnages of low-grade ore have created, among other things, a need for cheaper and more flexible ore transport. A relatively new development has been the adaptation of shaker conveyors to meet this need. Although widely used in coal mining, only in the last few years have shaker conveyors been used in underground metal mining. The equipment consists of a driving engine, either electric or air powered, upon which is mounted a drive trough supported in ball-bearing frames. The trough line, or conveying medium, is made up of a number of sections, each section connected to another, usually with bolts. The length of each trough section is controlled by the length that can best be handled underground, but is usually from 9 to 13 ft over-all. The length of a complete conveyor line is determined by the character and weight of material to be handled as well as by the size of the ore body. Trough lines vary in lengths from 100 to 300 ft and the trough has a cross-section area of 127 sq in., and is 22 in. wide by 6 ½ in. deep.

Jan 1, 1948

By C. G. Brehm

THE anthracite-producing region is in the northeastern section of Pennsylvania, and has an area of approximately 484 square miles. It is divided geographically into three separate fields, known as the Northern, Middle and Southern. The Northern field, with Wilkes-Barre approximately at its center, is a basin about 60 miles long and almost 6 miles wide at its greatest distance across. Generally speaking, it may be said that the coal meas-ures in this field lie horizontally, or on slight pitches, and consist of from 11 to 19 veins of coal, varying in thickness from several inches to several feet. The intervening strata between veins may be composed of slate, clay, rock or shale, or a combination of several, and are sometimes very thin. This condition often causes a treacherous roof, therefore roof sup-port and the attending hazard of mining are problems of concern. The Middle field is made up of a number of small basins of not very great depth, and the measures, which are in like number to those of the Northern field, are varying inclinations running from nearly flat to steep pitches.

Jan 1, 1938

The selection of a particular machine for production drilling is the most critical drill evaluation the pit engineer is called upon to make. It is a true engineering design problem requiring value judgments. Generally, the procedure follows these steps: (1) Determine and specify the conditions under which the machine will be used, including such service factors as labor, site, weather, etc. (2) State the objectives for the rock-breakage phases of the production cycle of operations--considering excavation and haulage restrictions, crushing capacity, production quota, and pit geometry-in terms of tonnage, fragmentation, throw, etc. (3) On the basis of blasting requirements, design the drill-hole pattern (hole size and depth, in- clination, burden, spacing, etc.) (4) Determine the drillability factors and select the drilling methods which appear feasible for the kind of rock anticipated. (5) Specify the operating variables for each system under study, considering drill, rod, bit and circulation fluid factors. (6) Estimate and compare performance parameters, including costs. Major cost items are bits, drill depreciation, labor, maintenance, power and fluids. (7) Select the drilling system that best satisfies all requirements with the lowest over-all cost.

Jan 10, 1967

A list of publications of the United States Bureau of Mines, complete from its establishment to the end of June, 1931, may be had upon request. In addition a monthly leaflet of new publications is issued and is sent to those on the mailing list of the Bureau. Publications are separated into three main divisions: 1. Sales Publications.-Those for which a charge is made. Any orders or remittances in payment for sales publications should be sent directly to the Superintendent of Documents, Government Printing Office, Washington, D. C., and not to the Bureau of Mines. Sales publications are classified into (1) Bulletins, (2) Technical Papers, (3) Economic Papers, (4) statistical reports of the mineral resources of the United States, (5) Monographs, (6) Handbooks, and (7) Schedules. Bulletins and Technical Papers present the results of scientific and technical investigations. Economic Papers are analytical studies of production statistics, sources, resources, .distribution, and industrial flow of mineral commodities. The Annual Report, entitled "Mineral Resources of the United States," includes chapters, published separately, on the production and consumption of metals and of nonmetallic minerals. Monographs give detailed results of extensive cooperative investigations of special

Jan 1, 1933

By J. V. W. REYNDERS

THE principal manganese deposit of Russia, I one of the four principal sources of the world's supply, lies on the southern slope of the Caucasus Mountains, in what is now the Republic of Georgia, district of Sharopan. Tchiatouri, the principal town, is midway between Tiflis, the capital of Georgia, and Poti, the shipping port on the Black Sea, about 130 " miles distant. The deposit can be most easily visualized by thinking of a nearly horizontal coal seam about 6 ft. thick, outcropping on the slopes about 600 ft. above the Kvirila River. One of the accompanying illustrations shows the river, which nearly bi- sects the district, of approximately 50 sq. miles in area, and with its tributary streams makes the topography rugged, while in the background are the snow-capped peaks of the Caucasus range. Another of the illustrations gives a closer view of the outcrop. The roof and floor of the deposit are good, so the methods of working are quite similar to working a coal seam, especially as most of the mineral is soft enough to be mined with a pick. Little machinery is used, except small cars for underground transportation.

