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By R. R. Odle

A laboratory and pilot-scale investigation of direct smelting of copper concentrates was conducted to determine the effect of concentrate analysis and the degree of roasting on the yield and quality of copper produced in a subsequent smelting step. A stoichiometric :mOdel of direct smelting is presented which predicts the? quantity of copper; slag, and white metal' prOduced'and the distribution of copper in these phases as a function? of the concentrate '(calcine) analysis.

Jan 1, 1983

By S. Shrestha

Magnesium-based alloys are of growing interest for many industrial applications due to their favourable strength-to-weight ratio and excellent castability. Mass reduction has advantages in many industrial sectors for example, in automotive, a reduction in mass improves fuel economy and can lead to more efficient mechanical systems by reducing the weight of moving parts like wheels, gears, pistons. However, the relatively poor corrosion and wear resistance limits the use of magnesium and its alloys in many potential applications. The patented Keronite® plasma electrolytic oxidation (PEO) process enables manufacturers to overcome such problems and, in its latest generation equipment has been developed to industrial realisation for high volume production. This paper presents microstructural characteristics and corrosion performance of two most widely used high pressure die-cast magnesium alloys AZ91D and AM6OB with a duplex corrosion protection coating system that comprised a thin Keronite pre-treatment followed by a subsequent automotive grade final powder coat.

Jan 1, 2006

By A R. Cruden, M S. Egglseder

The formation of banded iron formation (BIF)-hosted high-grade iron ore deposits in the Hamersley Province, Australia has been debated for decades. Although a structural control on their formation is widely accepted, only the roles of large-scale structures (ie faults and folds) formed by brittle and ductile deformation have been considered to date. However, the deformation of multilayered sequences in the Hamersley Province (ie the Mount Bruce Supergroup), with their contrasting rheological behaviours, creates challenges for understanding the complex structural framework at regional to deposit scales, including the significance for mineralisation and orebody location.Our approach to understanding these complex relationships is based on an established principle of structural geology, which is to extrapolate microscale structures to deposit-scale structures and vice versa, supported by state-of-the-art 3D modelling techniques. Complexly deformed hand samples associated with the Mount Tom Price iron ore deposit (Hamersley Province, operated by Rio Tinto Ltd) have been analysed and visualised with 3D explicit (Move™, Midland Valley Ltd) and implicit modelling software packages (Leapfrog™, AranzGeo Ltd) and supported by microstructural investigations (optical and X-ray microscopy) and fieldwork.Our study shows that the deformation of BIFs in the central Hamersley Province is controlled by microscale chemical processes (ie dissolution precipitation creep) due to rheological differences between iron oxide and chert layers, contrasting fluid flow properties and layer thickness variations. These processes account for the removal of vast amounts of silica, its transportation by diffusion in the presence of a fluid and reprecipitation at low-pressure sites. Consequently, this structural framework was used by different upgrading fluids to form iron orebodies.CITATION:Egglseder, M S and Cruden, A R, 2015. Evolution of a structural framework for high-grade iron ore deposits, in Proceedings Iron Ore 2015, pp 255–262 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By William Ferguson, Claude Deveau, Wade Hazel, Stephen R. Young, Allen Lussier, Robert Copeland

"LocationSometimes known as the Bernie Lake mine, the mine is located about 180 km east-northeast of Winnipeg on the northwestern shore of Bernie Lake, close to the Nopiming Provincial Park and the Manitoba-Ontario boundary. The mine is accessed from Lac du Bonnet which is linked to the provincial road system.Brief Description of OperationTantalum Mining Corporation of Canada Ltd. operates an underground mine employing ramp access, room and pillar mining, and shaft hoisting for the production of tantalum, lithium and cesium minerals. Daily campaigned crushing of the tantalum and lithium ores supply separate concentration circuits. Tantalum recovery employs conventional gravity equipment together with recently developed centrifugal concentration methods. All tantalum concentrates go to Cabot Performance Materials for the production of tantalum chemicals and metal. Lithium minerals are recovered using heavy medium separation and silicate flotation to produce spodumene and montebrasite/amblygonite concentrates. The lithium concentrates are shipped worldwide for use in ceramics, specialty glass and mold powders. Cesium processing involves the dry grinding of pollucite as feed stock for the recently built on-site chemical plant dedicated to tl1e production of cesium formate, a high-density drilling fluid for use in the oil industry."

