Search Documents

By James Dickson

Brief History of Discovery and Early Development In the first half of the nineteenth century, the only authority on the Pacific coast between the Columbia river and Alaska was exercised by the Hudson's Bay Company, who had established a series of forts and trading stations on the coast from the Columbia north to Millbank sound. The Hudson's Bay Company were chiefly interested in the fur industry, and the large influx of settlers from the eastern United States into the territory now known as the States of Oregon and Washington, about 1840, not only interfered with the fur business but involved the question whether the territory should be under the British or the American flag. Anticipating the possibility, later realized, of losing control of this area, the Company, in 1845, established their main fort and trading centre on the southern end of Vancouver island under the name of Fort Camosun; shortly afterwards changing the name to Fort Victoria. Realizing that their former policy of discouraging all attempts to develop any other business than the fur industry had lost them several hundred thousand square miles, the Hudson's Bay Company now set about encouraging settlers in the vicinity of Fort Victoria by disposing of lands to suitable parties and also to those in the employ of the Company. The usual pioneering stage was passed through with the starting of small sawmills, grain mills, etc., and the incidental work accompanying such efforts. Any coal required for blacksmithing or other purposes was brought from England around Cape Horn by the few ships that visited the Pacific Coast. About 1849, an Indian who was having his gun repaired by a blacksmith in Fort Victoria asked about the "black stones" used in the fire and, on being told that the "black stones" had to be brought a great distance, he informed the blacksmith that there was plenty of the same stone where his people lived. This information was immediately given to an official of the Hudson's Bay Company who talked with the Indian and told him that if he would bring some of the "black stones" he would get his gun repaired free and a present of a bottle of rum. Nothing more was heard of this coal until April of the following year, when the Indian came into Fort Victoria with his canoe loaded with coal, which was tested and found to be of good quality. It is reported that the Indian got his bottle of rum.

Jan 1, 1935

By H. Clare Horwood

"In the Red Lake area in northwestern Ontario the relationships between general structures and structures containing ore deposits are among the most unusual and most interesting of any in the Precambrian Shield. The more important orebodies, which are in the central-eastern part of the area, occur in a variety of rocks on the northeastern, eastern, or southeastern sides of a series of granite stocks. Other deposits in the western part of the camp also are structurally associated with granite masses .The relationships were determined in the course of general and detailed geological mapping by detailed analyses of the fracture patterns in the rocks adjacent to the orebodies. In every case it was found that the structures containing the ore were produced by compressive stresses from the direction of intrusion of the granite masses( 2).The Red Lake area lies in the Patricia part of the district of Kenora and is accessible by boat from Hudson or by airplane from Kenora, Sioux Lookout, or Winnipeg. A road from Vermilion lake, on highway No. 17, was opened in August, 1947.The first discoveries of mineralization in the area that proved to be of economic importance were made in 1925 by Lorne Howey and George McNeely for Haileybury interests and by Ray Howey and W. F. Morgan for Mcintyre-Porcupine Mines, Limited. Both prospecting ventures were organized because of information presented by Bruce(l) in his map and report for the Ontario Department of Mines. The discoveries, which were both along the same structure, a quartz porphyry dyke, later developed into the Howey and Hasaga gold mines. Other discoveries were made at intervals as a result of prospecting and development work on ground staked for its location."

