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By H. W. Smith, A. K. Bjerring

A nonlinear dynamic model for a flotation cell is developed, using a number of simplifying assumptions, the most important of which is that of essentially complete liberation in the feed material. Using this model, a complete dynamic model for a flotation circuit is developed and calibrated against steady- state process data. The dynamic response of the circuit to disturbances in input feed rate and composition is simulated, as is the response of a linearized and simplified model on which control design might be more easily based. Preliminary results indicate the practicability of the modeling technique. However, difficulties in matching steady-state operating conditions in one process stream, and the apparent importance of recycle streams as indicators of process operation, indicate that inclusion of at least one species of middling particle in the model should be considered.

Jan 1, 1969

By C. V. Millikan

TEMPERATURE measurement in wells is an old practice and geothermal gradients have been of interest to geologists for many years.1,2 Their application to the operation of oil wells is a more recent practice. It has long been recognized that temperature anomalies occur in drilling and producing wells but thermometers that could obtain a satisfactory record of the anomalies were not available.3 The normal geothermal gradient is con-sidered as being about one degree Fahren-heit for each 60 ft. of depth.4 This "nor-mal" gradient varies in different areas, but whatever it may be in an area there is little variation from the surface to as deep as the drill penetrates. The normal gradient is appreciably changed by gas expanding from the reservoir into the borehole or by the movement of fluid through a borehole while drilling, producing, or circulating. It is the resulting anomalies and abnormal gradients from which conditions in wells can be interpreted. Some of the applications of such interpretations are locating the position of oil or gas sands, permeable strata in a reservoir zone, gas-oil contact, source of water, casing leaks, and the top of cement behind casing.

Jan 1, 1940

By V. N. Mackiw, D. E. Weir, D. J. I. Evans

The world's largest reserves of nickel are found in lateritic ores. Commercial exploitation has been carried out for almost one hundred years; however, none of the plants currently in operation produce pure nickel but rather ferronickel, matte, impure nickel oxide or mixed sulphide precipitate. Over the past decade Sherritt has studied various processes, including the modified reduction roast-ammonia-ammonium carbonate leach process, for the production of pure nickel powder and briquettes from laterites. Nickel can be reduced to the pure elemental form at elevated temperatures and pressures from impure basic nickel carbonate slurries. Several methods were studied in the development of the process for working up the pregnant leach liquor and basic nickel carbonate to produce feed for the aqueous hydrogen reduction step in which pure nickel powder is produced. This paper is concerned only with the laboratory studies using the basic nickel carbonate slurry reduction procedures.

Jan 1, 1973

By Heinrich A. Kortmann

Specifications on the chemical, physical and metallurgical properties of the blast furnace burden are steadily becoming more stringent, especially in those countries where higher raw material and energy costs can be overcome only by improved technology. This paper describes the test methods for the relative predetermination of the criteria where the effects of temperature, gas composition and physical load in the blast furnace are duly considered. Data are presented to show the correlations between burden material tests and blast furnace results. Possible test methods for the direct reduction process are also discussed.

Jan 1, 1977

Elected Died 1895 *ABBOTT, AI ATTHUR 1908 1882 *ABBOTT, ARTHUR V 1906 1905 * ABE, MASAYOSHI 1909 1903 * ADAMS, CHARLES C. 1905 1905 * ADAMS, WILLAMS 1909 1903 * ADAMS, W. EDWARDS 1910 1884 *ADDY, MATTHEW 1896 1906 * AFFLECK, WILLIAM A. 1911 1889 * AKERS, WILLIAMS 1906 1905 * ALABASTER, RUPPERT C. 1911 1899 * ALBERGER, LOUIS R. 1911 1894 *ALLEN R B 1896 1905 * ALLEN, R. SCOTT 1906 1874 * AMIOT, H. 1892 1886 *AMSLER, CARL 1894 1898 ** ANFERSON, JOHN w. 1905 1895 *ÅNGSTROM, CARL 1901 1887 * ARCHBALD, JAMES 1910 1900 * ARLETT, GEORGE H 1906 1895 *ARMSTRONG, JOHN F 1898 1882 *ARNOLDS, HUGO 1886 1875 *ASHBURNER, CHARLES A 1889 1872 *ASIIBURNER, WILLIAM 1887 1883 *ATKINS, C M , JR 1885 1905 * AUSTEN, PETER T 1907

Jan 1, 1917

By F. D. Rosi, Walter R. Hibbard, R. I. Herron, H. T. Clark, O&apos

Introduction and Previous Work In the search to find a copper-base alloy with high strength properties, it was considered that the addition of a small amount of an age-hardening element to a binary system with useful strength properties might result in a series of alloys of theeretical and practical importance. The copper-nickel system was selected for its basic properties and chromium was added as the age-hardening element in view of the small percentage involved and its decreasing solubility with decreasing temperature. A study of the Cu-Cr binary alloys was undertaken as a preliminary investigation. However, in view of the response of these alloys to heat treatment, the scope of this phase of the investigation was widened.