Jan 1, 2000

By A. Kaina

The San Luis deposit is one of the few documented gold deposits on a detachment surface. This paper presents mineralogic and geochemical data that was gathered to characterize the mineralization, classify the ore deposit, and provide details of the ore forming process. Included are data on the paragenesis; alteration-mineral assemblages major and trace element geochemistry, and fluid inclusions. The San Luis deposit occurs on the western slope of the Sangre de Cristo Mountains adjacent to the San Luis Basin about 5 miles northeast of the town of San Luis in Costillo County, south-central Colorado. Mineralization was discovered in the district in the early 17th century. Production began in 1890 on lead-silver ores from which the district took the name the old name of "El Plomo". From 1897 through 1934 gold was intermittently produced. Battle Mountain Gold Company took an option on the property in 1987 and proved on ore body comprising an eastern block that has 1,277,300 t ore at a grade of 1.68 g/t and a western block of 9,744,000 t with a grade of 1.34 g/t. Production began in 1990. A companion paper by Benson (1994) describes the San Luis district and the ore body, hence the reader is referred to this or Robert and David (1990) for details of the geology from which the following is summarized.

Jan 1, 1994

By R. Schuhmann

The thermodynamic data and calculations which underlie the design of the Q-S process for coppermaking are summarized. The efficient production of crude copper and slag of low copper content in a single con¬tinuous converter requires the establishment and control of gradients in oxygen activity and other physico-chemical variables throughout the reactor. These gradients are established by stagewise introduction of oxygen and solid feed materials to provide: (a) flash oxidation of sulfides above the bath, utilizing the great bulk of the oxygen, (b) conversion of high grade matte or white metal to crude copper by bottom blowing with restricted bath turbulence, (c) close approach to equilibrium staging of converting and deconverting reactions along the length of the slag layer, from a maximum oxygen activity near the metal discharge end to a minimum at the slag discharge end, and (d) completion of slag cleansing by deconverting. In terms of the Phase Rule, the Q-S process involves a system with a minimum of 5 components (Cu, Fe, S, O, and SiO2) and several liquid, solid, and gaseous phases. Accordingly, basic data from previously reported studies on simpler systems are utilized to prepare an equilibrium diagram for the 5-component system and to generate a quantitative thermodynamic model for the Q-S process. This model shows in particular the ranges of oxygen activities (measured by equivalent CO2/CO ratios) involved in the Q-S process and the relations of oxygen activity to temperature and other important physico-chemical variables of coppermaking.

Jan 1, 1976

By Q. Chen, J. H. Zhang, M. Zhang, F. M. Zheng, Y. J. Zhang

The characteristics of air bubbles and gas dispersion in KYF flotation cell are studied using the method of the point conductivity probe and CFD simulation. With increasing of speed, the velocities of air bubbles increase slowly and the distribution of diameters exhibits little change. With increasing of aeration rate, the gas holdup is increased. However, the velocities and diameters of bubbles have no great change. The CFD predictions on gas holdup have good agreement with the experiment results. The gas holdup distribution in the center section is revealed. The gas dispersion in the middle and upper part of flotation cell is uniform. It would be helpful for bubbles and solid particles collision. The gas holdup of the lower part of flotation cell is scarce, and it agrees with the observation in experiment. The gas would accumulate at the suction side of impeller blades, and it would decrease the power consumption. The rotating speed and aeration rate have great effect on gas dispersion. With increasing of aeration rate, the gas holdup of flotation cell will increase. The increasing of speed would improve gas dispersion. The results are expected to help to optimize the performances of KYF flotation cell.

