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By D. J. Zuliani

A mass and energy balance for a modern electric arc furnace ("EAF") indicates that about 70% of the process energy losses are contained in the off-gas as chemical energy in the form of uncombusted CO and H2 and as thermal energy. Given the magnitude of the off-gas energy losses, improved EAF energy efficiency needs to focus first on controlling furnace practice to maximize "in-EAF" energy utilization and second, on recovering residual energy in the off-gas existing in the fume system. This paper focuses on the application of off-gas analyzers, sensors and process models to control and optimize "in-EAF" energy utilization efficiency. The paper will also discuss the application of heat recovery technology to EAF steelmaking.

Jan 1, 2015

By W. E. Oching, M. M. Ghomshei

Attracting and retaining workers in mining industry has become an uphill battle to many mining companies. As workers with significant experience retire, it is getting more difficult to attract not only new workers but also top talent to the mining industry to replace professionals exiting the workforce. To make matters worse, students’ enrolment in the post-secondary mining programs in Canada and USA is continuously declining year after year for reasons not directly linked to job market. This raises a question of how can the future needs of mining be met? This paper focuses on avenues for collaboration of industry and educational institutions to meet the current and future needs of mining. It provides effective approaches that mining institutes can engage with program advisory committees, role of the mining industry in supporting both faculty and students, how to harness the benefits of diverse workforce in the country and use of innovative technologies to attract young workers in mining. This work presents Human Resources (HR) professionals with tools that they can use to hire and retain skilled workers with strong interest to work in the mining industry. It also provides HR professionals with an opportunity to re-evaluate their restructuring practices during economic downturns as they reduce number of employees on temporary or permanent basis. The paper stresses the need of working together of the mining stakeholders including mining industry, academic institutions, First Nations’ communities and provincial(state) and federal governments to meet the current and future demands of mining as the industry experiences shortage of labour and low students’ enrolment in post-secondary mining programs. It is shown that mining educational institutes can enhance their programs and recruitments through establishing a better communication with all stakeholders. This communication can be facilitated by creating a national advisory board, to work with all mining programs at the national level for sustainable mining.

Jan 1, 2023

By G. B. Hudson

Previous papers (1, 2) pertaining to the treatment of uranium-bearing ores were concerned with the flotation of the radioactive minerals. In this investigation, the application of flotation to the removal of acid-consuming minerals from uranium ores was considered. Two pitchblende-bearing ores, which, because of the presence if dolomite were abnormally high acid consumers, were studied. In both in-stances commercial reagents of widely varying fatty acid composition proved satisfactory as flotation col-lectors, particularly at a pH of 10.5, for the carbonate minerals. From an economic viewpoint, however, Neo-Fat 42-12 was favoured. A mixture of sodium tripolyphosphate and citric acid was an effective depressant for the pitchblende in the ores. The tailings remaining after the removal of the dolomite by flotation contained, in one case, 88.5 per cent of the uranium in the original sample, and, in the other, 93.8 per cent. Analyses conducted on these tailings and on the original ores showed that

Jan 1, 1963

By Jun Xiao, Xiaodong Li, Chunming He, Daixiong Chen

"Benzohydroxamic acid with double dentate can react with copper to form cyclic hydroxyl oxime acid copper chelate, indicating a good selectivity for copper oxide minerals flotation, especially for malachite. The flotation results of the pure malachite mineral show a strong synergistic collecting effect between hydroximic acid and xanthate at a ratio of 3.5:1, achieving a malachite recovery of 95.5% when certain sodium sulphide is used as a sulphidizing agent in the optimal pH range. Thanks to the synergistic collecting effect, the flotation recovery of malachite of a real refractory ore flotation ,can reach over 92% under the optimum condition, a 12% higher than the recovery achieved with the conventional collectors. In industrial application, the flotation of the copper oxide minerals is improved , leading to a high efficiency utilization of copper oxide resources.INTRODUCTIONBeneficiation of copper oxide ore is one of the recognized challenges in mineral processing industry. Copper oxide ore is a vital component of copper resource in the world, which has abundant reserves. Majority of sulphide deposits has oxidized zone on the top, and some deposits are oxidized to become the large and medium-sized oxide deposits (Willam & Chavez, 2001). Most copper oxide ores have problems in processing such as high slime consumption, poor floatability, complex ore property and low flotation recovery, so it is of great significance in beneficiation of copper oxide ores to develop an efficient collector, especially for malachite (Fu & Gu, 1997; Wen, 2010; Riet, Kier & Elford, 1980). At present, sulphidization-xanthate flotation is the most important method for treating copper oxide ore. In recent years, due to the decreasing ore grade, the utilization of refractory copper oxide ore draws more and more attention (Zhou, 2003), except for sulphidization-xanthate method, chelating flotation method (Lu, 2009), chemical beneficiation method (Lenormed, Salman & Yoon, 1979), microwave radiation flotation method, hydrothermal sulphidization-flotation method (Mao, Wen & Fang, 2014) and ammonia leaching of sulphide precipitation-flotation method (Lekang, Stevik & Bomo, 2003) have occurred."

