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By A. Welty, T. Garn, K. Lyon, B. Jakovljevic, R. S. Herbst, M. Greenhalgh, Cytec Solvay Group

"Industrial rare earth separation processes utilize PC88A, a phosphonic acid ligand, for solvent extraction separations. The separation factors of the individual rare earths, the equipment requirements, and chemical usage for these flowsheets are well characterized. Alternative ligands such as Cyanex® 572 and the associated flowsheets are being investigated at the pilot scale level to determine if significant enhancements to the current separation processes can be realized. These enhancements could be defined as higher separation factors, reduced stage requirements, or reduced chemical consumption. Any of these enhancements can significantly affect the costs associated with these challenging separation proccesses.A mid/heavy rare earth element (REE) separations flowsheet was developed and tested for each ligand in a 30 stage mixer-settler circuit to compare the separation performance of PC88A and Cyanex® 572. The ligand-metal complex strength of Cyanex® 572 provides efficient extraction of REE while significantly reducing the strip acid requirements. Reductions in chemical consumption have a significant impact on process economics for REE separations. Partitioning results summarized Table 1 indicate that Cyanex® 572 offers the same separation performance as PC88A while reducing acid consumption by 30% in the strip section for the mid/heavy REE separation."

Jan 1, 2016

By W. R. Bacon

"MAGNETITE HAS BEEN found in many .parts of the coastal area of British Columbia, but the more important deposits are on Vancouver Island and Texada Island. The locations of these deposits are shown on Figure 1.Interest in the magnetite deposits dates back to the 1870s, when land was acquired on the southwest coast of Texada Island by the Puget Sound Iron Company. This ground included the Prescott, Paxton, and Lake deposits. During the years 1885 to 1903, and 1908, 28,898 tons of magnetite ore was shipped to the company's blast-furnace plant at Irondale, Washington, U.S.A. This production was almost entirely from the Prescott open-pits.In the years following the Texada Island discoveries, other magnetite deposits were found in the coastal area, and various plans were proposed to utilize the local ores in the establishment of a steel industry in the Pacific Northwest. None was carried to fruition but, in 1951, open-pit mining was begun at Iron Hill, Vancouver Island, to furnish iron concentrates for steel mills in Japan. In 1952 mining of the Texada deposits was resumed to supply the same market. Production figures for these recent operations are as follows:"

Jan 1, 1949

By Alfred W. G. Wilson

MR. F. E. LATHE: In studying any subject whatever, one should at least occasionally stand back from the canvas, as it were, and take a broad view of the picture. It is such a view of the subject of industrial minerals that Dr. Wilson has given us today, and, in consideration of our efforts to utilize Canada's resources to the utmost in the present emergency, it seems most timely. I shall confine my remarks on the subject to the resources of the atmosphere and hydrosphere. We seldom stop to realize our dependence upon the atmosphere, not merely as a source of the oxygen we breathe but also of other indispensable elements. As recently as the beginning of the present century, grave concern was felt lest the rapidly increasing population of the world should ultimately starve for lack of the nitrogen required for crop growth. I recently noticed a reference to the Scientific American for March, 1890-just fifty years ago-in which an account is given of work on the fixation of nitrogen, which, said the article, "leads to the conclusion that while cyanides and ammonia may be thus produced experimentally, there are as yet insuperable difficulties in the way of adapting those methods to industrial purposes". Y et, in the early part of the present century, the development of the arc, cyanamide, and synthetic ammonia processes of nitrogen fixation was such as to remove, for all time to come the possibility of a shortage of nitrogen. Today, the atmosphere is by far our greatest source of nitrogen, and the capacity of the nitrogen fixation plants of the world is at least 4,000,000 tons annually-much more than can at present be utilized. Pure oxygen or oxygen-enriched air offers great possibilities in metallurgy and industrial chemistry, but, so far, little application has been made. In a paper presented to the Institute in 1926, 1 pointed out the theoretical savings which could be effected by the use of oxygen in burning carbon-when the gases pass off at 2,460°F., the fuel saving is no less than 50 percent. The use of oxygen on a commercial scale is intimately tied up with the question of refractories, but we should not forget that the possible changes in metallurgical practice by the use of oxygen are truly of revolutionary character.

