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By Ralph V. Stewart

"The asbestos orebody is contained within ultrabasic rocks of Precambrian age, being located in the continuous permafrost zone of the Quebec Ungava Peninsula, some 300 miles north of the tree line at approximate latitude 61'49' and longitude 73°58'.The asbestos deposit is at the western tip of a folded ultrabasic sill complex which trends northeast and covers an elliptical area 4.5 miles wide by 15 miles long. Locally. the asbestos occurs in. a completely serpentinized dunite rock. The principal rock types in the vicinity of the ore-body originally consisted of dunite, peridotite and pyroxenite, all of which have experienced at least two periods of alteration, so that no fresh rock now remains.The main ore zone in the open pit is approximately one quarter mile in length, 150 to 200 feet in width, and plunges at 25 to 30 degrees in a northeast direction below surface, to a vertical depth of at least 1,200 feet, Consider¬able tectonic activity resulted in favourable structural conditions which culminated in the formation of the ore zone in its present form.The deposit consists principally of cross-fibre ""gash type"" veins which vary in length from several inches to several feet. The principal fibre vein direction is parallel to the dip of the enclosing serpentinized dunite and sill complex.Some of the problems encountered during diamond drill¬ing in permafrost are briefly discussed."

Jan 1, 1976

By C. Blawert

In spite of various corrosion studies on HPDC AZ91, there is no clear indication which microstructure gives the best corrosion performance. The skin with its fine microstructure is sometimes reported to have the best corrosion resistance, but there is no clear definition of the skin. If the skin is the outermost part of the casting and nothing is removed from it, then it is contaminated and the corrosion resistance is low. If the outermost skin is removed (about 25 µm) then a better corrosion resistance can be obtained. However this does not automatically mean that there is no other region in the bulk of the casting which could have a similar or even better corrosion resistance. Indeed, the corrosion measurements including potentiodynamic polarization and long term electrochemical impedance spectroscopy (EIS) revealed a lower corrosion resistance of the original as-cast skin about 100 pm thick. The thickness of this region is more or less independent from the thickness of the casting section. The surface region is free from any dendritic grain growth which influences the amount and distribution of the 13-phase and therefore the distribution of the most important alloying element Al. This could explain the different corrosion behavior. Further reason can be found in the enrichment of some impurities such as Fe in the near surface.

Jan 1, 2006

By G. G. Richards, Y. Oyediran, V. Chow

The oxygen softening process for partial removal of arsenic and antimony from lead bullion has been in use at Teck Cominco's Trail smelter since 1986. In this process, industrial oxygen is injected into bullion to remove As and Sb with the formation of an oxide slag. In Trail, the levels of these elements are reduced to concentrations suitable for processing in the Betts electrorefining plant. Recent moves toward the treatment of higher arsenic-bearing feeds have necessitated an increase in the process capacity to meet the specifications for drossing plant bullion. Process intensification trials were conducted in-plant to develop an operating strategy for higher bullion processing rates. This was preceded by a study conducted with McGill University to develop a fundamental understanding of the therm ochemistry and kinetics of the process. The results have yielded more effective control of the operation, and identified opportunities for further improvements.

Jan 1, 2008

By Robert E. Loftus

"The author discusses the growth in the use of ocean-going bulk carriers for the transportation of mineral commodities, and predicts future trends. The various types of tonnage carriers are described, along with the special discharging gear used, the costs involved and the duties of some of the personnel.THE FIRST CONSIDERATION in planning the ocean transportation of minerals is the type of vessel to be utilized. The modern 'Bulk Carrier' bas proved to be the most successful vehicle for the purpose. I would there-fore like to describe this fleet in some detail and at-tempt to show the impact that the bulk carrier bas bad on the movement of bulk materials."

