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By Ian Hattie, Mark R. Wilson, T. Kurtis Kyser, Brian W. Janser

Petrographic, chemical and isotopic compo itions of auriferous and non-auriferous quartz vei ns from the Sta r Lake and Flin Flin-Amisk Lake areas of northern Saskatchewan indicate diver e origins fo r the fluids associated with gold mineralization. In the Sta r Lake area, the metavolcanic , Star Lake pl uton, and heared mafic dikes have retained their original igneous 81 80 values. The 81 80 value of quartz from mi neralized veins vary by I per mi! and range from+I0 to+IJ. The only quartz ample having a 81 80 value outside th is range came from a vein not associated wi th a dike or gold mineralization . Quartz from the Star Lake pluton has identical 8180 value to the qua rtz from mi neralized vei ns which suggests that the vei ns and the pluton are related to imilar proces es. The diffe rence in 81 80 values between mi neralized and barren vein may erve a a potential exploration tool in this area. Because o34S val ues of a limi ted number of amples of pyrite from gold-bearing quartz vei ns at Star Lake correlate directly with gold content. the gold may have been syngenetic with the su lphur and the 834 value may be useful for exploration . 8180 values of co-existing quartz, calcite, and amphibole in the veins from Star Lake indicate that isotopic disequilibrium among the minerals is common, but the val ues also record a high temperature of formation (ea . 500°C) involvi ng a component of magmatic fl uid. TheoD value of hydrou mineral from Star Lake retain their original igneous values but whole rock values are generally much lower, an effect attributed to interaction of the minerals with a late meteoric water. In the Fl in Flin-Amisk Lake area, auriferou and barren quartz veins formed from a mixture of hydrothermal and metamorph ic flu id at lower temperatures (ea . 350°C) than those at Sta r Lake. Becau e there i no apparent correlation between 8180 values of the quartz with gold content or relative age of the vein , nor between the 834S val ues of pyrite and gold content, table isotopes appear limited as an exploration tool in the Fl in FlonAmisk Lake areas.

Jan 1, 1986

By The Hollinger Mill Staff

MR. E. L. Longmore (l), in presenting this paper at the Annual General Meeting, suggested that it was neither desirable nor necessary to read any but the briefest portion of the paper. He wished to emphasize that the scale of the milling operations at the Hollinger not only provided several units in continuous operation to ensure that the test work was being carried on under normal conditions, but also provided a large and competent staff to supervise such an extensive experiment and to criticize intelligently the recorded results. He wished to acknowledge the enthusiastic co-operation of the group of assistants whose excellent work was responsible for the confidence with which the conclusions could be presented. The following data were given as a supplement to the published paper. Following conclusion of the test work described in the paper, the size of the balls fed to the mill was changed from 3-in. diameter to 2Yz-in. Within a short time, a gradual rise in the tonnage rate took place and, as no other condition had been changed, the increased tonnage was credited to the changed character of the ball load. At present, the average daily tonnage for the mill with low discharge is 1,507 tons, an increase of 77 tons over the 1,430 tons ground when feeding a 3-in. ball. A similar increase in tonnage should be credited to the high-discharge test, if the 2;Y2-in. ball had been used at that time. This would raise the 1,117 tons ground at that time to a new figure of 1,177 tons. From a study made to determine those factors influencing the rate of pulp flow through the low-discharge mill, it became evident that the ball screen used on the high-discharge mill must have been restricting the flow through the mill, although this was not recognized at the time. Accord-ingly, it was decided to repeat the high-discharge run. Additional length was added to the 21-in. ring grizzly originally used, and the length of the reverse spiral was increased. The end of the grizzly was left open so that, if necessary, excess pulp might flow out. A coarse mesh 3 ft. by 3 ft. flat screen was provided to catch stray balls.

