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By H. R. Babitzke

The purpose of this investigation was to evaluate the potential of columbium-hafnium alloys as structural materials for use at elevated temperatures. The work described in this report was conducted to determine the properties of columbium-hafnium alloys and to select the more promising ones for further improvement. Properties determined in this report were machinability, hardness, workability, tensile strength, and oxidation resistance. Ten ingots, ranging from 100 percent columbium to 70 atomic-percent hafnium, were prepared and subjected to tests. The test results showed that the alloys with 33 and 50 atomic-percent hafnium were superior in workability, strength, and oxidation resistance. For the alloy series tested, the strength and hardness values increased with the increasing hafnium content. Maximum values were reached with 50 atomic-percent hafnium. The oxidation resistance was poorest at the 1 atomic-percent hafnium level but improved with increasing hafnium content through 70 atomic-percent. Eight of the ten ingots were fabricable at room temperature. The two remaining ingots, those with 5 and 10 atomic-percent hafnium, required hot-working.

Jan 1, 1962

By P. R. A. Andrews

"Areas of bubble contact were delineated for cassiterite in the presence of chloride, fluoride, sulphate, phosphate, oxalate and citrate ions using dodecylamine hydrochloride collector. The limits of pH, and the minimum collector concentration were established using the bubble pick-up technique.Bubble contact did not occur below the p.z.c. (point of zero charge), estimated to be 4.7, in the presence of chloride ion, and fluoride ion showed only a weak response in the same pH range. These anions are considered to act as indifferent electrolytes. Activation at pH values below the p.z.c. was obtained with sulphate, phosphate, oxalate and citrate ions; the greatest response was by oxalate and phosphate ions extending pick-up to between pH 2.0 and 2.5.Activation appeared to be strongest when anionic protonated species were in maximum concentration. Strong activation also corresponded to the formation of very stable metal ion species, thought to be formed on the surface of cassiterite, between exposed stannic ions and modifying anions; dodecylammonium ions being absorbed on the surface so modified."

Jan 1, 1991

By M. Yekeler

The critical surface tension of wetting values (Ye) of realgar (AsS), talc [Mg3si401o (OH) 2]' stibnite (Sb2S3), and sulfur (S) were determined by flotation in the absence of conventional flotation collectors as 38.7, 38.0, 35.5, and 30.0 dyne/cm, respectively. The surface tensions of flotation media were arranged by methanol. Separation of binary mixtures of these minerals was performed exploiting their Ye differences-which form the basis of the "ganuna flotation process". One step flotation test showed that sulfur floats preferentially from its mixtures with realgar and stibnite at recoveries of 73.6 and 70.7 % and grades of 81.7 and 91.2 %, respectively. The separation of stibnite from realgar gave a recovery of 4.1 % and a grade of 41.2 % for stibnite, indicate that a minimal Ye difference of 3.6±0.2 dyne/cm is essential for such separation when conventional flotation reagents are not used. This paper presents data and describes the approach employed in these separations.

Jan 1, 1994

By R. V. Lundquist

The work described in this report, part of the Bureau of Mines long-range program to develop methods of utilizing submarginal domestic sources of aluminum, was undertaken to investigate the effects of iron in the lime soda sinter process, The approximate Fe2O3 content in a sinter for maximum alumina and soda recovery was 8 to 9 percent. Fe2O3 appears to inhibit gelation, and 15.5 percent Fe2O3 produces effects similar to those produced by 1 percent sucrose. In the lime soda sinter process, aluminum silicates are sintered with limestone and soda ash to yield dicalcium silicate and sodium aluminate. The sodium aluminate is extracted by leaching in caustic solution. The solution is purified by heating in an autoclave with lime to remove silica, and alumina trihydrate is precipitated with carbon dioxide. The reactions involved in sintering and leaching are complex. A number of studies by the Bureau of Mines4-9 and others1 indicate that the iron content of sinters influenced the recovery of alumina and soda and the gelation characteristics.

