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By E. N. Harshman

The Wind River Formation of Eocene age is the host rock for large high-grade uranium deposits in the Shirley Basin. The major deposits are in a northwest-trending belt of sandstones that were deposited in stream channels and that were lithologically favorable for uranium accumulation. Paleotopography influenced the character and position of the belt. The major deposits within the belt are at, or near, the margins of large tongues of altered sandstone formed in the most transmissive parts of thick sandstone beds. At least two tongues of altered sandstone are present in the belt, one of which is 5 miles long, 3 miles wide, and 70 feet thick; the other tongue is somewhat smaller. Ore bodies consist of a few hundred tons to several hundred thousand tons of material containing from 0.10 to about 2.00 per cent U3O8. The ore mineral is uraninite associated with pyrite, marcasite, hematite, and calcite. Deposition is believed to have taken place when neutral to slightly alkaline, oxidizing, uranium-bearing ground water, on entering the basin, encountered a reducing environment. The reductant may have been H2S of biogenic origin. Geology played an important role in discovery, exploration, and development of ore in the Shirley Basin.

Jan 1, 1968

By C. H. Herty

AN earlier paper on absorption of sulfur by the slag in the basic open-hearth furnace included a brief discussion of the absorption of sulfur during the melting period. The data available at that time showed that the amount of sulfur absorbed by the melting scrap was proportional to the sulfur content of the furnace gases, and the following statement was made: "The conclusion may be drawn from these results that if a gas entirely free from sulfur were used during the melting, any iron in direct contact with the gases would be completely, or nearly completely, desulfurized before it reached the bath proper." The experimental work discussed herein deals with absorption of sulfur by the melting scrap when fuels with both high and low-sulfur content were used. Before taking up the experimental work let us consider the process as a whole as to the "flow" of sulfur. The input of sulfur occurs in: 1, the hot metal charged; 2, the scrap; 3, the stone or lime charged; 4, the ores charged; and 5, the gas. Sulfur goes out of the furnace in the steel, the slag and the gas. The distribution of sulfur in the furnace depends on the sulfur concentration in each of these materials and on the equilibrium conditions between them.

Jan 1, 1926

By J. R. Dawson, J. A. Glunt

Vesta No. 4 and 5 mines supply most of the high volatile coal required for Jones & Laughlin's by-product coke plants. Until 1944 all coal produced in these mines was loaded by hand. Pressure to mechanize at Vesta was brought on by the manpower shortage in World War II, and in 1943 a decision was made to change to mechanical loading. It was the opinion of those concerned that by use of selective mining the coal would be clean enough to be processed by the existing preparation plants. At that time coal cleaning at Jones & Laughlin consisted of hand picking the larger sizes at the mine tipples and wet washing at plants located at the Pittsburgh and Aliquippa Works. A typical section of the Pittsburgh seam as it occurs at Vesta is shown in Fig. 1. The 14 to 16 in. of drawslate immediately over the coal is too soft to be used for roof and must be taken down, leaving the rooster coal just above for roof. In selective mining an attempt is made to mine the coal under the drawslate first and then load out the drawslate separately as refuse. In full seam mining slate and coal are shot down at the same time and loaded out.

Dec 1, 1956

By John A. Meech, J. G. Paterson

Activated carbon is a strong adsorbent for amyl xanthate, capable of removing from solution up to a quarter of its own weight in xanthate. In selective flotation system where depression is unstable, separation efficiency increases with activated carbon additions. The improvements observed are brought about by two mechanisms. First, by removing stripped and residual collector ions from solution, competition between depressant and xanthate is reduced and depression is stabilized. In addition, the texture of the froth phase at high pine oil concentrations is modified by activated carbon such that better drainage between the air bubbles takes place, alleviating the mechanical entrapment of depressed mineral particles. In treating a bulk copper/lead concentrate produced from GECO ore, selectively between galena and chalcopyrite is increased when activated carbon is used. Although the rate of flotation of galena is marginally lowered by activated carbon, a small extension in the duration of flotation allows the lead recovery to increase by 19% at the same recovery of copper. An addition rate of 0.75 kg/ton (1.5 lb/st) of bulk concentrate is suggested as optimum from this testwork. However, the actual level used in the mill is dependent upon the residual concentrations of collector and frother in the bulk concentrate pulp.