Jan 1, 1954

"These guidelines, implemented in 2003, were recommended by the Diamond Exploration Best Practices Committee established by the Canadian Institute of Mining, Metallurgy and Petroleum. The guidelines are applicable to public companies and their consultants reporting diamond exploration results.“The guidelines are referenced in the Companion Policy of NI 43-101 with a statement that disclosure regarding the reporting of diamond exploration sampling results should conform to them.”Reporting GuidelinesThe following guidelines have been recommended by the Diamond Exploration Best Practices Committee established by the Canadian Institute of Mining, Metallurgy and Petroleum. These guidelines are applicable to public companies and their consultants reporting diamond exploration results.In respect of these guidelines, Diamond Exploration Results are results derived from the initial activities undertaken to investigate a diamond bearing prospect or deposit, to generate tonnage, grade and value estimates that cannot be classified as a Mineral Resource or Mineral Reserve. They do not address the earlier stage reporting of geophysical, geochemical or kimberlite indicator mineral results.Public reports of Diamond Exploration Results relating to mineralization not classified as Mineral Resource or Mineral Reserve must address the confidence limits of the result and contain sufficient information to allow a considered and balanced judgement of the significance of the results.The objective of these guidelines is to assist public companies and consultants in making appropriate disclosure of diamond exploration results by reporting in a manner which is:Uniform within the diamond exploration industry; Consistent with reporting from other industry sectors .Comprehensive .Unambiguous .The guidelines are not prescriptive. Materiality is the overriding principle that determines the information that should be disclosed. However, where a company or consultant deviates from the guidelines, the disclosure or technical report should state the extent to which the guidelines have not been followed, and the reasons for the deviation.The guidelines do not in any way replace jurisdictional reporting requirements (For example, the requirement for Canadian reporting issuers to comply with Canadian Securities Administrators National Instrument 43-101 by having technical disclosure endorsed by a Qualified Person as defined in that legislation)."

Jan 1, 2003

By J. L. Chakravarty, S. K. Dutta, S. Banerjee, D. Putatunda

"General purpose uniprocessor systems used in control applications, however fast they may be, at a certain stage attain saturation, forcing the user or designer to consider other avenues for solving the problem. This paper gives a broad overview of multiprocessing with special reference to transputers. Virtually all aspects, from parallel systems real-time control to artificial intelligence (AI) and expert systems, have been highlighted. The application of transpurters in unilayer and multilayer control are discussed in detail, with specific attention to sensor integration. Two case studies describe at length the utilization of transputers. IntroductionIn conformance with the high level taxonomy of parallel computer architectures as given by Ralph Duncan(l) (an improvement to Flynn's classification, which maintains the essential elements of useful taxonomy based on instructions and data streams), the MlMD architectures are categorized into two groups: (I) shared memory, and (2) distributed memory type. While the shared memory multiprocessors are more popular than the message-passing multiprocessors because they can be programmed in a conventional sequential fashion, their aspect of the architecture creates a perfonnance bottleneck. In contrast, message-passing multiprocessors (MPM) suffer from no such limitation and can attain linear speed increases that are directly proportional to the number of processors put into use. The MPM implementation also has its own advantages and disadvantages. Because the performance of the system is heavily dependent on it, the interconnection strategy in a distributed memory MIMD machine is of paramount importance. The transputer(2.J), a multiprocessor node of the distributed memory type, is becoming very popular. The advantages offered by the transputer make its application in the mining and processing industries very promising."

Jan 1, 1994

By H. Soltanzadeh

This paper summarizes semi-analytical and closed-form solutions that can be used to assess the poroelastic stress changes induced within a porous formation (reservoir) during a pore pressure change. Further, solutions are presented for the stress discontinuities at the interfaces between reservoirs and the rocks that surround them. When used in combination with rock failure criteria, these solutions enable relatively simple analyses of the potential for induced fracturing or fault reactivation within a reservoir or the rock immediately adjacent to it. The latter, in particular, is useful for assessing if the hydraulic integrity of the surrounding rock (i.e., the bounding seal) will be affected by a pore pressure change. The use of the approach presented in this paper is illustrated with an analysis of a pinnacle reef with dimensions and properties representative of reefs in the Zama oil field, northwestern Alberta, Canada. Scenarios of pore pressure decrease (during historical production operations) and pore pressure increase (during several years of acid gas injection operations) are analyzed, for three different idealizations of reservoir properties and geometry (two plane strain and one axisymmetric). These results suggest that that the potential for induced fracturing is not significant at any point within the reservoir or the surrounding rock for both the production and injection scenarios that were simulated. Similarly, fault reactivation was not predicted for the reservoir or any of the points that were analyzed in the surrounding rock. However, fault orientations having the greatest potential for reactivating during historical production operations were identified; thus, illustrating a means of using geomechanical models to focus geological characterization efforts on the features that are most critical to acid gas containment.