Jan 1, 1962

By J. F. Kemp

PARE Introductory Note. ........... 147 General Topography. ..... ....... 148 General Distribution of the Mines. .149 General Geology.............151 The Non-Titaniferons Ore-Bodies. .1. 54 The Lee Mine. ..........154 The Cheever Mine...........15.5 The Pilfershire and Pease Pits.........1.56 The Mineville and Barton Hill Groups........1.56 Introductory. ........... 156 The Mineville Group..........157 The Miller Pit..........158 Old Bed or Mine 23 .........166 Relations of Old Bed to Miller Pit. ..168 The "21 "-Bonanza-Joker Ore-Body,......168 Summary. .......... 170 O'Neill Shaft and Cook Shaft, .......171 The Barton Hill Group..........172 The Mines on Barton Hill........172 Fisher Hill and Burt Lot........173 The Chemical Composition of the Ores. .. 173 The Geological Relations of the Ores. .176 The "21 "Gneiss..........176 The Orchard Gneiss. . . . . . . . .178 The Barton Gneiss..........178 The Gabbro and Gabbro-Gneiss. . . . . . .180 Minor Rocks...........182 Mineralogical Relations of the Gneisses. ..183 Stratigraphical Relations of the Gneisses. . . . 183 The Origin of the Ores. ..190 Review of Hypotheses . . . . . . 191 Interpretation of the Ore-Bodies as Contact-Deposits on Gabbro,. 193 The Mineralogy of the Mines. . . .......195 Bibliography.............201

Jan 1, 1898

Strips of AA6111 automotive alloy were cast on a horizontal single belt strip casting simulator, Pure copper and carbon steels substrates plasma sprayed with different coatings for improving the strip surface quality, were used as chill moulds, Experimental studies revealed that a graphite coating provided the greatest benefit in achieving good surface quality. The interfacial heat fluxes during solidification of AA6111 strip were calculated by the IHCP method (Inverse Heat Conduction Problem). Temperature variations and cooling rates within the strips were then calculated through numerical simulations based on the time-dependent heat fluxes obtained by IHCP, The effects of casting parameters, including casting temperature and strip thickness, on interfacial heat fluxes, cooling rates and microstructures, were investigated, Although the maximum interfacial heat fluxes on the chill copper substrate were much higher than the results obtained from the steel substrates, the solidification times of the melts were mainly determined by strip thickness. Very fine equi-axed grains were obtained for both 1.2mm and 2.5mm thick strips thanks to the rapid extraction of heat, and effective grain refinement.

Jan 1, 2005

By Donald J. Drinkwater, M. C. Fuerstenau

Many important contributions to the more fundamental aspects of mineral processing have been made this past year. Mular1 researched the flotation characteristics of pure zinc oxide and also samples that had been doped with Al+++ and Cu++. Correlation of the response of pure zinc oxide to oleate flotation with a calculated zpc (from solution equilibrium) suggests that adsorption of oleate ion is coulombic in nature. Doping the sample with Al+++ (which will make the ZnO more n-type) had a marked effect on the maximum value of pH at which 50% recovery was obtained at constant collector addition. That is, when 0.5 mole percent Al+++ was added, the pH for 50% recovery was reduced by about four units. Treatment with Cu++ was found to have little effect on the flotation response of zinc oxide, even for additions of one mole percent. Since the zero points of charge of the Al+++ doped powders were not measured, it was not possible to correlate flotation data of these samples directly with charge phenomena.

Jan 2, 1966

By R. Bonnar, R. J. McH. Clark

"The Cheminis gold mineralization zone is approximately 6.5 km west of the Kerr Addison Mine along the Larder Lake Shear Zone, in the southern part of the Abitibi Greenstone Belt. The zone is very similar in appearance to the flow ore at the Kerr Addison Mine and occurs at the same stratigraphic position. Drilling has demonstrated that the gold mineralization at Cheminis persists to a depth of over 3000 ft .The mineralization is hosted by a pyritic, tuffaceous sediment which occurs within a sequence of volcanics and sediments which have been pervasively carbonatized. The gold is largely enclosed within pyrite grains and the amount of gold in the layers of pyrite increases in the layers closest to a graphitic f ault zone.It is suggested that the gold mineralization may be primarily related to the syngenetic sulphide concentrations formed during fumarolic activity on the seafloor along the Larder Lake Shear Zone. At a later stage a hydrothermal event associated with alkalic volcanism may have resulted in regional carbonatization and further concentration of the gold in the vicinity of fault zones."