Jan 1, 2015

By A. Garnier, K. Tremblay-Bouliane, B. Gaillet, S. Moineau, D. Tremblay

"A heptapeptide library displayed on M13 bacteriophages (phages) was screened to identify peptide sequences able to selectively bind to gold, chalcopyrite, sphalerite, pyrite, and silica ores, and to evaluate phage potential as bioflotation reagents. Many peptide sequences were isolated through biopanning and differed from known sequences. Adsorption isotherms were determined and a receptor/ligand interaction model was identified and used to compare affinity of peptide sequences toward ores. Some phage sequences have slightly lower affinity to sphalerite than other sulphides. Adsorption was higher on sulphides than on silica. Induction time measurements suggested filamentous M13 phages lower hydrophobicity of the ore surface.RÉSUMÉ Une librairie d’heptapeptides présentés sur des bactériophages M13 (phages) a été criblée afin d’identifier les séquences peptidiques affinitaires à des minerais d’or, de chalcopyrite, de sphalérite, de pyrite et de silice et d’évaluer le potentiel de ces phages en tant que de bio-réactifs de flottation. De nombreuses séquences peptidiques ont été isolées par bio-criblage et différenciées d’autres séquences connues. Des isothermes d’adsorption ont été déterminées et un modèle d’interaction récepteur–ligand a été identifié et utilisé pour comparer l’affinité des séquences peptidiques par rapport aux minerais. Certaines séquences de phages possèdent une affinité légèrement inférieure pour la sphalérite comparativement aux autres sulfures. L’adsorption sur les sulfures était plus élevée que sur la silice. Des mesures de temps d’induction suggèrent que les phages filamenteux M13 diminuent l’hydrophobicité de la surface des minerais."

Jan 1, 2016

By W. H. W. Husband

Rock salt has been mined by the solution method for many years in many countries. Attempts have been made in the past in Canada and various other countries to produce potash by the' same method. However, only Kalium Chemicals Limited (1) has been successful, possibly because the conditions in Saskatchewan are the most favorable conditions to be found so far for the development of a solution mining method for potash. There are significant differences in solution mining of rock salt and solution mining of potash. First, rock salt deposits are relatively pure in respect to soluble minerals, whereas potash is never found in the pure state and contains Substantial amounts of other soluble minerals, particularly rock salt. In comparison to rock salt, much less potash is dissolved and brought to the surface for the same amount of water circulated through the orebody. The amount of water to be evaporated per unit weight of product is a major difference. Much greater amounts of water must be evaporated when producing potash and the treatment of the brine is more complicated because other dissolved salts have to be separated. Secondly, the rock salt deposits, particularly the domes, are much thicker. Bed thickness is of prime importance because it determines the yield of a well and consequently the economics of the process. Furthermore, as rock salt provides a strong roof structure, larger cavities can be developed and this prolongs the life of the rock salt well.

Jan 1, 1971

By J. E. Matta

The Bureau of Mines made laboratory absorption measurements on oil shale samples, which showed that the amount of methane absorbed is proportional to pressure and oil yield, and can be much larger than would be predicted based solely on porosity. Oil shale cores collected in the field were also measured for their gas content using the Bureau of Mines direct method. Cores taken from deep locations and far from outcrops yielded more gas than cores from shallower locations or at outcrops, when taking into account variations in oil yield, and all data indicate that oil shale mines that are both deep and far from an out-crop will emit low levels of methane gas.