Jan 1, 1979

By W. R. Davison, C. A. Brown, J. P. Carstens

INTRODUCTION The phenomenon of heat-weakening of rock with 10.6 micron radiation from a continuous-wave C02 gas laser has been investigated in detail at the Massachusetts Institute of Technology for over 5 years. The programs at MIT have explored the basic nature of the heat-weakening phenomena and rock fracture caused by heating (e.g., Refs. 1 and 2), and have resulted in quantitative estimates of the relationship between the amount and parer level of heating and the resulting decrease in the modulus of rupture of a rock beam in a three-point bend test (Ref. 3). Results of the tests reported in Ref. 3 indicate a greater than 90% reduction in the modulus of rupture for granite beams heat-weakened by a laser. These results prompted the U. S. Department of Transportation to seek an assessment of the expected feasibility of employing the heat- weakening concept in a full-scale tunnel boring operation. Present- day continuous rock-tunneling machines have demonstrated tunneling time and cost savings over drill-and-blast methods, when used in rock types that are easily broken by the cutters. However, cutter bits have not yet been developed which can easily penetrate very hard rock

Jan 1, 1971

By C. Elbaum

If a thin layer of liquid gallium is spread on a surface of solid aluminum, the gallium penetrates high-angle grain boundaries at a very rapid rate and separation along these boundaries follows. An experiment was carried out to investigate this phenomenon. A well-annealed specimen of aluminum 99.994 pct pure, consisting of several large grains was used, Fig. 1. The dimensions of the sample were 25 mm wide by 2.5 mm thick and all the grain boundaries extended through the entire thickness of the plate. This sample was prepared by strain-annealing and, as can be seen in Fig. 1, contained one long, straight boundary. An examination of the crystal orientations showed this boundary to be a coherent twin boundary. The angular misorientations between the grains forming the other boundaries were all in excess of 20 deg. A thin layer of liquid gallium was spread on one side of the specimen at about 30°C (the melting point of gallium is 29.7"C). After the application of the liquid the temperature was lowered to about 27°C. The gallium remained liquid at this temperature and it can be seen from the A1-Ga phase diagram1 that the liquid was probably saturated with aluminum.

Jan 1, 1960

By Hassell E. Hunter

The Wyoming Minerals - Conoco Crownpoint Joint Venture represents the first time that big hole drilling has been exclusively used to develop a privately financed mine. Three shafts, one ten feet in diameter and two six feet in diameter, have been successfully drilled to depths of 2243', 2188' and 2188' respectively and lined with hydrostatic designed steel casing. The largest shaft is to be used to as a development shaft to handle muck and water from enlargement and station excavation of the other two shafts. A reverse fluid air assist circulation system with potassium base mud was used during drilling. The mud was cleaned by settling in steel lined tanks with assistance from cyclone type sand separators. Deviation was monitored with wireline gyroscopic surveying instruments at 30 foot intervals. Horizontal departure did not exceed 16 inches off perpendicular. Casing was designed to withstand full hydrostatic pressures with a 1.5 safety factor for the large shaft and 1.25 safety factor for the two smaller shafts. All casing welds were x-rayed prior to lowering the casing into the hole. Cementing the annular space completed the operation. The total time to mobilize, drill and move off the three shafts was 363 days. The drilling operation was completed ahead of schedule and under budget.

Jan 1, 1982

By J. T. Crawford

COAL-CLEANING plants using the launder process generally wash the fine coal (minus 3/8 or minus 5/16-in.) separately in a plant consisting of washing launders or troughs placed one below another and sometimes supplemented by additional washing equipment such as tables and jigs. The coal and its associated impurities enters the feed end of the top launder, with a current of push water. As the material moves along the impurities, being heavier than coal, settle toward the bottom of the launder and are drawn off, with some coal, through "free discharge" boxes to the launder below. These boxes were given their name because their discharge falls freely; that is, it does not discharge into a water seal. Thus the impurities are progressively concentrated in the lower launders until box products are sufficiently free of coal to be discharged to refuse. The overflows of the upper launders go to clean coal while the overflow of the lowest launder, and perhaps that of the one immedi-ately above, is usually recirculated to the plant feed. Thus the bulk of the clean coal is removed rapidly and the impurities are concentrated more slowly. The chief purpose of this paper is to present the cleaning data of such a plant under different operating conditions.