Jan 1, 2016

By Terence M. Gordon, Mati Raudsepp, Gregory M. Dipple

Four methods of measuring mineral abundance in a rock are examined for their potential in assaying for high-tech industrial minerals. One method uses X-ray powder-diffraction data and the other three rely on whole rock chemical data and information on mineral assemblages and mineral compositions. All four methods were employed to estimate wollastonite content in diamond drill core of skarn collected as part of an exploration program and are compared to visual estimates of wollastonite content from core logs. These techniques for assaying wollastonite span a considerable range ofaccuracy and expense, and combined, define a non-linear relationship between these variables. Accuracy increases rapidly relative lo expense up to total costs of about $50 per analysis. Assay methods in the $50-100 per analysis range have associated errors of 5-10% relative and probably suffice for most exploration programs. Improvements in accuracy above this level require a much larger investment. The most expensive assay technique (-$300 per analysis) yields the most accurate measurement of grade (relative error -1%). Its application may best be limited to periodic checks on other assay techniques and for fine-tuning ofmineral separation procedures.

Jan 1, 2001

By Fathi Habashi

"Hydrochloric acid (HCl), although more expensive than sulfuric, find uses as a leaching agent in reactions involving iron oxide. The reason for this substitution was the discovery that oxyhydrolysis of ferrous chloride by which HCl can be recycled economically. This avoided the pollution of the environment by ferrous sulfate. It was found further that the rate of leaching of sulfides is faster when HCl is used as compared with sulfuric apparently due to the formation of aqueous chlorine. In case of refractory gold ores, HCl leaching under pressure avoids the use of cyanide solution since gold chloride is produced which can be recovered by standard methods. Hydrochloric acid find also uses in the leaching of scheelite and apatite but its use in leaching clay and anorthosite is questionable.INTRODUCTION Sulfuric acid is the cheapest acid and is used as a leaching agent in many hydrometallurgical processes. However, hydrochloric acid (HCl), although more expensive since it is prepared by reaction of sulfuric with sodium chloride, has replaced sulfuric acid in many reactions involving iron oxide. It replaced sulfuric acid for the first time in 1960s in pickling of steel because of pollution problems (Habashi, 2000). Ferrous chloride produced in pickling can be economically decomposed to ferric oxide and HCl according to:2FeCl2 + 2H2O + 1/2O2 ? Fe2O3 + 4HCl (1)which also shows that the acid can be regenerated but ferrous sulfate cannot be economically decomposed to recover sulfuric acid for recycle. Since then, HCl has been used in many leaching processes. Hydrochloric acid is a corrosive acid and is usually handled in rubber-lined equipment. REGENERATION OF HYDROCHLORIC ACID Regeneration of HCl is conducted in fluidized bed or in spray roaster Fluidized bed oxyhydrolysis In a fluidized bed, ferrous chloride solution is introduced onto a bed of hot ferric oxide where heating is provided by the hot fluidizing combustion gases (Figure 1). The solution is fed on top of the bed of oxides. The liquid feed wets the outer layer of the hot oxide particles and is quickly evaporated to form a layer of new solid oxide on top of the existing oxide, thereby producing dense homogeneous particles."

