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By N. A. Abdel-Khalek

The objective of this investigation was to compare the results of counter-current flotation column versus conventional flotation cell for the cleaning of a sulphur ore and its discrete size fractions. The tests were carried out using diesel oil as a collector and alcohol as a frother. Generally, flotation column produced concentrates of higher grade. For example, the grade of a rougher concentrate for a given feed obtained with the column increased by 33% higher than that produced with the flotation cell. Such higher grade could not be obtained using conventional cell even after 3 cleaning stages. Moreover, the column gave superior results for flotation of fine and ultrafine particles.

Jan 1, 1991

By John T. Eastlick

The Banner mining district is about 70 miles northeast of Tucson in the southern part of Gila County, Arizona. Production from the district, valued at about $26 million, is chiefly from copper-silver-lead zinc ores. The stratigraphic section consists of Precambrian conglomerates, quartzites, dolomites, and limestones, Cambrian quartzites; Devonian limestones; dolomites, and shales; Mississippian limestones; Pennsylvanian limestones and shales; and Cretaceous volcanic and sedimentary rocks. Deformation of these rocks presumably started near the end of the Cretaceous, and extended into the late Tertiary. The sedimentary rocks were folded, faulted, and intruded by fine grained diorite, quartz mica diorite, and dacite porphyry. At least four distinct stages of mineralization are recognized. In the first stage of contact metamorphism and the second stage of hydrothermal alteration, favorable zones were prepared for ore deposition. Metallization occurred in three of the mineralizing stages. Magnetite, pyrite, and hematite were deposited near the end of the second stage of hydrothermal alteration. The third stage included the main deposition of sphalerite, chalcopyrite, bornite, and galena. In the fourth and final stage, minor amounts of sulfide minerals were deposited with a late anhydrite and quartz gangue. The ore deposits in the form of veins and veinlets, pipes, irregular massive replacements, and bedded replacements are localized by the extent and distribution of metamorphic and hydrothermal alteration, by the proximity to the intrusive contacts, and by the effects of structural development. Oxidized ores of copper, lead, and zinc constituted the principal production of the district prior to 1940, but, for the most part, supergene enrichment was of minor economic importance. The ore bodies of the district are in the mesothermal class of deposits, occurring as normal metasomatic replacement and vein types.

Jan 1, 1968

By H. Shafick Hanna

The major problems are identified the high phosphorus content and the fine dissemination or encapsulation of mineral impurities, in, ,the iron bearing minerals, A process which combined extreme fine grinding techniques with magnetizing roasting or flotation separation methods, is suggested. By these methods concentrates assaying 60-61 percent Fe exceeding the widely accepted upper limit of 56 percent Fe set for these ores, were produced with 75-90 percent iron recovery. Moreover it was shown that the phosphorus content of these concentrates could be reduced from 0.25 to 0.03 percent phosphorus by acid leaching. A brief discussion on production costs based on current and future developments in iron ore processing is given.

Jan 1, 1980

The development of a noise attenuated compressed air driven fan is described. The fan, which employs the jet reaction principle, possesses blade extension pieces which penetrate into an acoustically treated annular chamber. The dominant noise source, namely the air jets, is thereby partially suppressed. In addition, the increased moment arm of the jets leads to an improved propulsion effect which contributes to the improved aerodynamic performance of the unit.A typical measure of the improvement of this type of auxiliary mine ventilation unit is a 4 per cent increase in efficiency and a 10 dB (A) drop in sound level for a fan duty of 0·5 kPa and 1600 litre/s. This degree ofattenuation corresponds to at least halving the loudness level, a subjective noise measure.