May 1, 2009

By Xuanxue Mo, Kaihui Yang

"Abstract- The Laochang mine, located in the Sanjiang area of southwestern Yunnan Province of China, is a volcanogenic massive Pb-Zn-Cu sulfide deposit. It is hosted by a pyroclastic sequence of Barly Carboniferous age, namely the lower member of the Yiliu Group, which was intruded by syenite and rhyolite porphyry . The volcanic suite is basaltic or basaltic-andesitic in composition, has alkaline affinities, and is associated with the initial rifting along the margin of the Baoshan-Shanstate continental rnicroplate (Yang, 1989). The ores are typically Pb>Zn>Cu in composition, averaging 3.820Jo Pb, 3.51% Zn, from 0.01% to 1.85% Cu (0.107% av.), a high average content of Ag (113 g/t) and recoverable amounts of Au, Tl, Gd, Ga, Ge, In. A massive sulflde zone, in which lenticular and stratiform orebodies are localized in a sulflde-carbonate-silica shale unit or sulfldic tufflte horizon that usually overlies coarse-grained pyroclastic rocks, is underlain by a stringer sulflde zone developed in a subvolcanic intrusion or volcanic sequence. The sulfide mineral assemblages, from the top to the bottom of the deposit, are: realgar + orpiment - galena + sphalerite + pyrite- chalcopyrite + pyrite + pyrrhotite + arsenopyrite. Oxide and sulfate minerais occur rarely in the massive ores. The massive ores are generally fine-grained and banded, but coarse-grained ore, colloform and framboidal texture, and growth-zoned pyrite and sphalerite are common. Sedimentary features such as graded bedding, brecciated and deformed ore clasts, and chaotically emplaced blocks, are well preserved, indicating that the massive orebodies have undergone slumping and dis­ placement. Alteration is weak in the hanging-wall rocks, but strong in the stringer zone. Two dis­ tinctive alteration zones have been identified: the upper zone, characterized by an assemblage of quartz, carbonates, chlorite, albite, zeolite and sericite, and the lower zone containing diopside, trema­ lite, actinolite, gamet, clinozoisite, and epidote.The general features of the Laochang deposit are in accord with the descriptive mode! of VMS deposits (Lydon, 1984). However, it falls into neither the Zn-Cu group nor the Zn-Pb-Cu group chemically (Franklin et al., 1981). The depositional setting of the Laochang deposit is quite different from Cyprus or Besshi-type massive sulfide deposits. Laochang is hosted by alkaline lavas that were erupted in a submarine continental rift. Although some features of the Laochang deposit are similar to those of Kuroko-type deposits, there are remarkable differences in the alteration mineral assemblage, the proportion of ore-forming elements (lead enriched) and the amounts of oxides and sulfates. These suggest corresponding differences in ore fluid composition and the associated ore-forming environment. Thus, the authors suggest that the Laochang deposit may be a distinct type of VMS deposit."

Jan 1, 1993

By Kimberly Morrison

Strategically located within the Uravan Mineral Belt District of western Colorado, the Piñon Ridge Project is the first new uranium mill being proposed for construction in the United States in over 25 years. In 1992, dramatic changes to the US regulatory environment for uranium ore processing occurred making regulatory compliance an increased challenge for a new facility. Proposed as a 6.3 million tonne uranium milling operation, the mill will receive ore from a number of mines in the region. The project includes design and permitting of a uranium/vanadium processing facility, tailings cells, evaporation ponds, and ore stockpile pads. The focus of this paper is to provide an overview of the US regulations and how these regulations were applied to design of the mill facilities, as well as provide a status update on the project as the mill license application was submitted to the Colorado Department of Public Health and Environment (CDPHE) in November 2009.

