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By \/eena Sahajwalla, Alexander Blagus

This paper reports the effect of using High Density Poly-Ethylene (HDPE)/coke blends on the reduction behaviour of Mn3O4 to MnO at 1000°C. The results suggest that CH4 release increases with increasing HDPE addition. The results show that the rapid release of methane, over only the initial five minutes, limited the interaction of Mn3O4/MnO with CH4. With the devolatilisation of HDPE there was increased porosity in samples containing HDPE, assumed to be the major factor in differences of reduction rates.

Jan 1, 2011

By A. L. Mular

This paper provides a worthwhile contribution to the knowledge needed for calculating and using mathematical models of grinding circuits. The computer search algorithm proposed should remove much of the guesswork as well as reduce computer processing costs and improve the accuracy of estimated parameter values for grinding mill models.

Jan 1, 1970

By V. P. Mehrotra, D. W. Fuerstenau, A. -Z. M. Abouzeid

The use of pulverized coal for electric power generation results in the production of vast amounts of fly ash. One potential use for waste fly ash is the production of pellets for lightweight aggregates. This paper is concerned with the role of the physical and chemical characteristics of two different fly ashes in governing their agglomeration or pelletization behavior and their strength characteristics. In batch balling experiments, fly ash pellet growth was found to be extremely sensitive to the amount of moisture added. One ash (Mohave) exhibits marked pozzolanic activity whereas the other (Jim Bridger) does not. The pozzolanic activity has a very pronounced effect on pellet growth kinetics, moisture requirements, and the effect of various additives on growth kinetics. Slow drying under ambient conditions produces strong pellets from Mohave ash whereas Jim Bridger ash pellets lacking in pozzolanic activity are weak. Rapid drying at high temperatures results in weak pellets because water necessary for hardening is driven out of the pellet. Steam curing enhances pellet strength. Locked-cycle pelletizing experiments exhibit expected oscillation in pellet production rates and attendant fluctuations in pellet green strength.

Jan 1, 2004

By G. M. Ritcey, B. H. Lucas

In the conventional alkaline leaching of concentrate containing nickel, copper and cobalt, copper is usually removed from the system, prior to nickel reduction, by sulphide precipitation. A new process is described for the selective extraction of copper and separation from cobalt and nickel, using liquid-liquid extraction. General Mills LIX-63 dissolved in a kerosene diluent is the extractant. Trace amounts of co-extracted cobalt and nickel are easily removed by a scrub treatment, and copper is recovered from the extract by sulphuric acid stripping, thus providing a solution amenable to the oroduction of electrolytic copper. Estimated processing costs are included together with a proposed flowsheet.

Jan 1, 1972

By K. S. Coley, G. A. Irons, T. Kaneyasu

"It is very important to reveal the lime dissolution mechanism in steelmaking slag, to promote its dissolution without calcium fluoride, which is now almost forbidden for use in most industrialized countries. In this research, the purpose was focused on the development of an experimental method to measure the mutual diffusivity of Ca2+ under the condition of lime dissolution into slag. By forming diffusion couples using a ""vacuum slag aspirating technique"", the method was established. The following mutual diffusivities of Ca2+, in CaO-SiO2-FeO slag systems, imitating oxygen steelmaking slag, were determined using this method:4.1*10-10 m2/s at 1400°C for 27wt.%CaO-53wt.%SiO2-20wt.%FeO slag,4.3* 10-10 m2/s and at 1400°C for 20wt.%CaO-40wt.%SiO2-40wt.%FeO slag, and 1.3*10-10 m2/s at 1250°C for 20wt.%CaO-40wt.%SiO2-40wt.%FeO slag.It was also verified that, if the basicity and ferrite content of the bulk slag are low, then a calcium silicate film forms on the lime surface, and drastically deters the lime dissolution."