Jan 1, 1949

By Edward C. Mack, Ronald G. Stovash

INTRODUCTION Ronald G. Stovash General Superintendent Consolidation Coal Company Shoemaker Mine Moundsville, West Virginia Consolidation Coal Company's Shoemaker Mine is located in West Virginia's Northern panhandle near Wheeling, adjacent to the Ohio River. Steam coal is mined from the Pittsburgh #8 seam which averages 65 in. in thickness. The 10 in. of draw rock directly above the coal is taken on advancement, but remains when longwalled. The top consists of up to 12 in. of lower quality coal, and immediately over that, up to 10 ft of multi layered shales, coal, and bone. The cover ranges from 300 to 800 ft of shales and limestone. Two longwalls operate in the mine. The first longwall started in April 1975 and is retreating its eighth panel. This wall was the first to use shield supports in the United States. The second longwall started in September 1979 and is currently retreating its first 7,000 ft panel.

Jan 1, 1981

By Charles D. Russell, L. H. Jenks, W. J. Leas

A detailed description is given of an experimental method for determining relative permeability of porous media to gas. Results are presented for natural and synthetic cores. The experimental data for two and three phase systems are compared. The reproduci-bility of the equilibrium gas saturation ii demonstrated and the effects due to a variation in rate of gas flow are discussed. An attempt is made to correlate total permeability and rock textural factors with relative permeability to gas. Capillary pressure curves obtained simultaneously with the relative permeability curves are shown to be equivalent to those obtained in conventional displacement cells. INTRODUCTION The advances in petroleum reservoir technology during the past decade have made increasingly apparent the desirability of a simple, rapid, reliable metliod for obtaining relative permeability data on small cores. Such data are needed in order to study fluid mechanics in porous media and for the more refined reservoir behavior prediction calculations now under development. The early experimental work in this field was done by Wyckoff and Botset1 who measured relative permeabilities for gas-liquid mixtures flowing through

Jan 1, 1950

By Harry E. LeGrand

Most mine operations are hampered to varying degrees by excessive inflow of water into mines or scarcity of water for processing the materials. These internal problems are compounded in many cases by such external hydrological problems as lowering of ground-water levels in areas outside the mine properties, subsidence of ground surface, adverse geochemical changes, and pollution. The development of a mine below the water table disturbs the natural ground-water system, causing a convergence in the flow of water from a surrounding area. The mine becomes the apex of a depressed cone in the water table. The fact that mines are commonly located in complex and somewhat anomalous geologic environments prevents an idealized treatment of the mine as a well that would be similar to a water well in a homogeneous aquifer having isotropic conditions. Yet, adherence to some principles of ground-water behavior is helpful when combined with an understanding of the local geology. A program calling for an appraisal of all pertinent hydrological conditions prior to mining and during various stages of development should supply adequate information for mine officials to anticipate difficulties and to allow for corrective measures. Before and during mining operations there should be a mine hydrology framework and plan, in which there is continual upgrading of such considerations as anticipated actions, consequences of actions, remedial plans, and contingencies.

Jan 1, 1973

By A. Berthet

In the past two decades, of the successive steps leading from iron ore to finished steel, the production of liquid steel and its preparation for the casting operation has probably undergone the most drastic evolution. The reason for this is the development of oxygen converters (top blown and later on bottom blown) and UHP arc furnaces which are replacing the conventional processes such as the open hearth and basic Bessemer processes. These new processes have been great advances, but it would certainly be quite hazardous to assert that the situation will remain the same for the coming decades. In fact, with the advent of continuous steelmaking a new generation of processes has now arrived. The research and development programme at IRSID on continuous an a steelmaking began ten years ago has progressed systematically in the following stages : First a comparison was made on a small pilot scale of various techniques : for example, refining in a runner by top or bottom blowing, pulverizing the metal stream by oxygen, using the mixing effect of a vortex, etc. but for various reasons these processes proved unsatisfactory and were abandoned in favour of a method using the so -called "emulsion refining".

