Search Documents

By Jeffrey S. Loen

"The size, morphology, surface texture, per cent mineral inclusions, and bulk chemistry (Ag and trace elements) of placer gold particles vary systematically according to transport distance from source rocks, as indicated by a case study from the Pioneer district in Montana, and data from the literature.Placer gold samples show a rapid decrease in mean and maximum particle length, and a gradual increase in flatness index (F.I. = length + breadth/2 x thickness) from about F.I. = 2 in bedrock deposits, to as much as F.I. = 45 over transport distances of several tens of kilometers. Primary mineral inclusions (mainly quartz, sulfide minerals, and iron oxides) are mostly lost within 10 km to 20 km of fluvial transport; this loss of quartz and trace metals causes a major change in bulk chemistry of placer gold samples. Following the loss of inclusions and the development of flakes, edges of flakes are folded and the mean number of folded edges in a sample increases with distance. When viewed under the electron microscope, surface textures of placer gold particles also become progressively more pitted with distance.Analysis of placer gold particles can be used to help evaluate placer source-area problems (placers with no known hard-rock gold deposits). For example, coarse placer gold containing abundant inclusions indicates a proximal source. On the other hand, an abundance of thin flakes is evidence of a long transport distance and possible reworking from older gravels. Placer gold characteristics can therefore provide information on distance to mineralized source rocks."

Jan 1, 1995

By C. Allen, M. Gangal, J. Stachulak

"Most underground diesel equipment is equipped with diesel oxidization catalysts (DOCs) to reduce carbon monoxide and hydrocarbon emissions. DOCs do not alter nitrogen oxides concentrations but can promote the oxidization of nitric oxide (NO) to the more toxic nitrogen dioxide (NO2). Vale and CanmetMINING have been researching how to reduce worker exposure to diesel emissions by testing mining equipment DOCs. Results indicate a > 77% decrease in carbon monoxide concentration but a 46–315% increase in NO2 concentration for 8-mode test cycles. It is recommended that DOCs that increase NO2 emissions be evaluated regarding their continued use in underground operations.RÉSUMÉ La plupart des équipements miniers souterrains sont équipés de catalyseurs d’oxydation diesel (DOC) afin de réduire les émissions de monoxyde de carbone et d’hydrocarbures. Les DOC ne modifient pas les concentrations des oxydes d’azote mais ils peuvent faciliter l’oxydation du monoxide d’azote (NO) en dioxyde d’azote (NO2), plus toxique. Vale et CanmetMINING effectuent des recherches pour réduire l’exposition des travailleurs aux émissions de diesel en analysant les DOC des équipements miniers. Selon les résultats, une diminution > 77 % dans la concentration de monoxyde de carbone est atteinte mais elle est accompagnée d’une augmentation de 46 à 315 % de la concentration en NO2 pour des cycles d’essais à 8 modes. Il est recommandé d’évaluer les DOC qui augmentent les émissions de NO2 pour décider de la poursuite de leur utilisation dans les opérations souterraines."

Jan 1, 2016

By Robin N. Adair

The Halfmile Lake stratiform volcanogenic massive-sulfide deposit consists of pyrrhotiterich breccia-matrix sulfides and pyrite-pyrrhotite-rich layered sulfides that form a laterally continuous sheet stratigraphically underlain by an extensive pyrrhotite-chalcopyrite-quartz stringer zone. Mineralization is hosted by a sequence of felsic pyroclastics and volcanic-derived, fine-grained metasediments. The proportion of volcanic to sedimentary rocks indicates increasing vent proximity from southwest to northeast across the deposit area. Fine- to medium-grained felsic pyroclastics and roughly equal amounts of fine-grained metasediments comprise the stratigraphic footwall to the mineralization. Quartz-feldspar porphyritic bodies cut this sequence and may have provided the heat source for exhalite activity. Felsic tuffs, locally crystal-rich, and lesser amounts of metasedimentary rocks make up the immediate stratigraphic hanging wall. This sequence is stratigraphically overlain and locally interfmgered with mafic volcanics that contain substantial proportions of felsic fragments. Deposition of sulfides post-dated the beginning of felsic volcanism, which places the deposit in the middle of the Lower Tetagouche Group. Compositions of the volcanic rocks range from basalt to rhyolite and exhibit sub-alkaline affinities. Strongly overprinted whole-rock, trace-element, and REE geochemical signatures resulting from mineralizing hydrothermal activity confirm the genetic relationship between the stringer zone and the mineralized sheet. Large-scale D1 folding has overturned the entire sequence. D1 thrust faults and related sheath-like folds have profoundly affected sulfide distribution. D2 is manifested by a penetrative S2 foliation, and D3 is represented by large-scale open folds.

