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By J. Zachwieja

As part of a general review on study of surfactant blinding agents to improve gold recovery during cyanide leaching of carbonaceous gold ores, processes of CIL and RIL leaching using surfactants were investigated. When refractory ores were treated by surfactants, CIL and RIL leaching processes yielded significant improvement on gold recovery. This paper will discuss and compare the laboratory results from two different leaching processes on preg-robbing ores, as well as, illustrate the difference of potential fouling of the blinding agents on activated carbon and resins.

Jan 1, 2015

By S. C. Ellis

THE bituminous sand of northern Alberta has already an extensive literature, and most of the reports dealing with the subject are still available (see Selected Bibliography at end of paper). A phenomenon so striking and, as regards its extent, so unique, as the deposit in the vicinity of McMurray settlement could not fail to attract the notice of the early explorers, and we find references to it as far back as the latter part of the eighteenth century. However, scarcely a thought had been bestowed upon the possible economic value of minerals in the the remote northern parts of Canada before the second decade of the present century, and practically no detailed mapping had been done north of the town of Athabaska. The late Wm. Ogilvie made a track survey of Athabaska river in 1884, and surveys of certain lines-including the 23rd base line-had been completed by 1911. Between this base line and lake Athabaska, nothing had been attempted. Actually, no definite information at all was available regarding the character and extent of the bituminous sand when, in the earl y summer of 1913, a reconnaissance party set out from Athabaska for McMurray. At that period, the journey was made in summer by scow or canoe. No telegraph line had been laid, and a casual mail service by canoe or dog team once in three months formed the only means of communication with the outside world. The investigation has begun by the Mines Branch was continued during several subsequent years. The sand deposits were studied and sampled, the bi rumen was extracted from the sand and studied chemically and physically, and the economic significance of the deposit was given exhaustive study.

Jan 1, 1937

By D. A. Wheeler, Rémi Tremblay

"INTRODUCTIONDuring the last few years, through Column Flotation Company of Canada ltd, the Centre de Recherches minérales has worked on the column flotation of coal, phosphate, feldspar, talc, graphite, copper, lead-zinc and diamond ores. The operating companies and prospective deposits were located in Canada and in other countries. Since these projects were financed by the concerned mining companies, all results remain confidential unless we obtain permission to publish. Three companies have graciously allowed us to use their information which I will describe in this text. These are the Polkowice copper mine in Poland, the North Coast Industries ltd graphite deposit and a talc company which preferred to remain anonymous. I will also describe our 2 inch column which was used for all tests. Data is also given on how to scale-up the 2 inch column to industrial size.Figure 1 presents a schematic of a flotation column. Feed, at a controlled rate and pulp density, enters at about 1/4 of the height of the column from the top. A controlled rate of air is bubbled into the bottom of column through a fine-holed sparger. The column volume between the feed point and the top of the sparger is called the recovery zone. Tailings, at a controlled rate, always slightly greater than the feed rate, discharges from the bottom of the column. This difference in feed and tailings flowrates is called the bias. The floated mineral is carried through the recovery zone on air bubbles which rise into the cleaning zone which is that column volume between the feed point and the overflow at the top. As the bubbles rise in this zone they are washed of gangue material by wash water which enters over the top of the froth layer. The froth layer is maintained at a given depth during flotation but this depth will depend on the froth cleanliness, for quite a bit of cleaning by wash water is accomplished in this layer."

Jan 1, 1988

By F. J. Reichhardt

Abstract -The Molopo Farms Complex is a major, layered ultramafic/mafic, early Proterozoic intrusion which is totally covered by sediments of the Karoo and Kalahari Formations and situated in southern Botswana and northeastern South Africa. The approximately 3000 m thick, generally fine- to medium-grained ultramafic and mafic cumulates are intrusive into equivalents of Transvaal Supergroup sediments and lavas. Multiphase deformation resulted in tilting and segmentation of the Complex into individual tectonic blocks. Sr isotopes document at least two chemically distinct parental liquids which interacted in a complex manner to form an approximately 1000 m thick rhythmically layered succession which straddles the ultramafic/mafic boundary. Repeated mixing resulted in a complex cryptic layering pattern and numerous sulfide-enriched layers which contain significant PGE +Au concentrations.