Jan 1, 1940

By T. L. Tanton

Introduction Sturgeon River area, on the east side of lake Nipigon, Ontario, was the scene of a gold rush in 1934. According to press reports, the active staking during the latter part of the summer spread out rapidly from the early holdings until it embraced practically all of the lower basin of Sturgeon river in a belt up to ten miles wide extending west from Kinghorn for 35 miles to lake Nipigon. And, before winter set in, active prospecting and claim staking reached beyond lake Nipigon to areas where belts of ancient schists were known, notably west of Obonga lake. The writer's familiarity in past years with the areas to which attention has been directed admits of some observations on means of access in the field, the general geology, and the progress that has been made in identifying formations favourable for the occurrence of gold. Canoe Routes From the writer's observations in Sturgeon River area in 1917 and in the Obonga Lake area in 1933, it is recalled that there is, locally, a striking dif~ ference in the accessibility of the two areas by travel along canoe routes. Sturgeon River area is easily accessible from Kinghorn or Jellicoe stations on the Canadian National railways. Many small lakes, commonly of the linear type and with elongations east and west, occur among the forested rocky ridges near Jellicoe (Figure 1) and to the east and west along, or adjacent to, Sturgeon river. This stream has long stretches with gentle current between the falls and rapids. The drainage system provides excellent canoe routes (Figure 2), and the interruptions to travel (Figure 3) are remembered .as scenic features that were passed by portages with firm footing. West of Obonga lake, the streams flowing easterly to lake Nipigon may be followed through scenic canyons to a plateau of law relief characterized by extensive muskegs and shallow, brown-water lakes; and along small streams, where beaver dams have been destroyed, there are muck ponds where the usual alternatives of paddling or portaging can be dismissed in favour of the 'moosing' method of progress with the canoe (Figure 4).

Jan 1, 1935

By Maurice Hall Haycock

ONE result of the higher price of gold has been the exploitation of many low-grade deposits, the successful treatment of which depends upon obtaining high recovery of the contained gold. Modern methods have made it possible to recover gold from many ores formerly regarded as impossible to treat economically, but in order to apply these methods efficiently it has become desirable, and indeed in many cases indispensable, to gain precise information concerning their mineralogical and physical character. The most successful means of doing this is the use of the reflecting microscope. Reflecting microscopes had long been employed by metallurgists for studying polished surfaces of iron and steel when, thirty years ago, Dr. W. Campbell, of Columbia University, advanced the idea of using similar methods for studying opaque minerals (1). The immediate result was the completion of two microscopic studies, the first on Cobalt silver ores (2) and the second on Sudbury nickel ores (3). The idea was surprisingly slow in being adopted, and not until 1911 did it begin to spread through the universities of this continent. From then on, ore microscopy, or 'mineragraphy', made rapid progress, and, during the next fifteen years, research in universities of North America and Europe led to the development of somewhat specialized apparatus and technique. This phase of development, which resulted largely in contributions of a descriptive nature, furnished a mass of data from which the possibility of economic applications was soon recognized. Ore microscopy became an aid to the mining geologist in solving many problems of ore deposition. This soon led to its application in the study of ores and mill products in connection with their treatment. Its usefulness in this latter field has been very marked and has led to its widespread adoption by the mining industry.