Jan 1, 1968

By S. Mao

Total station has been predominantly applied in stationary survey scenarios in construction. With the moving target tracking and point survey automation functions, a robotic total station (RTS) lends itself well to more dynamic applications. Nevertheless, a RTS unit is still unable to track multiple targets simultaneously or to survey a target point when the line-of-sight is temporarily unavailable. In this paper, we propose a methodology to synchronize and automate multiple RTS units intended to address dynamic tracking and surveying applications in the construction field. By using the application programming interface (API) from the manufacturer, we implement the proposed methodology and the prototype system integrates two RTS units in regard to space and time and communicates survey command instructions among RTS units through wireless networks. The two RTS units can be operated to survey the two ends of one swinging sling concurrently in order to retrieve the actual length of the sling within several millimeters accuracy. Besides, in applications where line-of-sight between a target object and one RTS unit cannot be guaranteed all the time, continuous surveying can be materialized by automatically delegating the task to another synchronized RTS unit with clear view of the target object. A field test was conducted to demonstrate the application of the proposed automation approach in which sling length was measured of a rigging framework used for lifting industrial modules. The testing results are presented and achievable accuracy and reliability are discussed. The proposed solution overcomes the limitations of global positioning system (GPS) and laser scanning and holds high potential to provide cost effective solutions to many dynamic field applications.

Aug 1, 2013

By Z. S. Shao, X. Z. Li

"Sub-critical crack growth plays an important role in long-term creep failure in brittle rock. Based on micromechanics established by using relationship between micromechanical wing crack growth model and macroscopic strain, and comparing theoretical model with testing results, a method, which applies the theory to real rock, is suggested in this paper. Using this method, properties of creep, damage and progressive failure in brittle rock are investigated. Effects of stress state on creep failure time and steady-state creep rate are analyzed and graphically presented. The results are helpful to support structure design and service life evaluation of underground structures with high geostatic stresses. INTRODUCTIONDuring the long-term operation in underground space with brittle surrounding rock, due to chemical action between pore water and rock, the failure of rock often occurs at stresses below its short-term failure strength, which brings serious effect on the long-term stability of underground structure. Thus, the long-term strength of brittle rock attracted wide interests of scholars around the world. The static fatigue limit was predicted by exponential function that is derived from abundant experiment data of stress level and failure time(Schmidtke & Lajtai, 1985), and similar result by relationship between stress state and failure time was also suggested (Lau & Chandler, 2004; Aubertin et al., 2000; Sangha & Dhir, 1972). According to relationship between steady creep rate and stress state during creep, a critical stress that transforms steady-state creep to accelerated creep was studied and the long-term strength was suggested (Tsai et al., 2008; Ma & Daemen, 2006; Lajtai et al., 1991). Based on the results of experiment in compression, the long-term strength of rock was defined by stress at volume strain reversal. When applied stresses are larger than the long-term strength, the microcracks in the rock will grow constantly, damage of rock will increase and failure of rock will occur finally (Chandler, 2013; Bieniawski, 1967; Brace et al., 1966)."

Jan 1, 2015

By J. G. MacGregor

At this, the opening meeting of the Western Quebec Branch of the Institute, it seems fitting that the first paper presented should embrace a survey of the known mineral deposits occurring in the area, and also a review of ?the exploration methods that have brought about their discovery. And since the study of geological structures must always be the guiding principle of an intelligent exploration campaign, it also seems to be the appropriate occasion to review the geological situation from the economic angle, in an attempt to arrive at a re-statement of the known facts governing the deposition of the mineral bodies . . It is not my intention to confine my remarks entirely to the geological problems involved, but rather to pass under review the exploratory methods that have been employed in the past and that are presently being used, and to offer a forecast of the type of exploration campaign that will be largely adopted in the future search for ore.

Jan 1, 1929

By V. Fiedler, H. Lachmund, R. Bruckhaus

"After producing some 50 million tonnes of crude steel the two BOF vessels at Dillinger Hüitte steel plant had to be replaced in 2000/01 due to large deformations. The new vessel design was optimised after a number of theoretical evaluations.Refractory investigations were carried out as well as temperature measurements of the shell to provide a basis for selecting a suitable steel grade. This was found in a DH-GTS development - P420M HT - with high strength at elevated temperatures and excellent weldability and made it also possible to build the vessel without any cooling system.After putting the first vessel into operation the metallurgical results showed no remarkable improvement compared to the old vessel, and were therefore not satisfying. With the help of cold model investigations the arrangement of the tuyeres was modified to improve the flow conditions and the interactions between oxygen jet and the heterogeneous plume of the bottom stirring gas. Further optimisations were obtained by a variation of lance tips and a newly developed lime addition model."

