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By C. Y. Wen, H. O. HOPMAN

l. INTRODUCTION. IN casting a thermal balance of the heat generated and absorbed in a blast-furnace treating lead-, copper- and similar non-ferrous ores, assumptions have always to be made for the values of the heat of formation of slag. ? Considering that the larger part of the charge introduced into the furnace comes out in the form of slag, the significance becomes apparent of a lack of heat-values for the singulo-silicate, which is the type of slags commonly made. The aim of the present investigation is to supply these heat-values as far as possible with the apparatus and the time available. The heats of formation of the ferrous and manganous bi-silicates have been determined by Le Chatelier; 1 those of some silicates other than iron and manganese by Tschernobaeff:2 finally Richards 3 gives a figure for a copper blast-furnace slag of known composition. The existing data and those resulting from the present investigation are assembled in Table VI. II. MATERIALS USED. The materials used in the experiments were silica, ferrous oxide, and calcium carbonate. Silica.-The silica sold in the market as chemically pure usually contains small amounts of magnesia, lime, and alumina, and is therefore not suited for the work. The pure material was obtained from clear quartz crystals from Arkansas, broken in a diamond mortar and ground in an agate mortar to pass 1 Comptes rendus, vol. cxx., p. 623 (1895); vol. cxxii., p. SO (1896). 2 Revue de Métallurgie, vol. ii., p. 729 (1905); Electrochemical and Metallurgical Industry, vol. iv., No. 2, p. 72 (Feb., 1906). 3 Electrochemical and Metallurgical Industry, vol. v., No. 7, p. 266 furls?, 1907;) ; Metallurgical Calculations, vol. iii.,.pp. 474, 475 (1908).

Jul 1, 1910

By Peter G. Chamberlain

The surge in gold and silver prices during the 1970's attracted many new mining operators and has rekindled interest among experienced ones. With its low capital investment requirements and fast payout, leaching has attracted many operators--particularly those with small or low- grade deposits. Although in certain situations leaching offers many advantages over conventional mining methods, many operators are uncertain how these relatively new techniques should be implemented. Consequently the Bureau of Mines has prepared this circular to disseminate information on gold and silver leaching practices, techniques, and problem. Engineering data gathered from 26 operations indicate that most ores are leached in heaps following crushing and distribution on pads. Metal values are recovered from cyanide leach solutions using either zinc precipitation or charcoal adsorption. Potential problems that my hamper on block development of a leaching operation are poor percolation characteristics of the ore, calcium salt buildup, low temperatures, and solution losses. An extensive bibliography on gold and silver leaching is appended.

Jan 1, 1984

By Adams R. W

A commercial scale strong acid leaching plant was commissioned at the Risdon plant of the Electrolytic Zinc Company of Australasia Limited, a member of the Pasminco group of companies, in February 1988. It was designed to upgrade the lead/silver residue product from 26% to 37% lead, thus improving the realised value and increasing overall zinc recovery. This in turn enables the lead smelter treating the lead residue to improve its productivity. The equipment consists of two 250m3 bricklined leach tanks and two 6.5m diameter stainless steel high rate thickeners operating with counter current washing at 95¦C and 120 g/L H2SO4. The present filtration and drying equipment is also being replaced. Two 35m2 squeeze action filter presses equipped with horizontal plates are being installed, together with ancillary drying equipment to ensure that the final product complies with the transportable moisture limit. The new filtration plant is due to be commissioned in mid-1989.

Jan 1, 1989

By J. D. Miller, J. Hupka

Important aspects of kerosene penetration into tar sand have been investigated. The natural tar sand porosity was measured and used to analyze the performance of the hot water process. Subsequently, pretreatment experiments, using 20-kg tar sand samples (Asphalt Ridge and Whiterocks, Utah) and kerosene as a diluent were carried out at the expected summer temperature (26°C) and the expected winter temperature (-14°C). The natural tar sand porosity accessible by diluent has a crucial impact on the reduction of bitumen viscosity and influences the penetration time required for successful bitumen separation from tar sand by hot water processing. Thus, the tar sand porosity is a critical variable that determines appropriate operating conditions. Experimental results indicate that diluent penetration into the Asphalt Ridge tar sand (high porosity) is almost complete after 30 min, whereas for the Whiterocks tar sand (low porosity) the penetration process is much slower, being still incomplete after 15 hours regardless of the ambient temperature.