Jan 1, 2004

By X. -P. Zhang, L. N. Y. Wong

Shale gas exploitation initiated in North America has rapidly extended worldwide. Hydraulic fracturing is an emerging field technique for stimulating the gas reservoir. The study of cracking processes, particularly crack coalescence, is vital for a successful hydraulic fracturing to enhance the gas exploitation. Experimental studies have observed that the size effects of the constituent particles are significant on the cracking behavior of the rock specimens. To further investigate the size effects, the bonded-particle model (BPM), which is based on the discrete element method (DEM), is adopted in the present research. In flaw-containing specimens, by varying the crack resolution (?= a/2R), which is the ratio of half flaw length (a) to particle size (2R), the size effects on cracking behavior under compressive loading are studied. By keeping the flaw length constant, the particle size is varied independently in the BPM analysis. Decreasing the crack resolution increases the first crack initiation stress, but it has no obvious effects on the uniaxial compressive strength. The trajectories of the first cracks and secondary cracks hence generated have a higher resolution and are well-defined in those specimens possessing a higher crack resolution. On the contrary, in lower crack resolution specimens, the macroscopic first cracks appear to be wider and less continuous. These findings from numerical simulation clearly demonstrate particle size effects on cracking behavior. Special attention should be paid to these effects in future numerical study using the bonded particle model.

Jan 1, 2015

By N. Staroselsky

"Significant energy savings are often possible for centrifugal compressors operating in parallel by improved control strategy and improved instrumentation. Blow-off can usually be reduced by improved surge control combined with a better control strategy for loading and unloading the group of machines. More precise and stable pressure control then becomes possible. This improved control strategy will also decrease the frequency of operation near the dangerous limits of surge or overload or overspeed. A sample station of mixed centrifugal and reciprocating compressors is examined and a substantial energy saving with the recommended control strategy is projected from operating data. Present Operating Conditions of the Compressed Air StationThe Compressor StationThe compressor station described here has three centrifugal compressors and three reciprocating. It supplies a mine in New Brunswick.Compressed Air and Power ConsumptionFigure I and Figure 2 provide graphs of air consumption and pressure changes based on the owner's data.During the typical two-shift operating day (Fig . I) in the non-productive shift (midnight to 8:00 a.m.), the consumption stays at a level of 9,000 SCFM. This corresponds to a pressure of 110 PSIG. Then, after 8:00 a.m ., the air consumption starts to increase and th e pressure decreases. Around 10:00 a.m., the consumption reaches its maximum level at 97 PSIG. Around II :30 a.m., the air consumption starts to decrease because of the production drop during the lunch break of the first shift. Pressure increases again up to 109 PSIG. After the break, consumption rises to its maximum level over 16,000 SCFM andpressure drops to 97 PSIG.Around 2:30 p.m., the air consumption drops sharply to 9,000 SCFM because of the production decrease to zero level. This drop results from changing of shifts. The pressure at this time increases again up to 110 PSIG. The second shift (2:30 to II :30 p.m.) is an alogous to the first.During the three-shift operating day, the break around 4:00 . a.m . and the shift change around 6:30 a.m. cause sharp drops in air consumption. The pressure for almost the entire night shift stays near 110 PSIG because the station is working with blowing-off even under the maximum consumption. The analysis of Figures I and 2 shows that the pressure varies with the air consumption changes. During non -productive time (non-production shifts , shift changes and breaks) or during the night shift, the total station capacity is proportional to the discharge pressure. By decreasing the level of this pressure up to 97 PSIG, the flow of the station may be decreased during the non-production time as follow s:"

Jan 1, 1980

By M Reza Afshar

In this work a mathematical model was developed to study the effect of electromagnetic force on the magnesium melt containing nonmetallic inclusion in an electrical isolated channel. The electromagnetic force exerted on the inclusion induced by DC current field was calculated. A three dimensional turbulent flow equations were solved numerically to compute the velocity field within the channel. On the basis of computed velocity and magnetic fields, the trajectories of inclusions were calculated using the equations of motion for inclusions. Parametric studies were carried out to evaluate the effect of various parameters such as current density, channel diameter and particle density on the removal efficiency of inclusions from magnesium melts.