Jan 1, 2004

By Ryan L. Veenstra

This paper presents a modelling study of a cemented paste backfill in an underground stope. The model was developed to help provide a better understanding of what is happening in the stope during the filling stage of the stope. In order to do this, the model incorporates the paste rise rate, stope geometry, and time-dependent input parameters. This paper looks at the effect of geometry in two parts. The first part compares a series of simple rectangular stope models. These models differ in size both in two and three dimensions. The second part compares the results of four 2D models together and then to the field instrumentation data. Part of this section introduces the geometry and instrumentation within the test stope.

Jun 1, 2012

By R. Marleau, R. Assad, J. Dugas

"A study of the geological features of known occurrences of mineralization in Gaspe is the basis for a classification. Nickel, chromite, asbestos and some copper are pre-or syn-Taconic, whereas the most important deposits are tied to granitic post-Taconic stocks. Most occurrences are clearly related to igneous rocks: nickel, chromium and asbestos to Ordovician serpentinite; copper to volcanic rocks of different ages; and copper, zinc and lead to acidic intrusions with apparent zoning. Some lead-zinc deposits lying between the Grande Greve and York Lake formations are stratigraphically controlled. Some occurrences are tied to faults; e.g., the nickel-copper mineralization along the North Grand Pabos fault. Northerly-trending transverse structures appear to coincide with the Gaspe Copper, Mount McGerrigle (Tabletop) granite and Lemieux dome areas of mineralization. JEAN DUGAS, after graduating"

Jan 1, 1969

By J. W. Kramers, R. A. S. Brown

"Samples from seven test wells distributed throughout the surface-mineable area of the Athabasca Oil Sands have been evaluated to determine the amounts of heavy minerals present and the titanium and zirconium contents. The samples were treated to yield the size distribution of the titanium and zirconium minerals as well as their spatial distribution. The study has shown that heavy minerals are found throughout the surface-mineable area; concentrations range from 0.24 to 2.29 per cent (by weight), with a mean of 1.02 per cent. Titanium and zirconium contents vary throughout the area, and are found preferentially in the finer size fractions. •on the basis of preliminary calculations, the tailings streams from an oil sands plant would provide sufficient feed for a large-scale titanium pigment plant, and the tailings from one plant would provide sufficient zircon feed to satisfy Canadian demand for. metallic zirconium. Variability of the heavy mineral content and composition is such that the heavy mineral potential must be evaluated in detail for each mine site."

Jan 1, 1976

By John F. Kearney

After World War II Canada?s fledgling iron ore mining industry developed along the ill-defined Quebec / Labrador border near what became the town of Knob Lake and later renamed Schefferville. For about twenty-five years from 1954 to 1982 Schefferville was the epicenter of Canadian iron ore mining and the foundation of the Iron Ore Company of Canada. In about 1982 it all stopped, shut down, the miners moved away leaving behind a mining camp and a ghost town that have sat idle and almost deserted for the past twenty five years. The story looks set to change with new plans to re-establish the former mining operations in the historic mining camp. This paper outlines the proposal to reactivate the direct shipping iron ore operations in the Schefferville mining camp, and specifically the properties in Labrador owned or optioned by Labrador Iron Mines Limited (?LIM?), a wholly owned subsidiary of London Stock Exchange listed Anglesey Mining plc. The Schefferville mining camp is located about 1,000 km northeast of Montreal. There are no roads connecting the area to southern Labrador or to Quebec. Access to the area is by rail from Sept Iles to Schefferville, or by air from Montreal and Sept Iles.

May 1, 2007

By F. Ajersch, A. R. Hekmat

Apparent viscosities of hypo-eutectic (Al-7% Al) and hyper-eutectic (Al-35% Si) binary alloys were measured in the semi-solid state using a Couette type viscometer at variable shear rates. Analysis of the microstructural evolution demonstrates the differences in the rate and degree of attrition of the primary phase particles which are characteristic of the thixotropic nature of the semi-solid alloy. It was observed that the Si primary phase in the hyper-eutectic alloy is much more difficult to fragment than the dendritic a-Al phase in the hypo-eutectic alloy. For the case of the a-Al, the dendritic structure is broken down by attrition and fracture of the dendrite arms whereas the fracture of the Si hexagonal crystals in the hypereutectic alloy occurs along the {100} and {110} cleavage planes. Results are presented for fixed solid fractions of the primary phase at isotherm condition for each type of alloy.