Jan 1, 1940

By H. G. Papacharalambous, S. C. Sun

Experimental results indicate that wet cyclones could be effectively used for the preliminary classification of the tested synthetic abrasive materials, thus supplementing the currently used sedimentation method. An empirical formula is also proposed on the basis of the test data to calculate the particle size of separation. One of the basic operations in the abrasive industry is the classification of the crushed and ground materials into different sized products. The relatively coarse grains, plus 325 mesh, are commonly sized by dry screening with satisfactory results. On the other hand, however, the currently used grading tank, for classifying grains finer than 325 mesh, is intermittent. Consequently, it is difficult to operate efficiently and keep pace with erratic market requirements. Little success was made in an attempt to substitute air settling and continuous hydraulic settling for the grading tank, because size specifications1 for abrasive powders are very stringent and difficult to meet. Finally, a wet cyclone was chosen for experimentation. Even though wet cyclones have not been extensively used in the classification of abrasives; however, their performance as a classifier has been verified by Driessen2,4 on coal, McCarrel5 with manganese, and Herkenhoff6,7 on iron ore. Experimental work on silicon carbide, boron carbide, and fused alumina has shown that the cyclone

Jan 1, 1963

By Brandon H. Grove

In Austria's only producing field, at Zistersdorf, Erdoel Produktions-gesellschaft completed a single new producer, its well Gosting 6 coming in early in October for an average production of about 15 tons daily. For further testing within the proved part of the field this company's Gosting 7 was at the close of the year drilling in Pannonian strata at 760 m., and its Gosting 8 was rigging up. Outside of the proved area of the Zistersdorf field two further tests located on the Steinberg dome failed to find production in the known oil-bearing strata of the Sarmatian, and were deepened as wildcats into the Cretaceous Flysch. The first of these, Neusiedel 1, about one kilometer north of the known producing area, found oil in the Flysch beds at a depth of 1290 m. for an initial production of about 10 tons per day. The second test, Windisch Baumgarten la, is an old well previously considered a failure, which when deepened achieved a production of about 5 tons per day in the Flysch Inoceramus beds at 985 m. Neither of the foregoing wells is producing from a stratigraphically definable horizon, oil accumulation in the Flysch of this area being apparently controlled by tectonic breccias or related crevices.

Jan 1, 1937

By A. B. Boghani, R. H. Trent

A computer program has been developed to simulate evacuation of a mine in various configurations. The simulation input variables include characteristics of the mine, expressed in the form of a network of passages, properties of hoists and hoisting strategies, initial miner positions, ventilation and compressed air velocities, stench warning system and self rescuer capabilities. The simulation can be carried out for cases in which there is no fire, i.e., fire drill simulation, or for cases in which there is a fire at any arbitrary location. The fire is assumed to generate gases which impede movement of miners in the gaseous region. However, the thermal effects of the fire are not considered. The simulation output include the evacuation time for each miner, movement of the hoists, propagation of smoke through the mine passages and smoke exposure of the miners. Several illustrative simulations have been carried out to verify validity of the program and to demonstrate its capabilities. The computer program has been able to predict evacuation time, within 5 percent, for an actual fire drill. It is believed that this program can be used to evaluate evacuation performance of a mine, identify problem areas and demonstrate improvements due to the recommended corrective actions.

Jan 1, 1977

By Charles Mitke

(San Francisco Meeting, September, 1915) INTRODUCTION THE Copper Queen mine is composed of seven divisions which are operated through the following shafts: Division Shaft Depth, Air Current No. Feet Uncle Sam 600 Downcast (shut clown April, 1914, to 1 curtail production) Southwest 600 Downcast 2 Czar 400 Downcast 3 Holbrook 600 Downcast 4 Spray S00 Downcast (shut clown April, 1914, to curtail production) 5 Gardner 1,000 Downcast 6 1 Dallas 1,400 Downcast 1 Lowell 1,600 Upcast 7 Sacramento 1,700 Downcast " I I The workings of the different shafts are connected by motor-haulage drifts on the even numbered levels. The general location of the orebodies and workings is illustrated by the vertical projection of orebodies of the district as shown in Fig. 1. The Uncle Sam, Southwest, and Czar workings have many connections to the surface through raises and extensive cracks that were caused by moving ground. These divisions are cool and are ventilated entirely by natural means. The Holbrook is ventilated partly by natural and partly by artificial ventilation, while the Spray, Gardner, Lowell; and Sacramento are ventilated entirely by mechanical means. In some of the divisions mentioned above a considerable quantity of air exhausts through shafts of adjoining properties.