Jan 1, 1994

By G. M. Potter, J. B. Rosenbaum, Masami Hayashi

Most Japanese copper smelters are located in areas of concentrated industrial activity and high levels of atmospheric pollution. A review of unofficial sulfur dioxide emission control data from major Japanese smelters shows capture of 91 to 99.7 percent of the sulfur in the smelter feed. The bulk of Japanese smel ting capacity was constructed in the last 10 years. Six of the major sme lters use flash furnaces, and two use reverberatory furnaces. A prototype three-furnace continuous system is in use as a parallel train with reverberatory furnaces at one smelter. Most of the sulfur dioxide is manufactured into sulfuric acid. The remainder is captured by gas scrubbers that yield gypsum and sodium salts. Ready markets exist in Japan for the acid and other su lfur byproduc ts.

Jan 1, 1967

By AIME AIME

THE Annual Meeting-numerically the 162d meeting-of the American Institute of Mining and Metallurgical Engineers will be held at the Pennsylvania Hotel, 7th Ave. and 33d St., New York, Feb. 18-22, with the exception of the following events: the Mineral Industry Education Division will meet Sunday afternoon and evening at the Columbia University Men's Faculty Club, 400 West 117th St.; and a meeting of the Section Delegates, the annual business meeting of the Institute, and an executive session of the Board of Directors will be held in that order Tuesday afternoon in the Engineering Societies Building, 29 West 39th St., where the Directors will meet in the evening following their annual dinner to the Section Delegates. The Pennsylvania--one of the Statler group of hotels-was selected as headquarters because it has the physical equipment and facilities-for registration, technical sessions of all sizes, luncheons, social events, etc.-as well as the prominence and location desirable for an Institute annual meeting. (A tip for Tuesday afternoon and evening: You can walk underground from the Pennsylvania to within half a block of the Engineering Societies Building,)

Jan 1, 1945

By Harold J. Schock

The cases of no auxiliary ventilation and ventilation with tubing were mathematically modeled, using a turbulent dispersion model. The scooptram that is used to load is modeled as a variable-speed, variable-strength source of pollutants moving in and out of the dead-ended drift. Model predictions are compared to experimental measurements. A parametric analysis was performed to determine the effect of exhaust pipe location and time spent out of the drift, as well as to determine if a relationship existed between CO2 and NO levels. It was concluded from this analysis that when modeling a load-haul-dump cycle, it is necessary to use a model that has the capability of predicting changes in source strength as well as source location. It was also determined that four relevant factors include effective heading height, apparent longitudinal diffusion coefficient, transverse concentration gradient at the face, and average dispersion width of the exhaust jet. As these factors change with heading geometry and ventilation configuration, they were determined experimentally, Carbon dioxide was used as a tracer to calibrate the model; since, knowing the fuel flow rate, it is possible to calculate CO2 production. The above four factors in the computer model were calculated using a regression analysis, comparing predicted local concentrations to measured local concentrations. The model was then verified after this calibration process using additional experimental results. With the calibrated model, it is possible to predict pollutant concentrations at any location in the heading using an engine map and the previously calculated flow field. A parametric analysis shows that the exhaust pipe location can have a significant impact on operator exposure to exhaust gases. It was also shown that NO concentration varies directly with C02 levels. Predictions using the dynamic model are contrasted with constant source strength (pollutant flow rate) results. An analysis of these predictions for computing time-weighted average NO shows the dynamic model predictions of operator exposure to this pollutant to be less than one-half of the value predicted using a constant source model.