Jan 1, 1992

By Gaston Giuliani, Jérome Massot, Didier Bourlès, Lionel Siame

"Abstract - We present a new approach for the evaluation of the potential of emerald reserves in gem projects using beryllium (Be) mobility. The distribution of Be in the different phases of hydrothermally altered (albitized) black shale hosting Colombian emerald deposits indicates that Be mobility is associated with the breakdown of Fe-Mn oxyhydroxide phases. The amount of Be that can be mobilized (~0.7 x 10-6 g/g; i.e., 0.7 ppm) may represent up to 18 wt% of the total Be contained in the black shale. A mass balance calculation applied to a well-constrained alteration zone of the Chivor mines, and based on the quantification of Be that can be mobilized under hydrothermal conditions, gives an estimate of the total gem reserves of these mines. Resumé - Une nouvelle approche, basée sur la mobilité du béryllium (Be) pour l’évaluation des réserves d’émeraude dans des projets d’exploitation de gemmes est présentée. La distribution du Be dans les différentes phases minérales de schistes noirs hydrothermalisés (albitisés) qui contiennent les gisements d’émeraude colombiens, indique que le Be mobilisable se trouve dans les oxyhydroxydes de fer et de manganèse. La quantité de Be potentiellement mobilisable (~0,7 x 10-6 g/g; soit 0,7 ppm) constitue jusqu’à 18% poids du Be global contenu dans le schiste noir. Un bilan de masse appliqué à la zone d’altération hydrothermale des mines de Chivor et basé sur la quantification du Be mobilisable, donne une première estimation des réserves à émeraude de ces mines. rieur."

Jan 1, 1999

By Frank Wright

"The Icon Sullivan Joint Venture ore deposit was discovered in June, 1965 by Messrs. Paul Benard, Bob Galipeau and Mac Watson working under the direction of Mr. Andrew J. Troop, as employees of the Icon syndicate. The deposit is located on the Waconichici River as the south end of Baie du Poste of Lake Mistassini, approximately 45 miles north of Chibougamau. Property acquisition and Winkie drilling was followed by a diamond drilling program to evaluate the deposit. Stripping of the open pit area connnenced in the late fall of 1966 and the first test sample of ore was shipped to Chibougamau in December of that year.Regular ore shipments to the mill of Merrill Island Mining Corporation Limited for concentration commenced May 25, 1967. Production to December 31, 1970 amounts to 42,960,000 pounds of pay copper.The ore is chalcopyrite in white quartz dolomite, and it contains a very small amount of precious metals. The quartz dolomite assumes a flat to gently dipping attitude and is associated with a graphitic argillite contact zone on both hanging and footwall sides, in dolomitic limestone rocks. There is practically no other sulphide present in the ore.During the summer of 1969 a series of pre-concentration tests were completed and a Wemco heavy media sink float plant was installed in late 1969 and early 1970. This pre-concentrator eliminates at least one third of the ore mined in the form of barren quartz dolomite prior to ore shipment by truck to the concentrator in Chibougamau."

Jan 1, 1971

By M. B. Kime

"Discrete-element method (DEM) modelling is a powerful tool for studying particulate systems within the mineral processing industry. DEM simulations were conducted to investigate the power draw, load behaviour, and impact energy profile of an experimental ball mill under different milling conditions. The variables considered were mill rotational speed (percent critical speed), ball size, and lifter face angle. The simulation results indicated that the grinding efficiency would be enhanced by using 80% critical speed, 30 mm ball diameter, and 45° lifter face angle. These findings can be useful in guiding actual ball milling tests involving an ore sample.RÉSUMÉ La modélisation par méthode des éléments distincts (MED) est un outil puissant qui permet d’étudier les systèmes particulaires au sein de l’industrie de traitement des minerais. Des simulations par MED ont été menées de façon à étudier le profil de la consommation énergétique, du comportement de la charge et de l’énergie de rupture d’un broyeur à boulets expérimental dans diverses conditions de broyage. Parmi les variables prises en compte figuraient la vitesse de rotation du broyeur (vitesse critique en pourcentage), la taille des boulets et l’angle de coupe de la cornière élévatrice. D’après les résultats de la simulation, on pourrait améliorer l’efficacité de broyage en utilisant une vitesse critique de 80 %, un diamètre de boulet de 30 mm et un angle de coupe de 45 ° de la cornière élévatrice. Ces résultats peuvent se révéler utiles pour les essais concrets de broyage à boulets impliquant un échantillon de minerai."