Jan 1, 1937

By Jing Li, Weiqiang Lai, Joe Zhou, Jiezhen Ma, Shuibo Chen, Ashele Copper Company, Feng Gao, Guofu Feng

"Copper-zinc ores often contain gold and silver, which can be recovered into copper concentrate by flotation as by-product. The challenges for operations that produce copper, zinc, gold and silver are the separation of copper and zinc and the low grade of precious metals. Ashele copper-zinc ore in north China contains 2.38% Cu, 0.69% Zn, 0.21 g/t Au and 18.10 g/t Ag and the plant produces copper and zinc concentrates, with gold and silver being recovered into copper concentrate. Copper occurs mainly as chalcopyrite and Zn occurs as sphalerite. Copper is well recovered with a recovery of over 94%. However, the recovery of Zn is substantially low (around 50%) due to fine grain size of sphalerite. In addition, gold recovery is much lower than expected and only 33% of gold in the flotation feed was recovered. The grade of gold in copper concentrate is also lower than the required payable grade (1.0 g/t). To determine the cause for lower Zn and Au recoveries, a plant survey program was conducted on the operation. The information acquired shows that the loss of Zn was mainly in the copper concentrates (accounting for approximately 38% of the head assay); of which, 24% was liberated, 8.5% was associated with chalcopyrite and 4.6% was associated with pyrite, indicating that the separation of copper and zinc was the main cause for the Zn loss, with liberation being the second cause for Zn loss. Future effort in improving Zn recovery should be focused on the separation of zinc from copper. Gold in the ore occurs as both microscopic gold and submicroscopic gold, accounting for 36% and 64% of the head assay, respectively. Microscopic gold occurs mainly as native gold and electrum; it is relatively coarse with a grain size of 10 to 240 µm and a large portion can be recovered by gravity. Submicroscopic gold was mainly carried by pyrite (accounting for 38%), and to a less extent, by tennantite (15%) and chalcopyrite (10%). Gold in sphalerite is nominal (1%). It is suggested that more coarse gold and tennantite be recovered and a gold recovery increase can then be achieved to obtain a copper concentrate with over 1.0 g/t Au through flowsheet optimization. Gravity concentration should be investigated and may be worth added into the existing flowsheet to maximum the gold recovery and grade.INTRODUCTIONCopper-zinc ores containing gold and silver is a subtype of polymetallic sulphide ores. Unlike porphyry copper sulphide ores and iron-oxide copper-gold ores, this type of ores often contains substantial amounts of zinc and lead. Polymetallic sulphide ores are mainly distributed in Canada, such as at the LaRonde and Horne deposits. Other examples include Mt. Morgan in Australia and Boliden in Sweden. Globally, production and reserves from gold-rich VMS deposits account for 1370 t gold. This is equivalent to 1% of the world production and reserves, whereas the Canadian total for gold-rich VMS deposits is 870 t, representing close to 10 % of Canadian production and reserves (Gosselin & Dube, 2005a, 2005b). Flotation is the principal process for processing the copper-zinc sulphides ores, for subsequent smelting, roasting, or hydrometallurgical treatment. Oxidized copper-zinc ores can also be processed using leaching technology. For example, at LaRonde operation (a Cu-Zn-Pb ore containing 3-4 g/t Au and 60-100 g/t Ag) the flowsheet consists mainly of a copper flotation circuit and a zinc flotation circuit followed by a cyanidation process of flotation tails. The precious metals are recovered with copper concentrate, zinc concentrate and cyanidation of zinc tails via Merrill Crowe precipitation (Zhou et al., 2005)."