Aug 1, 2010

By M. Nusheh, C. Bumby, A-H. Puichaud

"Vanadium-bearing titanomagnetite ironsand deposits occur along a 480 km stretch of the west coast of New Zealand. In the present study, the leaching behaviour of NZ ironsand was investigated in hydrochloric acid (2–10 M) solution at 50–80°C for 2 h. The resulting leaching liquors exhibited Fe/V ratios in the range 150–180. The distribution of trace element contaminants between solution and solid residue was investigated, and processing conditions have been determined for rapid and efficient dissolution of Fe, Ti and V into the leaching solution. In addition, mineralogical analysis of raw ironsand and leached residues was performed in order to study the leaching mechanism. Samples were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy (EDX), X-ray fluorescence spectroscopy, qualitative and quantitative X-ray diffraction and inductively coupled plasma mass spectrometry (ICP). Results indicate that the dominant dissolution process follows shrinking particle mechanism. However, ironsand particles containing ex-solution lamellae exhibited a different leaching behaviour compared to homogenous titanomagnetite particles.INTRODUCTION Titanomagnetite ironsand (blacksand) forms Quaternary onshore beach and dune deposits and offshore marine deposits (Figure 1) along 480 km of coastline from Kaipara Harbour south to Wanganui on the west coast of the North Island (Christie, 2016). It attracted the attention of scientists from the earliest times (Galbreath, 1998). The principal minerals in ironsand are titanomagnetite (TTM), ilmenite, quartz and ferromagnesian minerals such as augite, hornblende, diopside, and olivine with smaller amounts of rutile and apatite (Mauk, 2016).Several large ironsand deposits have been discovered and exploited since the late 1960’s. The Waikato North Head and Taharoa mines are currently operating and they have a 2015 measured resource of 400 million tonnes in total and provide over 2 million tonnes of concentrate per year by simple cost effective magnetic separation process (Christie, 2016; Christie & Brathwaite, 1997). The concentrate contains not only 7–8% TiO2 and 56–60% SFe, but also 0.3–0.6% V2O5, is both a valuable titanium mineral and a source of vanadium. All the production is used for steelmaking industries. The other potential for utilizing more of this resource without requirement of integration into an iron and steel producing plant is to develop a hydrometallurgical route with advantages of higher efficiency along with lower emissions. Currently, there is no existing commercial process capable of extracting all three of these elements as industrial-grade commodity products. Acid leaching of TTM concentrate with higher degrees of recovery and selectivity is a key step in any possible hydrometallurgical route."

Jan 1, 2017

By Q. Liu, P. Katsabanis, J. A. Meech

A thermohydrodynamic computer code has been used to simulate dust explosions. For sulphide dusts, the thermodynamic predictions are used to investigate the effect of dust concentration, mineral content and inert materials as well as the quantity of sulphur dioxide produced. It was found that the amount of oxygen available for the explosion is very important and that the dust concentration which gives maximum explosion pressures is obtained at zero or slightly negative oxygen balance values. The sulphide minerals were found to have the following explosibility sequence: pyrrhotite, pyrite, chalcopyrite, sphalerite, covellite, chalcocite and galena, which is in agreement with mine experience. The results show that theoretical calculations can be used to predict explosion pressures and toxic gases produced by a dust explosion and therefore they can assist in the design of protective measures .

May 11, 1988

By R. Al-Hent, M. Aissa, J. Asfahani

"This paper presents regional radiometric gamma-ray spectrometry maps of Syria for total radioactivity (Ur) and surficial concentrations of equivalent uranium (eU). The maps were created by merging airborne and ground-based gamma-ray spectrometric survey datasets. On the regional radiometric eU map, eU anomalies are closely related to either phosphate and/or glauconite deposits. The Ur and eU maps delineate the boundaries of three phosphate deposits, close to the Palmyrides ridge, in the northern part of the Coastal Range and Syrian Desert. Scattered occurrences of uranium mineralization in other phosphate formations are attributed to secondary chemical and physical processes, rather than primary accumulation.RÉSUMÉ Cet article presente des cartes regionales radiometriques de spectrometrie gamma de la Syrie pour la radioactivite totale (Ur) et les concentrations en surface de l’equivalent en uranium (eU). Les cartes ont ete creees en combinant des ensembles de donnees, aeroportees et au sol, de releves de spectrometrie gamma. Sur la carte regionale radiometrique eU, les anomalies eU sont etroitement reliees aux gisements de phosphate et(ou) de glauconite. Les cartes Ur et eU delimitent les limites de trois gisements de phosphate, a proximite de la crete des Palmyrides, dans la partie nord de la chaine cotiere et du desert de Syrie. Des dispersions de mineralisation d’uranium dans d’autres formations de phosphate sont attribuees a des procedes chimiques et physiques secondaires, plutot qu’a une accumulation primaire."