Jan 1, 1994

By John Shirokoff, Ladan Khaksar

"Cyclic polarization technique and also potentiodynamic measurements were applied to study corrosion behavior of 13% chromium steels in chloride containing environment. Potentiodynamic measurements were performed at 25 and 75 °C with 0, 10 and 20 g/l NaCl in 0.01 M hydrochloric acid solution. At the same time, the significant pitting parameters such as corrosion potential (Ecorr), pitting potential (Epit), protection potential (Epro) and passive current (Ipass) of cyclic polarization curves with various NaCl concentration were analyzed and compared to describe the corrosion behavior of 13% chromium stainless steel. Surface measurement techniques such as SEM and EDS were used for morphology and analysis of corrosion products. The results showed that both temperature and Cl- concentration had significant effects on corrosion behavior of 13% chromium stainless steel in acidic solution.INTRODUCTION Of all the corrosion resistant alloys (CRA) used in oil and gas developments, martensitic stainless steels (MSS) are some of the most common ones these days. These steels not only have the advantages of normal steels: high strength, cost-effective, easy to manufacture, available in a wide variety of product forms, but they also have good CO2 corrosion resistance at higher temperatures as a result of their 11% minimum chromium content. One of the most common types of MSS used in the oil and gas industry is 13% chromium steel. NACE and API standards both reference several different varieties of 13% chromium steels for use in oil and gas projects(“Corrosion Resistant High Cr Steel for Oil and Gas Wells,” 2013). All types of 13% chromium steels have about 12 to 14% chromium and other minor alloying additions, and can be placed into two general groups: conventional and modified. Conventional 13% Cr steels (13Cr) are those most common in oil and gas, some of which are CA6NM (UNS J91150), AISI 410(UNS S41000), and AISI 420 (UNS S42000). These alloys have excellent corrosion resistance when compared to carbon steels up to about 300°F (150°C) and are used for a variety of wellhead, tubular, and downhole components however they have very limited resistance to cracking in H2S (Vallourec Group, 2015). Modified 13% Cr (M13Cr) steels came from the need for increased corrosion resistance at higher temperatures, increased H2S cracking resistance, and increased yield strength above 85 ksi (586 Mpa) primarily for tubular goods and other downhole equipment. These features were developed by taking a conventional 13Cr steel and adding nickel (Ni), molybdenum (Mo), copper (Cu), and other alloying elements. M13Cr provides better corrosion resistance than 13Cr up to about 350°F (177°C), yield strengths up to 110 ksi (758 Mpa), and also improved H2S cracking resistance(“Corrosion Resistant High Cr Steel for Oil and Gas Wells,” 2013)."

Jan 1, 2017

By John Steele

The goal of this project is to detect the presence of objects behind haul trucks and to provide an alarm to the driver if such objects are detected. Objects of interest include people, pickups, other equipment, and large rocks. Another goal is to see if the system can identify the existence of a berm and determine the distance from the truck to that berm, so a safe backup distance can be computed and used as a reference. This paper presents results that demonstrate that such a system is feasible and includes results from work at a local quarry. Architecture of the system is provided and the various subsystems are discussed. Details of the algorthims are included and discussion of the issues involved in developing a fieldable system are also included.