Jan 1, 1973

By C. Xiao, R. Chi

In recent years, the biosolubilization of rock phosphates by phosphate-solubilizing microorganisms has become a major topic of research studies. However, the microorganisms used in previous studies were mostly single and known species, and studies seldom focused on mixed communities of microorganisms or microbial consortia from natural environments. In this study, a microbial consortium from rhizospheric soil was used to solubilize two different compositions of medium- to low-grade rock phosphates — designated as ore samples 1 and 2 — in a laboratory-scale bioreactor. The microbial consortium showed good growth in the bioreactor, reduced the suspension pH and released soluble phosphates from the ores. Scanning electron microscopy with energy-dispersive X-ray spectroscopy showed the action of the microbial consortium on the ore surface. There was considerable corrosion on the ore surface, and 3.42 and 4.93 percent of the element phosphorus was removed from ore samples 1 and 2, respectively. Microorganisms were sampled from the bioreactor for the analysis of their community structures by Illumina MiSeq high-throughput sequencing. The analysis show that the suspensions added with different ore samples had different microbial diversities and richness. This study provides new insight into the biosolubilization of rock phosphates by a microbial consortium directly taken from rhizospheric soils.

By K. C. Corin, M. S. Manono, R. M. Manenzhe, J. G. Wiese

"Environmental concerns necessitate the recycling of process water within mining operations. Given that recycled water is chemically different from fresh water, and collectors are added such that they adsorb at the liquid-particle interface, changes in the aqueous phase are expected to affect collector adsorption. A Finnish nickel-copper ore was floated in synthetic plant waters of varying ionic strengths and plant waters obtained at Boliden Kevitsa Mine, with aerophine and sodium isopropyl xanthate as collectors. Of the tested waters, the copper thickener overflow was the least conducive to xanthate adsorption and valuable mineral recovery. The nickel thickener overflow, standard process water, and raw water were the most conducive to xanthate adsorption. For the raw water and nickel thickener overflow, increased adsorption correlated with increased valuable mineral recovery. Further, recycling xanthate retained in water affected the selectivity of the collector and hence the concentrate grades.INTRODUCTIONFlotation is a separation process that exploits the differences in the surface properties of the particles being separated. The efficiency of separation is dependent on the degree of hydrophobicity achieved by the particles meant to be floated, which are, in most cases, valuable minerals. The hydrophobicity is in turn dependent on the adsorption of the chosen collector onto the surfaces of the floated particles (Fuerstenau, 1984; Taggart and Hassialis, 1946). Empirical findings suggest that species dissolved in solution strongly influence collector adsorption and overall flotation response (Fuerstenau and Chander, 1986). Due to environmental concerns, it is becoming more pertinent for mining plants to recycle process water and hence limit the usage of potable water. There is an interest to ensure minimal discharge of plant water into the environment, as this water is typically polluted with process reagents that may render it toxic (Levay et al., 2001)."

Jan 1, 2018

By J. Dumont

"Usualmente en la mina se utilizaban maderos como: redondos, rollizos, pértiga, puntiles, productos de sierra. Posteriormente, con el desarrollo de la entibación metálica, se redujo el consumo de las mismas. En ese sentido, el presente texto describe el uso de la entibación de la madera que comprende los recursos, mercado, estudio morfológico, físico y mecánico, métodos de ensayos, agentes de destrucción, tratamiento de protección de las maderas de minas, entibación y posteo y su transporte en los pozos e interior de los grupos mineros Marlebach y Cuvelette. "

Jan 1, 1961

By Kouichi Nakano

Austenitic stainless steel, which includes nickel for stabilizing austenitic structure, is used for various purposes, for example, for structural material, corrosion-resistant material, biomaterial etc. Nickel is set as one of the rare metals and economizing on nickel as the natural resources is required. On the other hand, nickel is one of the metals that cause metallic allergy frequently. Therefore, high nitrogen stainless steel, where nitrogen stabilizes austenitic structure instead of nickel, has been developed in Japan and some of the foreign countries for the above reason. When high nitrogen stainless steel is fused and bonded, dissolved nitrogen is released to the atmospheric area, and some of the material properties will change. In this study, we bonded high nitrogen stainless steel by stud welding process, which is able to bond at short time, and we evaluate joint performance. We have got some interesting results from the other tests and examinations.