Jan 1, 1937

By M. Wittke

"In the course of the extension of the railway network in Israel, currently the two 4.6 km long tubes of the Gilon Tunnels on the line from Akko to Carmiel are being constructed. The tunnels run through the limestones of the Bina- and Yirka-formations, which locally are karstified. The maximum overburden amounts to 160 m.The limestones are mostly horizontally bedded and vertically jointed. Occasionally also inclined joints exist. The tunnels cross various fault zones, which mostly strike at an acute angle to the tunnel axis and are steeply inclined. The karstic cavities which were encountered during tunneling have partially been filled by clay. In the vicinity of the fault zones, the rock has often been strongly jointed and weathered respectively. The two single-track tubes have a cross section with vertical walls and an open invert. The tubes are connected by cross cuts with a spacing of approx. 250 m.During the tender phase, WBI has elaborated the tender design for a joint venture of a Chinese and an Israeli construction company. After the joint venture had been awarded the contract, the preliminary and the detailed design have been elaborated by WBI and the construction works have been guided. On the basis of the geological description, rock mechanical models have been elaborated, followed by stability analyses on the basis of the Finite Element method. The tunnels have been excavated according to the shotcrete method. The support in most areas only consisted of a very thin shotcrete lining and radial bolts in the area of the roof. Depending on the degree of jointing and weathering, locally advancing support by means of spiles has been applied.The internal lining of reinforced concrete has been constructed in parallel to the heading of the tubes. Mucking and delivery of materials was carried out through the cross cuts.The breakthrough was achieved in April 2014 and thus within schedule. The predicted distribution of the excavation and support classes along the tunnel has been in good agreement with reality."

Jan 1, 2015

By W. Kempson

"As has been noted on numerous occasions, the vertical shafts being sunk around the world are all tending to get deeper as we seek to take advantage of higher grades of minerals which can sometimes be found at greater depths. One of the challenges with these deeper shafts is the requirement to supply services to the mine’s operations at depth as well as the requirement to dewater the mine. Both the supply of water and the dewatering of mines is generally done using piping. With the greater shaft depths, this piping is now required to contain higher pressures as well as to accommodate changes in temperature resulting from normal mine operations. This paper will discuss the requirements for the design of high pressure piping in deep vertical shafts. The discussion will start with the general definition of the systems and the detailed design requirement. Once this is clearly outlined, we will discuss the options available for fulfilling these requirement as well as the advantages and disadvantages of each of the systems. We will finish with the installation recommendations and provide a basis for the maintenance of these systems. INTRODUCTION Piping in vertical shafts is used to provide a number of services in underground workings. These services vary depending on geographical location and the type of the ore body which is being mined. For example, in the Zambian Copper mines, one of the largest requirements for in shaft piping is for dewatering. Similarly in the Gold deposits in the West Wits basin as well as the deep level Copper deposits in Arizona, one of the largest uses for the piping is the supply of a cooling medium to underground workings to create a safe working environment (this can in the form of water or of glycol depending on the application). In South Africa, systems were installed which used the hydrostatic head which is generated from supplying chilled water to mines whose depths exceeded 2,000 m below surface. This chilled water was supplied as a closed system, allowing for high pressures to be generated which was then used to supply useful work (for example, Rock Drills, Face Cleaning and other ancillary services) whose power was traditionally supplied by compressed air or electricity. This system was initially researched by Chamber of Mine in South Africa. The design pressure range of these systems is 14 MPa to 18 MPa."

Jan 1, 2019

By J. H. Douglas, A. F. Matheson

"The Hard Rock is the most easterly producing mine in the Little Long Lac area. The Company was formed in 1934 to develop a surface showing of gold in quartz made by a prospector, W. W. Smith, in 1931. Although some ore was eventually produced from this discovery, the principal orebody, hidden below 10 feet of muskeg, was found about 1,000 feet to the north by exploratory diamond drilling early in 1938 from the No. 2 shaft workings at the 250-foot level.Production started in 1938 and to January 1, 1947, 201,000 oz. gold had been obtained from 1,165,282 tons of ore mined and 869,397 tons milled. Of this ore about 15 per cent came from the development and mining of the original orebodies discovered at the surface. The remainder came from the ore found by the underground diamond drilling done in 1938. Of the latter ore, the Company estimated, at January 1st, 1947, only 140,000 tons remained. The orebody, therefore, contained approximately 1,100,000 tons.OREBODIES AND GENERAL GEOLOGYThe orebodies of the Hard Rock mine are of two main types: the quartz ore of the south and No. 1 shaft zones, and the sulphide ore of the north zone. The quartz ore consists of white quartz veins mineralized with sparse, fine, light-coloured pyrite, or, less commonly, nests of coarse, crystalline, light pyrite. A little tourmaline, scheelite, pyrrhotite, chalcopyrite, arsenopyrite, and native gold are also present. Native gold occurs in a few places in quartz veins in exceedingly rich cemcentrations, apparently where there are large, light-coloured, pyrite crystals of imperfect form. The ore of the north zone is massive pyrite with arsenopyrite and in places pyrrhotite. Many short irregular quartz veins, from a few inches to 2 feet in width, are also present, but the quartz forms a very small percentage of the whole. The veins may be flat to vertical, and sulphides on one or both sides replace the host rocks. The gold is closely associated with the sulphides . The quartz is commonly barren except where it contains sulphides or along the borders of the sulphide ore zone where native gold is not uncommon in quartz stringers."

