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By W. A. Jones

"The Hollinger gold mine is in the Porcupine area, Cochrane district, in northern Ontario. The adjacent town of Timmins, which has a population of 25,856, lies 490 miles by railway north of the city of Toronto.The property was staked in the late summer of 1909. The original four claims were staked by Benjamin Hollinger, after whom the mine was named. Development commenced in the autumn of 1909 and mill construction in the winter of 1910. A catastrophic forest fire swept the district in 19ll, destroying the surface plant, so that the original 300-ton mill was not completed until June 1912. From that date up to December 31, 1945, 44,280,750 tons of ore have yielded 13,636,796 oz. gold and 2,613,354 oz. silver. The total value of the production has been $363,638,315.0REBODIES AND MINERALIZATIONThe orebodies consist of quartz veins, stringer lodes, and scockworks, with associated pyritized wall-rocks. The width of individual orebodies, as exposed by mining operations, ranges from 1 to 70 feet and averaged approximately 10 feet in 1942. The vein system forms a complex pattern in a favourable zone, which in places is 6,000 feet long and 4,000 feet wide. The deepest level being developed is 5,150 feet below the surface. Few veins are persistent for long distances, although some are continuous for more than 1,000 feet longitudinally and vertically.The host rocks consist of a closely folded series of Precambrian lava flows of Keewatin age. These are schistose and hydrothermally altered, but are believed to have originally been of intermediate to basic composition. The schistosity strikes N.70°E. and dips to the south at 75° to 80°. The structure of the formations is complex, but in the principal ore-bearing zone the general dip of the flows is to the south at a slightly flatter attitude than the schistosity."

Jan 1, 1954

By Unkown

The Province-wide road ban on movement of heavy loads has had the effect of curtailing or stopping development in several areas. In the Leduc area, the discovery well has been restricted in flow to only a fraction of normal due to limited storage space, but drilling at Imperial Leduc Nos. 2, 3, and 4 has been continued for the past few weeks. The No. 2 well is within 100 feet of the producing horizon and should be completed within the next few days. According to reports, it has been logging slightly lower, structurally, than the discovery well, but, regardless of the outcome, it has been an important test to determine westerly cross-section of the Leduc structure. No official reports have been made available of any tests made during the drilling of the well, but it is understood that promising oil and gas shows have been indicated in higher formations. Actual drilling operations have not been commenced by any of the other companies holding leases in the immediate area but it is expected that, when road bans are removed and equipment is assured, several wells will be commenced. Announcement has been made that Imperial Oil, Limited, will drill a well near Battle lake, about thirty-five miles southwest of the Leduc field. Location of the well has been made following an extensive seismograph survey of the area, with total depth of the test well expected to be in the 8,000- to 8,500-foot range. Drilling will be done with the heavy-duty rig last used at the De Winton test. Imperial Oil have abandoned hope of oil production in the Provost area after drilling nine wells, but will retain their interest in the gas field that has been developed. Of the wells drilled, four indicated gas flows ranging from 1,060 to 13,200 M.c.f. per day.

Jan 1, 1947

By A. S. Romaniuk

More than a decade ago, CANMET management recognized the need to make better use of existing technological information in mining and extractive metallurgy-two fields basic to the economic well-being of Canada. There were at that time no indexes or files dedicated to disseminating technical information for the many minerals mined and processed in Canada, including coal. CANMET, with the nation's largest research and library resources in the minerals field, was in a unique position to fill this need. Initial efforts were concentrated on building a mining file, beginning with identification of world sources of published information, development of a special thesaurus of terms for language control and adoption of a manual indexing/retrieval system. By early 1973, this file held 8,300 references, with source, abstract and keywords given for each reference. In mid-1973, operations were computerized. Software for indexing and retrieval by batch mode was written by CANMET staff to utilize the hardware facilities of EMR's Computer Science Centre. The resulting MINTEC file-one of the few files of technological information produced in Canada-is the basis for the national literature search service in mining offered by CANMET. Attention is now focussed on building a sister-file in extractive metallurgy using the system already developed. Published information sources have been identified and a thesaurus of terms is being compiled and tested. The software developed for CANMET's file-building operations has several features, including the selective dissemination of information and production from magnetic tape of photo ready copy for publication, as in a bi-monthly abstracts journal.