Jan 1, 2017

By E. Ghali, W. Zhang, G. Gabra, N. Sorour, G. Houlachi

The additives polyacrylamide, 1-Butyl-3-methylimidazolium chloride, Tetra-butylammonium bromide, Benzalkonium chloride and chitin are evaluated during zinc electrolysis from synthetic acidic sulphate electrolyte containing Mn2+ ions, in absence and in presence of 0.0055 mg dm-3 of Sb3+ ions. Galvanostatic polarization tests for 2 hours at 50 mA cm-2 and 38oC were carried out to determine the cathodic and anodic potentials, and current efficiency of the deposited zinc. Potentiodynamic polarization and cyclic voltammetry tests have also been employed to study the electrochemical behavior of each additive on the zinc deposit on aluminum electrode. Results showed that, in presence of Sb3+, adding 1 to 3 mg of 1-Butyl-3-methylimidazolium chloride increases the cell voltage by ˜0-7 mV. Current efficiency is increased by ˜4.90-6.40%; power consumption is reduced by ˜147-173 kWh t-1 by adding 1-3 mg, respectively. However, in absence of Sb3+, cell voltage is decreased by ˜7-28 mV, current efficiency is increased by ˜0.70-1.50%; power consumption is reduced by ˜41-47 kWh t-1 by adding 1-3 mg. The effect of the other additives on cell voltage, current efficiency, lead content and morphology of zinc deposit has also been examined. Surface morphology and crystallographic orientation of the deposit was studied using scanning electron microscopic (SEM) and X-ray diffraction (XRD), respectively. The content of lead in the deposit has also been measured using inductively coupled plasma spectroscopy (ICP).

Jan 1, 2015

By C. Hunt, J. Vivas, D. M. Allen

"In this paper we present the results of a combined remote sensing - numerical modelling study to improve our understanding of groundwater seepage in open pit and natural rock slopes, and to investigate the interaction between groundwater, in-situ stress conditions and brittle fracture. The location of seepage is a key element in the characterisation of rock slope stability in open pits and natural slopes; definition of the fracture network geometry and its inter-relationship with seepage, however, remains a challenge in engineering practice. Current techniques used to characterize groundwater seepage locations require direct access to the rock slope for a detailed and exhaustive investigation, and can be severely limited due to access and the limited coverage of the survey methods both with respect to the height and length of the sampled rock slope. Herein, we describe remote sensing methods, which allow the collection of structural and seepage information over a wide spatial area. Remote sensing techniques are shown to have the potential to provide additional insights into the orientation and general connectivity of fractures that may play a major role in the general stability of a rock slope. A preliminary methodology for the use of remote sensing in the characterization of seepage zones in a natural slope through the application of ground-based LiDAR and Infrared Thermography (IRT) is presented.One of the most challenging problems in rock slope engineering is the realistic simulation of fluid flow through fractured and deforming rock slopes. Deformation and the development of brittle fractures can cause significant local changes in the permeability and strength of the rock mass, potentially affecting rock slope performance. Understanding fluid flow through fractured and deforming rock slopes, especially in highly-stressed environments is of great importance for slope stability analysis. Changes in the interconnectivity of fractures during slope failure are an important, yet are relatively unstudied in rock slope engineering. We present the results of hydromechanical UDEC-Trigon rock slope models focussing on the potential role of brittle fracture in rock slope failure, its interaction with groundwater pressures, and the influence of the assumed in-situ stress ratio. Damage intensity parameters are used to characterize damage within different regions of a biplanar slope failure."

Jan 1, 2015

By Sunil S. Gandhi

Magmatic-hydrothermal deposits rich in magnetite and/or hematite form a broad group that includes monometallic Fe deposits and polymetallic (mainly Cu and Au) deposits. They show a considerable variation in deposit characteristics, but share the genetic processes of magmatic differentiation and related hydrothermal activity in intermediate to felsic melts, and in some cases involve brines and/or meteoric waters during mineralization. They include several world-class deposits. They range in age from Proterozoic to Recent, and form important metallogenic districts in Scandinavian, Canadian, Brazilian and Australian Shields, Circum-Pacific regions, and in China, Iran and Turkey. Monometallic deposits have been important sources of iron in the past and still contain significant resources of the metal, e.g., the Kiirunavaara deposit in Sweden. The giant Olympic Dam Cu-Au-Ag-U-REE deposit was discovered in 1975, and since then explorationists have focussed on search for analogues worldwide. This has brought to light a number of economically important new deposits and prospects, including examples in Canada. The discoveries have in turn prompted considerable research on individual deposits and the group as a whole. This short paper is an attempt to summarize the main aspects of the group from the literature cited in Gandhi and Bell (1996), and from the papers published recently in two milestone volumes on these deposits, edited by Porter (2000 and 2002).