Jan 1, 2016

By Douglas C. Fraser

"Geophysical data are often presented on maps, sections or profiles with minimal data processing. A common example is magnetic data, in which the diurnal-free raw readings are merely contoured on a map. Other examples include profile presentation of VLF-EM data, IP pseudo-sections and airborne EM anomalies which may be shown on a map with only the measured amplitudes indicated.In recent years, efforts have been directed to the portraying of data in more useful forms. A number of algorithms (i.e., manipulative procedures and equations) have proven to contribute significantly to the usefulness of geophysical data. Some can be applied manually; others are sufficiently complicated to require a computer. Some merely alter the data to a more useful geometric form without altering the units. Others yield quantitative estimates of source body parameters such as conductivity and shape. Several examples follow:1. A simple algorithm is in common use which transforms noisy non-contourable VLF-EM data into less noisy contourable data. The input is the dip angle in degrees or per cent and the output is also in these same units.2. A simple algorithm has recently been developed which allows multi-level dipole-dipole IP data to be contoured on a map. Again, the units are not altered.3. A relatively complicated algorithm is in common use which transforms non-contourable height-sensitive helicopter EM data into contourable resistivity data,4. An algorithm has been recently developed which transforms non-contourable height-sensitive EM data into contourable weight per cent magnetite.The purpose of all the above techniques is to present the data in a simplified form. This, in turn, allows an easier assimilation by the user of much of the information content of the data."

Jan 1, 1981

By Yongjun Peng, Yufan Mu, Rolf A. Lauten

"Chalcopyrite, a major source of copper, is commonly found associated with iron sulfides, particularly pyrite. The separation of chalcopyrite and pyrite by flotation is difficult due to the galvanic interactions between pyrite and chalcopyrite during grinding and flotation. Galvanic interactions may cause oxidation and dissolution of chalcopyrite, copper activation of pyrite and the formation of hydrophilic iron hydroxide coating. The overall effect may change the floatability of the components and lead to the misplacement of pyrite into chalcopyrite concentrate. The objective of this study was to investigate the effect of lignosulfonate-based biopolymers on the depression of pyrite in the flotation of chalcopyrite with xanthate as collector and the mechanism responsible for the selective depression of pyrite. The flotation results showed that biopolymers depressed the flotation of both copper-activated pyrite and chalcopyrite in single mineral flotation although to different extents. In the flotation of mixed mineral systems, biopolymers significantly depressed pyrite flotation but had a less influence on chalcopyrite flotation. The selective depression of pyrite by biopolymers was due to the preferential adsorption of biopolymers on copper-activated pyrite surface. Galvanic interactions between pyrite and chalcopyrite surfaces promoted copper activation on pyrite. Presence of cuprous ions on pyrite surface favored biopolymer adsorption by the formation of a complex between the cuprous ions and biopolymer molecules. The same galvanic interactions also facilitated chalcopyrite oxidation leading to the formation of hydrophobic polysulfide that enhanced the hydrophobicity on chalcopyrite surface. The biopolymer structure controlled the depression effect. The results showed that the biodegradable biopolymers are promising depressants for pyrite.INTRODUCTIONCopper sulfide minerals, such as chalcopyrite (CuFeS2), bornite (Cu5FeS4), chalcocite (Cu2S) and covellite (CuS), are the major mineral source for copper. They are often found finely interlocked with iron sulfides, especially pyrite (FeS2) (Owusu, Brito e Abreu, Skinner, Addai-Mensah, & Zanin, 2014). Pyrite, as the most abundant sulfide mineral, is perceived as gangue in most cases and should be removed from the associated sulfides to minimize its contamination of the copper concentrate (Owusu, Addai-Mensah, Fornasiero, & Zanin, 2013; Wang & Forssberg, 1991). The commonly used strategy to remove pyrite is flotation (Wang & Forssberg, 1991)."

Jan 1, 2016

By B. N. Church, J. J. Barakso, A. F. Bowman

"An evaluation of mineralization in the Goosly- Owen Lake area of central British Columbia is the result of a comprehensive geochemical study of rock samples obtained from a regional geological survey. The dispersion of metals in country rocks about a line of Tertiary intrusions suggests that these igneous bodies may be genetically related to known sulphide replacements, disseminations and vein deposits. The geochemical investigation is based on the determination of 12 elements from samples gathered from more than 800 scattered field stations. To assist processing and interpretation, the data are subjected to a variety of statistical procedures, including correlation of the elements, factor analysis, clustm• analysis and computer contouring of the elements. Some practical applications of rock geochemistry in regional exploration are indicated."