Jan 1, 2006

By K. G. Chipman

IN 1936, the Department of Mines and Resources was formed by the amalgamation of the former Departments of Mines, Interior, Indian Affairs, and Immigration. In the amalgamation, the Geological Survey and the Topographical Survey became the major divisions of the Bureau of Geology and Topography, which is a part of the Mines and Geology Branch which, in turn, is a part of the Department of Mines and Resources. The Topographical Survey was formed by combining the former Topographical Division of the Geological Survey and the air and ground mapping sections of the former Topographical and Air Survey Bureau of the Department of the Interior. The latter organization, previous to 1933, had been known as the Topographical Surveys Branch of the Department of the Interior. The amalgamation of 1936 definitely placed on the Topographical Survey the responsibility for the original mapping required for the development of our natural resources. The war has brought upon us the situation where all work has had to be in the furtherance of the war effort. With decreased staff and limited appropriations, the mapping on those scales which are directly concerned with the natural resources has been confined to the search for oil and strategic minerals. The reconstruction period will produce a different situation, with different problems. The past is behind us and it is necessary to prepare for the future. First, we should consider briefly a few general principles in the making and using of maps, then take stock of what we have, see what the needs are, and consider how we are to meet these needs.

Jan 1, 1944

By D. H. Ryan, J. T. Graham, A. Navarra, J. A. Finch, S. Somot

Pyrrhotite (Po) is widely considered to be the most significant mineral in the self-heating of sulphides. It is therefore desirable to determine the amount of Po in mineral samples. This is commonly accomplished through x-ray diffraction (XRD) or quantitative evaluation of materials by scanning electron microscopy (QEM-SEM). This paper introduces another quantitative method based on Mossbauer analysis that requires limited sample preparation and has the additional potential to detect the sulphur/iron ratio within Po. The technique is explored using pentlandite/pyrrhotite mixtures.

Jan 1, 2009

By R. K. Rajamani

Discrete Element Method simulation of charge motion in ball, SAG and autogenous mills has become a standard for design of mill internals, power draft evaluation, etc. Both two-dimensional and three-dimensional codes are being used. The two-dimensional code dominates the user market since the code completes a simulation in one or two hours. On the other hand, three-dimensional codes have been in the domain of specialists who can handle the complexity of the code and have access to parallel computing hardware. For the first time, this barrier is overcome via computing with graphic processing units (GPU). Commodity graphics cards now allow parallel computation with hundreds of processors. It is shown that the computational time has been reduced by a factor of fifty using GPU computing. Hence, SAG charge simulation results in three dimensions are achievable in a few hours using affordable desktop machines. The GPU computing shown here enables the three dimensional simulation into a manageable daily task for mill designers and researchers. On the technical side, the simulations can be elevated to a higher level of complexity to simulate breakage and transport. First, the speedup factor of fifty is established for the Nvidia GeForce GTX 580 graphics card. Next, four simulation tasks, consisting of AG, SAG and ball mills are reported. The simulation of AG and SAG mills are completed in less than 8 hours. The ball mill simulation with 1.25 million spheres is completed in 27 hours. In the near future, as the graphic card hardware advances the compute time can be halved.

Jan 1, 2012

The primary (sulphide) resources at Aphrodite are refractory in nature, requiring an oxidation process stage to be introduced to facilitate extraction of the gold. The company is investigating the use of pressure oxidation (POX) as the oxidation method for processing of high grade gold bearing concentrate it plans to produce at Aphrodite. POX has been used extensively around the world for the past 30 years and continues to be the favoured option for a number of refractory gold plants currently in the design and construction stages. Initial pressure oxidisation testing investigated the effect of temperature, pressure and grind size on a bulk flotation concentrate prepared from Alpha lode material. The concentrate averaged 47.3 g/t gold and was prepared from a composite of core samples averaging 1.49 g/t gold. Sub-samples of the concentrate were subjected to POX for 1 hour resulting in rapid oxidation during this very short period. Testing undertaken showed that there was a significant increase in sulphide oxidisation at higher temperature (220°C) and pressure (2,500 k/Pa) for the two grind sizes (75 and 20 microns) evaluated. The proposed flowsheet, OPEX and CAPEX are critical aspects for project development.