May 1, 2003

By M. Hardy

"The structural design of mine headframes is challenging due to the significant differences in the geometry, rigidity, and behaviour of these structures compared to conventional buildings. The differences are related to the main purpose of these structures, which is not human occupancy, but rather the support of hoisting equipment. The main objective of this paper is to present the seismic elastic behaviour of headframe structures in comparison with conventional buildings, which is the base case for the definition of seismic loads. This paper highlights the impact of backlegs on the dynamic behaviour of mine headframes, more specifically the resulting torsional sensitivity. INTRODUCTION The design of industrial structures is often governed by industrial processes rather than by architectural constraints. In ground-mounted hoisting plants, the structural configuration of headframes must allow clearances around conveyances and ropes while resisting the lateral loads associated with the hoisting equipment. Typically, these structures use backlegs to withstand the lateral loads, which leads to highly irregular structures with unconventional dynamic behaviour. The codes and standards applicable to the structural design of mine headframes in Canada are often incomplete or not adapted to the reality of practising engineers. This situation creates confusion, and engineers must look at various guidelines and international standards to support the engineering calculations required for the design of these structures. The loads resulting from the support of hoisting equipment, such as ropes and conveyances, are usually simple to calculate and are determined based on the information from manufacturer and industry related guidelines. Moreover, the loads associated with snow accumulation and wind are calculated applying the same methodology used for conventional buildings, without any major issues. On the other hand, the seismic loads are often difficult to calculate based on the methodology from the National Building Code of Canada due to the significant differences in the dynamic behaviour of the structures. The resulting structures may be either over-designed or worse, under-designed. Hence, there is a lack of uniformity in engineers’ designs. The latest edition of CSA S16-14 “Design of steel structures” includes Annex M (Informative) “Seismic design of industrial steel structures” to help designers close the gap between the requirements of traditional regulations and actual engineering practice."

Jan 1, 2019

By L. C. So, S. Faucher, S. Mostaghel, D. Sauter, S. -Y. Oh, S. K. Lee

"Molten material from pyrometallurgical furnaces is tapped at high temperature, carrying a large amount of heat. Traditional handling methods of slow air cooling or water granulation do not allow for the recovery of heat from slag and matte. Furthermore, water granulation adds an inherent safety risk of explosions. Recently, there have been numerous studies into processes attempting to recover waste heat. However, most of them have never been commercialized due to numerous challenges including scalability, cost, low heat recovery efficiencies, and difficulties in heat utilization. Ecomaister-Hatch has recently developed and commercialized a reliable and simple dry atomization system that allows for heat recovery while eliminating the use of water. Comparisons of pilot and commercialized dry atomization and heat recovery technologies will be presented and challenges of these technologies will be highlighted.INTRODUCTION Slag has traditionally been regarded as an undesired waste product from smelting operations with slag management focused on removal and disposal of “waste”. Over 500 million tonnes of slag are produced per year, carrying with it ~220 TWh of energy (Barati, Esfahani, & Utigard, 2011). Depending on the process, the energy content of slag ranges from 10-90% of the total energy input (Barati, 2011, Rodd, 2010). There has therefore been great interest in recovering energy from slag. Slag handling methods can broadly be classified into three categories: (1) dumping and slow cooling, (2) wet granulation and (3) dry granulation. As discussed below, only dry granulation routes are amenable to heat recovery. Slag dumping involves the slow cooling of molten material and crushing of the resulting solid. In this process, slag is dumped on the ground directly from furnaces or transferred to slag pots that are moved by rail or haulers and then dumped on the ground. The molten material is left to cool and solidify until it can be broken and handled by heavy machinery."

