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By Horace Pops, J. F. Libsch

THE discovery of SAP alloys (sintered aluminum powders) by lrmannl has stimulated investigations in other alloy systems.23 Not only do such alloys have good room-temperature properties, but they maintain high strength after prolonged service at elevated temperatures. In addition, they show high structural stability, including unusually high recrystallization temperatures. These characteristics are secured by dispersion hardening. For this investigation, Zn-ZnO alloys were selected. Practically, the fact that commercially pure zinc recrystallizes near room temperature prohibits strengthening and hardening by cold deformation and therefore limits the application of zinc where mechanical strength is important. Similarly, the poor

Jan 1, 1961

By R. W. Raymond

IX the death of William H. Scranton, which occurred at Oxford, N. J., June 19, 1889, the Institute has been called once more to mourn the loss of a name from the fast diminishing list of those who constituted its membership in the first year of its existence. But it loses more than a name—a friendly presence and an intellectual force have departed ; a fruitful life has been cut short. Mr. Scranton was born in Belvidere, N. J., on the 13th of January, 1840. He was the eldest son of Colonel George W. Scranton, the

Jan 1, 1890

A little more than a year and a half ago construction started on Canada's largest initial milling plant. Today the zinc concentrating plant 7 miles north of Barraute sits on ground that once was forest and clay flats. The plant is part of Barvue Mines Ltd. zinc-silver operation. Employees of the plant live in the model community of Barvue, built like the plant in record time. About 5000 tons of ore are handled by the plant daily, with an output of 200 tons of zinc concentrate. Management hopes to raise capacity of the $8 million plant to 6000 tons.

Jan 8, 1953

By G. P. White, J. M. Jones

Introduction Computer simulation is a technique that has been around for many years. Its applications include designing steel mills, planning space shots, or even developing ways to beat the casinos in Las Vegas. However, the use of computer simulation in surface coal mining is fairly recent. To promote its use, several government agencies, including the US Bureau of Mines, Forest Service, and Department of Energy, contracted with universities and private companies to develop computer simulation programs for surface coal mining. Some of these developers include McDonnell-Douglas Electronics Co., Pennsylvania State University, Montana State University, Fluor Mining and

Jan 1, 1985

By R. E. Hucko

Introduction The principal thrust of the US Department of Energy (DOE) coal preparation R&D program is to develop technology to reduce ash and sulfur content of US coals to levels where the resultant product can be formulated into a high quality solid or slurry fuel that could replace oil or natural gas in both new and retrofit applications. The coal preparation program is implemented by the Pittsburgh Energy Technology Center (PETC) and is conducted both in house and by a cross section of industrial organizations, universities, and national laboratories. Research is subdivided into three areas - coal characterization, beneficiation, and ancillary unit operations.

Jan 1, 1985

By W. C. J. van Rensburg

Exploration of unconventional mineral resources is stimulated by uncertainties about the cost and security of conventional resource sup- plies. Costs of the latter are likely to increase as a result of inflation, higher energy costs declining productivity, a lack of sufficient investment in politically volatile areas, or through cartel-like action. Exploration of unconventional resources is likely to be delayed by these same factors, insufficient research and development facilities, and a decline in capital formation. World economic growth is likely to be slow, so there will be more emphasis on material conservation. Therefore, the incentive to explore for unconventional resources may be reduced.

Jan 1, 1983

By Alexander L. Holley

A CHARACTERISTIC, and, to Americans, an amusing discussion of the three-high rail-mill, arose out of the reading of Mr. Lauth's paper on three-high plate-mills, at the Glasgow meeting of the Iron and Steel Institute. From the report of the meeting in the English papers, it appears that Mr. Menelaus, the celebrated rail-maker of Dowlais, could not wait for the discussion of Lauth's plate-mill, but launched at once into the British objections to the three-high rail-mill, which is quite another matter. The American mill, which is very different in principle and ar288

By D. J. Cox, J. P. Conway, A. E. Gooch

A two-year test conducted by the USBM's Spokane Mining Research Center (SMRC) has proven the feasibility of the yielding rockbolt, a concept which may prove very useful to the mining industry by providing ground support under a variety of conditions. The yielding rockbolt was originally developed in South Africa3 to overcome the limitations of conventional bolting in rock subjected to high-stress or rock burst conditions. The yielding effect is obtained by fitting the bolt prior to thread rolling with a smooth-bore die of internal diameter slightly larger than the shank diameter but smaller than the rolled thread diameter.

Jan 4, 1977

By W. Fletcher, R. C. Schenk

This paper outlines a well proven and highly successful approach for eliminating many of the problem and frustrations often experienced in plant startup. The approach was developed over a period of 25 years during which some 90 plants were commissioned. This paper discusses startup from the contractor’s perspective and highlights the requirement for detailed startup planning, careful coordination during the project final construction phase, and thorough checkout of equipment prior to introduction of feed. Performance of these services has demonstrated a valuable opportunity exists for the contractor to assist in the training of the plant operating personnel.

Jan 1, 1983

By G. C. Hewett

This portion of the State, being the northern half of its Pacific slope, is drained by four rivers, the Gunnison, Grand, White and Yampa or Bear, which, with the Green, flowing south from Wyoming, unite to form the Colorado. These streams, fed by the snows of the Rocky Mountains, fall from an altitude of 10,000 to 12,000 feet, at their sources, to 4000 feet, at the confluence of the Grand and Green in Utah, near the State line. This area, about 150 miles square, was the scene of great development in the periods subsequent to the Carboniferous; but earlier

Jan 1, 1889

By J. F. Cuderman

A technique using propellants has been developed for producing multiple fractures about a wellbore. The use of propellants having a range of burn rates permits precise control of combustion gas release and thereby of borehole pressurization. The pressure rise- time is the key variable governing fracture behavior. The peak pressure attained is of secondary importance and appears to be a function of in situ stress and loading rate. The fracture geometry is governed by the in situ stresses and pressure risetimes. The major fractures occur along the principal planes of stress and along apparent planes of maximum shear stress.