Jan 1, 2004

By M. Y. Williams

Introduction During the economic investigation of Pacific Great Eastern Railway subsidy lands, the P.G.E. Survey of Resources made a geological and mineral survey of a large part of the valley of the Peace river as included in the Province of British Columbia. The immediate valley of the Peace river was surveyed from the mountains to the Alberta boundary; the valley of the Pine river was surveyed throughout; and the Dominion block, 70 miles square and lying astride the Peace river, westward from the Alberta boundary, was very carefully surveyed. The writer was in general charge of the field work, and spent half the field season of 1929 and the field season of 1930 in the region . J. B. Bocock, however, did the major part of the work, spending two seasons, 1929 and 1930, in the area. General Conclusions The rock formations within the area discussed are all sedimentary and range in age from pre-Cambrian to recent. As might be expected, the minerals are in the main non-metallic, coal being by far the most important. Favourable conditions exist for natural gas occurrence, and suitable structures for petroleum concentration occur, although the high carbon ratio of the coals sheds considerable doubt upon the actual occurrence of oil in the area. Materials of minor interest are ochre, calcareous tufa, marl, limonite, gravel, and building stone.

Jan 1, 1934

By G. R. Guillet

Salt is restricted to five major beds in south western Ontario, totalling as much as 200 m in thickness. These beds are located at depths ranging from 270 m to 750 m below the surface, fringing Lake Huron and the Detroit River from Windsor to Kincardine, and extending inland as far as London. Manitoulin Island, the Bruce Peninsula and the north part of the Niagara Escarpment form the northeastern rim of the Michigan Basin, a major structural depression in which the salt was deposited 400 million years ago when much of North America was covered by the Silurian sea. Salt is mined underground at Windsor and Goderich; it is also brought to surface as brine through deep wells at Windsor, Samia and Goderich. Artificially- created caverns in salt beds are extensively used for storage of liquid hydrocarbons at Windsor and Samia.

Jan 1, 1984

By J. W. Craig

CHROME ore, which is used in Canada in the production of ferro-alloys, in a variety of refractories, and indirectly in many chemical industries, is both commercially important and scientifically interesting. The sight of chromium metal is familiar to all of us in the home, the office, the automobile. Chromium is synonymous with armaments: it is understood to be one of several essential metals in tanks, which played an important role in the defeat of France in the spring of 1940. Chromium, in other forms, comes into our daily lives by way of paint and leather, of the familiar green ginger-ale and beer bottles, and more indirectly in every pound of steel produced in the .Dominion. Necessary to our civilization in peace and war, the ores of chromium occur in many corners of the earth. This paper attempts to describe the chemical constitution of chrome ores, their world distribution, and the various chrome products and their industrial applications in Canada.

Jan 1, 1940

By L. B. Tsymbulov, L. Sh. Tsemekhman, A. N. Golov

Gipronickel Institute, JS is developing a process of continuous converting of Nicontaining copper matte and concentrates resulting in the production of blister copper and fluid NiO-containing slag in a two-zone Vaniukov furnace. The process under development is an alternative for the existing technology of blister copper production in converters, the latter being characterized with insufficient sulphur utilization, low direct copper recovery and the production of inconvenient for further processing solid slag on the basis of NiO and NiFe20 4- The results of pilot testing on processing of copper concentrate obtained from high-grade matte (HGM) separation in the two-zone Vaniukov furnace with the hearth area of 11.4 m2 are presented.