Jan 1, 1987

The Wednesday morning session was opened by President Joe Ward at 9:30 a.m. He complimented Walter Mueller, Program Chairman, for the excellent job he did as head of that very important committee. He also thanked all those on the various committees, speakers, and all who participated in making the 1972 meeting a success. He called on William S. Landers, Chairman of the Auditing Committee, to give his report. He read the report and asked for a motion of approval. Motion was made, seconded and approved. (See Treasurer's report on page 5.) A. E. Pagnotta of the Resolutions Committee read their report as follows: RESOLVED: Whereas, since the 67th Regular Meeting of the Rocky Mountain Coal Mining Institute. held at Park City, Utah, the Institute and the coal mining .industry has suffered the loss through death of service and fellowship of the following members: W. H. Carson James Dalrymple Edward H. Denny A. B. Foulger Thomas E. Graham G. R. Harris Frank Markosek Anthony C. Moschetti Harry Swihart Franklin B. Thomas

Jan 1, 1972

By S. Moussa

The formation of boron-doped nickel aluminides Ni3AI, (76 at. % Ni) from elemental powders by reaction synthesis using reactive sintering was studied. The process involves the mixing of elemental powders of nickel and aluminium with various wt % of boron up to 1 wt % boron. Nickel and Aluminium powders were mixed in the correct proportion to form the intended boron-doped nickel aluminide intermetallic. XRD, SEMI EDS, Image analysis and Archimedes principle; were used to study the effect of Boron addition on the final microstructure, bulk density, average grain size of as reactively-sintered nickel aluminides (boron-doped), compared with no boron addition. The results showed that at greater boron content than 0.3 wt %, a two-phase non-equilibrium microstructure of consisting of NiAI phase in NiJAI matrix was formed that have been primarily retained even after heat treatment for 5 hours at 1000 °C. Boron was present in solid-solution within both the NiAI and the Ni3AI (in greater amounts) phases.

Jan 1, 2001

By Greg Johnson

Maintenance needs information about assets to optimize availability and production needs information about performance and consumption to maximize output. In considering both these needs together as, ?Asset Optimization?, the information systems that support them are critical. The theory of Asset Optimization derives from the Lean Manufacturing concepts developed by Toyota, but some changes are required to apply this to mining operations. In particular, mining operations require automated systems due to their geographic spread and they need a strong emphasis on capturing under-performance losses as well as delays and stoppages in production. Leading metal miners and coal miners alike have applied these systems to good effect in the last 10 years. The concepts developed initially in minerals processing plants are now being applied to the mines themsleves as well as the mining logistics chain. Production increases of 5?10% are achievable with the right implementation and consideration of the some key lessons learnt in the last 10 years. Putting these lessons into action is one key step in the goal of optimizing asset performance and thus utilizing the resource at lowest cost.

Aug 1, 2013

By Russell C., Fleming

FOK, many years the officials of the Magma Copper Co. mine at Superior, Ariz., have had to contend with adverse conditions underground in the form of high rock temperatures, hot water, and high relative humidity. These conditions in the mine have been such that working the mine would have been impossible were it not for the constantly expanding and improved sys- tem of ventilation to produce bearable conditions in the working places. Results that have already been achieved make an interesting study of what can be done along those lines. From the time the mine was first opened in 1910 it has been hot. An idea of the conditions that have persistently been encountered can be obtained from parts of the mine that are not being worked at present or that do not yet have sufficient ventilation. Virgin rock temperatures as determined in drill holes at the faces range from 104° to 116°*. An observation made at the face of No. 5 West footwall drift on the 2800-ft. level.