Jan 1, 1954

By A. Dolatmoradi

Nanocrystalline structure formations produced by severe plastic deformation in Fe-0.15C with initial ferritic-pearlitic and IF steel with ferritic microstructures have been studied through microstructural observation and microhardness measurements. It was found that the nanocrystalline region first forms near the surface of samples due to localized severe deformation. It was also observed that the nanocrystallization rate of Fe-0.15C and IF steels and the deformed layer thickness in these two materials are different with similar milling conditions. The crystallite size and structural evolution of the samples during milling was studied by employing XRD and SEM.

Jan 1, 2010

By P. Radziszewski

Industrial practice in mineral processing shows that an important problem in understanding and monitoring in-mill parameters is due to the lack of fundamental knowledge and appropriate sensors. With the development and growing use of DEM charge motion simulators for mill optimisation and design, it is possible to describe the fundamentals of grinding mill behaviour, in improving the understanding of internal grinding mill dynamics and in developing solutions to industrial practice. The main challenge to bringing this DEM technology to the mill operator however was the need for substantial computing power and time. However, what about a simplified DEM charge motion model running in real-time? What about the use of sensor technologies to correct any possible drift in simulator prediction? Could such a technological system be used to predict mill performance and eventually be used for mill control and optimisation? Some of these questions are answered with the development of an "on-line" DEM charge motion simulator package (SAGTools?) along with that of a number of sensor technologies (liner wear, acoustic, instrumented ball) that can contribute to simulator precision. With the objective of bringing this modelling and sensor technology into the concentrator control room to assist operators, this paper aims to describe the main elements of this emerging and developing technology and discuss how it can lead to online mill performance prediction and eventual control.

Jan 1, 2007

By E. Ghali, A. D. Bas

"Treatment of oxide, e.g. roasted gold ores has received relatively less attention than sulphidic ones and recently, handling of oxide gold ores is becoming essential. In this study, the influence of roasted gold ore (RGO) slurry (at 35% solid ratio) on the electrochemical dissolution of gold has been examined using pure gold and iron oxide minerals (hematite, maghemite, and magnetite) as disc electrodes by zeroresistance ammeter mode either in one or two separate containers. The presence of slurry decreased galvanic currents, i.e. corrosion rates due to the release and increase in the amount of soluble and/or insoluble species that could retard further the anodic behaviour of gold. Higher galvanic currents were observed in two separate containers than that in one container indicating the primary importance of galvanic interactions. SEM-EDS results observed iron hydro/oxide coatings on gold surface in case of magnetite test. However, in case of RGO electrode it is not a perfect passivation, although somewhat decreasing trend was observed on gold dissolution. These findings have revealed that passivation is not only a laboratory phenomenon, but also it could be responsible for the slowdown of gold dissolution in industrial practice.INTRODUCTIONThe cyanidation of gold is an electrochemical corrosion process thus; the dissolution of gold can readily be studied by electrochemical techniques. The outcome/summary of previous electrochemical studies of gold leaching can partially be summarized as follows: Filmer (1982) and Lorenzen and van Deventer (1992) reported the negative effect of pyrite and pyrrhotite on gold leaching due to the galvanic interactions; Aghamirian and Yen (2005) studied gold galvanic corrosion in presence of sulphide mineral electrodes only in one cell using zero-resistance ammeter (ZRA) mode; Dai and Jeffrey (2006) discussed, individually, the anodic and cathodic behaviours between gold and sulphide minerals, and Azizi et al. (2010, 2011) used a bed reactor to examine the influence of sulphide minerals on gold dissolution in one and two separate cells. Accordingly, a slowdown in gold leaching has generally been attributed to the passivation phenomenon, although the indication of this phenomenon is still an undergoing debate. For instance, Mrkusic and Paynter (1970) identified the passivation as the film formation of dissolved species from calcine, Crundwell (2014) explained passivation, in the case of corrosion of metals, as the formation of a layer which is composed of a new chemical species on the mineral surface and this layer inhibits or blocks further reactions. He suggested that passivation is related to the oxidation of the metal, and the formation of a passive layer that retards the rate of dissolution by several orders of magnitude. Consequently, galvanic interactions, passivation phenomena, or combinations of them are considered significant electrochemical factors affecting gold dissolution (van Deventer, Reuter, Lorenzen, & Hoff, 1990; Azizi, Petre, & Larachi, 2012). It is important to note that generalizing the influence of a mineral/metal on gold dissolution may not be correct in all cases, since contrary behaviours/results (for pyrite) have been observed (Aghamirian & Yen, 2005). Therefore, electrochemical study of gold is still a subject of research and need to be examined further in detail."