Jan 1, 2007

By R. Bruce Graham

"For the purpose of this paper, the Chibougamau area is taken as lying between lats. 49°20’ and 50°10’ N;-longs. 73°45’ and 75°30’ W. It comprises an area of some 4,000 square miles and is centred 300 miles north of Montreal.The first recorded report of metal deposits in Chibougamau was that of James Richardson in 1870-71 (I). In 1903 discoveries of asbestos, copper, iron, and gold made by Peter McKenzie stimulated considerable activity in the district. By 1909 interest had become so marked that considerable pressure was brought to bear on the Quebec Government to build a rail-way into the region. It was finally decided to have an authoritative opinion on its economic possibilities, and the Chibougamau Commission was appointed for this purpose (2). They examined the district in 1910 and concluded that at that time a railway was not warranted. Nevertheless, the district continued to be prospected and from time to· time gold and copper discoveries were made. Thus the Merrill Island deposit was discovered in 1920, the Campbell Chibougamau Cedar Bay deposit in 1922, Obalski in 1928, Opemiska Copper in 1929, and Norbeau in 1930.Difficulty of transportation was a severe detriment to the development of the region. Consequently the Quebec Department of Mines completed a road into Chibougamau in 1949. Further activity was encouraged. The Chibougamau Explorers, Quebec Chibougamau Goldfields, and Kayrand deposits were found in 1950. ** The copper-siderite zones on Copper Cliff ground were found in 1952 and 1953. Opemiska Copper, Campbell Chibougamau Mines, and Chibougamau Explorers were encouraged to prepare for production following favourable exploration results."

Jan 1, 1949

By N. Saracoglu, J. P. Golightly, R. H. Wallis, J. J. Brummer

"In January 1974, the Minerals Division of Canadian Occidental Petroleum Ltd. made the strategic decision to add uranium to its active exploration commodities and through compilation studies selected northern Saskatchewan as the most attractive and cost-effective exploration area in Canada. In August 1974, 100 sq. miles were staked adjacent to Gulf Minerals' Rabbit Lake deposit and east of the Esso Minerals Midwest boulder train. Initial exploration was based on geologic models of the Rabbit Lake deposit.In the summer of 1975, surface surveys delineated radon anomalies which were drilled that winter and found to overlie anomalous concentrations of uranium in the regolith which forms the upper unit of the crystalline basement. Within the crystalline basement, one hole intersected graphite and pyrite with anomalous nickel-cobalt-arsenic. Geochemical and radiometric surveys followed in the summer of 1976. Drilling in the winter of 1977 intersected several zones of graphite and also anomalous, but uneconomic, uranium abundances. Also in 1977, Dahlkamp and Tan (1977) described the coincidence of graphite and uranium at Key Lake and ground EM surveys on CanadianOxy claims detected graphite conductors beneath 250 ft of Athabasca sandstone. Inco Limited joined the project in April 1977 as a 50% partner. The project area was then surveyed using the airborne INPUT EM method, which detected 84 miles of conductors, with associated graphitic metasediments. On the ground these were located with MaxMin surveys, and follow-up drilling located the ""Tent"" Lake uranium zone.In 1978, the Midwest and Dawn Lake discoveries were announced, 7 miles and 2 miles west of the Joint Venture (J.V.) claims; and, in part for this reason, the 1979 winter drilling was concentrated on the deeper west side of the property. Exploration hole 102-79 intersected altered and uraniferous rocks, but stepout holes were barren. Drill hole 153-79 tested an under-snow three-station radon anomaly east of hole 102-79 and intersected 33 feet of 7.51 % U3O8, confirming the disco very of the McClean North zone. The geophysical grid of the McClean North conductor system was extended and detailed a strong, continous conductor to the south, called McClean South. This was drilled in January 1980and hole 1004-80intersected 22 feet of 2.95% U3O8."