May 1, 2003

By Mike Rylatt

"The BHP Diamonds Inc. and Blackwater Group (Dia Met Minerals Ltd., Charles Fipke and Stewart Blusson) joint venture began production at Canada=s first diamond mine during the last quarter of 1998.Construction of the processing plant began in mid 1997. During the 1998 winter season, the heavy process plant equipment was delivered to the Ekati site, 300 km NE of Yellowknife, by the ice road. Towards mid 1998 the construction activities were complete and commissioning began. The mine officially opened in October 1998.Initial production of 9000 tpd kimberlite will be from the Panda pipe grading 1.09 ct/t at an average value of US$13O/ct.Processing starts with a gyratory crusher reducing the ROM kimberlite to 90% passing 15Omm before further reduction to minus 75mm in a WaterFlush crusher. The crusher product discharges into a 4m diameter x 7m long primary scrubber. After screening, the minus 75 +1 mm kimberlite is conveyed to a 250 ft feed bin ahead of the 1.7 m diameter x 1.1 m wide high pressure grinding roll. The HPGR produces 50% minus lmm in a single pass, the compacted flake product is dis-agglomerated in a secondary scrubber. The scrubber product is screened into a minus 25 +lmm heavy medium separation plant feed and conveyed to a 375t HMS feed bin ahead of two 150 HMS modules. Milled 270D ferrosilicon at a slurry density of 2.6 g/cc and HMS feed are pumped to three 420mm diameter cyclones. Heavy mineral concentrates, approximately 1 % of the plant headfeed, are pneumatically transported to the Recovery plant for final diamond recovery using wet high intensity magnetic separators and high intensity (attrition) milling prior to three stages of x-ray recovery. At full production, Ekati will produce approximately 2 kg/day of diamonds.This paper details the later commissioning phase and the first three months Oof operational activities during the build up to full production at the Ekati processing plant."

Jan 1, 1999

By T. Ward, K. Shah, K. Murray

The mining industry is processing deposits with ever decreasing grade at ever increasing operating costs while margins are under constant pressure by material substitution and recycling. We are reaching the point where building it bigger just isn’t good enough as social and environmental constraints become more intense. In response to the growing demands on our industry, Goldcorp has embarked on a journey to increase resources by converting Waste to Ore. Gravity pre-concentration and sensor sorting testwork has been completed on samples from our Canadian operations in order to determine the amenability of our mineralized waste to sorting and upgrading. As expected some material was amenable to sorting and a review of the economics supported demonstration plant testing. The ability to economically sort mineralized waste into ore and barren rock is being demonstrated by Goldcorp. It has been made possible by leveraging the experience mineral sizer manufacturers have gained in the oil sands and hard rock applications, seeking more energy efficient screening machines and embracing the advancements that ore and recycling sorter suppliers have achieved. The paper will discuss the testwork and results achieved to date from both the lab and demonstration plant.

Jan 1, 2018

By Sherwin F. Kelly

With the progressive exhaustion of ore deposits easily discovered by surface prospecting, the attention of scientists is being turned more and more to the employment of mechanical means for the location of ore bodies whose outcrops are not visible. The dip needle, the Eotvos Torsion balance, and various methods of electrical prospecting are illustrative of the modem tendency. Interest in the possibility of applying electricity to the solution of many of the prospector's problems dates much farther back than is usually realized. The first person to notice an abnormal intensity of electrical activity in the region of certain ore bodies was an Englishman, R. W. Fox, who experimented on the Cornwall copper and tin veins about 1830. Dr. Barus, in the United States, carried the early experiments a step further in his work on the deposits of Eureka, Nevada, about 1880. He made the very definite suggestion that the phenomena noticed would be of material aid to the prospector. Not until Professor Schlumberger, of the Ecole des Mines, Paris, took up the matter, shortly before the war, was any definite effort made to put electrical prospecting on a commercial basis. His work resulted in the establishment of sound principles and practicable field technique, for two distinct methods of prospecting.

Jan 1, 1924

By A. E. Boone

"The paper presents critical areas in which improved coordination of effort by industry, government and sup-pliers will be essential to continue the growth record of the Canadian mining industry into the 'seventies'. The analysis includes: exploration, production, mining methods, research and development, markets, management and industrial relations. Performance objectives are suggested where tangible results can be measured. The author suggests the methods by which the 'seventies' can be the greatest decade in the history of Canadian mining. It is indicated that a national mineral policy is essential to the Canadian mineral industry."

