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By Grainne A. Matthews

Jan 1, 2009

By Yves-Laurent Turcotte

Notre conférencier, Monsieur Yves L. Turcotte, Vice-président et Directeur général chez Promaintech Novaxa est diplômé en génie industriel de l?Université du Québec à Trois-Rivières et détient une maîtrise en gestion de projets de l?Université du Québec à Montréal. Il est une véritable sommité canadienne dans le domaine de l?amélioration de la performance des organisations. Provenant d'entreprises manufacturières et de services, il possède plus de 20 ans d?expérience en tant que développeur de technologies, conseiller et formateur auprès d?entreprises. Il a à son actif la réalisation de mandats dans plus de 400 entreprises. Il est reconnu pour sa grande capacité d?analyse et pour trouver des solutions novatrices et profitables aux problèmes des organisations les plus complexes. Aujourd'hui, il dirige Promaintech Novaxa, une division de DMR, qui a célébré son dixième anniversaire en 2006. Cette organisation ayant des places d?affaires dans la région de Montréal, Québec et Vancouver compte plus de 50 professionnels et a une carte de visite dans 16 pays. Les axes d?intervention sont le Management, la Productivité, la Fiabilité, l?Innovation et l?Amélioration Continue.

Feb 1, 2008

By Vladimir G. Kochnev

Crushing and grinding account for the major portion (60 to 80 percent) of the overall expenses for ore processing. Autogenous (AG) and semiautogenous grinding (SAG) have been considered a step forward in comparison to conventional grinding circuits with several stages of crushing and using ball (and/or rod) grinding mills (Bassarear, 1982, MacPherson, 1989, Pithois, Casalis, 1983, Maripuu et al., 1983). However, there remains room for improvement to existing AG and SAG technologies and both technologies have immense economic benefit potential. Experience gained by the Technics & Technologies of Disintegration Ltd. (TTD) in the research of grinding processes shows that grinding in AG and SAG mills can be performed in a more effective way. The company's approach comprises the following elements: ? Novel mill design. ? New liners and lifters. ? Novel discharge grid design. ? Technique of treating material of critical particle size. Comparative tests that demonstrated the usefulness of these innovations are described in this article. Currently, there are hundreds of AG and SAG mills in operation throughout the world. Application of new internal elements of the mills and reconsideration of the circuit design of the existing grinding equipment using present technological solutions would significantly increase the throughput rate and diminish power requirement.

Jan 1, 2008

By Holdgate G. R, Thompson B. R, Webster R. L, Bolger P. F

The Gippsland Basin in south-eastern Australia has an area of approximately 46 000 sq km. It is one of the world's major coal and petroleum bearing basins, with most of the former occurring in the smaller one fifth on-shore part. The stratigraphy, structure and economic resources of the Tertiary sedimentary pile is now well known through extensive drilling for coal and petroleum. In contrast, the older Cretaceous sequences through their lesser economic importance are relatively less explored. The sedimentational history of the Gippsland Basin has largely followed along similar lines of development to the many other southern Australian basins since the Cretaceous break-up of Gondwanaland. However, the scale of accumulation of coal and hydrocarbon source rocks is unprecedented and differentiates this basin, for reasons less well understood, from the others. Large scale open cut brown coal mining since the late-1920s has been carried out in the western extremities of the basin, while vigorous extraction of some two thirds of Australian petroleum products taken place in the offshore part. Brown coal seam thicknesses and economically winnable reserves are huge and outrank most other brown coal basins of the world. Development of the resource currently meets the need for electricity generation throughout the State of Victoria, but other future developments such as conversion to oil, being investigated.

Jan 1, 1992

By William Stewart

Recitations were taking place in the red schoolhouse at Orneville, Maine. It was winter and the snow lay deep on the ground, but some of the scholars were in bare feet, and only half as many hats hung on the pegs as there were potential wearers in the seats. That was forty years ago; and the pioneers of northern New England were more noted for their industry than for their possession of the fruits of it.