Jan 9, 1915

By C. McLean, Erickson, S. G. Kolb, S. C. Moore

The Grossschloppen vein-uranium deposit, Bavaria, West Germany, was examined with underground workings during 1980-82 by Esso Erz GmbH, an affiliate of Exxon Minerals Company (EMC). Geologic evaluation entailed dense drilling of a portion of the deposit from workings constructed specifically for the program. Discovered in 1977, the deposit was initially explored by surface diamond drillholes which allowed definition of a 30-60 m wide vein system discontinuously mineralized along a 1000 m strike length and to at least a 450 m depth. The underground program was conceives as a cost-effective procedure to answer quest ions on vein correlation, grade continuity and variability. A 1200 m decline allowed access for detailed sampling of approximately 10% of the known area of mineralization. Fanned drillholes, logged by gamma probe, were spaced to provide intersections of veins at 10 to 20 m intervals. Six cross-cuts also penetrate the pitchblende and uranophane mineralization which occurs in 0.1 to 2.5 m thick quartz veins. Detailed cross-sections and level plans were constructed for resource estimates of the intensively studied portion of the vein system. The program resulted in the discovery of local, high grade areas and an average grade in the evaluated area nearly double that expected from surface drilling.

Jan 1, 1984

By C. M. Marquardt

The minerals industry in general should bow in homage to the uranium milling industry. Those in the uranium milling industry have "spark- plugged" more progress in the application of instrumentation and control in the last 5 years than has been made in 50 years by the industry in general. Part of this real progress in the application of instrumentation and control has been born of necessity because milling processes are more complex. A lot of the impetus for instrumentation and control has come from the fact that the industry is new, the processes are new, and there are no hide-bound conventions to overcome. Part of it comes from the fact that much of processing is more chemical than metallurgical and the thinking of the process chemist has carried over into the plants. One need not elaborate on what instrumentation has done for the process chemical industries. Each new mill that is constructed, if of appreciable size, seems to employ more instrumentation than the previously completed plant. Plant A makes a break-through in the application of instrumentation to a particular part of the process and Plant B accepts this and goes one step farther, while Plant C, anticipating Plant B, makes two or three more steps before Plant B is entirely leveled out.

Jan 9, 1958

By W. H. Emmons

INTRODUCTION THE deposition of metalliferous lode systems takes place at considerable depths and no one may observe the process. We see only the end results of the process and from these we seek to construct a theory that will account for them. Because there is an obvious relation between many lode systems and intrusive igneous masses, it is a natural inference that they have formed by fluids that were expelled from such masses. The metalliferous lode systems have been deposited by ascending thermal fluids that have risen mainly from great irregular bodies of intruding magmas which are called batholiths. Probably 95 per cent of such lode systems have formed in connection with acidic or "granitic" batholiths and probably less than 5 per cent have formed in connection with basic intrusives. The study of lode ores, therefore, should include the study of the intrusion and differentiation of the batholith. It was noted long ago1 that certain tin-bearing deposits are commonly associated with small stocks. That small stocks are cupolas of larger intrusive masses has generally been recognized. Butler,2 in his studies of the ore deposits of Utah, showed that the chief deposits in Utah are in and near the stocks; that is near the "apically truncated

Jan 1, 1933

By A. J. Jacobs, J. W. Spretnak, R. Speiser

The activities of nickel in liquid iron-nickel solutions containing from 10 to 90 at. pct Ni were measured over the temperature range .1510° to 1600°C. A special function was devised whereby activities can be computed by a graphical integration using the results of chemical analyses on the vapor phase alone. The liquid solutions studied exhibit negative deviation from Raoult's law, but they approach ideality as the temperature is raised from 1510° to 1600°C. The maximum heat of solution is less than -8.0 kcal per mole. The entropy of solution is less than —2.5 kcal per mole deg at 1510°C, and changes negligibly as the temperature is raised. The liquid iron-nickel solutions do not follow regular solution behavior. THE activities of the components of a liquid alloy system can be determined in favorable cases from the partial pressure of the vapor in equilibrium with the liquid alloy.' Assuming that the vapor over the alloy behaves as an ideal gas, the activity of component i is given by the expression, Where the superscripts 1, v, and o signify the liquid, the vapor, and the pure component, respectively; the f's are the fugacities, and the P's, the pressures. The quantities Pi and Pi can be determined by the