Jan 1, 1979

By W. T. Gotheridge

The principal sources of coal-dust underground are, of course, coal, and the working of coal. Coal-dust is most dangerous when it is in the finest state of division. This class of dust is found mostly on the roads, being blown or shaken off the loaded trams in transit, or carried in suspension by air currents. The air current passing from the working faces may also carry dust in suspension into the return airway, and the air current from the surface may carry dust from the shakerscreens into the intake airways. The mosl dangerous dust we have to contend with is, (a) that which is most finely divided, and (b) that which contains the most volatile matter, including the inflammable occluded gases, and also oxygen absorbed from the air. According to experiments, coal-dust in a fine and dry state would intensify an explosion, in air free from fire-damp carrying in excess of 3 ozs. of fine dust or 6 ozs. of coarse dust per cubic yard. The volatile matter in the dust must be between 12 and 31 per cent. in the ash-free coal, the latter percentage giving the highest flame velocity. It is vary difficult to propagate flame where coal-dust contains a large percentage of stone-dust, (say 50 per cent.). Shale-dust or other incombustible dust containing no volatile hydro-carbons or carbonaceous matter will prevent the extension of an explosion if mixed with coal-dust in proportion of say 70 per cent., and if the dust is finely divided and dry.

Jan 1, 1924

By Jamel Sgaoula

During 1998 COGEMA Resources Inc. announced that operations at the Cluff Lake mine will be suspended indefinitely by the end of year 2000 as a result of deteriorating uranium market conditions. To remain profitable, Cluff Lake mine started an aggressive cost reduction program. A cost reduction team was formed to look for ways to lower production costs. The focus of this team was to screen all areas and to come up with ideas to improve the economy of the mine and ensure the viability of the operations over the remaining three years of operations. Among the areas where significant savings were achieved are: (1) replacement of portion of cement with fly ash in backfill; (2) backfill optimization; and (3) new shotcrete plant installation on site for bulk in-house shotcrete production. This paper details the research work carried out by Cluff Lake mine on these projects and results of its application.

May 1, 2001

By J. D. McFarlane, V. Robinson

"The paper begins with a brief account of the naturarly occurring resources of gypsum and anhydrite and a discussion of their relative value and utility as sources of sulphur. The fundamental chemistry of recovering sul-phur values from calcium sulphate is discussed. (a) Thermal decomposition -discussed as impracticable; (b) Reduction to calcium sulphide; (i) Total Reduction-The chemistry is outlined and the Dorr-Oliver and Bureau of Mines processes mentioned. The Elcor process is mentioned and certain deductions made from available information.(ii) Partial Reduction-This is stated as the basis of the only proven process, namely ""The Cement -Sulphuric Acid Process."" The possibility of recovering lime is mentioned as an aside, but dismissed for lack of commercial application. The history of the cement -sulphuric acid process is covered briefly and a list of plants in commercial operation included. A brief elementary account of the basic chemistry of cement production is followed by a discussion on raw materials and fuels. A short account of the flow scheme of a typical plant, with notes on the operating peculiarities, precedes an account of product quality. The latest developments which enable by-product gypsum to be used as a raw material are discussed, with an indication of how the flow scheme is modified. A statement of feasible plant capacities is followed by requirements of raw materials, services, labour, etc., and finally some indication is given of capital costs."