Jan 1, 1930

By A. Lashgari, V. Kecojevic

This paper presents research on the environmental impact of digging and loading equipment used in surface coal mining. Environmental impact was assessed through the measurement of equipment exhaust and dust emissions, and sound level. In this study, exhaust emission refers to carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx) and volatile organic compounds (VOCs). Dust generation refers to fine particles (PM2.5), inhalable particles (PM10) and total suspended particulate matter (TSP). Sound level refers to the sound pressure level at different distances from the equipment. Modeling of the environmental impact of digging and loading equipment was conducted using the Microsoft Visual Studio.NET software package. This research was a part of a broader project involving the development of a software system for the selection of productive, cost-efficient and ecofriendly mining systems, sponsored by the Appalachian Research Initiatives for Environmental Sciences (ARIES). This research may assist mining professionals in quantifying the environmental impact of digging and loading equipment, and developing strategies for reducing the overall impact of such equipment in surface mining.

Jan 1, 2013

The Wednesday morning session was opened by President John Reeves at 9:30 a.m. He thanked the various committees for the excellent work they did. He called on the Auditing Committee to give its report. Mr. Jack White reported that the Auditing Committee had properly checked the financial records of Mrs. Augusta Whiteside, Secretary-Treasurer, of this Institute and reports to the membership that these financial records are indeed accurate and in good order. We so sign our names to this. This Auditing Committee wishes to take this opportunity to commend and thank Mrs. Whiteside for her dedicated effort in keeping the financial records of the Rocky Mountain Coal Mining Institute in such excellent order. (See page 5 for printed Treasurer's Report) Mr. White asked for a motion to approve the records, it was made, seconded and approved. Mr. Meade Harker, Chairman of the Finance Committee, was asked to give his report. He stated that the Colorado contributors total was $630.00 and the Utah $39.0.00, making a grand total of $970.00.

Jan 1, 1970

By John A. Organiscak

Laboratory and underground studies were conducted by the Bureau of Mines to evaluate the effectiveness of a water-powered scrubber and a brattice partition to create a clean split of air for longwall workers at the tailgate. In simulated laboratory tests, the system was very effective in creating a clean split of air. Observed system efficiencies were 74 and 84 pct with induced airflows of approximately 2,000 and 2,500 cfm, respectively. Underground evaluations indicated that the system was capable of reducing respirable dust at the tailgate. The first underground evaluation resulted in protection efficiencies of 30.7 and 42.5 pct at scrubber water pressures of 150 and 450 psig, respectively. A 33.7-pct protection efficiency was observed in the second underground evaluation with a modified partition and the scrubber operating at 250-psig water pressure. To be most effective, the system should have the scrubber operating at a flowrate of 10 gpm at 500 psig to deliver a maximum quantity of cleaned air behind a well-sealed partition.

Jan 1, 1983

By Martin Encinas, Jesús L. Valenzuela, Jose R. Parga, Salvador Aguayo, Roy G. Lewis

Continuous laboratory solvent extraction of gold from cyanide solutions using LIX?79 guanidine based extractant has been investigated. Different variables that affected the selectivity and extraction include aqueous pH, extractant concentration, and modifier concentration. The extraction isotherms of the aurocyanide complex with respect to the other cyano anions were compared, and the following order of selectivity Au > Ag > Zn > Cu > Fe was observed. According to the pH isotherms, aurocyanide can be extracted in an alkaline media, and a better separation with respect to the other cyanoanions was obtained in the pH range 10.5-11.2. From the McCabe Thiele diagrams, better recovery was predicted when using LIX?79 extractant and tridecanol modifier at 10 vol.%. Stripping of the gold from the loaded organic was carried out at pH > 12 using NaOH and NaCN solution. The continuous tests indicate that a two-stage extraction followed by a single stage strip is adequate to obtain an overall process efficiency of >90%. Better results were obtained using a copper wash stage before gold stripping.