Jan 1, 1977

By Todd Schrauf, James Scott, Mark Smith

"Cyanide heap leaching of gold ores in areas with extremely low winter temperatures requires special considerations to prevent freezing of the leach solution. Factors that impact the solution temperature include ore temperature at the time of stacking and during operation, burial of drip irrigation lines, use of geomembrane covers and heating of the leach solution. Thermodynamic modeling was performed to simulate expected ore and solution temperatures under different operating strategies for Kaminak Gold’s Coffee gold project in the Yukon Territory. Mean monthly temperatures at the site ranged from a low of -22.5 °C (-8.5 °F) to a high of 13.6 °C (56.4 °F), while in situ ore temperatures ranged from -0.5° to about -1.5 °C (31 ° to 29 °F). The modeling results were used to optimize the operational parameters and indicated that a combination of drip line burial and heating of the leach solution during the winter months was required to maintain solution temperatures above freezing during the initial years of stacking, although as the size of the heap increased, heating was no longer necessary.Modeling objectivesThe successful operation of a cyanide heap leach under extremely cold winter temperatures requires the implementation of operational strategies to prevent freezing of the leach solution and the ore within the heap. Thermodynamic modeling of the heap provides the means to quantify the effectiveness of these different operational parameters on maintaining the required operating temperatures to avoid freezing within the heap. The operational parameters that were evaluated with the model included:"

Apr 1, 2016

By J. VAN DEN BERC

Tin production and export from the Far East are still a long way off from the prewar figures. The Malayan Peninsula, which had a rather good start directly after the war largely because of stock piles found in Singapore and elsewhere, has since been hampered in the rehabilitation of its tin mines and dredging operations by material shortages and, more recently and more severely, by revolts and attacks of communist elements and gangster bands. These hindrances make working in the mines dangerous and form a daily threat against the valuable and highly vulnerable dredges. Contrary to the conditions in Malaya are those on the tin islands of Billiton, Banka, and Singkep-all in the Netherlands East Indies-where the Dutch have re-established peaceful relations with the population. Dutch efforts since the fall of 1945 have been rewarded by continuously increasing production, extension of production facilities, and return of moderate prosperity, complete safety, and all-out co-operation among the population ? native and Chinese ? to the benefit of all concerned.

Jan 1, 1949

By Gang Guo, Zhong Liu

"In response to an increasing demand of anchored structures for underground space and transportation infrastructure in China, an innovative underreamed ground anchorage system was created. The novel anchorage system has provided more efficient functions with higher capacity at lower cost, because of the enlarged cylindrical body (known as ECB) sealed in capsule at bottom of anchorage. This paper presents the detailed structure of innovative anchorage system and its special features. To investigate the bearing mechanism of new anchorage, we evaluate its performance and failure mode based on the experimental results, and also indicate its strain-hardening load-displacement relationship. Unlike the shaft anchorages, it is identified no overall failure to be found in soil surrounding the underreamed anchorage. More importantly, the anchorage capacity is governed by the base resistance, which takes more than 80% of total pullout capacity resulting from the contribution of ECB. Finally a case history of anti-floating project introduces the new combined construction approach and procedure, which has provided the contribution to the quality control and cost efficiency.INTRODUCTION AND BACKGROUNDThe construction boom over two decades in China has resulted in an increasing demand for underground space and slope stability. The infrastructures market requires the more efficient anchorage systems for retaining structures, resisting uplift forces and slope protection. The major concern focuses on gaining higher capacity and lower cost resulted from perfecting anchorage systems. There are three main anchorage systems designed to achieve the above objectives: ? single bore multiple anchorage system (Barley 1997), ? regroutable anchorage system (Smoltczyk 1991), ? underreamed anchorage systems (Xanthakos 1991). Generally, the concept ? comparing with the other two, can be more competitive due to its distinct advantages. To improve the performance and durability of ground anchorages under the complex geological conditions and diversified engineering requirements, a number of different underreamed anchorage technologies had been used, which included cone - shape anchorage described by Liao, Wu and Shu (1997) in Taiwan, Soilex anchorage developed in Sweden (Massarsch et al. 1997), Soletanche anchorage proposed in France, blasting anchorage used in Czechoslovakia (Hobst and Zajic 1986), jet-grouting anchorage innovated in Europe (Anon 1988), as well as deep mixing anchorage created in Japan (Cheng et al. 2000).The underreamed anchorage systems have the remarkable advantages compared to the shaft anchorage system. However, there are also some weaknesses inherent in the underreamed systems. For instance, the mechanical underreamed anchorage is unsuitable in sand or waterbearing ground, because the enlarged hole is easy to collapse, and it is hard to ensure the quality of anchorages. On the other hand, relying on the blasting in deep hole, the geometrical space and dimension of enlarged hole is uncontrollable, meanwhile, the continuous blasting operations may easily cause the serious ground deformation and the negative effects to the completed anchorages."