Jan 1, 1969

By V. H. Valenzuela

Materials in process or in stocks are quite relevant items in almost every plant, particularly in mining operations, where efficiency in rate of recovering material of interest becomes a key issue when production costs are evaluated. A manager requires information to do an effective use of the resources, especially when raw materials are involved. Losses associated to leaking, efficiency in the transformation process, performance of equipment, and operating conditions are a short list of items which must be properly identified and evaluated. Operations supervisors require information in order to keep key process variables under control. Because of these information needs, it is absolutely necessary to carry on a series of activities related with installation and maintenance of measuring equipment, sampling equipment, sample preparation, chemical analysis, statistical analysis, data handling and reports generation. These pieces of data must be managed on a wise manner in order to get the most of it, keeping always on mind data reliability. Normally, information related with metallurgical balance and even more, the metallurgical balance concept, is handled under an accounting criteria which does not allow dealing with the real world. This situation happens because the criteria utilized do not consider aspects such as bias and uncertainty associated with every measurement that affect the quality of the information and therefore conclusions drawn from it. The purpose of this paper is to give a few rules, necessary to follow, in order to develop an adequate Metallurgical Balance System for an operational point of view. The Gaussian approach for error propagation is used as a basis, allowing one to know the actual uncertainty of the balance and the way how it can be improved. A few real applications of this concept are listed, detailing experiences obtained from practice.

Jan 1, 2007

By W. R. Tyson

Pipelines for the transport of gas and oil are being designed to operate at increasing pressures in increasingly harsh environments. The steel used to construct these pipelines must have adequate toughness to tolerate weld imperfections (i.e. withstand bending strains) and to arrest running cracks (i.e. to prevent propagation of axial fractures). The problems posed in specifying suitable toughness parameters and the approaches currently being used to measure them are discussed.

Jan 1, 2005

By W. P. Corking

"The purpose of this paper is to describe the relationship of the goldbearing ore to structure at the Pickle Crow mfoe. Information beyond this scope may be found in the reports and papers of Hurst( l), Bothwell(2), Thomson(3) , and Monette( 4).The property lies on Crow river, in Patricia district, 80 miles northeast of Allanwater, and about 125 miles northeast of Sioux Lookout on the Canadian National railway. From April of 1935, when the mill began operation, to the end of 1944, a total of 564,890 oz. gold and 49,275 oz. silver were recovered from 958,416 tons of ore.Mining on the property is at present carried on in two separate orebodies, the Howell and the No. 2 vein. Stoping has been carried on from every level on the Howell vein to a depth ot 2,450 feet below the surface and from several levels on the No. 2 vein through a mile long cross-cut on the 750-foot level to the Howell vein workings. A steadily increasing volume of ore is being obtained from the No. 2 vein.Each of the two orebodies consists of vein quartz with small amounts of other gangue minerals either in a single vein or a stockwork of veins. Both lie within sheared walls and carry gold in the free state. Fig. 1 shows the position of the veins with respect to the surrounding rocks. It will be noted that the delineation of the beds of iron formation shows that the lava flows and minor, interbedded sediments that make up most of the country rocks are areally folded and contorted.STRUCTURENearly all gold found to date in sufficient quantity and concentration to make ore in the Pickle Crow area is confined to these major quartz veins . Both strike a little north of east and dip north, and in both cases the attitude of the enclosing rocks is somewhat more north of east in strike and more steeply north in dip than that of the veins. As a result of this disposition both veins migrate across their enclosing rocks at a moderate angle in both dip and strike. (In this connection it should be noted that No. 2 vein dips at a considerably flatter angle than its host rock, but has a very pronounced rake to the northeast, effecting the same result as in the Howell vein.)"

Jan 1, 1954

By R. P. Hackl, P. G. West-Sells

Carbonaceous gold ores are particularly attractive for leaching by ammonium thiosulfate as the gold thiosulfate complex is not significantly adsorbed by the organic carbon present in the ore. A technically and economically feasible process for treating these ores with ammonium thiosulfate has been developed. In this process, gold is extracted by leaching the ore with ammonium thiosulfate, the solution is separated from the ore by counter - current decantation, the gold is recovered by precipitation with ammonium sulfide, and finally the gold containing product is upgraded by reacting the elemental sulfur present in the precipitate with ammonium sulfite. The precipitation filtrate is recycled back to the grinding step to close the solution balance. Reagent consumption is not excessive. Besides precipitating gold, the precipitation step removes most deleterious solution impurities and converts a portion of the polythionates back to thiosulfate. This paper discusses the optimization of the leaching, precipitation, and upgrading steps. The results of a 10 kg/h pilot plant campaign are also discussed.