Jan 1, 1926

By T. P. Harrington, P. G. Doctor, K. A. Prisbrey

Crushing and grinding ore consumes so much energy that it represents a major component of total processing costs. While it has been estimated that only about 0.6% of the total energy expended in grinding is actually used to create new surfaces, accurate measurement of this quantity is difficult. If energy expended in crushing and grinding could be more directly measured, alternatives for increasing efficiency of the processes could be evaluated more effectively. Since the energy intensity associated with rock fracture is related to fracture sonority, it should be possible to use this sound (acoustic emission) to measure the actual energy expended. However, it is difficult to apply this approach because the mill environment is so noisy. To make the approach practical, a method for differentiating acoustic emissions caused by rock fracture from those caused by extraneous noises must be found. Pattern recognition analysis may provide such a method. This paper presents the results of pattern recognition analysis to make two types of differentiations: acoustic emissions caused by crushing two types of minerals (quartz and chrysocolla) and those caused by two extraneous noise sources, and acoustic emissions produced by each mineral.

Jan 1, 1982

By Evans B. Mayo

As a result of studies distributed over the earth- including ocean basins as well as continents- some tectonists recognize four dominant structural trends: 1) northwest; 2) northeast; 3) nearly east- west, or equatorial; and 4) nearly north-south, or meridional. Baker' proposed a theory to account for these trends and Sonder5 called their world-wide arrangement the regmatic shear pattern. Moody and Hill6 proposed a much more complicated shear network which, although fascinating and perhaps ultimately useful, will not be followed here. In a recent review of deformation within the Cordillera, Wisser7 mentioned the four fundamental directions. The fact that many geologists deny the existence of the regmatic shear pattern implies that the fundamental structures are far from obvious. It may mean, also, that some geologists are not accustomed to examine regional and world maps analytically. The maps require much study, and certain features, should be isolated on overlays. Even so, with the present limited knowledge, uncertainties remain. The following analysis is a qualitative experiment, subject to change as information accumulates, and should be supplemented by the western sheet of the Tectonic Map of the United States.8

Jan 11, 1958

By Charles E. Johnston

By substituting photoelectric automatic car loading for mechanically induced hydraulic automatic loading and by protecting the process against operational failures, the engineering staff at International Minerals & Chemical Corp.'s Carlsbad potash mine has developed a reliable loading process that operates without an attendant. The photoelectric control, developed primarily because of frequent failures in the hydraulic control system, has not changed the basic loading operation and physical layout. Mine-run ore ranging in size from minus 200 mesh to 30-in. lumps is dumped onto a conveyor belt which discharges into a so-called "flop gate chute" which in turn, feeds the ore into six-ton capacity mine cars. Each car is filled progressively by moving the entire trip forward. When a car is filled 12 in. above its rim, the direction of flow into the car is reversed 180º and filling of the next car back is begun while the entire trip is moved forward again. Once the next car is properly spotted under the front chute, the flow is again directed to the forward position.

Jan 9, 1962

By O. Lietard, J. Yvon, R. Mercier, J. F. Delon, J. M. Cases

INTRODUCTION Fineness is one of the main characteristics of powders and this parameter is the object of several definitions based on criteria connected with their uses as well as their determination methods. In trying to obtain the best reaction surface, fineness is characterized by the determination of the specific surface, but in other cases, particle size analysis is used. These two main methods are not, in fact, entirely independent and their complementary nature provides information concerning the morphology of the particles. In the case of a product formed by isodimensional spheres, the relationship between the specific surface and the diameter is well known: [S = 6 spd] where p is the specific weight of the material and d the diameter of the spheres. With no monodimensional spheres, but rather a granulometric distribution whose occurrences follow a mathematical law (1), the relationship is more complicated. The relationship between the specific surface measured by gas adsorption and the data of the particle size analysis is much more difficult to predict in the case of asymmetric porous particles, whose particle size distribution curves do not correspond to a known statistical law.

Jan 1, 1980

By J. W. Downey, M. V. Nevitt

DURING the course of the present investigation of alloy phases involving transition metals, phases were found in the systems Os-Ta, Os-W, and Ir-Ta. The (Os, W) phase was also recently reported by Raub.1 Pertinent information is given in Table 1. The approximate composition range of sta- bility was determined metallographically on arc-melted buttons that were annealed 72 hr at 1200°C and water quenched. X-ray powder patterns were obtained with a 114.6 mm diam powder camera using filtered copper radiation. The composition for (Os, W) given by Raub (66 atomic pct W) is in agreement with the composition range reported here. However, the lattice constants reported by Raub are: a0= 9.913±0.007, c/a= 0.515. The reason for the discrepancy between the lattice constants reported by Raub and those given here is not known. Acknowledgments The authors wish to thank M. H. Mueller and H. W. Knott for assistance with the X-ray diffraction work, and R. A. Morris for the preparation of the alloys. This paper is based upon work performed at the Argonne National Laboratory under the auspices of the Atomic Energy Commission.