Jan 1, 1900

By C. K. Leith, W. J. NEAD

(Glen Summit Meeting, June, 1911.) . ONE Of the most significant developments in the iron industry in recent years has been the discovery and opening of enormous reserves of low-grade ore in eastern and northeastern Cuba. The two principal fields are the Mayari and the Moa, situated on Nipe bay, in the Province of Oriente. A less well-known district of the same type is that of Baracoa, at the east of the island, and another is in Camaguey province in central Cuba. In the comprehensive estimates of the iron-ore reserves of the world, published during the summer of 1910 by the International Geological Congress in Sweden,' these Cuban deposits are estimated at about 2,000,000,000 tons. Certain it is that the reserve is a large one. The Spanish-American Iron Co., the Juragua Iron Co. (Bethlehem Steel Co.), the U. S. Steel Corporation, and others have been active in this exploration.. The Spanish-American Iron Co. has established a port for the handling of these ores at Felton, has built a railway 16 miles to the ore-fields, and has opened up deposits for steam-shovel mining. Its expenditures have reached an aggregate of about $6,000,000 in preparation for the handling of these ores. Shipment of the ore to Sparrow's Point, Md., has begun and may be expected to rise to a considerable amount in the near future. The ore reaches this point at a cost per unit of iron considerably lower than Lake Superior ores, and the presence of a low percentage of nickel gives a desirable steel. It is not the purpose of this article to consider these ores from a commercial stand-point, but rather to discuss their-origin. If our conclusions are correct, they throw light on the character of the deposits which should have some commercial significance. 1 The Iron Ore Resources of the World, an inquiry made upon the initiative of the Executive Committee of the Eleventh International Geological Congress, Stockholm, vol. ii., p. 795 (1910).

Mar 1, 1911

By J. Drzymala, K. L. Wolters, T. Chmielewski, T. D. Wheelock, D. H. Birlingmair

Microflotation tests were conducted with a modified Hallimond tube equipped with a fritted glass disk and magnetic stirrer to determine whether the results would support an equation that predicts a linear relationship between particle size and the reciprocal of particle density in water for a specified flotation recovery in a given time. Data obtained with the tube for either hydrophilic or hydrophobic solids fit the equation satisfactorily. It was also shown that the natural flotability of molybdenite is somewhat less than that of elemental sulphur and that sodium dithionite is a good depressant for sulphurised pyrite. In addition, it was found that the untreated pyrite and galena used in the study were hydrophilic and did not float by particle-bubble attachment.

Jan 4, 1992

By John Newby, Ulf Gwildis, Fred Marquis

From the Brightwater Conveyance System in Seattle to the Second Narrows Water Supply Tunnel in Vancouver, BC, the design and construction of deep-lying tunnels in the Pacific Northwest often require the incorporation of deep portal shafts. Alluvium overlying marine and glacial deposits combined with the high regional seismicity is the common geologic setting. The latest example illustrating the development of shaft design for this scenario is the 40-m-deep shafts of the Annacis Island Wastewater Treatment Plant New Outfall System. The main components of the shafts include the initial lining, providing the excavation support system to be used for launching and receiving a 5-m-diameter TBM; and the final lining, designed to withstand all static and seismic loads and to remain viable for the intended design life. This paper presents design and construction considerations for these shafts against the background of and lessons learned from past project experiences.