Jan 1, 2016

By H. J. B. Couto, J. G. S. Puelles, M. L. Torem, R. H. Rojas, A. G. Merma

Understanding the limits of fine particle flotation is fundamental to achieving a significant and selective separation. Conventional flotation processes are not suitable to treat these particles because of their low collision efficiency. This problem can be overcome by decreasing the bubble size or by increasing the apparent particle size. However it is worth noting that the use of small bubbles or micro bubbles also involves some disadvantages such as their low momentum resulting in a slower process comparing with conventional flotation. Electroflotation is an attractive alternative for treating fine particles with small bubbles less than 100 µm, generated by the electrolysis of water. In this sense, this study assesses the effect of current density and pH on bubble size in a binary electroflotation cell. An increase in the bubble generation rate was reported with an increase in current density. In addition, at acid pH values, the size of oxygen bubbles increased and conversely decreased at basic pH values; this may be due to the electrostatic attraction between the oxygen bubbles and the anode resulting in a greater nucleation time. An opposite trend was observed with the hydrogen bubbles. These results are in agreement with their electrokinetic studies, which reported that at acid conditions the bubble surface may be positively charged for both the hydrogen and the oxygen bubbles. Finally the bubble size was slightly affected by the electrolyte concentration, resulting in smaller diameter bubbles at higher concentrations.