Jan 1, 1983

By J. Satur

In copper mineral processing, pyrite coexisting with copper sulfide minerals like chalcopyrite is separated by flotation as tailings and its oxidation in tailing dams causes the formation of acid mine drainage. This paper proposes carriermicroencapsulation (CME) as a new method for suppressing pyrite flotability, as well as its oxidation. In this method, an organic carrier combined with Ti is used to form a thin Ti02 layer on pyrite, which gives a hydrophilic property and acts as a protective coating against oxidation. To form the coating, a ground pyrite sample was treated with Ti-catechol complex solution under various conditions. Bubble pick-up experiments and flotation experiments showed that the treatment of pyrite with Ticatechol complex changed the hydrophobic nature of pyrite into hydrophilic even in the presence of xanthate as a flotation collector. Oxidation testing of the CME-treated pyrite by 0.02 kmol m-3 HN03 showed that Fe release was suppressed by the CME treatment with respect to the control. This is assumed to be due to the formation of Ti02 coating on the pyrite surface. The effect of CME treatment on chalcopyrite wettability is also discussed.

Jan 1, 2007

By I. I. Inculet, M. A. Bergougnou, J. D. Brown, R. M. Quigley, D. K. Faurschou

"Coal from Hat Creek, B. C., has been successfully beneficiated to remove ash while retaining calorific value by a dry electrostatic separation process using a fluidized bed for triboelectrification. Two samples of Hat Creek coal used in the beneficiation experiments have been characterized particularly with respect to their mineral and clay content. The calorific value recovery exceeds the simple dry coal recovery because of the heat lost in altering the clay minerals of the ash fraction during burning. Recoveries and ash contents of the beneficiated coal are comparable to recoveries by water washing, but the dry process avoids the potential water pollution problems.IntroductionProposals have been made which suggest an interim Canadian coal production target for the end of the century which will require a four- to fivefold increase over the 1977 production. This implies a nominal annual growth rate of about 6070 to achieve a production rate of 115 to 140 million tonnes/year. Whether or not this target is realistic, it is becoming increasingly evident that coal must be utilized more fully on a world-wide basis. The crisis in Iran has provided the latest stimulus to renewed interest in Canadian coals for domestic use and export.The emerging new era of coal utilization for fuel and chemical feedstock will not, however, generally tolerate the level of coal technology which prevailed prior to the availability of abundant cheap oil and natural gas. Economic, environmental and resource management considerations will necessitate, for example, the use of improved methods of beneficiating coal. Continued development and application of conventional processes, principally aqueous, involving heavy media and cyclones will solve many of the problems. However, less conventional processes may be preferable or necessary in certain applications."

Jan 1, 1980

By L. J. Han, Y. J. Zong, S. Y. Wen, J. J. Wei

"Stress strain curves characteristics, deformation and strength properties, and failure process and characteristics of sandstone samples under different stress states were analyzed through triaxial compression tests carried on using TAW-2000 microcomputer control electro-hydraulic servo rock triaxial test system. The experimental results reveal that peak strength, residual strength, elasticity modulus and deformation modulus increase linearly with confining pressure, and failure models transform from fragile failure under low confining pressure to ductility failure under high confining pressure. Macroscopic failure forms of samples under uniaxial compression was split failure paralleling to the axis of samples, while macroscopic failure forms under uniaxial compression was shear failure, the shear failure angle of which decreased linearly with confining pressure. There were significant volume dilatation properties in the loading process of sandstone under different confining pressure, and then based on acoustic emission damage and volumetric dilatation damage the damage evolution properties of samples were analyzed, and damage constitutive model were established, realizing the real-time quantitative evaluation of samples damage state in loading process. INTRODUCTIONDamage is a phenomenon that micro defects in material under monotonic loading or reloading will lead to progressive decrease of the cohesion and damage of volume units. Many scholars at home and abroad have carried out systematic researchers on damage evolution characteristics and constitutive model of rock, and have achieved a series of remarkable results in this field. Lu Y.D. (2004) studied the complete stress-strain curve’s characteristics of marble under triaxial compression, and established the bilinear elastic-linear strain softening-residual ideal plastic damage constitutive model. Ren J.X. (2001) studied the damage evolution laws of coal and rock mass by computerized tomography triaxial loading system, realizing the quantitative evaluation of damage state. Zhang Z.L. (2011) studied the deformation and failure mechanism of strong weathered sandstone by triaxial compression test, and analyzed the damage evolution processes and established the damage evolution equations based on the density method. Li X.J. (2012) studied the microscopic damage characteristics of siltstone under triaxial compression by scanning electron microscope and digital image technology, and analyzed the statistical distribution characteristics of cracks azimuth angle, length, width. Zhou J.W. (2012) studied the strength, deformation and fracture damage characteristics of sandstone by uniaxial cyclic loading and unloading tests, and defined damage variable based on linear damage mechanics theory and acoustic emission (AE). Cao W.G. (2006) established a new damage model and a statistical damage constitutive model of rock under specific confining pressure according to the force of damaged part and undamaged part in rock on the base of statistical damage theory. Li S.C. (2014) studied the damage evolution characteristics in the whole uniaxial compression process of sandstone by electrical resistivity and AE, and proposed a status qualitative criterion for rock damage."