Jan 1, 2016

By F. Xie

Low gold and silver leaching kinetics has been commonly observed in traditional gold-silver cyanidation process, especially in those heap-leaching operations. The reactivity and availability of oxidant was believed to be the critical limitation for gold and silver dissolution. The occurrence of silver sulfide such as acanthite (Ag2S) in the ore may also result in low overall silver extraction. Leaching of gold and silver sulfide in the ferricyanide-cyanide solution has been investigated through rotating disc tests and the assistant effect of ferricyanide on increasing the dissolution rate of gold and silver was noticed. The potential use of ferricyanide as an auxiliary oxidant in gold/silver cyanidation process was proposed based on the results of leaching of gold-silver ores.

Jan 1, 2014

By A. Hayatdavoudi, D. Chitila, F. Boukadi

"Shale oil and gas have provided a tremendous boost to energy production in the United States even though the characteristics and behavior of shale are yet to be fully understood. Hydraulic fracturing is often applied to horizontal shale wells to stimulate production. This experiment seeks to determine effects of cyclic variable temperature, water vapor and exposure time on shale micro fracture propagation. We used 22 small Pierre shale specimens and subjected them to aforementioned conditions. Fractures developed in 19 specimens. Combination of high temperature and high water vapor generated the largest number of micro fractures on the specimen surfaces.INTRODUCTIONShale oil and gas have contributed immensely to energy independence in the United States. Most if not all shales depending on their total organic content (TOC) and their clay content bear the promise of being a source rock. For example, the Eagle Ford shale play, located in south Texas, is one of the key contributors to the recent rise in oil and gas production in the United States. Data from the U.S. Energy Information Administration (EIA), published in 2014, states that monthly oil production from Eagle Ford wells increased from 340 barrels per day (bbl/d) in January 2009 to nearly 1 million bbl/d in June 2013. Natural gas production has also increased at a similar rate over the same period, from 5.8 million cubic feet per day (MMcf/d) to nearly 4,000 MMcf/d (EIA, 2014).According to the railroad commission of Texas (RRC) 2014 published information, the Eagle Ford shale play is an important play because it produces gas and more oil than other shale plays in the United States. It is an organic-rich play with carbonate shale percentage in the 70% range in south Texas and the shale content increases moving to the northwest. High carbonate proportion renders this play brittle and suitable for hydraulic fracturing treatments."

Jan 1, 2015

By J. Drelick

Among the wide variety of modern surface chemistry analytical techniques, contact angle measurements still remain attractive for wetting characterization of solid surfaces. The captive-bubble and sessile-drop techniques are the most popular methods for the examination of flotation systems. Systematic measurements of advancing and receding contact angles for several three-phase systems using the captive-bubble and sessile-drop techniques show that the contact angle measurements depend on the technique used and may differ significantly for some heterogeneous and rough solid surfaces. Importantly, it was found that these discrepancies in contact angle measurements depend on the bubble (drop) size. Contact angles as measured with the static captive-bubble technique are compared with those measured with the dynamic captive-bubble technique, in which the capture of a bubble at the solid surface results after buoyant transport and attachment The dynamic captive-bubble technique allows for the formation of much smaller bubbles than is possible with the static placement technique in which a bubble is placed at the solid surface with a microsyringe. Although this dynamic technique cannot be recommended for the systematic wetting characterization of solid surfaces, its significant advantage is the ability to examine the contact angle/bubble size relationship over a wide range of bubble sizes, from several micrometers to several millimeters in diameter.

Jan 1, 1995

By D. J. Bauer, V. E. Shaw

Bastnasite concentrate was processed to recover total rare - earth content and obtain high - purity ceric nitrate . Reaction of the concentrate with 45 percent caustic soda for 1 hour at 180 ° C in stainless steel vessels resulted in 99 - percent conversion to rare - earth hydroxides . A drying step followed by solution in nitric acid produced a tetravalent cerium fraction amenable to extraction with TBP . Single- stage separatory funnel experiments resulted in 90 -percent recovery of ceric nitrate at a purity of 99.9 percent . Fractional extraction in pressure - bubbler columns resulted in 98.5 - percent recovery of 99.5 -percent - pure ceric nitrate .