Jan 1, 1976

By J-F. Béland, N. Parson

Aluminum extrusions are widely used for automotive crash management systems due to their superior specific energy absorption capabilities, as compared to steel. The Al-Mg-Si alloy series can be readily extruded into complex multi-hollow profiles, as required in crash systems, and can be used to target a range of desired strength levels. This paper focuses on the development of an axial crush test protocol and evaluation of the crush performance of common 6XXX series alloys for a variety of tempers. The observed crush behaviour is then compared to tensile test results.

Jan 1, 2015

By B. L. Moreau

Certain gas wells tend to form hydrates in the production tubing. This paper outlines a method developed and used by the Author's company to overcome the problem. The injection of glycol to control hydrates results in sufficient dehydration to allow the gas to be trans-ported through a field-gathering system b a treatment plant. Sub-surface injection of glycol also offers a method of introducing corrosion inhibitors into the gas stream. The major operating difficulties have been overcome and the system is now in use in the northeastern part of British Columbia.

Jan 1, 1958

By C. Cutts, K. Wheatley

The Dragon Lake Zone (uranium prospect) comprises a N160º trending vein that is approximately 110 m long, up to 5 m wide and from 1 to 40 m high. The zone is mostly within altered sandstone of the Fair Point Formation, the basal unit of the Paleoproterozoic Athabasca Group, but it also extends downward (up to 3.5 m) into basement rocks that occupy the northerly trending Maybelle River Shear Zone (MRSZ). This subvertical shear zone separates graphitic paragneiss and weakly deformed granitoid rocks to the east from non-graphitic paragneiss and foliated granitoid rocks to the west. The Dragon Lake Zone cuts across both the MRSZ and N060º-N070º-trending cross-faults that offset the shear zone but not the mineralized vein, which contains values up to 54.5% U over 50 cm core length. Strong chloritization occurs in graphitic paragneiss and sandstone adjacent to mineralization. Silica was depleted from the basement rocks and redeposited at the borders of the 5-15-m-wide alteration zone, as well as within overlying sandstone of the Manitou Falls Formation. There are minimal alteration effects in the overlying Lazenby Lake Formation. Geochemistry shows that the alteration zone in the Fair Point Formation is highly anomalous in metals, most notably in Ni, As, U, Pb, Co, and B. Clay within this zone is illitic and Fe-rich chlorite is also present. Brittle deformation is not as widespread or as well developed in the Fair Point Formation as it is in the overlying Manitou Falls Formation, which is extensively brecciated and contains some anomalous metal values.

Jan 1, 2013

By A. C. Headon, K. W. Lam, D. P. Dautovich

"Microbiological activities affecting the performance of materials have been encountered in diverse situations within Ontario Hydro. Case histories of bacterial problems which are presented include ground rod corrosion at transformer stations, corrosion of a bare steel cooling water intake structure in Lake Huron and corrosion of steel components in a nuclear generation station vacuum building. Possible microbiological activities which may affect the corrosion behaviour of containers for the disposal of nuclear fuel waste in the future are discussed, as are bacterial actions suspected of causing an odour problem in residential water heaters.IntroductionBacteria are ubiquitous. Except by use of sterilization methods, bacteria -free environments are no t possible to find. Bacteria lie dormant in hostile environments, spread easily through air and water currents and reproduce rapidly under favourable conditions. Although different types of bacteria have different preferable conditions for growth, they are highly adaptive and in general, whenever there is a source of water and carbon (carbon dioxide or organic matter), there will be bacterial activities . These activities often induce or enhance costly metallic corrosion in industries and water odour problems in rural water supplies . Underground structures and systems in contact with natural water or water containing organic matter are most susceptible to bacterial attack.The types of metal-degrading bacteria , their characteristics and the conditions for growth have been reviewed extensively in the literature(1,2,3). There are several often encountered groups of bacteria which, through their metabolic processes, may lead to the degradation of metals. A large variety of bacteria produce corrosive in organic or organic acids as waste, such as the well known formation of sulphuric ac id by aerobic sulphur oxidizers . Anaerobic sulphate reducers produce hydrogen sulphide which is corrosive and has an obnoxious smell, slime-forming bacteria from slime which shelters sulphate reducers and iron bacteria oxidize ferrous to ferric ion which precipitates as hydrated oxides creating oxygen concentration cells . The following are bacterial problems encountered in Ontario Hydro. Although the number of recognized cases has been few, they show the diversity of location and environment where bacterial problems could arise. These include ground rod corrosion at transformer stations, corrosion of bare steel in a water intake structure, corrosion of steel in a nuclear generation station vacuum building and an odour problem in residential hot water tanks. In addition, possible bacterial- enhanced corrosion in containers for future disposal of nuclear fuel wastes are also discussed."