Jan 1, 2014

"Bay d'Espoir is in the approximate center of the south coast of Newfoundland. The geology of the area can most conveniently be considered in terms of three units: (1) an Ordovician or older polydeformed terrain termed the Little Passage Gneisses; (2) a Lower-Middle Ordovician volcano-sedimentary sequence assigned to the Baie d'Espoir Group; and (3) granitoid intrusive rocks of mid-Paleozoic age. Mineralizing events accompanied the formation of the latter two units.The Baie d'Espoir Group comprises a dominantly sedimentary sequence of pre-Middle Ordovician shelf and distal turbidite sediments deposited on the eastern margin of Iapetus. A significant volcanic component is, however, present in the Isle Galet Formation, consisting of up to 30% felsic volcanic rocks interbedded with sedimentary and epiclastic rocks. The Isle Galet Formation hosts several disseminated to thinly bedded Pb-Zn-Ag occurrences associated with altered felsic tuff and graphitic shale. They occasionally grade laterally into pyrite iron formation and appear to have been deposited in a very distal volcanic environment. The Isle Galet Formation is a time equivalent of the mineralized pre-Caradocian island-arc sequences of central Newfoundland, but differs from them both in style of volcanism and in the nature of the associated mineral deposits. It is, however, comparable in many respects to mineralized volcanic sequences in the La Poile Bay area of southwestern Newfoundland.Mineralization associated with granitoid rocks in Bay d'Espoir is best developed around the southeast margin of the North Bay Granite, where two-mica leucogranite forms a marginal phase. Numerous minor base metal showings occupy quartz, quartz-carbonate and barite veins in the adjacent sedimentary rocks. Collectively, the showings exhibit a well-developed, zonal pattern around the granite margin; molybdenite (±py, cpy) predominates near the contact, giving way outward to galena (±sph, py, asp, cpy) and eventually to stibnite (±asp, py) at the periphery. Mineralization associated with granites in similar settings elsewhere in southern Newfoundland includes tungsten in the Grey River and Granite Lake areas and molybdenite in the Rencontre Lake area."

Jan 1, 1982

By P. Srinivasan

Corrosion is a major operational problem in amine-treating plants causing significant expenditures each year, Corrosion may become more severe when the amine plants contain process contaminants ? namely heat-stable salts. The heat-stable salts enter the plants with feed-gas streams and makeup-solution, and/or are produced within the plants by reactions of alkanolamine and available carboxylic-acid anions, This work investigated interaction corrosion effects that may exist in amine-treating plants containing a mixture of heat-stable salts, The investigation was experimentally carried out in a 5 kmol/m3 monoethanolamine (MEA) solution containing 0,20 mol/mol carbon dioxide (CO2) loading at 80°C under atmospheric pressure using carbon steel 1018, Six heat-stable salts, including formate, oxalate, bicine, acetate, thiosulfate and chloride, were tested with a series of salt combinations, Potentiodynamic Polarization, Tafel Extrapolation, and Cyclic Polarization were used for revealing corrosion behavior, determining corrosion rate, and examining the pitting tendency, respectively, Results show that thiosulfate induces the most corrosive environment when present either individually or in the form of salt mixtures.

Jan 1, 2005

By R. T. Erskine

"The No. 6 orebody is located 6 miles from the main op.eration of Brunswick Mining and Smelting Corporation Limited and includes open-pit and primary gyratory crushing facilities. Ore is transferred by truck to the secondary crushing facility at the main plant. About 3,500 tons of ore per day are crushed to minus % in. and ground to 68 per cent minus 400 mesh in rod and ball mills for flotation feed. Conditioning and aeration precede rougher flotation, and four stages of cleaning bring concentrates to a grade of 42 per cent Pb + Zn + Cu. Middling products are reground and refloated in a secondary flotation circuit, producing a cleaner feed and a final tails product. Primary bulk concentrate is treated with sulphur dioxide and steam-heated to l 70°F and the majority of the gangue is floated off, leaving a product that assays 57 per cent combined Pb + Zn + Cu and is suitable for marketing. This material is thickened, filtered, dried and loaded into railway cars for shipment to the smelter. Reagent use on flotation is conventional, with many compromises in dosage required to maintain the recovery of lead and zinc in the most advantageous proportions. Many refinements in the flowsheet have been made since start-up in 1966, and more may be made as laboratory and plant testwork indicate possible improvements."

Jan 1, 1971