Jan 1, 1964

Let’s start off with your assessment of the mining industry. Today, the status of the mining industry is stronger than it has been over the previous few years. While mining continues to be a major part of the world’s economic foundation, the industry is gaining strength due to rebounding metals and minerals prices. And now, with these rising prices and the changes the industry instituted during the years when mining-related commodities were selling at low prices, our stronger, more productive and internationally competitive industry should flourish. Mining remains an essential business and the industry is far ahead of the game when it comes to the trend of globalization as a key to sustained growth. Also, the industry continues to realize increased productivity through technological innovations. And an increasing number of countries are moving towards capitalism, which opens doors for exploration and mining within their borders. After looking at all of these factors, I believe that the mining industry will only continue to gain momentum in the future.

Jan 1, 2004

By X. Cheng

A series of batch flotation tests was performed on chalcopyrite-quartzite, pyrrhotite-quartzite, and on chalcopyrite-pyrrhotite-quartzite mixtures. Pulp potential measurements in the flotation tests of single sulfide minerals indicated that each sulfide mineral had its own optimum potential range for flotation. When these results were used to select the potential ranges for the separation of the two minerals from their mixture, their flotation responses changed and the selectivity of separation was adversely affected. A possible mechanism involving surface alteration through galvanic interaction is discussed. A method to improve the selectivity of flotation separation was proposed.

Jan 1, 1992

By Earl S. Bardwell

The determination of suitable and safe annealing temperatures is one of the most important problems arising in the operation of a copper rolling mill. Certain of the larger mills have worked this problem out for themselves and in these mills the operation has become more or less standardized. In some of the mills pyrometers are used to measure the temperature of the annealing furnaces and careful watch is kept to see that overheating does not take place. In a considerable number of the mills, however, dependence is placed entirely on the judgment of the operator. The almost total lack of literature bearing on this subject seems sufficient warrant for the publication of this paper. ' The discussion of this subject naturally divides itself into two parts: (1) The effect of annealing temperature on physical properties; and (2) changes in the microstructure of refined copper due to cold rolling and annealing. I. The Effect of Annealing Temperature on Physical Properties For the purpose of investigating this phase of the subject six test bars were selected, varying in oxygen content between the limits of 0.036 and 0.070 per cent. The chemical composition of each of these test bars was as follows: Bar Number 1 2 3 4 5 6 Copper + silver...... 99.95 99.92 99.945 99.94 99.95 99.93 Oxygen.............. 0.041 0.070 0.046 0.050 0.036 0.058 As + Sb............. 0.0038 0.0038 0.0038 0.0038 0.0031 0.0031 The bars were heated in an electric muffle to about 1,650" F. and rolled into rods. The rods were annealed, pickled, and drawn to No. 12 B. & S. gauge wire. The wire which was to be used for the annealing test was cut into 38-in. lengths and each length made into a coil 6 in. in diameter. The separate coils were marked so that they might readily be identified

Jan 1, 1915

By Hongshuang Di, Tianyu Zhang, Huiqiang Huang

A CMnSiAl transformation induced plasticity (TRIP) steel was used to study the effect of retained austenite on room-temperature mechanical properties. The steel plates with retained austenite were obtained by hot rolling, cold rolling and subsequent continuous annealing. The starting and finishing temperature of hot rolling are between Ac1 and Ac3. Reduction ratio of cold rolling is 75%. The continuous annealing is carried out at different intercritical temperatures. The relationship between work hardening exponent and retained austenite was discussed. The results show that, the Ac1 and Ac3 were much high because of the alloy elements, and the temperature range between them was wide. Due to the high hot rolling temperature, the grains was hereditarily refined as a result of dynamic recrystallization. Annealing at intercritical temperature of 930 ºC, retained austenite with relatively high stability reached a maximum volume fraction of 25%, a maximum total elongation of 30.2% and a best ultimate tensile strength × total elongation of 20.1 GPa·%. Instantaneous work hardening exponent reflects strengthening mechanisms at different strain stages. The TRIP effect of retained austenite is the main mechanism during deformation. With retained austenite of sufficient amount and high stability, continuous work hardening was observed in the tensile specimen of 930 ºC.