Jan 1, 1972

By Donald W. Gentry, John F. Abel

This paper presents some of the results of a rock mechanics instrumentation program designed for, and implemented at, longwall panel 4N at the York Canyon Mine near Raton, New Mexico. The objective of this particular instrumentation program was to determine the response of the rock mass to longwall mining of a thick coal seam utilizing shield-type supports. Measurements were made in the rock along the ground surface, above the coal seam, in the coal seam, and immediately below the coal seam. Longwall test panel 4N had a total developed length of 762 m (2500 ft) and a face width of 168 m (550 ft), Fig. 1. The seam mining height in the panel area was approximately 3 m (10 ft). The average depth of overburden above the panel is 107 m (350 ft) although it ranges from 73-134 m (240-440 ft). Roof support at the face was provided by 116 Hemscheidt 320 HSL shields. These shield-type supports weigh 11.4 metric tons each.

Jan 3, 1978

By Marcie A. Greenberg, John C. Patton, R. Tim Thompson

The Fence Lake Project is located in the Salt Lake coal field, an extension of the San Juan Basin. Geologic formations exposed in the Project area range in age from late Cretaceous to Quaternary. Coal is encountered in the Moreno Hill Formation (upper Cretaceous). Salt River Project (SRP) followed the basic textbook approach for the exploration, regional appraisal, detailed reconnaissance, detailed surface detailed and three dimensional sampling (physical exploration). SRP is exploring this property as a potential fuel source for the Coronado Generating Station. Therefore, for the physical exploration stage, the quality sampling program was designed from a utility company viewpoint to determine possible impacts to the Station. Exploration drilling was completed in spring, 1982; September, 1982, and summer, 1984. Engineering, environmental, and land acquisition studies - in the Summer, 1984 Program to more closely evaluate the potential Fence Lake Project coal supply option for the Coronado Generating Station. Studies, including drilling, are ongoing at this time.

Jan 1, 1985

By A. E. Outerbridge

It has been generally accepted as a fact that cast-iron, under the influence of repeated shocks, becomes brittle, and will finally break under a blow which otherwise it would have withstood. It will probably surprise metallurgists, therefore, to learn that experiment disproves the supposed fact, and establishes exactly its opposite. The result of about a thousand tests of bars of cast-iron of all grades, from the softest foundry-mixtures to the strongest car-wheel metal, enables me to assert with confidence that, within limits, cast-iron is materially strengthened by subjection to repeated shocks or blows. It is very well known that the usual process of annealing castings—such, for example, as car-wheels—increases their strength by relieving cooling-strains. But it is not well known (if known at all prior to this announcement) that the molecules of cast-iron are capable of movement—for they do not touch each other*—without the necessity of heating the casting, and that they can thus rearrange themselves in comfortable relation to their neighbors, and relieve the overcrowding near the surface of the casting. In more technical words, a molecular annealing may be accomplished at ordinary temperatures which will release the strains in the castings, precisely as does annealing by slow cooling in heated pits or ovens. A statement so surprising should not be made without sufficient data to establish its correctness beyond cavil, since it is contrary to former

Jan 1, 1897

By G. K. Burgess

G. K. BURGESS* and R. W. WOODWARD,? Washington, D. C.-From a metallurgical standpoint, there are several ways in which a reduction of the tin consumed in commercial non-ferrous and white-metal alloys can be effected. First, a reduction of the tin, content of the alloy; second, substitution of part or all of the tin content by some other metal; third, a substitution of a different type of alloy, which in some cases also involves a change in mechanical design. The Bureau of Standards has been studying these methods of conservation for tin alloys, particularly in regard to babbitts and bearing metals, bronzes, and solders. Much of the information secured by the Bureau was obtained from answers to questionnaires sent to manufacturers and users of these materials, so that, in general, any of the following suggestions or recommendations can be considered as being practical and as having already been thoroughly tried. Bearing Metals There is no question that the tin content of nearly all bearing metals can be reduced to some extent, and in some cases actually eliminated

Jan 12, 1918

By M. C. Van Camp, J. D. Miller

Preliminary results are reported regarding the design and development of a pilot scale air sparged hydrocyclone for cleaning fine coal 590 pm (- 28 mesh) containing 24% ash and 1.6% sulfur. The principle of separation is the flotation of hydrophobic coal particles in the centnjugal field generated by the fluid flow in the air sparged hydrocyclone as discussed in another publication. This 152-mm (6-in.) hydrocyclone has a nominal capacity of 0.9 t/h (1 tph) and experimental results suggest that separations vastly superior to a water-only cyclone are possible. In addition the separation efficiency is as good, if not better, than that achieved with conventional flotation cells. For example, typical results indicate that 75% clean coal can be recovered at 15% ash leaving a tailing product of almost 50% ash. These experimental results coupled with the high capacity of the air sparged hydrocyclone (imagine a retention time for flotation of only two seconds compared to two minutes for conventional flotation) may represent a significant breakthrough, not only in coal preparation technology, but in the flotation of fine particles in general.