Jan 1, 2005

By R. F. Engler

"IntroductionThe Coal Branch region of west-central Alberta has been the focal point for unprecedented exploration and development activities over the past ten years prompted by the renewed markets for high-quality thermal coal. Although mines were developed and operated extensively throughout the region from 1910 until 1960, information relating to the detailed stratigraphy of the coal measures and their areal distribution tended to be localized to individual mine sites. Continuity along trend was impaired by a paucity of outcrop restricting geologic mapping to stream bank and roadside exposures. Recent studies and subsequent publications by Jerzykiewicz and McLean of the Geological Survey of Canada (1978, 1980) have established a detailed sedimentological model and defined the stratigraphic nomenclature for the region . The term Coalspur Beds has been adopted to describe the coal-bearing sequence between the overlying Paskapoo Formation and underlying Brazeau Formation. Complete sections of the Coalspur Beds have been compiled from sub-surface borehole data and published by Manalta Coal Ltd ., Dentherm Resources Ltd. and Luscar Stereo Ltd. This paper is an attempt to correlate this information on a regional basis to illustrate trends within the Coalspur Beds."

Jan 1, 1986

In-Situ Leaching (ISL) process plants are low cost producers for uranium deposits where the geology is suitable. In the 1970s, a three-year pilot ISL program occurred on gold ore from the Ajax Mine, Cripple Creek District, Colorado, using a chloride and iodide solution [1]. The test was halted due to poor results. With gold and silver the international ISL progress has been slow; however the potential for low capital expenditure (CAPEX) and operating expenditure (OPEX) with large low grade deposits is real. Unless the metallurgy has been demonstrated there are significant risks which could be fatal flaws to an ISL gold or silver project. The metallurgy of gold ISL projects is far from simple and it is early days with project development.

Jan 1, 2011

By Tong Gao, Jingyu Qin, Xiangfa Liu, Zengqiang Li, Yaoxian Zhang

"The recycling of aluminum materials is a green industry while Al–Si–Fe is a typical scrap aluminum alloy. The key point of recycling Al–Si–Fe alloys is to separate Al and Fe. A method by introducing Al–Si–Fe alloy into Mg melt has been investigated in this work. A separation layer with gathered Fe–rich and Al–poor Fe3Al0.7Si0.3particleswereobtained at the bottom of the cooled ingot, indicating that ß–Al5FeSi phase evolves to Fe3Al0.7Si0.3,and quantities of Al are released to the upper Mg matrix simultaneously. However, the evolution of Al3Fe by adding binary Al–Fe alloy into Mg melt is different. It is supposed that element Si plays an important role in the phase evolution procedure, thus affects the performance of this method.INTRODUCTIONThe rapid development of aeronautic, automotive and aerospace technologies strongly depends on the consumption of materials while sustainable development is the future direction. Aluminum is a recyclable material and Fe is one of the most common impurities. Fe can be introduced into Al alloys by adding low–purity alloying materials and by using unprotected ferrous crucible, tools, or equipment (Belov, Eskin, & Avxentieva, 2005; Lu& Dahle, 2005).For instance, wear–resistant rings are usually inserted into piston head when producing Al–Si pistons and an infiltration procedure by putting the cast iron rings into Al melt before casting is always essential. As a result, both the re–melting of pistons and the reuse of Al melt for infiltrating rings lead to the enrichment of Fe element, which can be even high to5 wt.%(Viala, Peronnet, Barbeau, Bosselet, & Bouix, 2002).It is widely known that coarse ß–Al5FeSi particles will form in high Fe–contained Al–Si–Fe alloys which is harmful for the mechanical properties. In the past decades, several methods to eliminate the harmful effect of ß–Al5FeSi have been investigated which can be widely referred (Munson, 1967; Lee, Kawamura, Inoue, Cho, & Masumoto, 1997; Suárez–Peña& Asensio–Lozano, 2006; Eidhed, 2008).These methods can be divided into two kinds. One is to aggregate and remove the Fe–rich phase through the methods of centrifugation, gravity filtration or magnetic separation. The other way is modifing the morphology of flake–like ß–Al5FeSi by overheating the melt or adding neutralized elements. However, these traditional methods are rarely used due to respective disadvantages, while the commonly used method in industries is using primary aluminum for dilution. However, only less than 30wt.% of scrap Al can be added into primary Al melt for each melting work while it also results in the decrease of product quality simultaneously(Zhang, Liu, & Liu, 2016)."