Jan 1, 1984

By J. U. MacEwan

Introduction The equilibrium between copper, zinc, and chlorine may be considered as the simultaneous equilibrium of the two separate chemical reactions of formation of the stable chlorides of copper and zinc at the temperature of the reaction i.e., l440°K. (1,167°C., 2,133°?F.)§ [Zn(g) +Ciz(g) ZnCl2z(g). ... (1) ] [2Cu(l)+Cbi'g) Cu2Cl2(l 1 ....... (21 ] Subtracting, [Zn(g) +Cu2(Clz(l i ZnClz(g) +2Cu!l) ... . (3) ] If this reaction is carried out with a copper-zinc alloy at some constant temperature above the melting point of brass, and at a total pressure of one atmosphere, the equilibrium concentrations obtained will depend on the free energy decrease .of the reaction as written in (3) and on the activities of the various components in. the reaction mixture. If the equilibrium is examined from the point of view of the phase rule, it is a three-component system, and if it exists in two phases (liquid and gas) it will have three degrees of freedom. If the restrictions of constant temperature and pressure are imposed, the degrees of freedom are reduced to one. This means that, in a two-phase system under these conditions, each different alloy phase will be associated with a gas phase of constant composition.

Jan 1, 1951

By V. G. Papangelakis, G. A. Moldoveanu

The use of anhydrite (AH) seed, control of acidity levels and ageing were assessed as means to promote the conversion of freshly produced metastable gypsum generated in-situ to the less soluble anhydrite phase and force deposition of calcium sulphate on seed as opposed to on equipment as scale, while achieving lower terminal aqueous calcium concentration as well. It was found that moderate sulphuric acid levels (0.25M) and ageing in the presence of AH seed accelerated the gypsum-AH conversion, achieving 100% transformation of the metastable gypsum generated in situ to the more stable, less soluble AH in 6-7 days, while lower/nil acidity did not promote more than 30% AH conversion for 10 days, even in the presence of AH seed. These findings indicate that anhydrite seeding, ageing and incomplete neutralization are beneficial for scale control as well as achieving lower calcium levels, thus rendering the resulting solution more amenable for recycling.

Jan 1, 2015

By W. de Klerk, M. B. Thorpe

Golden Star Resources Bogoso operates in Ghana’s Western Region. The gold recovery plant includes; a flotation circuit producing a concentrate for the BIOX® process that oxidizes sulphides before a CIL circuit; and a dedicated CIL circuit. BIOX® uses bacteria, therefore water from the BIOX® and CIL plants remained separated; CN water could not be introduced into the flotation / BIOX® circuit. The operation built a process water inventory with high TDS and installed a process water treatment plant (PWTP). Water was released in compliance the permits but containing some thiocyanate. The PWTP brine was returned to the TSF, further exacerbating the TDS. The operation experienced a drought removing the traditional water sources; the team evaluated the options to maintain production - various water streams were laboratory tested provided options for water use. The paper presents the story (treatment chemistry and process chemistry) of continued operations by treating stored water and PWTP discharge water with peroxide; brine usage within the CIL circuit, which increased gold recovery (laboratory testing) and reduced the TDS. Water flows were further modified to include hydraulic tailings re-mining to a CIL circuits. Details of the recovery, basic chemistry and costs savings are provided.