Oct 1, 2019

By Y. Mitani, H. Ikemi, K. Kitamura, H. Honda

"Instead of carbon capture and geological storage (CCS) that does not rely on structural aquifers, injecting carbon dioxide into sedimentary rock deep underground has been considered. For advection velocity of the fluid is slow, the permeability of sedimentary rock deep underground is low. In order to perform the CCS on the low permeable sedimentary rock, it is necessary to clarify the behavior of long term storage properties of carbon dioxide (CO2).In this study, the permeability and storativity of CO2 injected into low permeable rock has been evaluated. The injection of supercritical CO2 has been conducted on the specimen of Ainoura sandstone (unit weight: 2.39 g/cm3, porosity: 11.9 %) saturated with water by using flow pump method. The experiment has been set up to reproduce the similar condition of deep underground reservoir under 20 MPa confining pressure, 10 MPa pore pressure, 35°C temperature and 3 µl/min CO2 injection rate. In order to prevent an increase in pore pressure, the boundary condition on the outlet side of specimen has been kept a constant pressure.As a result, it has been possible to observe step by step the change of the differential pressure between both ends of specimen. Furthermore, the relative permeability and specific storage of rock under supercritical CO2 injection has been examined by the theoretical analysis of flow pump permeability test incorporating Darcy’s law for two-phase flow. It is observed that CO2 has been transmitted gradually while CO2 stored in the rock. It is also clarified that residual water has existed in specimen after showing the constant differential pressure in the end of the experiment. Using the results of the experiment, 3D core-scale flow-simulation by using TOUGH2 has been conducted due to confirm the flow of fluid and CO2 distribution in the specimen. From the experimental results and analytical solution to them, permeability and storativity are identified, and simulation results support the validity of the experimental results."

Jan 1, 2015

By Sunil S. Basarkar, Dilip M. Dewaikar, Rajesh H. Gajjar

"A load transfer program AXPILE was developed for simulation of the loadmovement characteristics of socketed piles of the Mumbai reg ion. This program used empirical relationships for ultimate shaft resistance at pile-rock interface recommended by Zhang and Einstein (1998). According to their recommendation, ultimate shaft resistance at pile-rock interface is related to the square-root of uniaxial compressive strength of intact socket material by a parameter C, which ranges from 0.4 for smooth sockets to 0.8 for rough sockets. Results of three instrumented pile load tests were compared with the AXPILE generated results. The comparison of analytical and field estimates of the unit shaft resistance confirm the recommendations of Zhang and Einstein (1998) on the unit side shear parameter c,, which was found to be in the range of 0.35 to 0.67.INTRODUCTIONInstrumented pile load tests were carried out on the test piles at the Bandra-Worli sea link project in Mumbai city of western India. High capacity socketed piles were required to take up loads from the superstructure. Hence, in addition to the available toe resistance, an accurate measurement of the shaft resistance in socket portion was desired. The instrumented load tests incorporated Osterbergcell (0-cell) assisted by strain gauge instrumentation to estimate the shaft resistance mobilization in the socket portion.AXPILE load transfer program was developed for load-movement simulation of socketed piles (Basarkar, 2004). The load transfer algorithm based on Coyle and Reese (1966) was incorporated in this program, which used empirical correlations and functions to account for load transfer in piles through shaft and toe resistance.This paper compares the computed unit shaft resistance from the AXPILE program with the measured values recorded from the instrumented pile load test."

Jan 1, 2005

By M. T. Davisson

Pile compression load capacity prediction methods are divided into four categories for purposes of discussing their reliability compared to static load test results. The categories considered are: 1) static analysis, 2) driving formulas, 3) wave equation analysis, and 4) dynamic measurement and analysis. It is concluded that any method of static analysis that works for the geological deposit in question may be satisfactory. However, any given method can be quite wrong when applied to other deposits of soil that are different in terms of their engineering and geological characteristics. Dynamic formulas are found to be theoretically unjustifiable. The ready availability of the wave equation analysis for microcomputers eliminates the need to utilize dynamic formulas. The wave equation analysis is found to be the best analytical method for making predictions both for design and for construction control. Dynamic methods of measurement and analysis are found useful, but have limitations that have caused troubles on many projects. Two case histories are presented that show the limitations of dynamic measurement and analysis, and of the wave equation analysis. Soil deposits exist that defeat both the wave equation and dynamic measurement techniques; static load tests are currently the only method of proving the load capacity of piles in such soils.