Jan 1, 1981

By G. A. Savanick

Borehole (slurry) mining, where a tool incorporating a water-jet cutter and a downhole slurry pump mines phosphate through a borehole, was field tested in northeastern Florida as part of a US Bureau of Mines program to increase the domestic availability of critical minerals. About 1.5 kt (1700 st) of phosphate ore were mined at 23.6 t/h (26 stph) from a depth of 76 m (250 ft). The borehole was filled with water during mining for roof support and to assist slurry pumping. Underwater cutting was enhanced with an air-shrouded water jet. Mined cavities were backfilled to prevent subsidence after abandonment. Roof subsidence during mining was avoided only when the cavity was filled with water. Environmental monitoring before, during, and after mining included hydrological studies and measurements of water quality. Significant water quality changes occurred only in the zone being mined and were confined to the immediate area of the borehole.

Jan 1, 1986

By McHenry Mosier

SUMMARY MERCURY is one of the strategic metals of which the supply has been raised from critical uncertainty to more than enough for essential demands. Work by the Bureau of Mines has contributed substantially to increased production of mercury in the United States and to consequent accumulation of Government stocks. Other contributing factors have been higher prices for mercury and Government loans to operators. The Bureau has undertaken 13 exploration projects, 10 of which have been completed. This work has comprised 28,376 ft. of several types of drilling and 23,798 lin. ft. of surface trenching, and has indicated commercial ore containing 34,800 flasks of mercury and marginal ore containing 26,200 flasks, a total of 61,000 flasks; equivalent, respectively, to domestic production for 8 months, 6 months, and 14 months. As Government stocks are now adequate, domestic production (currently at the rate of 50,000 flasks per year) is gradually being curtailed through Government control of labor and operating supplies.

Jan 1, 1944

By Pingchao Ke, Zhihong Liu

Fe(III)-As(V) precipitates were synthesized from the Fe(II)-As(V)-SO42--H2O system at 90°C in initial Fe(II)/As(V) molar ratios of 4.0 and 5.0, respectively. The synthesis were carried out by introducing oxygen gas into the system to oxidize Fe(II) ions into Fe (III) ions, and at the same time, adding aqueous sodium carbonate solution into the system to neutralize the acid released by the hydrolysis reactions, with the purpose of keeping the pH constant at 1.5±0.05. The precipitates obtained were characterized by XRD, chemical composition analysis, SEM, XPS, and Raman spectrum. The results indicated that the particles in the precipitates were in the morphology of irregular aggregation with their sizes in the range of about 1–4 µm. The precipitates consisted of scorodite, ferric arsenate and amorphous hydrated ferric oxide, of which amorphous hydrated ferric oxide formulated as Fe(OH)x(SO42-)y. The characteristic XPS peaks of Fe-AsO43- and Fe-O in the precipitates located at 711.8 and 713.3 eV, separately, and the existence of amorphous hydrated ferric oxide led to two series of shake off lines developed over the end of high binding energy of Fe2p XPS. The precipitates were stable in TCLP tests at pH 4.93 for 60 hours with the arsenic concentrations in the leaching solutions being 0.27 mg/L and 0.59 mg/L for the precipitates prepared in the initial Fe(II)/As(V) molar ratios of 4.0 and 5.0, respectively. The tests for the long-term stability of the precipitates were carried out by leaching them for 40 days at 25°C under various media in the pH range from 9.50 to 10.57, and the results showed that the precipitates synthesized in this study were much more stable than those by previous researchers.

Jan 1, 2017

By W. J. Fene, J. J. Forbes

Through education, investigations, and studies and an expanded coal- mino inspection program the Bureau continued to dischargo the responsibility placed on it by Congress 39 years ago for promoting safety and health in the mineral industries. Although much still remains to be dono, definite progress was made in combating physical and psychological hazards in mines and plants. Accident-prevention cours os for coal-mine supervisory officials and special courses for coal-mine safety committeeman were inaugurated. First- aid, mine rescue, and other safety training was conducted for those engaged in all branches of the mineral industries. Assistance was given in recovery work after mine explosions and fires. Studies to reduce the danger of roof falls, the greatest single cause of fatal mine accidents, resulted in the development and adoption of new coal-mine roof-support techniques. Knowledge of the explosion and health hazards of mine and plant dusts and ways of pre-. venting them were advanced. Electrical equipment was tested for safety of operation in gassy coal mines, and emergency mine communications apparatus was developed and tested. More progress was made in the study of controlling flood waters that threaten life and property in the Pennsylvania anthracite region. More coal-mine inspections were made than in any previous year, and an impressive number of improvements resulted from the Federal inspectors' recommendations, even though many of them went unheeded. A program of con- trolling fires in inactive coal deposits on the public domain and private property was instituted during the year.