Jan 1, 2017

By Hang Zhao, Xinping Li, Pingan Wu, Yi Luo

The deep-buried rock surrounding the Jinping II Hydro-power Station was taken as the engineering background. Using model specimens of classified rock materials to simulate fractured rock mass under high in-situ stress conditions, the test about acoustic propagation law on single fracture model of specimen under different pressures and different angles were carried out. The variation of p-wave velocity in fractured rock mass and axial stress-strain relationship in the whole test procedure was also studied. Based on damage mechanics principle and the acoustic wave propagation in cracked rock mass, comparative study on damage constitutive relation of fractured rock mass under high in-situ stress in consideration of equivalent strain and equivalent energy was performed. As the results showed, with the change of axial stress level under constant confining pressure, the change in wave velocity can be divided into three stages: slow increase (small variation in amplitude), rapid reduce (large variation in amplitude ) and accelerate reduction. When the confining pressure is constant, the maximum p-wave velocity and the peak strength of specimens increases with the decrease of the crack angle. When the crack angle is constant, the maximum p-wave velocity and the peak strength of specimens increases with the increase of confining pressure.It is identified that the theoretical calculation results of constitutive relation about elasto-plastic damage model containing variable wave velocity in the fractured rock mass is consistent with the model test results.Therefore,the constitutive relation can provide reasonable suggestions for engineering practice.

Jan 1, 2015

By Sarah Bélair, Denis Beltrami, Deka Moussa Ragueh, Valérie Weigel

"Scandium is a highly valuable element belonging to the rare earth elements (REE) but it has different chemical and physical properties from those of lanthanides. This metal is generally used in aluminum-scandium alloys and in fuel cells but the development of its market is slowed down by its high price (more than 1000 US$/kg for a 99.0% grade product). Indeed, the low scandium content in the continental crust (an average of 22 ppm) and the difficulties to extract it selectively from solutions containing high impurity concentrations increase the cost of the recovery processes. Nowadays, scandium is primarily recovered as a byproduct.ERAMET is developing a hydrometallurgical process in Gabon (Mabounié) in which the scandium content in the deposit reaches 10 to 100 ppm. The Maboumine project consists in the extraction and purification of uranium, niobium, tantalum and REE from Mabounié ore. In the frame of this hydrometallurgical project, ERAMET had also studied the feasibility to recover scandium as a byproduct. During the ore leaching, uranium and rare earth elements including scandium are solubilized into the pregnant leach solution (PLS). Among the various methods investigated to recover scandium from the PLS, liquid-liquid extraction using Primene JM-T as extractant was chosen and tested first at laboratory scale and then at pilot scale. Selective stripping of the loaded organic was carried out by using phosphoric acid solution, allowing the selective recovery of scandium from thorium and zirconium partially extracted from the PLS by Primene JM-T under the process conditions."

Jan 1, 2016

By M. Leroux, C. J. Martin, S. R. Rao, J. A. Finch

"The effect of nitrogen on the flotation separation of sulphides from complex ores from Brunswick Mining and Smelting (New Brunswick) and Mattabi Mines (Ontario) was investigated. The most significant finding was enhanced pyrite floatability after as little as 3 minutes nitrogen conditioning. This was used in a novel sphalerite/pyrite separation process developed on the Brunswick ore. After aeration and Cu/Pb bulk flotation in air using xanthate the slurry was nitrogen conditioned, xanthate added and the pyrite floated in nitrogen. As an example up to 70% pyrite recovery with about 20% sphalerite recovery was achieved. Sphalerite was recovered from the pyrite tailings and the pyrite concentrate by copper-activation, raising the pH to 10 and floating in air. About 65-70% recovery at 35-40% Zn grade was achieved compared to 25% Zn grade by the conventional route. The process offers a promising alternative to current practice which seeks to depress pyrite at all stages. A possible mechanism of the effect of nitrogen is presented. INTRODUCTIONUse of gases other than air in froth flotation has been reported from time to time. [Podobnik and Shirley, 1982; Lin and Metzer, 1975]. Of all the gases, nitrogen would appear to hold the greatest practical promise because of its easy availability and chemical inertness. It is used in froth flotation in chalcopyrite-molybdenite separation [Redfearn, 1983]. The use of nitrogen in polysulphide chalcopyrite. this case is mainly to reduce the oxidation of a compound (Nokes reagent) used as a depressant for There is no reported use of nitrogen in the flotation of other sulphide minerals."