Jan 1, 2016

By D. E. Macdonald

"Approximately 2.0 million tonnes of phosphate rock is imported from the U.S. to Alberta annually and is used in the production of agricultural fertilizers. No phosphate rock is presently mined in Canada, although sources of igneous phosphate have been mined in the past. Sedimentary phosphate rock is found in nine geological units within the Cordilleran Foothills and Front Ranges region of Alberta. The Devonian-Mississippian Exshaw Formation, Permo-Pennsylvanian Rocky Mountain Supergroup, and the Jurassic Fernie Formation have the best potential f or future development. Most of the phosphate rock in Alberta is of low grade and lies within restricted land use areas. The best over-all resource potential lies in the Fernie basin area of southeastern British Columbia, in the Fernie Formation. The possibility of deep phosphate rock deposits in the plains region should be examined.Phosphate rock is mined in Idaho, Utah, Montana and Florida, and is shipped to Canadian fertilizer plants for processing. Raw phosphate rock is acidified, usually with sulphuric acid, by a wet process. Varying amounts of ammonia are added, and the fertilizer is pelletized. Future research, in western Canada, is needed in the beneficiating of low-grade ores and in the area of in situ mining. At the present time, phosphate rock sells for around US$50Itonne, and Alberta fertilizer companies probably pay in the range of C$7D-$85Itonne for U.S. phosphate rock delivered to the plant. Environmental concerns about phosphate rock processing are centred around gypsum tailing ponds, and radioactive wastes.U.S. supplies of phosphate rock are secure until the year 2000; however, by this time, the richer deposits in the U.S. may be exhausted. Alternate deposits, such as the ones in Alberta and British Columbia, might then be considered. Phosphate byproducts, such as uranium, vanadium, fluorine and rare earth elements, may help in making the processing of low-grade Canadian phosphates economically feasible."

Jan 1, 1988

By Yongjie Bu, Wei Sun, Zhiyong Gao, Yuehua Hu, Hongbiao Tao, Runqing Liu, Central South University

"The flotation behavior of O-isopropyl-N-ethyl thionocarbamate (IPETC) and pH for chalcopyrite and galena was studied through pure mineral test, adsorption quantity determination, solution chemistry calculation and Materials Studio simulation. The results show that the recovery differential value of chalcopyrite and galena is about 20% when pH of the pulp 9.5 and IPETC is 7×10-4 mol/L, the flotability differences of the two minerals is significant. There is competitive adsorption between OH? and IPETC on mineral surfaces, it lead to galena flotability is lower than chalcopyrite flotability. IPETC can remove the hydration layer on mineral surface and adsorb on active sites for collector adsorption, minerals have a better hydrophobicity.INTRODUCTIONCopper and lead are two of the most widely used metals in industrial and living, their applications include building construction, various metal alloys, heat and electricity, machine manufacturing (Zhang et al., 2014). Chalcopyrite and galena are the major source of copper and lead, normally they associated with each other. With the growing use of these resources, high grade and dissemination large particle sizes minerals are less and less, the use of low grade and complex dissemination minerals have to be paid more attention (Chen, Ye, & Li, 2010; Liu, Sun, Hu, & Wang, 2009). As the special properties and complex composition of copper-lead sulfide ore, flotation separation of chalcopyrite from galena effective is a research emphasis and difficulty point in mineral processing (Bruckard, Sparrow, & Woodcock, 2011).In the separation process of chalcopyrite and galena, it is rather important to choose effective collector (Huang, Wang, & Liu, 2014). Enlarging and using the two mineral flotability will be a good basis and start in flotation (Reyes-Bozo et al., 2014). Qin et al. (2013) made a great deal of research on flotation separation of copper/lead concentrate, collector O-isopropyl-N-ethyl thionocarbamate (IPETC), butyl xanthate (BX) and ammonium dibutyl dithiophosphate (ADTP) were investigated, BX and ADTP floated both chalcopyrite and galena well, specific adsorption appeared in the surface of mineral, the problem was the collectors were not selective enough, however IPETC showed better selective."