Jan 1, 2014

By Daniel Hiroshi Taira Anese

O objetivo desse trabalho consiste no estudo do grau de sensitização do aço UNS S31803 envelhecido a 700ºC por ensaios de reativação potenciodinâmica de duplo loop (DL-EPR). Para isso corpos de prova do aço em estudo foram solubilizados a 1175ºC e envelhecidos a 700ºC em tempos entre 10 min e 360 h. Corpos de prova metalográficos foram utilizados para caracterização microestrutural que foi realizada por meio de técnicas de estereologia quantitativa a partir de imagens de elétrons retroespalhados e análises magnéticas usando o ferritoscópio. Os ensaios DL-EPR foram conduzidos em solução 2M H2SO4 + 0,5M NaCl + 0,01M KSCN à 30ºC em amostras polidas. Observou-se que o comportamento eletroquímico do aço UNS S31803 possui forte influência da microestrutura, já que o grau de sensitização (GS) aumenta com o aumento do tempo de envelhecimento, devido à formação de fases intermetálicas que empobrecem as regiões adjacentes em Cr e Mo.

Aug 7, 2018

By A. Rahmanab, A. Torpy, M. I. Pownceby, M. N. Zaman, N. Haque, W. Bruckard, J. Tardio

Ilmenite is the principal feedstock for producing TiO2 - used in paints, plastics and paper and the production of Ti metal. The Brahmaputra River system in Bangladesh represents a potentially new source of ilmenite concentrated within sandbar placer deposits and the current study presents results from beneficiation and characterisation studies conducted on Brahmaputra River Fe-Ti oxides. Characteristic of fluvial systems, the ilmenite concentration is low (~0.5 wt-%), however extensive annual dredging for waterway navigation provides the economic impetus to recover saleable ilmenite. The Fe-Ti oxide suite derived from magnetic fractionation comprises homogeneous ilmenite, titanohematite and hematite, although many grains exhibit complex exsolution within the (Ilm-Hem)ss series. The textural variability results in difficulty generating a pure ilmenite feedstock with the bulk concentrate typically being low in TiO2, containing 31.0 wt-%TiO2 and 62.7 wt-% (Fe2O3). Results are interpreted via an analysis of the implications for producing a commercial-grade ilmenite concentrate suitable for TiO2 production. Keywords: Ilmenite, titanohematite, Fe-Ti oxide exsolution, TiO2 production

Jan 1, 2020

By Robert L. Frantz

Progress and improvement continue to be the bywords of a dynamic coal industry. The industry continues to gain strength and expand its horizons in the face of competition from atomic energy and the problems of restrictive legislation. The direct contribution of coal mining and transportation to the national economy is about $3 billion a year ac- cording to a study made by the National Coal Policy conference. Coal remains the backbone of the power industry producing almost two-thirds of all the electrical energy generated by fossil fuels and one-quarter of all the energy consumed in the nation. Power supplied by electric utilities increased 6.9% last year. The chairman of the Federal Power Commission predicted a 7.5% growth rate until 1980 for the nation's electric output. Some 80,500 MW of fossil fired power plant capacity are on order or under construction before 1974, compared to a present capacity, all sources, of about 290,000 MW. The comparable new additions of nuclear power plants is expected to total about 51,000 MW.

Jan 2, 1969

By J H. Kyle

Cyanide is a significant cost in gold processing, as well as an environmentally sensitive issue. It has been suggested that precipitation of cyanide from leach liquors as copper-iron-cyanide compounds such as Cu2Fe(CN)6 may account for part of the total cyanide consumption. This may be especially true for ores that are rich in both copper and iron minerals. Ammonia addition has been shown to decrease the cyanide consumption by copper. Cu2Fe(CN)6.xNH3 precipitates have also been postulated to form during conventional cyanide detoxification processes, using oxidants such as SO2/air, with ammonia arising as a breakdown product from the oxidation of free cyanide. The present work has examined the conditions under which such precipitates may form, particularly in gold plant process and detoxification liquors. Ammonia and pH were found to have a large effect on the extent of precipitation. The compounds that were formed were found to comprise mainly Cu2Fe(CN)6.7H2O, as well as a range of NH3-bearing variants. The stabilities of the various precipitates are important from an environmental perspective. The long-term stability of copper ferrocyanide precipitates in tailings dams may be a problem under alkaline conditions and when some free cyanide is present, elevating the measured total cyanide in solution significantly. Case studies including data from actual plants are also considered, and the importance of these effects is reaffirmed from these results.

Jan 1, 2000