Jun 13, 2021

By Frank L. Hess

BERYLLIUM is demanding more of the limelight, and the output of beryllium copper (containing 2% to~ 3 per cent of beryllium) seems to have grown 60 per cent above that of 1936, which was double that of 1935. There is increasing interest in beryllium-aluminum alloys and small quantities are being marketed at $50 per lb. for the contained beryllium. Other alloys also can be produced. Further price decreases for beryllium copper (now $23 per lb. for the contained beryllium) seem , possible and desirable. No difficulty has been experienced in obtaining beryl and a 'reserve stock has been built up. One supplier heretofore found reliable has offered to furnish 200 tons per month. Supplies during 1937 have come from the Black Hills in South Dakota, Colorado. India, and South America

Jan 1, 1938

By Barbara Rutter, Phillip Mulligan

This research investigates how changes in shock tunnel geometry affect the pressure versus time waveform. The Large Arena Test Simulator (LATS), which is composed of four different rectangular sections connected by three expansion sections, was used to determine how the changes in geometry affect the shock wave profile.

Feb 1, 2020

By Henry A. Wentworth

(New York Meeting, February, 1912.) ELECTROSTATIC separation of ores in its present form is generally known as the Huff' process from the name of Charley H. Huff, of Boston, Mass., through whose constant and persistent labors (with the invention of Clinton E. Dolbear as a basis) the successful commercial process embracing separative machinery and the various electrifying devices has been developed step by step, and the finances for the long period of development provided, and the method finally established and recognized throughout the world as an important and successful addition to the ore-dressing department of metallurgy. The permanent field-success of electrostatic separation began in 1908 with a 20-ton Huff experimental mill built specially for the purpose by the American Zinc, Lead.& Smelting Co., in Platteville, Wis., a plant which was a success from the start and was gradually increased in capacity as the market-conditions warranted to 100 tons of concentrates per day. Much credit is due to the above-mentioned company for its initial venture, and for its assistance in applying the process to field use. Prior to 1908 electrostatic separators had been installed and operated (but for a comparatively short time, however) in a number of places; some under the patents of Mr. Dolbear by himself and associates, and some under the patents of Lucien I. Blake and Lawrence N. Morscher, by W. G. Swart, mining engineer, of Denver, who has always been a courageous advocate of electrostatic separation. Due to the difficulties experienced in the generation of the electrical charges, the primitiveness of the separators, the wooden construction instead of iron as at present, the lack of control of the electrical fields and other difficulties overcome by the later inventions of the Huff Electrostatic Separator Co.,

Jun 1, 1912

By Hormando Leocadio, CWM van der Geld, Julio Cesar Passos

Impinging water jets promote high heat flux extraction rate. Steel industry widely employs the process for accurate temperature control to improve the microstructure and to ensure adequate mechanical properties. The range of surface temperatures, heat fluxes and cooling rates are very large, which makes it important to obtain an accurate value of the heat transfer coefficient. This paper presents an experimental and numerical study of the heat transfer behavior of a high temperature (450°C - 900°C) steel plate cooled by a water jet at 20°C to 70°C. High-speed imaging (up to 20,000 fps) within water jet impingement zone allowed the characterization of the boiling regimes in the early stages of cooling. The effects of initial temperature, water jet temperature and velocity on the heat transfer coefficient were analyzed by inverse heat conduction method that predicts the heat flux and temperature on the top surface from temperatures measured with thermocouples inserted in test plate. Heat transfer is strongly affected by the initial temperature of the hot steel, water jet temperature and, less intensely, by jet velocity. High cooling rates start when liquid water is in direct contact with surface temperatures above 700°C.The results will contribute to the enhancement of the temperature cooling control on the runout table and cooling model employed at Usiminas Hot Strip Mill.

Oct 1, 2019