Jan 1, 2016

"Cambior currently has nearly 80 exploration properties, acting as operator on about 60 of these. The company's exploration budget has increased to over $11,100,000 for 1990. On-going efforts recently yielded a new gold discovery on the Douay- Vezza property, a joint venture project with Inco and Vior. Cambior continues to seek out new opportunities, recently acquiring an option agreement on the Sleeping Giant project in Quebec and four new exploration agreements in the United States, through its Reno office. Other nearly-concluded joint venture agreements have also given the company entries into Indonesia and Guyana.SummaryWhen it acquired SOQUEM's assets on August I, 1986, Cambior also acquired interests in 45 exploration projects. The subsequent mergers with Aiguebelle Resources and Sullivan Mines in 1987 brought the total number of exploration projects to 83, most of which are concentrated in northwestern Quebec. Cambior's strategy emphasizes gold exploration, and exploration activities were, therefore, initially limited to the Val d'Or and Rouyn-Noranda mining camps, where Cambior has a large portfolio of properties. Approximately $25.8 million has been spent on surface exploration in this area since the formation of the company, resulting in the discovery of the Mouska deposit and four sub-economic zones on the Porcupine, Forbex, Bloc Sud and Flavrian project s. In 1988, Cambior became involved in projects in the United States to which the company expects to allocate about 38070 of its 1989 exploration budget."

Jan 1, 1990

By C. Díaz, A. D. Dalvi, C. E. O'Neill

"Roast-reduction smelting (RRS) of nickel concentrate, combined with flash smelting of copper concentrate, was one of the process options that Inco considered as a means of meeting its 1994 sulphur dioxide abatement target at its Copper Cliff operations. RRS involves deep roasting the nickel concentrate in fluid bed roasters. The roaster off-gas is treated in a sulphuric acid plant, and the low sulphur calcine is reduction smelted with coke in an electric furnace to yield a sulphur-deficient matte. The latter material is converted to Bessemer matte in Peirce-Smith converters, with minimal evolution of sulphur dioxide, and the converter slag is reverted to the electric furnace. Excellent nickel and cobalt recoveries (Ire obtained. This paper discusses the development of RRS, including extensive commercial scale testing at Inco's Thompson Smelter, and its key operating parameters. IntroductionReduction of sulphur dioxide emissions has been a long-standing endeavour at Inco. At the company's Ontario Division, as shown in Figure 1, sulphur dioxide emissions were reduced from about 2 million to 685 000 tonnes per year over the period 1970-1985. Most of this impressive improvement was the result of a sustained research effort which led to increased rejection of pyrrhotite from the ore during milling while maintaining an acceptable nickel recovery. Between 1970 and 1985, the combined grade of the separate nickel and copper concentrates feeding the Copper Cliff Smelter increased from about 10070 to about 'lIJ0J0 Cu +Ni and the combined S/(CU +Ni) ratio decreased from about 2.8 to 1.65."

Jan 1, 1994

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 Michel Gauthier, Pierre Marcoux, Gaétan Morin

"The recent opening of Muscocho's gold mine at Montauban, as weil as the discovery of several new copper-gold showings of a similar nature near the confluence of the Saguenay and St , Lawrence has revealed the existence of a new metallogenic gold province which is located within supercrustal units of Helikian age within the Grenville Province. Three metalliferous belts have been identified, each one of which is related to a series of SW-NE trending faults. The first is located in southeastern Ontario and southwestern Quebec. The second extends from the Balmat-Pierrepont mining district of New York State up to the Lac St. Jean region of Quebec, and includes the Montauban camp. The third follows the St. Lawrence river in Charlevoix County and along the north shore of the Gulf of St. Lawrence.The gold mineralization which is present in the central portion of the Grenville Province is of two types: either stratiform or vein. Deposits of the first type, of which the Muscocho is the type locality, are economically the more interesting of the two. Not only is this mineralization stratiform, but also shows a distinct affinity to AI-rich, Mg-rich or calc-silicate-rich bands. As is the case with the Bousquet and Hemlo regions of the Superior Province, they are associated with layers which are rich in sillimanite and occasionally staurolite. A second parallel between the Bousquet and Montauban deposits might be the presence of manganesian gamets, which have been recognized at the two localities. Some of the mineralization in the central Grenville Province is located within thin bands of iron formation which are rich in arsenic.The stratiform gold deposits of the central Grenville Province are of exhalative origin and are located within a volcano-sedimentary terrane. It is probable that a part of the gold present in these Helikian deposits have been derived by remobilization of Archean mineralization. The vein showings form as a consequence of the remobilization of the Helikian strata during the Grenville metamorphism,"