Jan 1, 2017

By Minghui Li

China is the largest coal producer in the world. In 2012, the coal production in China is 3.65billion tonnes, accounting for approximately 49% of global coal production. The raw coal production in 2012 was 3.8% more than the year 2011. 56% of total raw coal has been washed. The increase in raw coal production also promotes technology to be developed and brings separation capacity become larger and larger in coal processing in China. At present, over 40 extra-large scale coal preparation plants (each plant has capacity of more than 10 Mtpa) are in operation in China, the largest one is 32.5 Mtpa. Heavy medium separation are widely used in new built coal preparation, the washing limit for thermal coal feed lower and lower, the equipment selection tends larger which brings the whole washing system simplified, the local equipment developed and manufactured are more and more used. By discussing designs of several typical thermal coal preparation plants and coking coal preparation plants in China, this thesis introduces the current design of China?s extra-large coal preparation plants, and sums up the prevailing design features and trends of extra-large coal preparation plants.

Aug 1, 2013

By William Winsor, Harold L. Snyder

"AbstractShould oil and gas be proven in commercial quantities on the Labrador Shelf, current technology is not adequate for production operations in this severe environment, which includes yearly invasion of pack ice and icebergs. The fishery of this section of the North Atlantic is a vital resource to which a major oil spill or blow-out would impose an intolerable burden, This means that production systems must be designed and built to be fail-safe.The experiences of mining in Bell Island and Cape Breton have shown that it is possible to operate beneath the ocean floor, and this technology may hold the key for safe, reliable and economic production, This paper attempts to define particular problems and outline possible solutions.IntroductionOUR DISCUSSION is subject to the assumption that large hydrocarbon reservoirs will be discovered in the sedimentary basin of the Labrador continental margin. The petroleum industry has not attempted to operate in a harsher area. The Labrador coastline is exposed to North Atlantic storms and icebergs year’round, Arctic pack ice occurs up to six months of each year. However, there is no doubt that, if sufficient hydrocarbon potential is outlined, development will proceed."

Jan 1, 1977

By E. Rezazadeh Azar

Dump trucks are the main mean for hauling earth material within and outside of the construction and open-pit mining jobsites. The real-time monitoring of the material transportation trips is beneficial for proactive equipment management, volume estimation, and productivity measurement. The traditional manual observation is tedious, non-real-time, and expensive; therefore remote sensing technologies, namely GPS and RFID, have been employed for this reason. Ordinary construction videos are another costeffective alternative to monitor dirt loading and hauling operations in real-time. A vision-based system has been developed to recognize and count hauling trips. This system has three modules including object detection, tracking, and action recognition. This system processes videos taken from access roads in which it recognizes dump trucks and then tracks them throughout the viewfinder. The action recognition module is designed to reject false alarms and also terminate tracking. This way, the system is able to count the number of hauling trips and also record the time between each trip. Several state of the art computer vision algorithms were employed to develop this system. Some of these algorithms were modified using spatiotemporal information to minimize the inherent errors of the vision-based methods. The experimental results showed considerable performance of the system for practical application in the construction and mining sectors.