Jan 1, 1988

By Karl Houseley, Dr. Robert J. Chapman

"A gravity concentration process has been applied to ores from the Clogau Mine, north Wales, the Tyndrum deposit, central Scotland and an alluvial ore from Leadhills area of Scotland. In the case of the Welsh ore and the alluvial deposit the gold grains in the concentrate and tailings streams have been characterised in terms of their three dimensions.In the case of Welsh ore, the thickness of a gold grain has been shown to be the single most important factor in determining behaviour in a gravity concentration operation. Six indices were used to quantify the overall geometry of the gold grains and those which incorporate a thickness term have proven to be effective in predicting the destination of gold particles within the concentration circuit. It is proposed that the most simple of these, the Heywoods flakiness ratio, has potential for the control of milling operations as an alternative to the established practice of characterising the size of the mill discharge.The effect of grain geometry on the recovery of fine gold has been studied using Tyndrum ore. The recovery of gold by gravity concentration increased from 20% to 70% when the criteria used to design the milling operation was the prevention of over grinding of gold grains.The destination of alluvial grains in the concentration circuit did not show such dependence on shape, and this has been attributed to the effective classification of all the gold grains in the sample by fluvial action producing a population of similar geometric characteristics."

Jan 1, 1996

By Michael K. Watkeys, Jacobus E. Potgieter, E. Guy Charlesworth, Carl R. Anhaeusser, Roger L. Gibson, Alexander F. M. Kisters

Intrusive features of cupriferous noritoids from the deeply eroded Proterozoic granite-gneiss terrane of the Okiep Copper District in South Africa illustrate the emplacement of basic magmas into a mid- to lower-erustal environment. The small, easterly trending intermediate to basic intrusions of the so-called Koperberg Suite display a wide variety of geometries, occurrence and emplacement modes, including dike-, sill- and plug-like bodies. Coeval granulite-facies metamorphism, partial melting and ductile deformation of country rock gneisses during intrusion of the basic magmas led to emplacement and dilation processes of the intrusions which differ significantly from those described for dikes and sills at shallow crustal levels. Regional tectonic stresses are largely negligible due to very low differential stress [( )] during deformation and intrusion, which permits emplacement at high angles to the principal compressive stress and which follows favorably inclined structural anisotropies. Dilation of the basic intrusions is largely determined by compositional differences of host rocks and occurs by thermal erosion, i.e., assimilation of wall rock gneisses. Low length-to-width ratios of basic to ultrabasic dikes and predominantly diapir-like outlines of mesocratic bodies are indicative of low viscosity contrasts between the mafic magmas and high-grade metamorphic host-rock gneisses. Buoyancy-controlled ascent of the basic to intermediate intrusions is expressed by a broad compositional zoning of basic bodies with respect to the granite-gneiss stratigraphy. Various intrusion modes within the stratigraphic column of the granite-gneiss sequence reflect a lithological and structural stratification of the seemingly homogeneous granite-gneiss terrane.