Jan 1, 2014

By W. A. Jankola

Teck Cominco Metals Ltd. operates an integrated zinc-lead smelter at Trail, British Columbia, Canada. The zinc circuit comprises three parallel operations: conventional fluid-bed roasting, direct zinc pressure leaching of concentrates and atmospheric leaching of zinc oxide fume recycled from the lead smelter. The products from these three areas are combined in the main leaching plant where they undergo iron purification. Unlike most leaching circuits, the leach process in Trail begins with an acid leach and is followed by a neutral leach. An evaluation was undertaken to determine if the process at Trail could be improved by converting to the conventional neutral leaching process with a subsequent acid leach of the residues. This paper explores the results of these tests and the implications for Trail Operations.

Jan 1, 2006

By R. Howard

"In projects involving resource development and plant optimization, the use of in-mine geophysics can deliver considerable benefit. The value proposition lies in using very high resolution downhole measurements to model process-plant outcomes. The calibration procedure used to convert in-situ physical properties into process engineering parameters is illustrated using two iron ore projects. Data correction was related either to orebody structure or mineral formation. The deliverable from this approach is a series of high-definition sections indicating the variability of ore delivered to a front-end separation plant and parameters for mine scheduling and stockpile design needed for maximum product yield.RÉSUMÉ Dans des projets de développement des ressources et d’optimisation de l’usine, l’utilisation de la géophysique minière peut engendrer des bénéfices considérables. La valeur de la proposition réside dans l’utilisation de diagraphies à très haute résolution afin de modéliser les résultats de l’usine de traitement. La procédure d’étalonnage utilisée pour convertir les propriétés physiques in situ en des paramètres d’ingénierie de procédés est illustrée en se basant sur deux projets de minerai de fer. La correction des données porte sur la structure de la masse minérale ou de la formation minérale. Les livrable attendus de cette approche sont une série de sections à haute définition, signalant la variabilité du minerai livré à une usine de séparation de première ligne, des paramètres pour l’échéancier de la mine et la conception des haldes requis pour une production optimale."

Jan 1, 2016

By Yves Caron

Résumédes travaux effectués De septembre 2009 àmai 2011 ? Plus de 21 000 m de forages complétés en avril 2011 et près de 9 000 échantillons ? 2,7 km de décapage, 52 tranchées et 852 m de rainures ? Estiméde ressources 28 mai 2010 (SGS Géostat) ? Essais métallurgiques en laboratoire (automne 2010) ? Étude économique préliminaire (janvier 2011)

May 1, 2011

By G. M. Ross, I. M. Ross, J. A. Scott

"The otherwise waste heat in many water streams in the mining industry can be used to provide space heating of adjacent infrastructure including laboratories, workshops, and offices. This can be achieved by using heat pump systems, which can work as a replacement or in conjunction with existing space heating. In the example investigated—process cooling streams at an ore smelter—the analysis provided illustrates that annual heating costs can be 19% lower and a simultaneous 62% reduction in CO2 emissions can be achieved.RÉSUMÉ Dans l’industrie minière, la chaleur qui serait normalement perdue des circuits d’eau pourrait servir à chauffer des structures adjacentes incluant les laboratoires, les ateliers et les bureaux. Cela pourrait se faire en utilisant des systèmes de thermopompes, qui pourraient remplacer ou s’ajouter au chauffage existant. Dans l’exemple étudié, des circuits de refroidissement de procédé à une fonderie, l’analyse fournie illustre qu’il est possible de réduire les coûts annuels de chauffage de 19 % et d’obtenir une réduction simultanée de 62 % des émissions de CO2."