Aug 1, 2013

By Davood Moradkhani, Maryam Rasouli

"The present study reports solvent extraction and separation of zinc from concentrated nickel sulfate solution. In our previous study, Zn and Cd in cold filter cake (CFC, 45-55% Zn, 11-16% Cd, and 2.5-4% Ni) were extracted by alkaline leaching followed by electrowinning processes respectively. The strip solution from electrowinning process, was a pregnant liquor solution (PLS) containing 16.8 g/l Ni and 4.2 g/l Zn. In this work, PLS is subjected to the solvent extraction process for separation of traces of Zn from high grade nickel. The zinc free raffinate containing 16.6 g/l Ni sulfate solution will flow to nickel electrowinning plant for cathode production. Di-(2-ethylhexyl) phosphoric acid (D2EHPA) is the organic phase used in this study. The effects of various parameters such as organic phase concentration (10- 40 % v/v), pH (1.5-3), and temperature (25 and 45°) are investigated. Zinc over nickel separation factor increases by increasing pH from1.5 to 3. The results show that 98.7% of Zn was loaded at25°C O/A ratio of 1, pH 3, and 10% vol. D2EHPA. A 10 M NaOH is used for pH control. However, replacement of pH controlling agent with ammonia solution (25%. v/v) results in interesting observations. Ammonia addition, reduces the solubility of Ni2+ cations in solution. Nickel starts to precipitate from raffinate in a crystalline bluish-green form. The obtained crystals are characterized by XRF and identified to be nickel-bearing analog of boussingaultite, a rare sulfate mineral of nickel with chemical formula of Ni (NH4)2(SO4)2.6H2O. The crystallization rate of crystals is studied. It is a slow precipitation process with 75% in 4 days.INTRODUCTION Annually, many hydrometallurgical processes such as electrowinning, solvent extraction and leaching are applied to waste filter cakes in Zanjan, Iran. These additional processes on filter cakes are critical from both environmental and economic points of view. CFC (cold filter cake) is a toxic but valuable filter cake (45-55% Zn, 11-16% Cd, 2.5-4% Ni, and 0.2-1.5% Cu) produced in many zinc production plants. Our research group at Research and Engineering Company for Non-ferrous Metals (ReCo.), developed a series of hydrometallurgical methods for extraction of zinc, cadmium and nickel from CFC (Moradkhani, & Rasouli 2012). The recovery of zinc and cadmium with alkaline leaching and electrowinning was successfully studied. The strip sulfate solution from cadmium electrowinning unit, contains high concentration of nickel with some traces of zinc impurity. This pregnant liquor solution (PLS) was analyzed and reported to contain 16.8 g/l Ni and 4.2 g/l Zn. In this work, PLS is subjected to the solvent extraction process to separate Zn from nickel (Fig. 1). The organic phase stripping solution containing 4.2 g/l zinc and 200 ppm nickel can be circulated and used in the acidic leaching step. This generates nickel solution with high purity suitable for nickel cathode production."

Jan 1, 2017

By G. J. Biefer

"Fatigue and corrosion fatigue measurements were carried out on five commercially available metals -four steels and an aluminum alloy -which are used as structural materials in mine shaft conveyances. In the corrosion fatigue measurements, drain waters collected in the shafts of three different Canadian mines were used as corrodents. The mine waters had been selected on the basis of their relatively large differences in acidity and/ or composition.It was found that the corrosion fatigue strengths of the four steels were similar, despite their differences in tensile properties, and that the type of water used in the tests had little effect on the results. Mild steel showed the highest and most consistent values of the damage ratio (ratio between the corrosion fatigue and the plain fatigue strengths at 107 cycles). The corrosion fatigue behaviour of the aluminum alloy (ASTM Type 6061-T6) was found to differ markedly in the three mine waters. A high damage ratio (i.e., superior performance) was shown in a mine water in which the corrosion attack was uniform; much lower damage ratios were shown in waters which produced localized corrosion attack. Corrosion rates were too low to be deter-mined conveniently by conventional weight-loss methods, but calculations from polarization curves provided a rapid demonstration that corrosion rates were distinctly lower in the mine water which produced high damage ratios."

Jan 1, 1967

By K. A. Clark

SEPARATION of the oil from the bituminons sands of the Athabaska area of Alberta has been a subject of study by the Research Council of Alberta. The results of the study have been published in the Annual Reports of the Council. However, the last Annual Report in which there is mention of bituminons sand separation is that for 1934. The attention that is being directed toward the bituminons sands at the present time calls for an up-to-date summary of the work of the Research Council of Alberta on the hot-water separation process. STATEMENT OF FUNDAMENTALS OF HOT-WATER PROCESS Studies of the hot-water separation process have been largely empirical in nature. The objective sought has been a complete recovery of oil from the sand in the form of a separated oil which, itself, is free from mineral matter. Various procedures have been tried in the hope of attaining this objective and a very considerable mass of observations and background of experience have been acquired. lt is rime that a theory for hot-water separation should commence to emerge. As a start toward the formulation of such a theory, the statements which follow regarding the constitution of bituminons sand and its reactions with water and air are presented. It is not pretended that they are entirely correct, but it is believed that they lie not far from the truth. (1) Bituminons sand is an aggregate of sand, clay, oil, and water. The sand consists mainly of quartz particles of 100 ta 200 mesh size and smaller, but also of particles of other minerais including mica, rutile, ilmenite, tour-maline, zircon, spinel, garnet, pyrite, and lignite. Clay occurs interbedded with the bituminons sand, of which, also, it is a constituent. lronstone nodules of all sizes up to eight inches in diameter are likely to be present in the bituminons sand beds. The oil is viscous, naphthenic, and of a specific gravity slightly greater than that of water. The oil content ranges up to, and sometimes even exceeds, 17 per cent by weight. Rich bituminons sand from beds not invaded by water has a water content of 3 to 5 per cent by weight. The water is probably present as a film around the sand particles. The oil surrounds the moist sand grains as an envelope. (2) Water wets quartz and other siliceous minerals more readily than does mineral oil. Consequently, water tends to displace the oil film surrounding the quartz and other siliceous particles when the bituminons sand is mixed with water. Whether the oil is completely displaced depends on the properties of the water. That is to say, the materials dissolved or suspended in the water modify its wetting properties.