Jan 1, 2007

By Reda M. Bakeer

"Measurements obtained during load testing of two steel H-piles driven at a site in Northeastern Mississippi are discussed. The general site conditions, equipment used, testing procedures and results of the pile load tests are presented. Both piles were tested in compression and one of the piles was subsequently tested in tension. The piles were instrumented with strain gauges and extensometers to measure the mobilized soil resistance and pile movement. Three different “zero strain” conditions were used to determine the mobilized soil resistance and residual loads due to driving or a load cycle. It was concluded that the effect of residual loads on driven piles could be significant. Driving residual loads influenced the magnitude and distribution of the load transfer curves more than those due to a load cycle. Results of the tension test were impacted by the residual loads from the previous compression test performed on the same pile.INTRODUCTIONSeveral factors affect the performance of a deep foundation system including the subsoil conditions, loading settings, pile type and installation method. Residual stresses develop in piles particularly due to pile driving, but they are typically not accounted for in the analysis (Fellenius 2002). Siegel and McGillivray (2009) presented an assessment of residual loads measured during load testing of instrumented auger-cast-in-place (ACIP) piles. The magnitude and distribution of residual stresses along the pile shaft and toe depend on the pile installation method, previous load cycles and time effects. Poulos (1987) reported that residual load due to driving at the pile toe is independent of pile driving equipment and may significantly affect the results of a pile load test. Hunter and Davisson (1969) reported results of pile load tests performed in compression on fully instrumented piles driven in cohesionless soils along with a discussion of the effects of residual loads. Tension loads of about 445 kN (100 kips) were measured at the pile toe after driving. Unloading residual compression load at the toe was detected as “apparent” tension since the instrumentation was zeroed prior to the test. The researchers suggested a graphical approach to obtain the “corrected” load distribution curves considering that residual load will dissipate following the tension test. Holloway et al. (1975) conducted a study on the effect of residual stresses due to pile driving and developed a computer software that accounts for residual loads. Briaud and Tucker (1984) suggested a method to account for residual loads based on the results of 33 pile load tests performed in mostly cohesionless soils."

Jan 1, 2017

By L. A. Cramer

Platinum metal was first utilized by the Inca civilization in South America where it was found in alluvial deposits along the San Juan and Atrato rivers that lie between the Andean mountain range in Colombia and the Pacific Ocean. The nuggets found in these rivers average between 77% and 86%platinum, 7%?8% iron and small amounts of copper, gold and other Platinum Group Metals (PGMs). The Incas often alloyed platinum with copper to increase its workability and fabricated various ornaments from it.

Jan 1, 2001

By G. S. Scott

In the course of the investigation into the causes, behavior, and control of mine fires, which the Bureau of Mines is now conducting, some attention was given to the subject of spontaneous heating. It is self-evident that the temperature of a pile of broken coal will rice if the rate of generation of heat exceeds the rate of brat dissipation and will fall if the opposite is the case. Factors that affect the rate of generation of heat are:

Jan 1, 1941

By S Adamson

Morphological analysis of alluvial gold recovered from the same segment of a placer by four common commercial methods indicates that gold shape and the presence of quartz intergrowths or sulphide overgrowths substantially influence the recovery efficiency of each method. The amount and types of gold saved by each method varies according to the different hydrodynamic conditions under which each of the methods operates. Reverse circulation drilling has the lowest efficiency and preferentially loses moderate-high flatness gold and intergrown or overgrown gold particles with relatively low density. Gravity riffle, hydraulic riffle, and jigcentrifugal concentrator systems respectively save progressively more of these problematic gold morphotypes, but still lose significant and sometimes substantial amounts (of profit) to the tailings. Because of the differences in recovery efficiency, reverse circulation drilling probably underestimates the grade of most placers and may have resulted in bypassing several economic deposits. Losses to tailings by commercial recovery plants arise from inadequacies in fundamental plant design features. These inadequacies compromise plant efficiency by limiting the ability of plants to simulate the wide range of hydrodynamic conditions necessary to operate effectively throughout placer systems. Incorporation of sand pumps and multiple recovery methods into the more sophisticated plants only partly overcomes these inadequacies. At best, efficiency will be maximised in a few segments of the placer determined by individual plant design, and will decrease progressively upstream and downstream of those segments. Without prior knowledge of the morphological characteristics of the gold to be mined, it is difficult to choose the most appropriate plant design, or to estimate what proportion of the gold will be recoverable by any given plant. If the relevant relationships are not considered beforehand, the recovery plant is likely to lose a significant proportion of the gold, and sacrifice maximum profit.