Jan 1, 2016

By G. Gabra, M. Nagamori, J. J. Panneton

"RESUMELa calcination contrôlée de 10 serpentine permet de produire de 10 magnésie active. Le degré de I'activation est mesure par 10 solubilité du magnésium dans les acides faibles tel que I'acide acétique, La serpentine contenue dans les résidus d'amiante du Québec peut donc être activée par calcination. Le teneur en magnésie active des rejets d'amiante calcinés est fonction de divers paramètres: température, temps de calcination, granulométrie, etc. Les rejets d'amiante de différentes provenances démontrent des comportements thermochimiques différents qui sont étudiés dans Ie présent travail au moyen d'ATD, de TG, de la diffraction des rayons X et de la lixivation par l'acide acétique. On constate qu'un maximum d'environ 80% de la magnésie totale peut être activé dans certains rejets d'amiante du Québec et Ie degré d'activation dépend de la provenance.vIntroductionOn sait depuis longtemps que la serpentine, Mg3Si2O5(OH)4, un silicate hydroxylé de magnésium, devient amorphe lorsqu'elle perd de I'eau d'hydratation entre 600 et 700 °C. La serpentine ainsi calcinée est alors dissociée en magnésie et en silice. Cette magnésie, dite active, est soluble dans un acide faible ou même dans les solutions de sels d'ammonium.Plusieurs precédés chimiques ont été proposés afin d'extraire sous forme de composés magnésiens la magnésie de la serpentine. La plupart de ces procédés comportent une activation par calcination de la serpentine préalablement à une Iixiviation par un acide ou par une solution d'un sel d'ammonium.Malgré la contamination par Ie fer et par d'autres éléments, les compositions chimiques des rejets de différentes mines d 'amiante du Québec, présentées au tableau 1, sont très proches de la serpentine typique. Puisque Ie degré d'activation de la magnésie varie grandement d'une serpentine à I'autre lors de la calcination, la première étape de la recherche sur la transformation chimique des rejets d'amiante du Québec se résume à une étude de leurs comportements thermochimiques."

Jan 1, 1982

By Denis Racicot

"L'Abitibi québécois a produit essentiellement de l’or, du cuivre, du zinc et de I' argent, ainsi que de faibles quantités de nickel, de plomb, de molybdène, de bismuth, de lithium, de fer et d’amiante. Depuis l’ouverture de la mine Horne en 1927, cent-cinquante mines ont contribué à la production de 1 420 tonnes d’or de 4,1 millions de tonnes de cuivre et de 4,7 millions de tonnes de zinc. Les productions minières annuelles ont été d'importance variable: des records de production ont été établis en 1955 pour I' or avec 35 tonnes et, vers 1965, pour le cuivre, le zinc et la quantile globale de minerai extrait avec respectivement 130,000, 275 000 et 13 millions de tonnes. Deux dépressions généralisées ont eu lieu, l’une vers 1946 et l'autre, a lafin des années soixante-dix. Des ralentissements de la production ont été observes pour le cuivre en 1953 et le zinc en 1959. Depuis le debut des années quatre-vingt. I' or et, de façon plus irreguliere, le zinc sont en progression, landis que le cuivre, malgre une hausse en 1983. pour suit son dec/in.La teneur de récupération des mines d’or est demeurée régulière et n’a subi qu’une faible diminution au cours des quarante dernières années. Célie du cuivre a diminué d'environ 50% dans la même période, landis que celle du zinc a subi d’import antes variations, aussi bien positives que négatives. Près des trois quarts des mines d'or ont une durée de vie inférieure à 12 ans et la distribution des tonnages de minerai extrait montre un maximum pour la classe de 100 000 à 1 million de tonnes. Du cote des mines de métaux de base, la durée de vie est plus étalée et les volumes de minerai ont une occurrence maximale dans la classe de 1 à 10 millions de tonnes.Concernant la distribution géographique de la production minière dans l'Abitibi québécois, le camp minier de Rouyn-Noranda vient en tête pour l’extraction de minerai et la production d’or et de cuivre. L’est sui vi par le camp de Val d'Or pour le minerai et l’or, landis que le camp de Chapais-Chibougamau occupe la deuxième place pour le cuivre avec une production équivalence a 60% de celle de Rouyn-Noranda. Le camp de Cadillac-Malartic suit de tres pres celui de Val d'Or pour ce qui est de I' or. Finalement, dans le casdu zinc, le camp minier de Joutel-Matagami domine largement avec une production qui a connu un développement accélère depuis 1963. Une analyse pré liminaire de ces données indique qu' i/ subsiste unpotentiel encore élevé de production d'or, décuivre et de zinc dans I' Abitibi québécois. ABSTRACTThe Quebec portion of the Abitibi belt has essentially produced gold, copper, zinc and silver, as well as some small quantities of nickel, lead, molybdenum, bismuth, lithium, iron and asbestos. Since the opening of the Horne mine in 1927, one hundred and fifty mines have produced 1420 tons of gold, 4,1 millions tons of copper and4,7 millions tons of zinc. Annual mine production has fluctuated: production records were established in 1955 for gold with 35 tons, and around 1965 for all extracted ore copper and zinc with respectively 13 millions, 130 000 and 275 000 tons. Two main recessions have occurred, the first around 1946 and the second during the late seventies. Cut backs in copper and zinc production occurred in 1953 and1959. Since the beginning of the eighties, gold production and to a lesser extent zinc production have been in progression. Except for a small jump in 1983, copper production is still declining.The average recuperation grade of gold mines has been quite steady and has only slightly diminished in the past forty years. The average copper recuperation grade was halved during the same time interval. For zinc there have been important ups and downs. At least three quarters of gold mines have an average lifespan of 12 years the tonnage distribution shows a peak in the 100 000 to 1 million tons class. Base metals mines show a more widespread life expectancy and have a tonnage peak in the 1 to 10 millions tons range"