Jan 1, 1994

By W. Yang, R. Rajasingam, B. Tadesse, K. Mohanarangam

Copper electrowinning is a complex electrochemical process that involves the production of LME grade copper from copper rich electrolyte. The process involves the deposition of the copper ions onto the cathode from copper rich electrolyte with the production of oxygen bubbles at the anode. Acid mist is produced by these oxygen bubbles bursting at the electrolyte free surface. It is an undesired by-product of the Electrowinning process which unchecked could result in mist generation higher than the recommended time-weight-average exposure limit. Various approaches to alleviate the problem have been adopted by companies, all with varying degrees of success. All of these have been attempts to treat the symptom acid mist rather than the inherent problem, often proving expensive and, in some cases, ineffectual. In this paper, a new method was developed for acid mist quantification based on ‘total acid mist’ capture above the EW cell under well controlled conditions. With the use of sophisticated diagnostic analytical tools and measurement techniques it was possible to study all the operating variables including current density, flow rate, temperature, etc. independently and their effect on bubble size, bubble velocity, gas hold-up as well as acid mist generation and its droplet size. Results show that total acid mist capture increases with an increase in current density but remains more or less constant between 300–500 A m-2. Total acid mist also shows an increase with increasing electrolyte temperature. These findings are substantiated with the aid of bubble size and gas hold-up measurements with the transparent EW cell.

Jan 1, 2019

By Robert Cameron, Colin Ashton, John MacNeil, Leo Piciacchia

"The in pit dam construction and utilities relocation, known as the East Mine Corridor Relocation (EMCR) project, was developed to extend the life of the east side of the Base Mine pit by two veal's. This will result in the recovery of an additional 80 million barrels of oil and delay expenditures associated with the opening of the North Mine by two years. To accomplish this, a large in pit earth structure was required to provide a new embankment foundation for relocating a public highway, four powerlines, a natural gas back-up pipeline, a substation, and a conveyor train. This structure would also he required as a temporary dam 10 contain mature fine tails on the west side until mining is completed in the east mine corridor area, that will then be filled with fluid.The in pit dam, known as The Highway Berm, is 2.5 km long, 63 m high and has 42 million m3 of engineered soil added to the already existing end-dumped soil volumes. To complete the design and construction of a structure of this magnitude, in the very short time frame of two-and-a-half years, presented many new challenges. The main challenges faced were: designing while construction was ongoing; designing without the use of clay cores or sand filters; using relatively non-select overburden material; proper dewatering and base preparation; changing from construction of 50 m high spoil piles to a high specification construction operation; compacting lifts with heavy haulers; constructing during the winter; and monitoring movement of the structure with satellites."

Jan 1, 1995

By E. G. C Charlesworth, M. J. Robertson

"Gold mineralization in the Main Reef Complex at Sheba Gold Mine is hosted within shear zones in a sequence of shales and greywackes of the Fig Tree Group. Competency contrasts between these rocks and a steeply dipping chert unit provided a locus for the development of right lateral steeply dipping shear zones. A set of flatter dipping shear fractures crosscut these zones with their intersections defining a system of en échelon ore shoots. Mineralization is both of vein type and disseminated strata-controlled replacement type. The latter occurs mainly within the wall rocks to the shear zones. Arsenopyrite and pyrite are the major sulfides, with arsenopyrite being confirmed largely to greywacke beds and pyrite to the more iron-rich shale units. Gold was introduced, together with minor sphalerite, pyrrhotite, chalcopyrite and early arsenopyrite, toward the end stages of a first pyrite phase. The mineralizing fluids were introduced along dilated cleavage planes and, emanating from these, produced a series of replacement fronts. Mineralization was syntectonic to late tectonic and occurred under conditions of progressive deformation, resulting in sulfides which are concentrated in the hinges of shear-related folds and semimassive sulfides within tension fractures which are folded, attenuated and fractured. An analysis of the structures shows a sequence of events in which an initial ductile simple-shear event with a steep sense of movement was succeeded by a more brittle strike-slip event. Mineralization is temporally related to the latter. This evolution in structural style was probably related to reactivation of the Sheba Fault as a transcurrent fault during emplacement of large granitoid bodies."

Jan 1, 1994

By F. S. Hoseinian, M. Irannajad, M. Safari

In this study, the effect of chemical interactions of materials used in ion flotation on the removal of Ni(II) ions from low concentration synthetic wastewater was studied. Sodium dodecyl sulfate (SDS) and ethylhexadecyldimethylammonium bromide (EHDABr) as collectors and methyl isobutyl carbonyl (MIBC) and Dowfroth250 as frothers were used. To investigate the effective parameters and interactions of them, 16 experiments including 6 level variables were performed by supporting DX7 software and on the bases of 2-level factorial method. In the first step, the tests were conducted in a Hallimond tube. The result showed that collector of SDS and frother of Dowfroth 250 had appropriate interaction with each other at pH = 3. In the second step, optimal results from the first step were evaluated in a mechanical flotation cell. The removal of Ni(II) ions increased by increasing the time of flotation and they have a direct relation with the water removal. The kinetics study shows that the order and the rate of removal of the reaction do not follow any of the zero-order, first-order and second-order equations. The flotation rate curve on the removal of Ni(II) ions will divide the separation process to two stages, a fast flotation rate at the first stage and a slow flotation rate at the second stage. Ni(II) ions removal was obtained 88% at the best condition.This study showed that the use of ion flotation was a very effective method for Ni(II) ion removal from industrial wastewaters.