Jan 1, 2001

By L. "Andy" Anderson, Stephen N. Short, James E. Friant

Since the introduction of "boxhole" drilling in South Africa in 1973, the concept of a blind raise, drilled upward from below, has become an accepted mining practice. A combination machine, capable of constructing raises to a mining level below, or blind raising upward from a single setup position adds a further dimension in versatility. A machine with these dual operating modes was designated by The Robbins Company as the 53R and was introduced into the Western Deep Level Mines, South Africa in 1984. The unit is powerful (200 hp) and compact (18,000 lbs., in a 10 ft x 4 ft 5 inch x 4 ft 6 inch package). This paper describes the design considerations for the new machine, provides field data from early trials, and looks briefly at its overall market and potential.

Jan 1, 1985

By Flor De Cock

The paper reflects part of the work from the European Regional Technical Committee on Piles (ERTC3) during its mandate between 1994 and 1999, and, in particular, describes the find­ings from an International Seminar held in 1997 in Brussels on European practice for design­ing axially loaded piles. The seminar included contributions from 17 European countries, each of which provided a synopsis of their respective national design approaches. This paper pays particular attention to the design methods based on laboratory and in-situ test data for both bored and displacement piles.

Jan 1, 2002

By M. Baumann

Introduction Gold Quarry is one of the largest gold deposits in Nevada, located along the Carlin Trend, approximately seven miles north of Carlin, NV. Owned and operated by Newmont Mining Corporation, as of December 31, 2005, Gold Quarry had produced over 13 million ounces of gold. Multiple simulations were constructed for gold and metallurgical variables using the Stepwise Conditional Transformation method. Analyses of these simulations have been used for a variety of purposes, including an assessment of uncertainty with various ore types. This assessment provides insight for improved modeling and reconciliation. Geological Framework Gold Quarry is a large, low-grade disseminated gold deposit hosted in Silurian-Devonian aged sediments at the Chukar/Alunite-Good Hope fault intersection. Gold bearing hydrothermal fluids appear to have migrated upwards along the Chukar/Alunite and Deep Sulfide Feeder faults and then moved outward along favorable stratigraphic horizons and structural intersections.

Jan 1, 2007

By Don A. Toth

Until recently, the fire protection systems used to protect mining equipment were based on generically designed, off the- shelf concepts. These systems were reliant on single agent approaches and were generally comprised of a series of small twenty or thirty pound chemical canisters that would discharge their contents when triggered by thermal detection means. As the equipment grew in capacity, the logic used to increase the protection was to add more chemical canisters to the system. Hydraulic excavators and large-scale mining trucks grew dramatically in size into the 1990?s and beyond; with this growth came the increase in major losses due to fire. This was evidenced throughout this period, and continues to be of great concern today. During this presentation you will learn of the significant changes that have come about as a result of this history. Today, dual-agent products, infrared detection and unit-specific, engineered systems are the primary phrases used when discussing how to best protect this equipment from fire loss. This session is a must for anybody looking to optimally protect their equipment assets and for those looking to renew and/or secure new insurance for high value equipment in the future.