Apr 1, 1950

By B. R. T. Simoneit

The conversion of organic matter to petroleum by hydrothermal activity is an easy process, occurring in nature in many types of environments. Geologically immature organic matter of marine sediments is being altered by this process in Guaymas Basin (Gulf of California), Escanaba Trough and Middle Valley (northeast Pacific), Bransfield Strait (Antarctica), and Atlantis 11 and Kebrit Deeps (Red Sea). Contemporary organic detritus and viable microorganisms are also converted in part to petroleum-like products by the same process when present to become entrained, as for example on the East Pacific Rise at 13o N and 21o N and on the mid-Atlantic Ridge at 26oN. The hydrocarbon products (methane to asphalt) generated in all these areas have been elucidated in terms of composition, organic matter sources, and analogy to reservoir petroleum. This petroleum represents a major input of carbon to the primary chemosynthetic productivity of hydrothermal vent systems and may be important to interactions with metals in hydrothermal ore formation.

Jan 1, 1991

By Joseph A. Olmstead

Literature concerned with management and supervisory training was reviewed and analyzed from the perspective of relative effectiveness of various training methods for improving knowledge and awareness, changing attitudes, improving problem solving skills, improving interpersonal skills, and improving on-the-job performance. Conclusions were drawn relative to each method and the current state of the field of management and leadership training. A 168 item annotated bibliography is presented.

Jan 1, 1980

By A. E. Jenkins, L. A. Baker, N. A. Warner

Rates oj decarburization of levilated Fe-C droplets conlaining 5.5 to 0 pct C have been measured at 1660°C. Gas mixtures of 1, 10, and 100 pct 0, with helium diluenl were used at velocities of 12.5 and 62.5 cm per sec. Rates were independent of carbon concentration in the mell and in good agreement with the calculated rule of oxygen diffusion through the gas boundary layer. The effects of flow rale and total pressure are as predicled and the rates are approxitnalely 2.5 times those with CO2 as oxidant. The mass-transfer correlation used incorporaled the efject of natural convection as well as forced conrection. Graphile spheres are shown to oxidize at the same rate as Fe-C droplets under the same experimental codlions. It is concluded that, for high carbon concentrations in the melt, the rate of- decarburizalion is controlled wholly by the rate of gaseous diffusion. Rate measurements with pure CO, are reported for low carbon concentrations where CO bubbles nucleate within the droplet. Under these circumstances the decarburi-zation decreased with carbon concentration and it is proposed that carbon diffusion is significant in conlrolling the decnvburization rate. In an earlier paper1 decarburization rate measurements were reported for levitated Fe-C alloys at 1660°C but with CO2 as the oxidant. The decarburization rate was found to be independent of carbon concentration in the melt but slightly affected by total pressure. The authors were unable to explain the slight pressure effect but in all other respects the results were consistent with control by diffusion in the gas boundary layer. Subsequent work has been directed at finding the reason for the slight pressure effect and whether the kinetics with oxygen as oxidant parallel those with CO2. Recently Ito and Sano2 have shown that with water vapor-argon atmospheres the decarburization rate is gaseous diffusion controlled until an oxide film appears on the surface. In this work the melts were contained in crucibles. MASS TRANSFER IN THE GAS PHASE In the earlier analysis1 only forced-convection mass transfer was considered. Subsequent recognition of the existence of some free-convection mass transfer explained the observed small effect of total pressure on the decarburization rate. Steinberger and Treybal3 and Kinard, Manning, and Manning4 have developed correlations involving the linear addition of the contribution of radial diffusion, free and forced convection. Steinberger and Treybal&apos;s correlation was chosen as the most applicable to the present work since it correlated most of the data available in the literature and handled the low Reynolds number region exceptionally well. The correlation for (Gr&apos;Sc) < 108 is where Nu&apos; is the Nusselt number for mass transfer based upon the total surface of a sphere in an infinite medium, G&apos; is the mean Grashof number for mass transfer defined by Eq. [2], Sc is the Schmidt number (µ/pDAB)f, Re is the sphere Reynolds number (dpu,pf/µf), p is the viscosity of the gas (poise), p is the density of the gas (g cm-3), Dab is the binary diffusivity for the system A-B (sq cm sec-&apos;), dp is the sphere diameter (cm), u is the approach velocity of the gas (cm sec-I), and subscript f denotes the property value is computed at the film temperature Tf defined by Tf = +1/2(To + Tr) where To is the specimen temperature and T, is the approach gas temperature (oK). Natural convection occurs when inhomogeneities exist in gas density. These may be caused by concentration gradients, temperature gradients, or both. In the present work the temperature gradient between the sphere and the bulk gas was very large and in some cases, for example the runs with pure oxygen, the concentration gradient was also appreciable. The Grashof number defined by Mathers, Madden, and piret5 was used since it took account of both temperature and concentration gradients: where Gr&apos; is the Grashof number for mass transfer (p2fgd3|-yA-yA|/µ2f), Gr is the Grashof number for heat transfer (p2f gd3p|To - T,]/µ2fTf), Pr is the Prandtl number (cpµ/k)f, g is the acceleration due to gravity (cm sec-&apos;f, a is the concentration densification coefficient (1/p)(ap/ayA)T, yA is the mole fraction of component A at the gas-metal interface, yA is the mole fraction of component A in the bulk gas stream, cp is the heat capacity of the gas per unit mass at constant pressure (cal g-I OK-&apos;), and k is the thermal conductivity of the gas (cal cm-&apos; sec-1 OK-1). Mathers et al. tested this combined Grashof number