Jan 1, 2018

By Gae On Kim, Ki Baik Kim, Suk Hoon Kang, Tae Kyu Kim, Sanghoon Noh

"Advanced radiation resistant oxide dispersion strengthened steel (ARROS) is being developed as a fuel cladding tube material for future nuclear reactor system applications. The research activities consist of advanced radiation resistant ODS steel development and fabrication technology development of ODS steel structural components. One candidate material with a chemical composition of (in wt%) Fe-10Cr-1Mo-0.5Mn-0.1V-0.25Ti-0.35Y2O3and was selected as representative materials, and this material was named as the advanced radiation resistant ODS steel (ARROSTM).On the basis of this ODS steel composition, an optimized fabrication process of structural components such as plates, sheets and tubes has been established through various process conditions in mechanical alloying, hot/cold working, and heat treatment processes. These R&D activities are expected to contribute to the realization of ODS materials in the future.INTRODUCTIONA sodium-cooled fast reactor (SFR) is being developed at the Korea Atomic Energy Research Institute (KAERI) with a view to economics, safety, reliability, and sustainability. The prototype Gen-IV SFR with a capacity of 150 MWe is under design, and this prototype reactor is scheduled to operate from 2028. For a commercial SFR system application, it is necessary to develop an advanced structural material having both high creep strength and irradiation resistance at high temperatures (Jeong, 2014). Oxide dispersion strengthened (ODS)steel is one of the most promising structural materials because of its excellent creep and irradiation resistance on the basis of uniformly distributed nano-oxide particles with a high density, which is extremely stable at high temperatures under a neutron irradiation environment for a prolonged operating period(Kim, 2016). As the first step, several batches of ODS steel were designed and the candidate samples with a 2 kg scale each were fabricated by mechanical alloying, hot isostatic pressing and hot rolling processes. The mechanical properties of these samples were evaluated. Up to now, two candidate materials with chemical compositions of (in wt%) Fe-10Cr-1Mo-0.5Mn-0.1V-0.25Ti-0.35Y2O3 was selected as representative materials, and these materials were named as the advanced radiation resistant ODS steel (ARROSTM).The next step was to optimize the fabrication process of the ARROS compositions for in-core structural components such as the fuel cladding tubes of a SFR. An optimized fabrication process of fuel cladding tube with a composition of ARROS has been established through various process conditions in mechanical alloying, hot consolidation, hot/cold working and heat treatment processes. Joining technologies of the ODS steel tubes is being developed using solid-state welding such as magnetic pulse welding, friction stir welding and diffusion boding. It is expected that the development of ARROS will contribute to the realization of a commercial SFR with high economics and sufficient safety in the future. In this paper, the study of fabrication process of ARROS structural components is introduced."