Jan 1, 1970

By J. Jung, W. Keller, A. Zucht

"The agitator design for nickel high pressure acid leach autoclaves (HPAL) is critical with regard to the process result, i.e., the recovery rate. Further considerations during the design phase are the avoidance of acid hot spots which reduce the lifetime, due to corrosion of the wetted parts, including components manufactured from titanium. Besides the process knowledge to design HPAL autoclaves, tools such as, Computational Fluid Dynamics (CFD) supplemented by lab testing allow the design of optimized agitation systems. This paper describes the effect that different feed point locations have on instantaneous blending of the reactants. Furthermore, experiments and CFD show where abrasion issues might occur and how to obtain information about the static and dynamic forces acting on internals. We show how simulations can be validated by lab testing to ensure that the CFD models are applied in an appropriate way.INTRODUCTIONAgitated systems in hydrometallurgical processes have to comply with multiple process tasks and in many cases have to withstand extreme operation conditions such as pressure up to 50 bar, elevated temperatures of up to 250°C and exposure to very acidic or alkaline environments and abrasive ores. The process tasks range from instantaneous mixing of reactants, homogeneous suspensions of up to 65% wt. solids with coarse and heavy particles, enhancing the solid-liquid mass transfer for leaching, dispersing large volumes of reactants (gas-liquid, liquid-liquid mass transfer) and moreover to transport generated heat e.g., from exothermic reactions through the vessel walls or internal heat exchangers if required. For economies of scale, agitator systems have reached sizes of 5000 m³ for large open leach tanks with impeller diameters of approx. 6 m, while autoclaves nowadays have exceeded 5.5 meters in diameter with a power demand for a single compartment drive between 300 - 400 kW. In parallel all process industries require a more efficient use of resources, to generate less by-products and higher yields, while ore-bodies tend to be less qualitative and new process routes (e.g. direct leach) are developed. Besides all these facts the mixing solution must be robust and economic. In this paper we want to address our approach in the development and designing of HPAL agitation equipment."

Jan 1, 2012

By A. L. Rutledge, R. S. Nichols

"Waste dump development at the Fording River Operation s in British Columbia began in 1971. In 1981, several unique as well as unplanned situations provided an opportunity to study water flows through waste dumps.The key to the drainage is naturally segregated rock sizes .created by end dumping from the crest of a pile. The largest size material accumulates at the toe. Flow rates along the base of the studied dumps varied from 2,800 to 13,500 m3/day or 0.032 to 0. 156 m3/s (1.2-5.5 cfs}. Sediment concentrations in the water ranged from 1 to 1,800 mg/I.This paper describes water flows through dumps of varied lithology and maturity. The results suggest that neither long-term water flow nor contained sediments in small streams are jeopardized when crossed by end-dumped fills.IntroductionThe Fording River Operations are located in southeastern British Columbia approximately 115 km north of the United State s and 10 km west of Alberta, within the medial range of the Rocky Mountains. All production is carried out at elevations ranging between 1,600 and 2,200 m above sea level.The property is within a continental climatic zone, with temperature extremes of - 40°C in January to +35°C in July. The average annual precipitation of 335 mm of rainfall and 390 cm of snowfall feeds the numerous seasonal, small drainage courses along the Fording River valley.Since start-up in 1971, 149 million bank cubic met res of waste from truck-shovel and dragline mining have been placed in numerous dumps or ""spoils"". The dumps were developed to the point that several unique situations could be studied. During the peak run-off period of May-June 1981, water flow studies were performed on dumps of varied lithology and maturity. This paper describes the results of the study."