Jan 1, 2016

By Q. Shi, Q. Feng

"The influence mechanism of chlorite on the flotation of pyrrhotite was investigated through flotation tests, Zeta potential measurements, optical microscope photos, solution ion measurements and absorption measurements. It is observed that, the addition of chlorite influences the flotation of pyrrhotite seriously. The IEP (isoelectric point) of pyrrhotite and chlorite is 7.6 and 4.3 respectively, in the condition of slight alkalinity, both pyrrhotite and chlorite are negatively charged, and the hetero-aggregation will not occur. With the existence of oxygen in solution, the iron ions are dissolved from pyrrhotite surface because of the oxidation of pyrrhotite during pulp conditioning. The dissolved iron ions adsorb onto the surface of chlorite in the forms of iron hydroxyl and iron hydroxide, and the adsorption results in the opposite charge of chlorite surface. As a result, the hetero-aggregation between pyrrhotite and chlorite occurs. The adsorption of chlorite changes the surface property of pyrrhotite and restricts the adsorption of amyl xanthate onto pyrrhotite surface, and then decreases the flotability of pyrrhotite.INTRODUCTIONIn sulfide ores processing, magnesium silicate bearing gangue minerals often report to the concentrate causing downstream processing problems as well as increased smelting costs. Talc,chlorite and serpentine are gangue minerals commonly encountered in complex sulfide ores (Engel, Middlebrook, & Jameson, 1997; Pietrobon et al., 1997; Witney & Yan, 1997; Chen, Grano, Sobieraj, & Ralston, 1999a, 1999b; Bremmell, Fornasiero & Ralston, 2005; Senior & Thomas, 2005; Wang, Somasundaran, & Nagaraj, 2005; WieseHarris & Bradshaw, 2007). All of them are characterized with uniform crystal structures consisting of silicon-oxygen tetrahedron and magnesium-oxygen octahedron. The magnesium-oxygen octahedron layers are broken during the liberation of serpentine to expose the magnesium-oxygen bonds with strong ionicity and hydration, which results in natural hydrophilicity of serpentine. In water, the hydroxyl on serpentine surface ruptures and dissolves into the aqueous phase while the Mg2+ remains, resulting in surface positive charge (Tao, 2012). As serpentine has a positive potential at alkaline condition, it is therefore likely that it will attach through electrostatic attraction to the negatively charged mineral surface and reduce both the flotation rate and recovery of target minerals (Lu et al., 2011). For talc, characterized as good natural hydrophobicity, the liberation comes from the interlaminar fracture to remain molecular bonds on surface with weak hydration. Being naturally hydrophobic, talc easily reports to flotation concentrates, thus reducing concentrate grade (Shortridge, Harris, Bradshaw, & Koopal, 2000; Beattie, Huynh, Kaggwa, & Ralston, 2006). Meanwhile, both molecular bonds and magnesium-oxygen bonds are exposed on chlorite surface when liberation occurs, resulting in moderate natural hydrophobicity between serpentine and talc (Tao, 2012). And thus the mechanisms of influence of chlorite on sulfide ores are more difficult to study."

Jan 1, 2016

By E. Essadiqi, P. Poruks, D. Boyd, D. Emadi, I. Yakubtsov, T. Turi

This paper reviews the results of an extensive study of microstructures and mechanical properties in bainitic linepipe steels. The research was carried out as a collaborative project between Queen's, Stelco and CANMET. Basic studies of phase transformations and mechanical properties in these steels established important relationships between processing schedule and microstructure evolution, and between final microstructure and mechanical properties. The best combination of strength and toughness properties is obtained with a microstructure comprising a matrix of intragranularly-nucleated bainite (`acicular ferrite - AF') and small (~ 0.5 µm) dispersed particles of martensite (`M/A'). We describe this as a dual-phase AF+M/A microstructure. An experimental study on 15-mm thick plate determined the window of steel composition and processing parameters which gives the dual phase AF+M/A microstructure. The minimum strength and toughness properties for Grade 621 (X90) linepipe steel can be achieved by either a lean steel composition (0.04C-1.77Mn-0.04Cr¬0.32Mo-0.31Ni-0.29Cu-0.08Nb) with extreme processing parameters, or by a higher alloy composition (0.04C-2.07Mn-0.50Cr-0.51Mo-0.04Nb) with a more industrially realistic processing schedule. It is proposed how this approach could be extended to obtain higher strength linepipe grades.

Jan 1, 2005

By S. Kelebek, Gerhard W. Heinrich, Peter F. Wells

"The review and optimization of process stages is an integral part of the program to improve the metallurgical performance of the Strathcona Mill. Improved primary grind size distributions, streamlining of rougher-scavenger circuits and increased platinum recoveries were the target of plant and laboratory scale tests. The results can be summarized as follows:• Decreasing the primary grinding cyclone vortex finder diameter for nickel/copper ore gave significant increases in overall copper recovery and improved rougher flotation selectivity.• The scavenger flotation stage in the circuit treating copper ore was found to contribute little to this circuit's copper recoveries -yet to be essential for acceptable recoveries of nickel, platinum and gold. The elimination of this stage by re-routing the tailings from the copper ore rougher into the nickel/copper ore rougher feed has lead to lower gangue recoveries to the nickel concentrate and to improved copper-nickel separation, while reducing equipment operating costs.• Surface aging effects such as oxidation are known to decrease flotation recoveries of platinum minerals such as sperrylite. The conditioning of an intermediate non-magnetic process stream with copper sulphate prior to thickening increased the platinum recoveries in the subsequent flotation stage by approximately 10%."