Jan 1, 1983

By James R. Gage

THE lead deposits of Missouri may be divided into three districts, the southwest, middle, and southeast. As too much time would be required to devote a detailed account to each district, only a description of the modes of occurrence of the lead ores in the southeast district will be given. The lead mining region proper of Southeast Missouri is embraced in an area of about twenty-five miles in width by about one hundred in length. The country embraced in this district is very broken, and traversed by ridges from one hundred to three hundred feet in height, with an occasional knob rising higher. Porphyry forms almost the entire substructure of the region, with here and there outcrops of granite. The crystalline rocks were eroded into ridges and valleys before the deposition of the limestone took place. These porphyries are older than the Silurian limestones, and "belong (according to Pumpelly) to the Archaean (Azoic) formation, of which they may be the youngest member in Missouri. They are the near equivalents, in point of age, to the great iron-bearing rocks of Lake Superior, New Jersey, and Sweden."12/02/2007

Jan 1, 1875

By Robert C. Emmett, Donald A. Dahlstrom

FOR many years gravitational classification has been employed as a basic tool in beneficiation of minerals and coal. While improvements have been made to increase efficiency and fields of application, the basic flow pattern has remained relatively unchanged in most gravitational classifiers. Feed slurry is introduced into a settling pool wherein the coarser solids settle against either an upward or horizontal fluid current, or a combination of both, and are withdrawn in a concentrated underflow stream. The finer solids below the classification point possess too low a settling velocity and thus are primarily swept out through a weir overflow by the bulk of the fluid. Because of its simplicity, efficiency, and low power and maintenance costs, gravitational classification finds a wide acceptance for separations in the range of 20 to 325 mesh.

Jan 10, 1953

By Howard L. Hartman, Burke O. Trafton

There is a fruitful area of computer competence which has gone virtually unnoticed by the mining industry. This is in the solution of its numerous fluid-flow distribution problems, involving the circulation of air, water and other fluids in conduits through mines. Typical of these is the mine ventilation system, which circulates air through mine openings to the working faces. The networks of interconnected airways in large mines-often resembling a tortuous maze or labyrinth defying representation by schematic, let alone solution-must somehow be resolved and analyzed, if effective and safe control of the ventilation is to be maintained. These are admirably suited to programming for solution by high-speed electronic computer. Not only can direction of flow be determined but quantity and head loss as well. EARLIER EFFORTS AT NETWORK SOLUTION The only prior attempt to solve mine ventilation networks by digital computer methods was made by a Japanese investigator1 in 1958 whose work went unpublished. Unfortunately, he employed a method of network analysis little used in the United States and one which could accommodate a maximum of only 30 airways. While his analysis seems unnecessarily cumbersome and involved, it did suggest that a digital computer approach was feasible.

Jan 9, 1963

By Martin C. Kuhn, Lawrence G. Stevens, J. Mark Richardson

The majority of the world's known and anticipated reserves of nickel ores are lateritic deposits At present, there are several different process alternatives for recovering nickel and other desired metal values from laterite ores An overview is given of the selective reduction roast/ammoniacal leach process, one of the processes in commercial operation.

Jan 1, 1981

By Gloyd Wiles

THE eastern section of the Park City dis-trict is drained to an elevation of 6300 ft. by means of the Ontario drain tunnel owned and maintained by Park Utah Consolidated Mines Co. This elevation represents a depth of 920 ft. in Park City Consolidated Mines Company's property. When development below the goo-ft. level was commenced, sinking was at-tempted through an incline winze in the fissure. The intensely fractured quartzite forming the walls of the vein could not be held after water was encountered, so it was decided that further sinking should be done in a vertical winze far enough in the foot-wall to be in the more solid quartzite out-side the fractured zone containing the vein. Progress was good until a depth of 200 ft. below water table was reached, where the flow of water became serious. Sinking pro-gressed 300 ft., to the 1200-ft. level, and there approximately 750 gal. of water per minute was being pumped. The last 20 ft, of sinking cost more than $200 per foot direct charges, whereas the over-all cost for the 300 ft. was $100 per foot. This high last cost was caused by excessive lost time in pumping. Crosscutting to the vein disclosed the fact that the 1050-ft. level had been devel-oped only after drainage had been effected from the 1200-ft. level, but that the 1200-ft. level could not be opened because of the

Jan 1, 1940