Apr 1, 2005

By John H. Schissler

INTRODUCTION AND SUMMARY Complex copper-lead-zinc ore is mined from underground workings high in the Western Cordillera of the Andes mountains about 100 km in a stralght line north of the city of Arequipa in southern Peru. The Madrigal mine is situated in a steep-walled canyon into which the six operating levels "daylight". Production is from cut-and-fill stopes currently producing approximately 740 dry metric tons per day. The Santa Rosa vein, the most important producer in the district, outcrops for a distance of about 4 km, bearing N 75º W and dipping about 70º NE. In places the vein splits into two or three branches; widths of each vary between 1 and 4 m and total mineralized widths of up to over 8 m occur. Principal ore minerals are chalcopyrite, galena and sphalerite. Ore reserve grades for the Madrigal mine average about 1.45% Cu, 2.6% Pb and 5.0% Zn, 2.9 ozAg per metric ton. [Compania] Minera del Madrigal is a California limited partnership; the general partner and operator is [Compania] Madrigal, a wholly-owned subsidiary of Homestake Mining Company. HISTORY Shallow workings found on the Santa Rosa vein were probably made by the Spaniards during colonial times in their search for

Jan 1, 1977

By B. C. Paul, R. Q. Honaker, K. Ho

Recent research has shown that froth flotation is not effective at treating fine coals (-28 mesh) containing a large portion of middling particles. Due to their relatively large density differences, middling particles can be separated more efficiently using gravity-based processes. The ability of gravity separators to treat fine particles has been limited by the lack of particle inertia relative to the surface drag forces. However, particle inertia can be enhanced by the application of a centrifugal field. A commercial-scale centrifugal Falcon concentrator capable of treating a mass flow rate of greater than 1 tph continuously has been used to evaluate its feasibility for treating fine coal as an alternative to froth flotation. Tests conducted on a -28 mesh fine coal circuit feed have found the Falcon concentrator to be very effective at cleaning the 28 x 325 mesh size fraction. For an Illinois No. 5 coal sample, the ash content was reduced in the 100 x 325 mesh size fraction from about 18% to 8% while achieving a high combustible recovery value of nearly 97%. In addition, the total sulfur content was substantially decreased from 2.6% to 1.7%. The effects of the critical operating parameters on separation performance have been studied and their values optimized.

Jan 1, 1995

By J. David Gunn, Richard W. Lawrence

Gold and silver often occur finely disseminated in sulphide minerals such as pyrite. The use of biological leaching to dissolve pyrite and liberate gold has been extensively studied for a concentrate from the Porgera deposit, Papua New Guinea. The successful operation of a continuous bioleach circuit has been demonstrated. Bioleach residues were cyanide leached to extract gold and silver, and unreacted pyrite recovered for recycle to the bioleach. A 26 day steady state continuous bioleach test on a concentrate assaying 14.3 g/tonne Au and 87.0 g/tonne Ag produced residues with an average 73.5% weight loss and a pyrite oxidation of 88%. Cyanidation and recovery of pyrite from the cyanide residues for recycle gave overall recoveries of 92.1% gold and 74.6% silver. A proportion of the remaining precious metals was found in the bioleach solutions and may be recoverable. Losses to tails were 3.0% gold and 8.1% silver. Final tails represented 14.3% of the feed weight and averaged 1.84 g/tonne Au. A description of the continuous bioleach circuit and bioleach residue handling procedures, and the results of the study are presented. The features and advantages of biological oxidation as a pretreatment for refractory precious metal ores and concentrates are discussed.

Jan 1, 1985

By C. P. Lazzara, R. A. Franks, G. F. Friel, J. C. Edwards, J. J. Opferman

A series of four coal combustion experiments was conducted at the National Institute for Occupational Safety and Health's (NIOSH) Pittsburgh Research Laboratory (PRL) in the Safety Research Coal Mine (SRCM) to evaluate the response of fire sensors to a small 0.61 m square smoldering coal fire which transitions to flaming combustion in the presence of diesel emissions. An optical path smoke sensor alarmed earlier than a point type diffusion mode ionization smoke sensor which alarmed prior to a CO alert value of 5 PPM above ambient. The presence of steady state diesel emissions resulted in a decrease in the optical smoke sensor analog output voltage signal by less than 1.4 pct for the three coal fire experiments in which a diesel engine was operating, whereas the ionization smoke sensor output decreased between 10.8 and 26.7 pct after the initial surge of the diesel engine. A commercial diesel discriminating fire sensor did not alarm for a fire in the one experiment for which it was used. The results of the experiments demonstrated that an optical path smoke sensor might be used to detect a coal fire under the experimental conditions considered of starting a diesel engine followed by a slowly developing coal fire.