Jan 1, 1996

By I. C. Edwards, D. C. Smith

THE milling plant of Bicroft Uranium Mines Limited at Ban-croft, Ontario, was one of the first in Canada to employ ion excl1ange for the selecti1•e recovery of uranium from acid leach liquors. The ion ex-change circuit started operating early in November, 1956, and by June 1 I959, had handled more than two million tons of pregnant solution containing I,830,000 pounds of U3Os. Each column had been saturated and eluted about 430 times. The ion exchange columns are the conventional fixed bed type. Uranium is eluted from the resin with a sodium chloride-sulphuric acid solution and is precipitated continuous-ly with magnesia. After filtering and drying, the precipitate, or "yellow cake," is packaged in drums for shipment to the refinery.

Jan 1, 1962

By Charles "Chick" Rodgers, Anthony Sarion

"With declining feed grade and increased production targets, it became necessary to upgrade Key Lake's eight stage counter current decantation (CCD) circuit. Following laboratory trials, mill operations recognized that dilution of the feed slurry and buffering of the feed density variations would improve thickener throughput. Plant testing resulted in the installation of Outokumpu's Supaflo ""Floe-Miser"" system. The circuit's flowsheet, instrumentation and control strategy were also upgraded along with the thickener feedwell modifications. The paper will also discuss these modifications and the implementation of the current control strategy.IntroductionCameco Corporation's Key Lake operation is the largest single uranium producer in the world. Current production is fourteen million pounds of uranium oxide (U 308) per year. It is owned 2/3 by Cameco and 1/3 by Uranerz Exploration and Mining with Cameco as the operator.The mine is 570 kilometres north of Saskatoon on the southern edge of the Athabasca basin. Access to the mine is by an all-weather road and a private airstrip.Process DescriptionThe Key Lake milling process consists of five individual plants: crushing and grinding; leaching and counter current decantation (CCD); solvent extraction; yellowcake precipitation and ammonium sulphate crystallization; and bulk neutralization (Figure 1 -Simplified Mill Flowsheet). A detailed mill flowsheet can be found in the appendix."

Jan 1, 1998

By W. H. Mathews

"The Hardie group of cinnabar claims is in the interior of British Columbia; 25 miles northwest of the city of Kamloops. It is one of a number of mercury; properties scattered along a north trending belt 20 miles long and up to 5; miles wide. In all but one of these properties cinnabar is associated with; dolomite veinlets in zones of carbonate alteration in bedded rocks of Triassic; and Cretaceous (?) age; or in intrusives cutting these bedded rocks. No dolomite alteration or cinnabar mineralization is known in the undoubted Tertiary rocks adjacent to the mercury belt.The mercury showings of the Hardie group lie for the most part in a granitic stock cutting Cretaceous (?) volcanics. The rock in this intrusive shows marked variations in texture and has been described in earlier reports as granite and granodiorice, granite porphyry, and trachyte or dacite porphyry. At Hardie mountain the cinnabar mineralization, unlike that of the other properties, is associated with a fine-grained, almost chalcedoni c, quartz; carbonates, though present, are of minor importance. Some of the most interesting showings are found in an adit in the southeastern part of the property where cinnabar mineralization shows a very distinct structural but not a genetic relationship to a brown porphyry dyke 2 to 8 feet wide cutting a phase of the stock that may best be described as aplitic"

Jan 1, 1954

By Jin Li

The tensile properties and microstructure of AZ91 Mg alloy before and after equal channel angular extrusion (ECAE), and the fracture behavior during tensile testing for as-extrusion and ECAE AZ91 were investigated. The alloy was performed ECAE from one to eight passes at 498K. The elongation decreased with the pass number increasing after ECAE. Grains were refined, partial coarse ß-Mg17Al12 phase fell to pieces, fine ß-Mg17Al12 precipitated in the AZ91 Mg alloy after ECAE. During tensile test the a-Mg/ ß-Mg17Al12, a-Mg/Al8Mn5 interface and the grain boundaries in a-Mg matrix acted as the crack initiation sources. The frequency of micro-cracks at the a-Mg/ß-Mg17Al12 interfaces and grain boundaries increased after ECAE, which accelerated the growth and coalescence of the micro-cracks during tensile test and resulted in the decrease of elongation of AZ91 Mg alloy by ECAE.