Jan 1, 1968

By N. S. Dalal, Xiaoya Sun, Xianglin Shi

"The in vivo toxicity of vanadium(V) has been found to correlate with the depletion of cellular glutathione and related non-protein thiols. With a view to understanding the mechanism for this observation, we have investigated the oxidation of glutathione, cysteine N·acetylcystcinc and pcnicil· lamine by vanadium(V), using electron spin resonance (ESR) and ESR spin trapping methodology. The spin trap used was 5,5-dimethyl-l-pyrroline I-oxide (DMPO). It is found that the oxidation of these thiols by vanadium(V) generates the corresponding thiyl radicals and vanadilim- (IV) complexes. The results suggest that free radical reactions play a significant role in the depletion of cellular thiols by vanadium(V) and hence in vanadium(V) toxicity. 1. INTRODUCTIONThis communication reports on the identification of thiyl radicals formed as intermediates in the reaction of vanadium(V) with glutathione (GSH) and related nonprotein thiols. This study was undertaken because the biochemical mechanism of vanadium toxicity is still not fully understood,. despite being a topic of current research activity [1-20). As to possible clues, it is known that vanadium is most toxic when administered in its pentavaient state [21), and that vanadium(V) administration into laboratory mice reduces cellular levels of NAD(P)H and GSH [22). While the oxidation of NAD(P)H by vanadium has been studied extensively [16-20), that of glutathione and related non-protein thiols has been paid less attention. On the other hand, GSH and related thiols are important cellular antioxidants [23). Their functions include decomposing lipid peroxides and protecting cell membranes [23-25). Thus any reduction in the cellular contents of such nonprotein thiols after vanadium exposure may result in the accumulation of lipid peroxides which might ultimately lead to tissue injury. With a view of finding the mechanism for this thiol depletion process, we have investigated reactions of non-protein thiols with vanadium(V). Particular attention has been paid to the detection of thiyl radicals, since it has been postulated [l] (but not experimentally proven) that the glutathionyl radical (GS·) might be an intermediate in the reaction between vanadium(V), NADH and GSH. We have used electron spin resonance (ESR) and ESR spin trapping methodology for investigating the reactions of GSH, cysteine, N-acetylcysteine and penicillamine with vanadium(V). The results show that the corresponding thiyl radicals are indeed formed in the one-electron reduction of vanadium(V) by all of the above mentioned thiols."