Jan 1, 1960

By R. A. Vandermeer, P. Gordon

The study of recrystallization in cold-worked metals is complicated by the impossibility of making direct three-dimensional optical measurements. Metallo-graphically, theinternal three-dimensional features of samples must be inferred from their intersections with the two-dimensional plane of polish. The inherent difficulties involved in this procedure have led— particularly during the last few years—to some instances of rather doubtful interpretations of experimental data in terms of nucleation and growth rates in recrystallization. In the present paper an analysis ; is given of the recrystallization characteristics in a polycrystalline alloy containing 0.008 wt pct copper in ZONE-refined aluminum *and an effort is madf to reemphasize the necessity in such studies for attention to the proper statistical relationships between one- two- and three-dimensional features of opaque samples. It is shown that, in common with several recently described cases for other types of transformations,1-5 recrystallization in this alloy can best be rationalized on the basis that all nucleation took place essentially at time zero—i.e., there is no significant time-dependent nucleation during annealing—and that the kinetics are controlled exclusively by the growth-rate parameters. This is true despite the fact that the number of

Jan 1, 1960

I. PRESIDING OFFICERS. At all Business meetings of the Institute the President, or, in his absence, the Vice-President, or, in the absence of both of them, any other member of the Board of Directors to be chosen by the meeting, shall preside. At all other meetings of the Institute the President of the Council or, in his absence, one of the Vice-Presidents, if present, shall preside II. ORDER OF BUSINESS. At each Business meeting of the Institute the order of business shall be as follows 1. Reading of minutes of preceding meeting. 2 Report of the President. 3. Report of the Treasurer. 4. Report of the Secretary. 5. Election of Directors. 6. Election of Members of the Council. 7. Reports of Standing Committees. 8. Reports of Special Committees. 9. Special Orders 10. Miscellaneous business. This order of business may be changed by a vote of a majority of the Members and Associates present in person or by proxy. The usual parliamentary rules shall govern all meetings of the Institute except in cases otherwise provided by the Constitution or the By-Laws. At all sessions of the Institute other than business meetings, the order of proceedings and the time of adjournment, shall rest in the discretion of the presiding officer

Jan 1, 1917

By Keith Leonard Sutherland, Ian William Wark

Mercaptobenzthiazole and its sodium salt are marketed under the trade names Flotagen and Flotagen S respectively, for use as collectors for cerussite and other minerals. The structural formulas for sodium rnercaptobenzthiazole and for sodium ethyl xanthate are: Chemically there is a resemblance between the two compounds, though the free acid (mercaptobenzthiazole itself) is much more stable than xanthic acid. Both are readily oxidized, e.g., by iodine to disulphides, and can be estimated by iodometric titration. Qualitatively they are similar as collectors in flotation, although there are quantitative differences between them that may be important in practice. It is deduced that the influence of the nitrogen atom is subordinated to that of the sulphur atoms, and that the dominant group of these compounds is the mercapto group —SH or —5Na. The general method of investigation has been based on contact tests. Two temperatures, 10" and 35" C., have been chosen, and with a standard concentration of 20 mg. per liter of mercaptobenzthiazole (i.e., of the free acid) the influence of alkali, cyanide and copper sulphate on contact at sulphide mineral surfaces has been studied. This standard concentration corresponds to about 19 mg. per liter potassium ethyl xanthate; it brings out the differences between the minerals better than a higher concentra-

Jan 1, 1939

By Georges Fleming

The new burden preparation plant of ARBED Luxembourg, Belval- Works, which comprises 2 large sinter strands, is equipped with a process computer connected to a comprehensive process control system. The main jobs done by the computer are the control of the raw mix composition, and thus the monitoring of the stacking of the piles at the bed-blending plant, and the optimization of the sintering process. Among the optimization criteria, quality is considered as the most important. The sinter quality, characterized by the mechanical strength and the state of oxidation, is controlled automatically. The control system which we have dev loped is highly reliable; as a result, the standard deviation of Fe++, for the control of bivalent iron, has been narrowed to 0,5 % and the standard deviation of the IS0 + 6, 3 mm index, for the control of the mechanical strength, has been kept within 1 %. Thanks to these results, the combined savings in fuel consumption at the sinter plant and at the blast furnaces have covered the total costs of the optimization project in 2 years. By applying automatic control, the optimum driving range of the sinter plant has been defined and these new guidelines are used for monitoring the sinter production.

Jan 1, 1977