Jan 1, 2006

By D. K. Sarkar, Jiawei Xiong

"Self-assembled monolayers (SAM) on the aluminum substrates are used as the adhesion promoter between two aluminum substrates when bonded with the adhesive in adhesive bonding technology. Traditional surface analysis tools are not capable of identifying the presence of SAM on a surface; therefore, EIS has been used to determine their presence on the aluminum substrates. In this study SAMs have been deposited on aluminum using the monomer of (3-Glycidyloxypropyl)trimethoxysilane (GPTS) organosilane. AA6061 aluminum alloys substrates were chemically cleaned with NaOH and HNO3 to remove the native oxides, followed by immersion in silane solutions. In a second method, SAMs were prepared by applying a spin coating of silane solution to the samples. The prepared SAM coated aluminum samples were analysed by EIS in the three electrode corrosion cell using a diluted alkaline solution. The impedance of the SAM coated aluminum is found be higher than the as-received aluminum. It has been also observed that the open circuit potential (OCP) of the SAM coated aluminum is higher than the as-received aluminum. Both elevated values of the impedance and OCP confirm the presence of SAM on aluminum.INTRODUCTIONSelf-assembly (Schreiber, 2000) is defined as the spontaneous formation of complex hierarchical structures from pre-designed building blocks, typically involving multiple energy scales and multiple degrees of freedom. Generally speaking, SAMs are created by the chemisorption of ""head groups"" onto a substrate from either the vapor or liquid phase followed by a slow organization of ""tail groups"" of a molecule. Typically, head groups are connected to a molecular chain in which the terminal end can be functionalized with groups such as –OH, –NH2, –COOH, or –SH to vary the wetting and interfacial properties (Chauhan et al., 2007; Ulman, 1996; Vashist, Lam, Hrapovic, Male, & Luong, 2014). Though there exist several methods to prepare SAM (Chauhan et al., 2007; Chen, Yang, & Zhang, 2014; Cho, Park, Jon, & Choi, 2007; Igor Luzinov, 2000; Reis, de Melo, & Costa, 2006; Song, Zhai, Wang, & Jiang, 2006; Sugimura, Hozumi, Kameyama, & Takai, 2002; Vashist et al., 2014), the two methods vapor phase (Song et al., 2006; Sugimura et al., 2002) and solution(Chen et al., 2014; Igor Luzinov, 2000) are commonly used. Recently, many articles have been published on the fabrication of superhydrophobic surfaces with SAM technology (Cho et al., 2007; Pan, Shen, Shang, & Xing, 2012; Siddaramanna, Saleema, & Sarkar, 2014; Song et al., 2006). Brassard, Sarkar, and Perron (2011) successfully obtained a superhydrophobic film by applying fluoroalkylsilane via self-assembly on monodispersive silica. SAMs are also reported as good candidates for anti-corrosion and adhesion promotion (Chen et al., 2014; Saleema, Sarkar, Paynter, Gallant, & Eskandarian, 2012). However, papers on the characterization of SAM properties are rarely seen. The most commonly used substrate for SAM is silicon and the method implemented is scanning probe microscopy (SPM) such as atomic force microscope (AFM) (Igor Luzinov, 2000; Moores, 2011; Zhang, 2003, 2005). Igor Luzinov (2000) analyzed the epoxysilane SAMs’ surface morphology and microstructure properties using scanning probe microscopy (SPM) and ellipsometry on single-crystal silicon wafers. SAMs have been used to improve the adhesion bonding of aluminum or plastics but no characteristic data have been presented yet (Saleema et al., 2012; Telegdi, 2007; Wang, Xu, Luo, Wang, & Wang, 2009). Recently, Reis et al.(Reis et al., 2006) have studied SAM of alkane diphosphonate (Gardobond X4661) on Al 5052 alloy samples by EIS in a naturally aerated sodium sulfate solution."

Jan 1, 2016