Jan 1, 1990

By E. J. Matson

Under the investigation for critical and strategic minerals the Kaiser mine, formerly the Baxter fluorspar property, in northeastern Mineral County, Nev., was explored. The work comprised excavating 32 trenches averaging 90 feet in length, 8 feet in width, and 1 1/2 feet in depth. The trenches were excavated across the strike of the ore body to enable the engineer to spot the diamond-drill holes; 7 such holes were drilled, aggregating 3,276 linear feet. A total of 20 core samples and 107 sludge samples was taken. The work under this program indicated that the fluorspar southwest of the deposit extended laterally and also at depth at least 250 feet below the 400-foot level. INTRODUCTION The Kaiser fluorspar deposit is in the northeastern portion of Mineral County, Nev. Mining was begun about 1928, and the property has been a consistent producer of both Acid- and Metallurgical-grade fluorspar. The mineralized zone has been developed along a strike length of about 2,000 feet and to a depth of over 700 feet along the dip.

Jan 1, 1957

By I Mason, A Wellington, J Hargreaves

Many people are familiar with the use of marine echo sounders which are used by fishermen to monitor water depth and locate schools of fish. Similar technology has recently been used in some West Australian mines to provide detailed maps of ore contacts and other geological structures. Whilst drillhole intersections provide details of the location of a contact at a point, echo sounding can be used to obtain a continuous profile of the contact. A series of profiles together with drillhole intersection data can be used to build a more accurate geological model than can be inferred from drillhole intersections alone. The benefits of this are more complete ore extraction, less dilution and the ability to make more informed financial decisions. This paper presents a case history which demonstrates the successful application of the technology.

Jan 1, 2000

By Byron M. Bird, Earl R. McMillan

"The method and apparatus described herein was developed at the Northwest experiment station of the Bureau of Mines, Interior Department, in cooperative research work with the University of Washington. A fuller description will appear in a bulletin entitled ""study of coal washing problems in the Pacific Northwest, to be published by the University. During the past four years this Bureau and the University have been co-operating with various coal companies in the Pacific Northwest in an extensive study of coal washing problems. Much of the valuable data resulting from this study has been obtained with the well-known float-and-sink test. This test has known for a number of years****, but its possibilities have not been thoroughly understood. A few investigations have developed apparatus and technique suitable to their needs, but these were not adopted to the conditions faced in the Northwest. Thus, the necessity arose for designing suitably equipment and working out a method of procedure or technique in carrying on the fundamental studies of coal washing by means of the float-and-sink test method."

Feb 1, 1924

By E. Morrice

The metallurgical laboratory data developed in this study indicate an improved electrowinning process for producing higher purity cerium ingot. A typical sample of the Reno electrocerium contains 99.9 weight-percent cerium and the following impurities: Total other rare-earth elements, less than 0.04 percent; iron not detected; silicon and aluminum, less than 0.02 percent each; calcium plus magnesium, less than 0.01 percent; carbon, 0.01 percent; oxygen, 0.002 percent; hydrogen, 0.0003 percent; and nitrogen, 0.0015 percent.

Jan 1, 1960

By Chengliang Jliang, B. K. Parek, Xuxin Shao

Of the impurities present in phosphate ore, dolomite is the most difficult to remove due to the similar chemical compositions of the impurities and also adsorption of dissolved species of dolomite onto phosphate. A new amphoteric surfactant was found to be a suitable collector for separation of dolomite from phosphate. Flotation results showed that the new amphoteric collector had a high flotation selectivity for dolomite in wide pH ranges. The flotation study of francolite and dolomite in each other&apos;s supernatant demonstrated that the dissolved ions had little effect on the selectivity of the new collector, but were detrimental to the flotation separation using sodium oleate as collector. A phosphate concentrate with 35.2% P2O5 with 90% recovery was obtained using 290 g/t of the amphoteric collector from a mixture of francolite and dolomite containing 26.2% P2O5. The rejection of MgO was 81.41%.

Jan 1, 1999