South Dakota State Geological and Natural History Survey, State University, Vermillion, S D. A list of publications will be sent upon request Many of the publications are out of print A series of Biennial Reports of the State Geologist will be sent upon receipt of three cents for postage on each, and are available as follows: 1918-20, 1920-22, 1922-24, 1924-26, 1926-28, 1928-30 Available Bulletins of greatest interest are: Bulletin 4, Pre¬liminary report of the geology of the Rosebud Reservation (1909), 10 cents; 10, Possibilities of oil in South Dakota (1922), 10 cents A series of Circulars (5 cents each) deals with the possibilities of oil and gas in various parts of the state, as follows¬ Circular 8, Eastern Pennington County (1921), 9, Western Dewey County (1922); 10, Northern Dewey County (1922), 12, Eastern Harding County (1923), 13, Northern Ziebach County (1923); 20, Western Ziebach County (1925), 23, Northeastern Meade County (1925); 27, Western Corson County Other Circulars (5 cents each) are: Circular 16, The natural resources of South Dakota (1924), 22, Structures ,in northern Haakon County (1925); 24, The Ragged Butte structure (1925), 25, The structure of western South Dakota (1925), 28, Structures in western Haakon and eastern Pennington counties (1926)

Jan 1, 1933

By P. B. Demarsh

"Location: - Mine village of Perron, 11 miles east of Val d’Or in northwestern Quebec.Life; - Started production 1932, ceased 1951.Ore: - Flat lying quartz tourmaline veins within granodiorite. Gold values related to coarse segregations of pyrite. Specific gravity 2. 80.Capacity: - 30 tons 1932-35; 125 tons 1935-37; 350 tons 1937-51.Assay: - Heads 0.21 to 0.34 oz. per ton. Grade obtained by mining 600 tons daily, sorting belt reject 250 tons, balance to milling; tailings loss 0.003 to 0.005 oz. per ton; extraction 9 8. 5%.Grind: - 70% minus 200 mesh. Detention time 26 hours.Treatment: - Cyanidation process.Reagents: - Per ton, aero cyanide (NaCn) 0.36; unslaked lump lime 1.50; zinc 0. 03; lead acetate 0. 006; steel consumption 2. 50.Water: - Equal mixture of swamp creek water and underground seepage.Cost: - Per ton, sorting and crushing 0.21; grinding 0.31; cyanidation 0.11; filtration 0.05; precipitation 0.02; miscellaneous 0.22; total 0.92.Power: - Hydro-electric, 25 cycle, 12, 000 volts reduced to 550 volts.Labour: - 95% Maritime and European, balance Quebec and Ontario.Tailings: - Absorbed over large swampy area on barren mining claims.Personnel: - 1 7 men including supervision.Flow sheet: - Canadian Mining Manual 1947"

Jan 1, 1966

By Walter Steiner, Claus Becker

INTRODUCTION General Switzerland is a densely populated country in the heart of Europe. With its total surface of 41.300 km2 and a population of 6,8 million in 1986 the average population density is 163 capita / km2. The population density is lower than in Germany (245 capita/ km2) or the Netherlands (355 capita/km2). The USA have a population density of 26 capita/ km 2. However, sixty percent of the Swiss surface is covered by the Alps and another ten percent by the Jura mountains the remaining thirty percent of the surface is covered by the Swiss plateau where the majority of the population lives. The population in the inhabitated areas is thus substantially higher and may possibly reach those in major metropolitain areas. Due to the high population density in Europe in general and Switzerland in particular future traffic demands cannot be fulfilled sole by car or plane. Environmental and land-use constraints lead to the third option for growing transportation needs: High-speed rail (Bovy, 1990). Switzerland has developed its own approach to promote public transportation and in particular rail transportation: "Rail 2000" (Stalder, 1990). The system "Rail 2000" is based on a series of hubs distributed over Switzerland where easy connections can be made.

Jan 1, 1991