Jan 1, 1982

By P. Personnet, D. Wheaton, E. Couzinie, V. Demetriou, Brooks. W., G. Girault, M. Meyer, L. Charbonnel

A common problem in Gas Treatment Centers (GTC) from primary aluminium smelters is the temperature of the gas to be treated : above a threshold, filtering media are irreversibly damaged. The traditional way of dealing with high gas temperature is to dilute with fresh air, which implies over sizing - and therefore higher cost for - the GTC in order to have the capacity to treat this dilution air without compromising on pot suction. A system was developed which decreases gas temperature without having to use dilution air. This system is based on water pulverization in gas collectors. The water vaporization leads to a temperature decrease of the gas. A pilot system was trialed in our R&D unit. Satisfactory results led to the development of an industrial system based on Envirocare equipment (partnership), which was trialed in our production plant in Tomago (NSW, Australia). This patented system was then generalized in this plant, which is now using it with success during austral summer.

Jan 1, 2006

By S. W. Marcuson, P. J. Mackey

The 1973 Oil Embargo and succeeding disruptions in supply had a profound effect on energy costs and consumption patterns in the developed world. This was especially true in the USA where post World War II growth, fueled by low-cost imported oil, left the country dependent on uninterrupted oil shipments from the volatile Middle East. In this atmosphere, Professor H.H. Kellogg of Columbia University, convinced of the necessity of good environmental stewardship by the writings of the era’s leading environmentalists, developed a methodology for evaluating energy and process efficiency of metallurgical processes and wrote a series of papers describing and applying the techniques. One of these, "Energy Use in Sulfide Smelting of Copper" is recognized as a seminal work which both described the state of energy usage in copper smelting in the mid-1970’s and portended future developments. The background to these papers is examined and the current and past Cu-Ni matte smelting practices in Canada are examined in the context of the results. Data from early 20th century publications describing reverberatory and blast furnace operation is employed to show that energy consumption for much of the century was several multiples higher than that calculated for best reverberatory operation in the 1970’s.

Jan 1, 2015

By B. Drew, K. Budna, C. Wenzl, D. Gregurek, A. Spanring

"The metallurgy of nickel and cobalt and of copper is closely interlinked when processing sulfidic Ni-Co ores and Cu-Co ores. The respective furnaces are typically lined with magnesia-chromite refractories, which are exposed to multiple and complex stresses. The selection of the processing route, furnace type and slag system will be dictated by the specific ore type available, this will determine the individual refractory wear mode. This paper evaluates the common refractory wear mechanisms, namely infiltration, spalling and chemical attack by various slag systems, as well as sulfur attack, as observed when processing primary sulfidic ores. All these wear parameters, which are discussed in this paper, lead to a severe degeneration of the brick microstructure and a decreased lining life. Therefore, a detailed investigation and understanding of the wear mechanisms through “post mortem studies” is an important prerequisite for the refractory producer. Based on such research results, combined with specific process knowledge, appropriate brick lining solutions for nickel and cobalt processing furnaces can be recommended.INTRODUCTION The metallurgical production of cobalt and nickel and of copper is closely interlinked to the mineralogy of the respective ores: cobalt is found in African Cu-Co ores as well as in Co-rich nickel ores (laterites and sulfides). Also, Co-bearing secondary raw materials contain the mentioned elements in different contents. In pyrometallurgical processing of sulfidic ores, cobalt is generally recovered as a by-product during the production of copper and nickel, whereas it is normally not recovered separately during the processing of nickel laterites but remains in the FeNi product. Besides various hydrometallurgical production routes, the pyrometallurgical processes involved comprise smelting (i.e., production of a Cu-Ni-Co-Fe matte in electric or flash furnaces), converting and refining (i.e. removal of Fe and S as well as other elements from matte by oxidation). The ongoing trend to use higher oxygen enrichment in process air enables higher intensity processes but also increases the oxidation potential in the vessel. Therefore, during smelting and especially during the oxidative treatment in converting and refining, some amounts of valuable metals are also transferred to the slag in their oxides form. A subsequent slag treatment is then applied for recovering valuable metals from the slag, namely allowing an economic material stream handling and minimizing metal losses. This is often done in a slag reduction furnace. Additionally, copper and nickel are very good collectors for precious metals and platinum group metals (PGMs) - therefore, depending on the content of these metals, an additional refining process is used to recover these valuable metals from the matte or metal phase (Elvers et al., 1997; Davenport et al., 2002; Crundwell et al., 2011)."