Jan 1, 2015

By W. T. Irvine

"The Britannia ore deposits are approximately 20 miles north of Vancouver; and occur in a prominent ridge facing Howe sound. A large ironstained bluff first attracted the serious attention of early prospectors. This; upon investigation; proved to be the outcrop of a large copper orebody. The highest outcrops were 4; 300 feet above sea-level.The original discovery was made in 1888, but no real development took place until 1902. The first mining was done in what came to be known as the Jane orebody, and some production was obtained from this in 1905. Underground exploration led to the discovery of several other orebodies. The first main adit, the 1,050-foot level, was driven to tap the ore at an elevation of 3,300 feet above sea-level. During succeeding years, however, long adits were driven from points lower down on the mountain side. These, with connecting shafts, followed the ore to horizons well below sea-level. The lowest working has now reached to 880 feet below sea-level. The property has been in almost continuous operation since its original exploitation in 1905. Until the end of 1944, 732,414,420 pounds of copper and 261,125 ounces of gold had been produced from the mine."

Jan 1, 1954

By K. Hawboldt, J. E. Halfyard, C. Bottaro

The removal of sulfur from leach residues has been practised in the zinc industry using a combination of flotation and hot melt filtration. The process is highly dependent on the nature of the concentrate and the subsequent residue. When the mineral constituency of the residue alters, the process can encounter significant operational challenges. An alternate method of converting elemental sulfur to water-soluble polysulfides was applied to leach residue from Vale's nickel demonstration plant in Argentia, Newfoundland. Reaction parameters, sulfur purity and other key indicators are discussed as is the potential commercial application.

Jan 1, 2011

By J. Duriez, L. Scholtès, F. V. Donzé

"Fracture propagation process in brittle rock is investigated by means of numerical simulations performed with an adapted formulation of the discrete element method. The progressive failure mechanism is simulated through the breaking of the bonds making up the cohesion between the elements constituting the simulated medium. The use of appropriate contact laws associated to a near neighbor interaction feature provide the model the ability to reproduce fundamental characteristics of brittle rock behavior such as, for example, high values of the tensile to compressive strength ratio. Great attention is given to accurately describe the properties of the pre-existing joints or faults in the model. A specific joint model gives the possibility to define a tailor-made behavior of the discontinuity surfaces without suffering from discretization bias.Compression test simulations are performed on pre-flawed samples and compared to experimental results in order to validate the numerical approach for describing the initiation and propagation of fractures in brittle rock under mode I+II loading. It is shown that the crack mechanical parameters can greatly influence the fracturing pattern, in particular its frictional properties. Overall, the numerical simulations reproduce fairly well the failure patterns that are obtained experimentally.The discrete model is then used to study mode I+III loading to give an insight into fracturing problems occurring at the scale of the continental crust. The ability of the model to support mechanically the physical modelings performed with wet clay or sandbox is shown. As an example, the model is used to track the development of a twist crack system (wrench fault) through the nucleation and coalescence of microcracks."

Jan 1, 2015