Jan 1, 2017

By Steve Simard

Suite aux excellents résultats, obtenus avec la technologie des détonateurs électroniques dans des chantiers longs trous de grandes dimensions, nous avons décidé d?étendre cette technologie dans les ouvertures, dans le dynamitage de piliers et dans différents chantiers complexes. Cette technologie nous a permis d?effectuer l?abatage de chantiers avec un très grand nombre de trous sans détériorer le terrain. L?équation est bien simple avec les détonateurs électroniques, plus gros sont les dynamitages moins de fois les épontes se font ébranler, moins de blocs d?effondrement se retrouvent dans les points de soutirages entre les dynamitages et plus la fragmentation est meilleure. La flexibilité d?opération que nous avons obtenu avec les détonateurs électroniques est difficilement quantifiable, mais elle nous a permis de maintenir notre rythme de production mensuelle même avec certains chantiers complexes. Il est bien certain que l?utilisation des détonateurs conventionnels a encore sa place dans une mine conventionnelle comme Beaufor, mais l?utilisation des détonateurs électroniques a aussi sa place dans certaines situations spéciales. Pour terminer, bien que la technologie des détonateurs électroniques soit encore dispendieuse, nous pensons encore l?utiliser pour optimiser certains dynamitages et ainsi maintenir notre flexibilité d?opération.

Oct 1, 2004

By John A. Allan

The subject chosen for this paper is not a new one, but the subject matter is so extensive that something new can always be said .about it. We are just beginning to realize how little is actually known about the character of Alberta coal, except for a few general facts. The object of this paper is not to explain that our previous information, in whole or in part, on the coal resources of Alberta, has been incorrect, but rather to present some new facts obtained as a result of recent study in the field and in the laboratory. As field investigation continues the problem of determining the character of a coal seam for any great distance laterally becomes more and more complex. Our present knowledge of Alberta coal deposits should not be discussed before due reference is made to those great pioneers who blazed the trails for later geologists, by recording their observations on the general geology of Alberta. Geologists, to-day, particularly those of us who are striving, year after year, to unravel the mysteries of stratigraphy, palaeontology, and structure, in so far as these are related to the coal resources of Alberta, fully realize our indebtedness to those three trail-makers, Dawson, McConnell, and Tyrrell. Had these geologists not recorded their observations correctly, nor interpreted the broad geological facts contained in Nature's book, with still uncut pages, how much slower would have been the progress of our coal knowledge in the succeeding years. It is true that many of the interpretations given to observations by these pioneers have had to be changed as a result of closer studies, but we must also expect that the geological interpretation from present day observations will be changed by future workers, as Nature's book is read and re-read.

Jan 1, 1925

By A. Ouellette, E. Nilsson

"Preventative maintenance is a burden for equipment users but a demand from the machine suppliers to ensure performance. Machine availability depends on preventative maintenance being followed.Mining equipment is becoming more and more sophisticated and productive, yet less and less time is available for preventative maintenance. Manufacturers invest in reducing costs, simplifying operating requirements, and lowering maintenance requirements, but it is the users who must invest more heavily in the advanced maintenance systems to keep the units operating.IntroductionPreventative maintenance has been, and still is a key factor in avoiding disturbances in production due to equipment downtime. Manufacturers ask for it in extensive maintenance schedules, check lists, programs, etc. often with a ""threat"" that, if not performed, the machine guarantee will not be valid. Modern mining and construction machinery has become sophisticated, like all other machinery, with elaborate hydraulic, electric and electronic systems and computerized controllers. Maintenance organizations within the mining industry have grown to heavy cost centres just to keep up the availability of the equipment.It is difficult for machine manufacturers to have maintenance programs that suit every user. International suppliers have to deal with different cultures, education levels, environments, organizations, etc. Maintenance programs recommended by manufacturers often do not meet some user's needs while they are ""overkilling"" to others. Preventative maintenance schemes recommendations of what to do, in what frequency, etc.) usually fit mechanical components in the equipment, e.g. wear measurements, crack indications, lubrication, oil changes, etc. But how does one perform preventative maintenance on huge hydraulic systems, electrical and electronic systems and computers? Failures in these systems usually occur without any warning and are more or less impossible to predict. Another difficulty in creating effective preventative maintenance programs for these kinds of systems is the relatively low volume of mining and construction equipment that is produced per year. For example, although Atlas Copco is one of the largest manufacturers in the world of underground blast hole drilling machines, the company still does not produce more than a few hundred drilling jumbos per year. These are made in more than 10 different models, with different systems and components, and very often are custom adapted to the end user's requirements."