Jan 1, 2017

By F. Henríquez, V. Iriarte, L. Vinnett, J. Yianatos, F. Díaz

Metallurgical characterizations of the collective (Cu/Mo) and selective flotation plants were carried out in Minera Los Pelambres, Chile. The selective plant allows the valuable minerals of Cu and Mo to be separated. The evaluation involved two surveys consisting of metallurgical sampling as well as residence time distribution (RTD) measurements to determine load distribution. The RTD data were obtained in real-time by means of the radioactive tracer technique. In addition, metallurgical data was reconciled and supported by effective residence times. In the collective plant, a performance comparison of parallel rougher circuits was carried out, which included a bank of six mechanical cells of 250 m3 and banks of nine mechanical cells of 130 m3. In the selective plant, the Cu and Mo evolution along the plant was evaluated. The results in the selective plant allowed for performance evaluation of mechanical and pneumatic cells in primary flotation. In both plants, mineral losses were evaluated and their relationship with circuit configuration (cell types and circuit layout) was determined. The metallurgical characterization was a powerful tool to evaluate circuit performance and to detect improvement opportunities at industrial scale.

Jan 1, 2015

By V. J. Southey

HOLLINGER mining operations have required development by 24 vertical shafts having a total length of 28,160 feet. Seventeen of these are sunk from surface and seven are interior shafts. Four surface shafts and three interior shafts are now active and, excepting the recently completed new main ore-hoisting shaft, the remainder are either abandoned, or are used for passes or for ventilation. The new shaft bottoms 60 feet below the 3,050 level, but there is much work to be done before it is placed in service. The term 'shaft practice' is intended to include shaft construction and a general treatment o typical equipment. It is a large subject for an organization the size of Hollinger and this paper is intended only to present the salient features. The writer wishes to thank the management for permission to publish this information and to acknowledge the advice and criticism o A. G. Irving, chief engineer, and the willing co-operation of other members of the Hollinger staff.

Jan 1, 1939

By E. Uzun

"In this study, H2SO4 and HCl leaching behaviour of an ore sample containing 1.87% of Ni, obtained from the Karaçam (Eskisehir-Turkey) lateritic deposit that started operation recently was investigated. Acid concentration, temperature and reaction time were investigated as variables by comparative leaching tests and the optimum leaching conditions were selected on teh basis of Ni, Fe, Co and Mg behaviour. For H2SO4 leaching, optimum leach parameters were 95°C, a 12 normal H2SO4 concentration and 90 minutes of reaction time, and under these conditions Ni and Fe dissolutions were 97.6% and 95.4% respectively. On the other hand, 70°C, an 8 normal HCl concentration and a reaction time of 90 minutes were found to be the optimum parameters for HCl leaching, and Ni and Fe dissolutions found were 97.1% and 97.8%, respectively.INTRODUCTION Today, nickel and various nickel compounds are obtained from sulphide and lateritic nickel ores (Moskalyk & Alfantazi, 2002). Even though about 72% of the world's nickel reserves constitute lateritic ores, only about 42% of nickel is produced from these ores. The decrease in production from sulphide deposits, on the other hand, and increases in the use of nickel in the iron and steel, and battery production sectors, and especially the production of nickel cast irons in recent years, have accelerated the importance of making use of lateritic deposits (Luo et. al., 2010; Chang et. al., 2010). In the beneficiation of sulphide nickel ores, mostly pyrometallurgical methods are used. On the other hand, about 39% of lateritic ores are beneficiated by pyrometallurgical, and 61% are beneficiated by hydrometallurgical methods (USGS, 2009). In laterite beneficiation, the ore properties are of significance; that is to say, limonitic ores are eneficiated by high pressure acid leaching or via the Caron process, nontronitic ores are beneficiated by high pressure acid leaching or heat treatment (smelting), and ores containing serpentine by pyrometallurgical methods (Berezowsky, 2004; McDonald & Whittington, 2008a; Dreisinger et. al., 2015)."