Jan 1, 2016

By Randolph A. Pax, Brian Cornish

The operation of grinding mills in an ore processing circuit is supported by monitoring the input and output variables. These can include the feed ore size distributions, ore feed and water addition rates. The outputs can include the discharge undersize density, oversize tonnage rate and the P80 of the discharge. The grinding mill performance is judged by the power draw, recycle rates and discharge grind size. Conditions inside the mill are inferred from loads cells or bearing pressures and past histories. An overall noise value is sometimes used to evaluate the load as well as the occurrence of excessive impacting of steel balls onto the liners/lifters of the mill. This paper presents results of the internal behaviour of a mill using non-contact stationary microphones located close to the mill outer shell (Pax, 2012). The noise generated by a mill can be attributed to a number of events that occur inside these mills and suitably analysed can provide real-time determinations of in-mill behaviour and can provide powerful insights into the operation of the primary comminution tumbling mills. The acoustically determined signals including a specific 'steel' signal, water hold-up, integrated area together with a classification of impact events. Specific results from case studies will show information of the trajectories inside a mill, steel to rock ratio as well as rheology effects. By incorporating a self-consistent understanding methodology for the in-mill processes from an array of microphones, the information can be used to diagnose the dynamic conditions inside a mill.

Jan 1, 2016

By M. K. Aly

"ABSTRACTThis paper briefly describes the mining method proposed for the iron ore deposits in Wadi Shatti, western Libya. The iron ore produced will be used in the steel plant at Misurata on the Mediterranean coast. GeologyThe Wadi Shatti is located in the central part of western Libya. Flat iron-bearing sedimentary rocks are exposed with remarkable regularity in this valley. It occupies an area 200 km long by approximately 20 km wide trending in an eastnortheast direction between Jabal Fazzan in the north and Zel1af Sand Dunes in the south (Fig. I). Only a part of this valley has been ful1y explored by drilling on a 400- by 200-m pattern in an area of 18 km2 south of the town of Taroot. Farther to the south, no exploration by drilling can be done due to the presence of sand dunes .The iron-bearing bed is about 10to 15m thick, with a dip of 2 to 4 degrees in a southerly direction . The overburden consists mainly of clayey sandstones, 4 to 5 m thick, in the northern part, increasing to 35 m in the southern part. The iron ore bed consists of three different layers, from the floor upward: (1) Lower Reduced Ore (LRO), having a varying thickness of 1 to 7 m; (2) Magnetic Ore (MO), with a thickness varying from 4 to 12 m mainly in the central part of the area; and(3) Upper Reduced Ore (URO), with a bed thickness varying from 0 to 7 m."

Jan 1, 1980

By B. A. Kjarsgaard, C. J. Mwenifumbo

"Abstract - Natural gamma-ray measurements were made in the GSC Smeaton drillhole as part of the borehole geophysical classification of kimberlite pipe 169. In addition, forty samples of Cretaceous sediments (shales, siltstones, and sandstones) and thirty-five kimberlite samples, selected from the drill core, were analyzed for major and trace elements. These elements included potassium (K), uranium (U), and thorium (Th), which are the main naturally-occurring radioactive elements.Different phases of the kimberlite, and the Cretaceous sediments which show variations in the gamma-ray activity, can be easily delineated on the gamma-ray logs. The gamma-ray logs indicate that the radioactivity in the kimberlite derives mainly from Th, and, to a lesser extent, U. Most of the kimberlite units are enriched in Th and U relative to the Cretaceous sediments, and these radioelements are mainly hosted by accessory apatite and perovskite, and minor zircon. Potassium concentrations are low in the kimberlite. The higher K concentration in the sediments clearly distinguishes the Cretaceous sediments from the kimberlite.The U/K and Th/K ratios show important and distinct differences between the two major types of volcaniclastic kimberlite. Kimberlite lapillistones have higher U/K and Th/K ratios than the olivine crystal tuffs. Furthermore, standardized U/K and Th/K geophysical logs can be used to separate marine reworked olivine shoreface sands from other shallow marine sediments that contain kimberlitic detritus. The identification of different phases and/or stratigraphic facies of kimberlite on the basis of radioelement distributions means that gamma-ray spectrometry can assist exploration, particularly in regard to diamond grade distribution."