Jan 1, 1991

By A. H. Daane, R. L. Myklebust

The yttrium-manganese system has been investigated by thermal, metallographic, and X-ray diffraction methods. There are three intermetallic compounds present: YMn2 which melts congruently, YMn4, which undergoes syntectic decomposition, and YMn,, which undergoes peritectic decomposition. The compound YMn4 is ferromagnetic at room temperature with a Curie temperature of 214°C. There are eutectics at 25.2, 60.9, and 82.0 wt pct Mn which melt at 878°, 1100°, and 1075°C, respectively. Crys-tallographic data are given for YMn4, and YMn12 . The terminal solid solubilities are low. In a general program of study of yttrium metal in this laboratory some alloy systems of this metal with elements of the first transition period have been examined. This work was originally instigated by experiences in cladding yttrium with jackets of some protective metals such as Inconel for high-temperature service in air.' In some cases a low-melting phase was observed to form between the Inconel and the yttrium resulting in failure of the samples. In characterizing this reaction, a survey was made of the systems of yttrium with chromium, manganese, iron and nickel,, and it was found that a eutectic was formed between these metals and yttrium on the yttrium-rich side of the system. This present study of the Y-Mn system was carried out to examine in more detail the alloying nature of yttrium, and to correlate trends that have been observed in previous related studies. It was observed by Voge13 that in the systems of lanthanum, cerium, and praseodymium with each of the metals in the first transition series, the tendency to form compounds diminished in the order nickel, cobalt, and iron while no compounds were formed with manganese, chromium, or titanium. Beaudry and Daane4 observed a similar behavior in the systems of yttrium with some members of the first transition series except that the tendency for compound formation was greater. Both the Y-Ti5 and Y-Cra systems consist of simple eutectics, while in the Y-Fe,7 Y-CO, and Y-Ni4 systems, there are four, eight, and nine compounds, respectively. In addition to the above trends, the similar atomic radii and electronegativities of yttrium and thorium invite a comparison between their alloying behaviors with a common element such as manganese. In crys- tallographic studies, Florio et al.' have identified three intermediate phases in this system which are ThMn2, Th6Mn23, and ThMn,,. Gschneidner and Waber10 have examined published information on alloy systems of the rare-earth metals and have correlated this information with current alloying theory. From their study, they predicted that the Y-Mn system would contain one intermetallic compound. On the basis of this prediction, the trend in the alloying behavior of yttrium with the elements of the first transition series and the alloying behavior of thorium with manganese, one might expect from one to three intermetallic compounds to form in the Y-Mn system. A consideration of Hume-Rothery's rules of alloying based on size-factor, electronegativity, and valency suggested a small terminal solubility and possible compound formation. The present study was undertaken to confirm these predictions of low terminal solid solubility and compound formation and to establish the general alloying behavior of yttrium with manganese. EXPERIMENTAL Materials. The manganese used in this investigation was obtained from the Foote Mineral Co. as electrolytic plates of 99.9 pct stated purity; the yttrium metal was prepared in this laboratory. Table I gives the analyses of these materials. For the solubility studies at the yttrium-rich end of the alloy system, distilled yttrium, whose major impurity was 200 ppm Ti, was used. Preparation of Alloys. The alloys were formed by comelting the two metals in an are-melting furnace under an atmosphere of argon. The buttons thus formed were inverted and remelted three to five times to promote homogeneity. Due to the high vapor pressure of manganese, it was assumed that the weight lost during are-melting was all manganese. This assumption was based on the very good agreement observed between calculated compositions and chemical analyses of several alloys. The compositions of the dilute alloys used for solid solu-

Jan 1, 1962