Jan 1, 2017

By Robert Yobou, Jacques Naho, Benjamin A. Allou, Jacques Carignan, Huan-Zhang Lu, Jayanta Guha, Koffi Pothin

"Résumé - Les seules productions de columbo-tantalite en Côte d'Ivoire sont effectuées dans les éluvions, colluvions et alluvions d'Issia, au Centre-Ouest de la Côte d'Ivoire. Même si un lien direct avec les roches granitiques est suspecté, aucune attention particulière n'a été accordée à l'étude de la minéralisation primaire en relation avec l'évolution de ces granites et des pegmatites associées. Ces granites, qui sont en intrusion dans les roches sédimentaires du Protérozoïque inférieur, comprennent: le granite orienté à deux micas (type Lobo), le granite orienté à muscovite dominante (type Bitapia) et le granite porphyroïde non orienté à muscovite dominante (type Issia). Les résultats de cette étude indiquent que les pegmatites à Nb-Ta-Be-Li sont liées au granite de type Issia. Les observations de terrain et les analyses sur roche totale montrent que: (1) les trois principaux granites de la région sont de type-S et peralumineux dans leur composition, (2) ils ont été formés pendant la période tardi- à post-Éburnéenne, (3) le granite de type Issia fut le dernier à se former.Les pegmatites liées au granite de type Issia ont été classées en quatre types : A- pegmatites stériles; B- pegmatites à Be; C- pegmatites zonées à Nb-Ta-Be; et D- pegmatites zonées à Be-Nb-Ta-Li. Les pegmatites zonées comprennent les zones suivantes: I- zone à aplite; II- zone graphique; III- zone à albite, microcline, béryl et columbo-tantalite; IV- zone à microcline massive; V- zone à quartztourmaline. Ces pegmatites présentent une zone d'altération métasomatique externe.La minéralisation de Ta, Nb, et Be est liée à la zone III des pegmatites de types C et D, la minéralisation de Li est associée aux greisens qui peuvent être observés n'importe où dans les pegmatites de type D. Les données de terrain et de laboratoire indiquent que le granite de type Issia est la roche parentale des pegmatites à éléments rares de la région. Les pegmatites minéralisées sont distribuées seulement autour du granite de type Issia et les patrons des terres rares des granites et ceux des pegmatites à éléments rares sont très similaires. Les analyses de la composition totale montrent un lien génétique entre le granite de type Issia et les pegmatites à éléments rares. Il est suggéré que les pegmatites ont été formées durant le transport et la cristallisation fractionnée du magma. Les éléments rares sont restés dans le liquide résiduel jusqu'à ce que les conditions favorables à leur précipitation soient atteintes.L'établissement de ce lien génétique ouvre des voies pour des nouvelles stratégies d'exploration."

Jan 1, 2005

By M. Kreuh

Crystalline Mg(OH)Cl and amorphous Mg2(OH)3C1 were successfully isolated from a hydrolyzed molten salt electrolyte sample in this work, It was found that the chemical form and crystallinity of the hydroxylchloride were controlled by the cooling rate of the molten sample when it was taken. Crystalline Mg(OH)Cl could only be obtained by cooling the molten electrolyte sample at a rate not faster than 0.6 °C/min, Upon more rapid cooling, the hydroxylchloride species precipitated as Mg2(OH)3Cl, The behavior of these solid hydroxylchlorides when contacted with fresh and non-hydrolyzed molten electrolyte at 550°C was also examined, It was found that the Mg(OH)Cl rapidly dissolved in the hot electrolyte and did not decompose into MgO at that temperature as would be expected from the literature, The dissolution rate of solid Mg2(OH)3Cl was found to be so slow by comparison that it resulted in the complete decomposition into MgO which thereafter was incorporated into the electrolyte as a suspended solid phase rather than dissolution.

Jan 1, 2004