Jan 1, 1990

By A. Hayatdavoudi, K. G. Sawant, F. Boukadi

"In this work, we found that contact between shale and water results in development of micro fractures. Based on results of experiments on Pierre shale, we conclude that appearance of micro fractures begin with saturation of capillaries, ionic and diffusive transport of water into the shale clays and once capillaries are saturated, the cause of micro fracture propagation is the conversion of ionic activity/exchange to excess pressure that did not exist before fracking. Based on these findings, the spread of micro fractures appear to be a time-dependent phenomenon which has not been addressed in the existing macro/micro fracture models.INTRODUCTIONShale has often been involved as a hazard in drilling operations. This hazard can be defined as “destabilization” of shale. When contacted with water-based drilling fluids, some shales readily swell and sometimes, cause the wellbore to cave-in, slough, wash-out, close, and pack-off, impeding the drilling by sticking the drill-pipe. However, once drilling reaches the desired depth or length, the casing is set, cemented, and perforated, and then actually we wish to initiate fractures and destabilize the shale formation, using hydraulic fracturing.Clays constitute a major portion of minerals in shale. These clays contain a large amount of free energy which is the main factor for “slick” water adsorption/absorption. In fact, the reason for using “surfactants” in hydraulic fracturing fluids is to make the penetration of the fluid into the capillaries much easier, thus water meets with less resistance to enter the small capillaries. Also, the result of high capillary suction pressure is due to small Angstrom size capillaries, smaller pores and presence of ions and hydrateable metal atoms. The free energy is thus, related to all the above mentioned and other affects. Capillary pressure, osmotic pressure and other pressures are responsible for creating the micro-fractures in shale, thus, increasing the network of micro-fractures which leads to more gas production. The objective of this study is to evaluate the pressures of the individual ions which are released by the diffusing “slick” water into shale. These pressures would be added to the above mentioned capillary pressure, osmotic pressure, bacterially-induced pressures, chemically-induced reaction pressure, pressure due to exchangeable ion-transport, pressure due to release of free energy of solvation and eventually to the pore pressure as suggested by Terzaghi’s equation."

Jan 1, 2015