Jan 1, 1985

By A. Mitura

The paper presents the initial investigation of possible energetic applications of chosen wastes from groups: 06, 03, 05 and 01, including coal slimes being secondary product of hard coal processing. These categories of wastes are catalogued according to the polish law, where 06 ? wastes from production, preparation, purchasing and application of products of non-organic chemistry; 03 ? wastes from wood processing and from plates and furniture, celluloid mass, paper and card board production; 13 ? oil wastes and wastes from liquid fuels; 01 ? wastes produced by searching, extracting, physical and chemical processing of ores and other mineral raw materials. The change of combustion heat value was evaluated in produced energetic mixtures containing these types of wastes together with the change of their individual components. All combinations of ingredients were taken into consideration giving 256 various mixtures, from which 36 were selected to investigation. This allowed the performance of statistical factor analysis. For such prepared materials the application of regressive method was proposed in purpose of calculating combustion heat value and then the comparison of empirically determined and theoretically calculated heat values was performed. The change of regressive coefficients can be determined by the nature of Hess law (eq. 1) what was investigated and the attempt of its explication and validation was done.

Aug 1, 2013

By F. Sorenson, P. A. Castellarini, F. Garbarino, M. N. Garcia

"Recently, significant efforts to improve productivity from the tight intervals of the Mulichinco Formation within the Sierra Chata Field in the Neuquén Basin have been ongoing. Because conventional high quality reservoirs were being developed in this field, a proper reservoir understanding and completion approach was applied. After developing these high permeability reservoirs, the operator began evaluating the tight intervals and new areas within the field, but a completely different approach was necessary to achieve motivating production improvement.An extensive study to help enhance reservoir understanding and identify key factors controlling productivity of these tight intervals (which tend to be in the range of 5 µD) has been ongoing. Some of the issues discussed in this study are 1) petrophysical review, 2) rock properties calibration, 3) geomechanics understanding, 4) faulting and micro faulting/lineaments description, 5) stimulation and completions review and, 6) understanding key production drivers.As in many other tight reservoir projects, a considerable area of the reservoir must be effectively stimulated during the hydraulic fracturing process to achieve economic productivity. Two critical issues hinder these objectives. First, the low permeability in addition to a pore pressure close to or even lower than hydrostatic are critical characteristics when attempting to flow back the well and clean up fractures. Second, very high horizontal stress anisotropy resulting from a strike slip stress regime promotes the generation of simple planar bi-wing fractures. It is well-known that this fracture geometry will contact much less reservoir area compared to more complex fractures, as the operator would normally intend to create at very low permeability reservoirs.This paper discusses these issues and how they were addressed. A pilot drilling and completion program was initiated during 2012 to validate this study. Key factors include well location relative to formation unconformities, their orientation relative to the far field principal stresses, hydraulic fractures generated, and overall completion design."