Jan 1, 1999

By G. Sperlins

"IntroductionBrenda Mines Ltd. is a low-grade open-pit mining and milling operation located near Peachland, B.C. Brought into production in late 1969, the plant treats an average of 30,000 tons per day of an ore that contains 0.130% copper and 0.030% molybdenum.The operation is divided into six areas of responsibility, namely the mine, mill, plant, accounting, industrial relations and purchasing /stores departments.The purchasing and warehousing area handled in excess of 11,000 items valued at $31,000,000 in 198J. Over and above this, the warehousing area issued in excess of 74,000 line items valued at $15,000,000 during that same period.Materials Management- DefinitionWhat is meant by the term ""Materials Management""? Reference to the dictionary will reveal that a material is ""that of which anything is composed or may be constructed; the tools, instruments, implements', etc. for doing something"". Management is defined as ""the act, or manner of managing; the skillful use of means to accomplish a purpose"". Presumably combining these words defines materials management.Of greater importance are the materials managers who will carry out the function. At Brenda Mines Ltd., all employees and suppliers contribute to the materials management function. Each has a specialized knowledge of the materials used in his field. Each has a different view concerning the use and description of the same material. The key is to focus this knowledge so as to make the materials management system useful to everyone."

Jan 1, 1982

By André Chagnon, Yvon Héroux

"Résumé - Cette étude porte sur l'altération de la matière organique et des argiles dans les boues carbonatés dévoniennes du faciès ""F"" de la Formation de Pine Point et ses équivalents stratigraphiques la Formation d'Evie et l'unité bitumineuse de la base de la Formation de Horn River. La matière organique se compose principalement de bitume solide et de quelques fragments de fossiles (organo­ clastes). La majorité des échantillons ne renferment que de l'illite et des interstratifiées illite/smectite.Si on compare les températures d'homogénéïsation (Th = l00°C) des inclusions fluides de la sphalérite et des dolomites associées à la minéralisation aux températures estimées à partir de la réflec­ tance de la collinite (84°C à ll7°C), l'on ne peut pas conclure à la présence d'une anomalie ther­ mique dans le district minier de Pine Point. De plus, la réflectance des organoclastes n'est pas plus élevée dans le district minier de Pine Point que dans les localités plus éloignées des gîtes. L'analyse des minéraux argileux conduit à la même conclusion : aucune anomalie thermique n'est décelable dans les unités échantillonnées à l'intérieur du district minier de Pine Point quelque soit l'indicateur utilisé.La kaolinite et la matière organique altérée, affichant des valeurs anomales de sa réflectance, se trouve essentiellement en présence de soufre et de sulfures. Cela suggère une origine authigène de la kaolinite et une altération de la matière organique reliées au phénomènes de minéralisation.Abstract- The alteration of organic matter and clays is studied in the Devonian Pine Point Formation carbonate muds, ""F"" facies, and its lateral equivalents the Evie Formation and the biturninous unit at the base of the Horn River Formation. The organic matter is mainly composed of solid bitumen with few fossil fragments (organoclasts). Most samples contain only illite and mixed layer illite/smectite.If we compare the Th(l00°C) from fluid inclusions of sphalerite and dolomites associated with mineralization to the temperatures calculated from the reflectanœ (Ro) of the collinite (84°C to 117°C), we cannot detect a thermal anomaly in the Pine Point mining district. This result is based on the reflectance values of organoclasts from the mining district that are not higher than those reflectance values measured on organic matter (OM) away from the ore deposit. A similar conclusion is reached from the clay study: none of the parameters used allow us to identify a thermal anomaly in the samples from the mining district.The kaolinite and the altered OM showing anomalous Ro values mainly occur with sulfides and sulfur. This association suggests an authigenic origin for the kaolinite and an alteration of the OM due to the mineralization events."

Jan 1, 1994