Jan 1, 1984

By John H. Bassarear

By 1968, Cyprus Pima was milling 34.5 kt /d (38,000 tpd) of copper ore using a conventional flowsheet consisting of three stages of crushing, rod milk and ball, mills. A 13.6 kt /d (15,000 tpd) expansion was put onstream late in 1971 using primary crushing, semiautogenous milk, and ball mills. Identical ore is treated in both concentrators. This paper shows the weight and life of each liner for each crusher and each mill over a four year period from 1974-1977. Media consumption is shown for the same period and a comparison is made between the two reduction methods.

Jan 1, 1983

By R. J. Wasilewski

OBSERVATIONS have been made that the substitution of antimony for bismuth in Bi2Te3 leads to anomalies in some of the electrical and magnetic properties of the Bi2Te3-5S2TeS alloy system at the composition ratios 2 Bi2Te3 : 1 Sb2Tes and 1 Bi2Te3 : 2 Sb2Te3. Airapetiants and Efimova1 have reported the peaking of the nondegenerate hole mobilities, at these compositions for sintered materials and ascribe the peaking to the formation of ordered alloys. From a study of these materials produced by the Bridgeman

Jan 1, 1962

THE bellows are important and necessary agents in most melting processes. In addition to seeing that these have sufficient soft cloth, extend far and wide, and are of good design, including good valves and good long tubes, and that they cannot break and lose the air received, it is very important to give attention to their installation so that they may easily effect their purpose. Therefore I now wish to proceed by noting some common devices for moving them, both with water and with man power, so that you may make use of them as the need arises.

Jan 1, 1942

By L. A. Adorjan

The tensile strength of agglomerate models due to capillary forces has been determined by computation of the exact surface profiles. Graphs showing tensile strength as a function of moisture content and contact angle me given for spheres in cubic arrangement. Another model of cones attached to cube faces, in cubic packing, provides a better representation of angular particle agglomerates. An algebraic formula approximating tensile strength as dependent on surface tension, particle size, moisture content, contact and cone angles was developed. The phenomenon of "capillary evaporation" due to high negative capillary pressures is explained and its influence on tensile strength of agglomerates is evaluated.

Jan 1, 1977

By J. Nolan, B. Ande’n, E. Lindgren

Field testing was conducted at the Strassa Iron Ore Processing Plant to evaluate high-gradient magnetic recovery of iron from the plant's tailings. The installation is the first commercial application of the Sala Continuous High-Gradient Magnetic Separator (HGMS) Model 480 Carousel. The objectives of the five-month testing program included optimization of the operating parameters using SSDEVOP techniques to maximize iron recovery, along with establishing a long-term operating history for the SALA 480 HGMS Carousel. The effectiveness of the optimization procedure, the net benefit in term of iron recovery, and equipment performance are discussed in the paper.

Jan 1, 1983

By Donald Towse

Geothermal energy can substitute for and compete with other fuels, but until now it has been used only in special situations where it costs much less than alternate fuels. Geothermal heat is expected to be developed where it can: (1) compete with alternate fuels, (2) replace scarce fuels, (3) be more environmentally acceptable, or (4) is especially adapted to local needs. Economic problems in development include the often high capital costs of wells and gathering systems and the long lead-times required for electric generating plants. The large investment and long payout times for large industrial uses adversely affect the economics.

Jan 1, 1977

By G. J. Cardwell

The rock and mineral analyst will be called upon to determine both the major and minor constituents in materials as varied as rocks, soil, sediments, concentrates and various liquids. These analyses will have interactions requiring extraction, matrix modification, and background correction. Analytical methodologies include classical gravimetric methods, such as fire assay, emission spectroscopy, X-ray fluorescence, atomic absorption, inductively coupled plasma, and neutron activation. With these capabilities the analyst can be called on to determine three-fourths of the elements in the periodic table. How can the earth scientist pick the method best suited for his particular sample?

Jan 1, 1984

By W. E. Crandall

The No. 4 shaft and hoist at Hecla Mining Co.'s Star mine have been in operation for seven months, and as development of new mining areas proceeds in the lower portions of the mine, the system is being depended upon more extensively for personnel and material handling requirements. The hoist plant is handling full payloads, at rated speeds, over a vertical distance of 5650 ft. One of the special features of this hoist is its precision braking control under all hoisting conditions. Tests indicate that emergency stops can be made with safe deceleration rates and minimum rope and conveyance oscillation.

Jan 1, 1971

By E. P. Klier, V. Weiss

IN studies of the X-ray diffraction line geometry of iron with chromium radiation using techniques aimed at minimizing the background intensity, Kp and Ka emission satellites* were resolved with three techniques. These satellite lines are present with sufficient intensity to lead potentially to erroneous structure analysis, if not properly interpreted. The techniques used were: 1) film technique with un-filtered radiation and polycrystalline specimen, 2) film technique with unfiltered radiation and single crystal, and 3) counter technique with unfiltered radiation and single crystal. An example of results obtained with technique 1 is given in Fig. 1.

Jan 1, 1958