Jan 1, 2015

By Lloyd A. Clark

"The kuroko deposits, which are extremely variable in size, comprise both stratiform layers of clastic sulphide particles and cross-cutting vein and disseminated components. The ores lie on the flanks of rhyolitic lava domes which have risen from a postulated subvolcanic magma chamber that provided cupriferous hydrothermal solutions and also acted as a heat source driving ground-water convecting cells. The polymetallic sulphides precipitated initially in explosion craters, pipe fillings and feeder veins as rising hydrothermal solutions mixed with sea water. As sulphides clogged the plumbing system, minor phreatomagmatic explosions produced layers of sulphide fragments on the adjacent sea floor. One to ten repetitions of this process produced multiple fragmental sulphide beds. Each deposit formed in a relatively short space of time, because only minor tuff beds are intercalated in spite of active volcanicity in the region. In this model, the heated ground waters convecting through thick piles of acidic pyroclastic rocks leach the zinc, lead and barium later deposited as kuroko ores. As the subvolcanic pluton cools, the supply of silica and copper wanes and the minor counter-circulation cells above the pluton are replaced by main cell fluids bearing zinc, etc. This change in solution flow is abrupt rather than gradual, as the plumbing system is somewhat disrupted by the magmatophreatic explosions that create each ore layer.IntroductionKnowledge of the kuroko deposits ha s greatly expanded during the 25 years since modern recognition of their volcanogenic origin. However, one aspect of the ore s, which may be of unique importance in their genesis, has received little attention. That is the fragmental character of much o f the sulphide ore, which was briefly referred to in a previous publication (Clark, 1971) and is examined in more detail by Barton (1978). Most researcher s have concentrated their attention on or e deposition above and beyond the vent, which is inconsistent with the geology."

Jan 1, 1983

By K. E. Waters, J. E. Nesset, F. Rosenblum, J. A. Finch, S. Moon

"Some materials when exposed to various conditions can exhibit a rise in temperature without requiring an external heat source. Generally referred to as pyrophoric or self-heating substances, they challenge the safety of materials handling, storage and transportation. Reliably assessing the self-heating potential of materials is thus essential. Over the years a number of test protocols have been developed. A widely accepted method is that recommended by the United Nations to certify the safety of shipping pyrophoric goods. Our test work on sulphide materials has shown that the U.N. test can give false negatives if the sample oxidation history is not considered. Depending on the degree of oxidation (“weathering”), the same sulphide material can exhibit self-heating ranging from safe to hazardous. For concentrates, oxidation can occur during storage and transport making the sample weathering history an important consideration in the test work. To make the U.N. test, and other single-stage self-heating procedures, more reliable in assessing self-heating potential when testing sulphide materials, it is suggested that a weathering step be incorporated in the test protocol. This test work for two sulphide samples, an ore and a concentrate, demonstrates the impact of incorporating a weathering stage in the test protocol. INTRODUCTIONSelf-heating occurs when exothermic reactions produce heat faster than can be dissipated to the surroundings. Numerous substances self-heat, ranging from wood chips and powdered milk to coal and sulphide minerals (Beever & Crowhurst, 1989; Hudak, 2002). Mixtures of sulphide minerals, most notably those containing the iron sulphide pyrrhotite (Fe(1-x)S), commonly encountered in the extraction of base metals (e.g., copper, zinc, lead, and nickel), are particularly prone to self-heating (Rosenblum, Nesset, & Spira, 2001; Payant, Rosenblum, Nesset, & Finch, 2012). In the mining and subsequent processing stages, the minerals are progressively liberated and finely ground, then separated, usually by flotation, with the resulting concentrates stored and transported to smelters for metal extraction. At most of these stages the sulphides are exposed to both moisture and oxygen, conditions that promote partial sulphide oxidation and the formation of elemental sulphur. Studies have shown that pyrrhotite, in particular, readily oxidizes to form elemental sulphur (Bernier & Li, 2003; Belzile, Chen, Cai, & Li, 2004; Somot & Finch, 2010). The elemental sulphur becomes fuel for further self-heating as the temperature of the mineral mixture increases above 100 oC (Rosenblum & Spira, 1995; Somot & Finch, 2010). It is believed the propensity of pyrrhotite to self-heat is a result of its iron-deficient, and hence somewhat unstable structure. It is worth noting that pure metal sulphides (with the exception of pyrrhotite) do not exhibit appreciable self-heating. A mixture of minerals sufficiently different in their electrochemical rest potential is required to initiate self-heating at ambient temperatures (Payant et al., 2012)."

Jan 1, 2016