Jan 1, 1958

By T. M. Allen, W. H. White

THE Greenwood-Grand Forks area of southern central British Columbia, known as the Boundary District, has a long history of mining exploration and production. At the turn of the century this was the premier copper mining camp in the British Empire, its total production amounting to some 20 mil- lion tons. Most of this ore came from the great Granby mines at Phoenix, but the Motherlode mine at Deadwood camp, 6 miles to the west, and several mines in Summit camp, 5 miles north of Phoenix, made important contributions. The large deposits were exhausted in 1918 and the district since has seen only desultory exploration and salvage operations. The orebodies are mineralized skarn zones in limestone members of a thick series of Upper Paleozoic sedimentary and volcanic strata. Chalcopyrite is the primary ore-mineral. Copper carbonates and silicates occur sparingly in outcrops, but the oxidized zone generally is very shallow. Much of the surface is mantled by glacial drift which in most places ranges in thickness from 2 to 15 ft. In some of the hanging valleys, however, the glacial drift may be as much as 100 ft thick and may assume drumlin-like forms.

Jan 1, 1954

Membership at the end of the year 1951 was 19,711 including 2228 Student Associates. The data in the third column include these Student Associates. 1. This includes all the cash dues income received from new and old members of all grades. 2. All cash initiation fees received. 3. Net income received from advertising in the three journals. The figure was $72,273, for MINING ENGINEERING; $39,844 for the JOURNAL OF METALS; and $31,564 for the JOURNAL OF PETROLEUM TECHNOLOGY. Income in 1950 was $54,572, $30,390, and $18,443 from these sources, respectively. 4. Receipts from individual sales, nonmember subscriptions, and multiple subscriptions of members. 5. Includes Transactions volumes and the Petroleum Statistics volume. 6. Sales of all other printed matter except special volumes sponsored by certain Funds. Includes a considerable sale of preprints and reprints of technical papers. 7. Does not include dividends and interest from certain Funds whose income reverts to those Funds. 8. Miscellaneous income not included in any of the above categories. 9. The total income compares with $493,197 -in 1950, an increase of $29000.

Jan 1, 1952

By E. J. Hammer

Crushing and grinding of gypsum demands con- trolled processing to a fineness suitable for further treatment of the mineral into end products, and into various sizes of material which are themselves saleable products. The majority of gypsum tonnage ultimately ends up in stucco for wallboard. Therefore, mineral reduction is normally designed toward this end, but it is done in a manner that permits drawing off intermediate products to meet various customer requirements. This forces companies into compromises at times in equipment installations. Normally, 5 to 6 different sizes intermediate to the end product are marketed and these are generally the fineness of material to be used as stucco for wallboard. These sizes are produced by controlled crushing, grinding and sizing. How Ore Characteristics Guide Processing First, gypsum as a mineral (CaS0;2H,O) is number two on the Mohs scale two of hardness; only talc is softer, Despite being soft, gypsum is tough, a factor which is of critical importance when developing equipment specifications. In addition, of the increasing volumes of rock handled, the associated and included impurities such as anhydrite, silica or lime- stones are found to be relatively abrasive.

Jan 1, 1970

By L. O. Howard

Much work has been done recently on the lead-antimony system1 in connection with lead-rich alloys of commercial importance containing less than 20 per cent. antimony. Dean, Zickrick and Nix have called attention to the perpetuation in the literature of several erroneous data, such as a eutectic temperature of 228° C. at 12.5 per cent. antimony, instead of 247° at 13 per cent. The series is given as a classic example of a straight eutectiferous series in such late books as those of Heyn and Grossmann, 2 Jeffries and Archer,3 Guillet and Portevin,4 Pulsifer,5 Rosenhain,6 and Liddell,' as well as the somewhat earlier works of Hof-man (1918), Wang (1909), and Williams (1920). The work of Dean has definitely shown a solid solution of antimony in lead at about 2.5 per cent. antimony. While lecturing to a class in general metallurgy at the University of Idaho, the writer had the students prepare a series of lead-antimony alloys for the purpose of illustrating methods of thermal analysis. Proper proportions of powdered antimony (sold as C.P.) and test lead were mixed and melted in graphite crucibles under a reducing cover. Cooling

By Lawrence W. Teufel

A method to determine in situ stress directions and magnitudes from anelastic strain recovery measurements of oriented core has been used to determine the principal horizontal in situ stresses in the Rollins Sandstone in a deep well near Rifle, Colorado. The principal horizontal stress directions were determined directly from the principal horizontal strain recovery directions. The principal horizontal stress magnitudes were calculated from the principal strain recovery magnitudes, overburden stress, and Poison's ratio of the rock using a viscoelastic model. The accuracy of the in situ stress directions and magnitudes determined from anelastic strain recovery measurements was substantiated by a direct comparison with open-hole hydraulic fracture stress measurements. The anelastic strain recovery method predicted the magnitudes of the maximum and minimum horizontal principal stresses to be 54.5 MPa and 51.9 MPa, respectively; with an azimuth of N63ºW ± 8º for the maximum horizontal stress. The hydraulic fracture stress measurements yielded maximum and minimum horizontal principal stress magnitudes of 49.6 MPa and 46.8 MPa, respectively. The azimuth of the maximum horizontal stress ranged from N50ºW to N70°W.

Jan 1, 1984