Jan 1, 1992

By D. J. W. Piper, T. Hundert, G. Pe-Piper

"Abstract - Potentially commercial deposits of kaolin are found in the fluvial Lower Cretaceous Chaswood Formation, the sedimentologically proximal equivalent of deltaic sediments of the offshore Scotian basin. The geological setting of the kaolin deposits has been interpreted from high-resolution seismic-reflection profiles and boreholes, and mineralogical studies on one reference borehole. The kaolin is a product of early diagenesis involving meteoric water below the water table. The distribution of kaolin is controlled by the presence of intraformational unconformities that were sites of ground water recharge, and are marked by the development of oxisols above the water table. Such diagenesis was facilitated by interbedded, loosely consolidated, permeable sandstone. The highest-grade kaolin deposits are found in areas close to river belts, where overbank muds were not sufficiently drained to develop paleosols, but where later uplift created intraformational unconformities. In the sandstone, meteoric water flow altered feldspars to kaolin, thus yielding commercial silica sand deposits. It also altered ilmenite to rutile, which is concentrated as secondary placers in modern rivers that have eroded the Chaswood Formation and tills derived therefrom. Sommaire - Des dépôts de kaolin potentiellement économiques ont été notés dans la Formation de Chaswood d'’âge Crétacé Inférieur, laquelle constitue un équivalent latéral en milieu fluviatile aux sédiments deltaïques du bassin de Scotian. Le contexte géologique de ces dépôts de kaolin a été interprété a partir de profils de seismique-réflection à haute résolution, de sondages, et d’études minéralogiques sur un sondage de référence. Ce kaolin est un produit diagénétique précoce formé par de l’eau météorique sous le niveau de la nappe phréatique. La distribution du kaolin est contrôlée par la présence de zones de recharge associées à des discordances intraformationelles marquées par le développement d’oxisols au-dessus du niveau de la nappe phréatique. La présence d’interlits de grès perméables faiblement consolidés a contribué à l’efficacité de ce processus diagénétique. Les dépôts de kaolin les plus riches se trouvent en périphérie des rivières, là ou les boues de la plaine d’inondation n’étaient pas suffisamment bien drainées pour permettre le développement de paléosols, mais où des mouvements verticaux subséquents ont crée des discordances intraformationelles. La circulation d’eau météorique dans les grès a entraîné l’altération des feldspaths en kaolin, générant ainsi des dépôts économiques de sable de silice. Elle a aussi causé l’altération de l’ilménite en rutile, que l’on trouve dans des placers secondaires situés dans des rivières contemporaines qui ont érodé la Formation de Chaswood et les tills qui en sont dérivés."

Jan 1, 2006

By Y. Wang

In this paper, the tribological and electrochemical corrosion properties of Al2O3/polymer nanocomposite coatings were studied using a micro-hardness test, a single-pass scratch test, an abrasive-wear test, and finally an electrochemical technique such as potentiodynamic polarization measurement, The coatings containing Al2O3 nanoparticles showed improvement in scratch and abrasive resistance compared with polymer coatings; this improvement is attributed to the dispersion hardening of Al2O3 nanoparticles in polymer coatings, Corrosion test results showed that the embedded Al2O3 nanoparticles in the polymer matrix do not sacrifice the corrosion resistance of the polymer itself.

Jan 1, 2005

By Jiachen Wang

Longwall top-coal caving mining is one of the major mining methods for extracting thick coal seams in China. The top-coal caving longwall mining was began to use in the 1980s in China, and got the rapid development. The development of the top-coal caving mining technology in China, the achievements and the theoretical aspects progress of this method are described in detail in this paper. And the main technical model of China's top-coal caving mining is introduced in this paper. This paper also introduces the application of large-cutting-height mining in China and the technical level it has reached.

Aug 1, 2013