Jan 1, 1944

By Eiichi Sato, Koichi Kitazono, Hiroshi Masuda, Kenta Higane

"The present study investigated the low-temperature creep mechanisms in ultrafine-grained (UFG) aluminum manufactured by accumulative roll bonding. UFG aluminum with grain size 0.39 µm showed steady state creep even at room temperature under low stresses as confirmed by the creep curves in the strain rate–strain plot. The low-temperature behavior was divided into four regions by three distinctive stresses, sI, sII and sIII: sI (=45 MPa) is denoted as the micro-yielding stress with which dislocations start movement, sII (=85 MPa) the dislocation-multiplication stress above which dislocations multiply with creep deformation, and sIII (=171 MPa) the conventional yield stress above which macroscopic plastic strain is generated. During low-temperature creep, below sI, negligible plastic strain is generated. Between sI and sII, creep deformation with stress exponent 2.5 occurred, which is accommodated by dislocation absorption into grain boundary and grain boundary sliding, similarly to the low-temperature creep of HCP metals. Between sII and sIII, creep deformation with stress exponent 7.0 occurred, whose mechanism is similar to the low-temperature creep of coarse-grained aluminum. Above sIII, power-law breakdown occurred.INTRODUCTIONIt is well understood that the creep deformation brings about at high homologous temperatures (T/Tm) of >0.4, where Tmis the melting point, with diffusion processes. Recently, the importance of aluminum is increasing for cryogenic temperature parts such as a metallic liner or a cap in high pressure-hydrogen vessels, and the presence of creep behavior in aluminum at room temperature has become recognized (Matsunaga, 2013;Kassner, 2015).In HCP metals and alloys, especially intitanium, steady-state creep behavior appears at room temperature with apparent activation energy of1/10 of that for self-diffusion(Neeraj, 2000; Matsunaga, 2009).On the other hand, Kassner (2015) claims that aluminum shows creep behavior at room temperature with apparent activation energy of 4/5of that forself-diffusion, but never reaches the steady state. We should note that it is derived from the data obtained from short-term creep tests of few hour, and Matsunaga (2013) already claimed the presence of steady state in room temperature creep in aluminum with activation energy of 1/5of that for self-diffusion.The mechanisms for low temperature creep are considered different between HCP and FCC metals: in HCP metals, grain boundary sliding is observed and is thought to accommodate piled-up dislocations at grain boundaries through absorbing them. The so-called slip-induced grain boundary sliding occurs with low number of activated slip systems(Matsunaga,2009).On the other hand, in FCC metals, many activated slip systems bring about work hardening with dislocation cell structure formation. In the initial stage of creep, it results in primary creep (Kassner, 2015), but Matsunaga (2013) claimed that once the annihilating of a cross-slipped dislocation to another reaches balance, steady state is established. It has been, however, strongly required to show more convincing experimental verification for the presence of steady state in FCC metals at low temperature."

Jan 1, 2018

By Arthur Barnes, Mika Muinonen, M. J. Lavigne

"The carbothermic reduction of chromite ore to produce high carbon ferrochromium is among the most energy intensive metal extraction processes performed, due not only to the highly endothermic nature of the reduction reactions but also the very high operating temperatures required for the smelting operation to separate the chrome-containing alloy from the discard slag.KWG Resources and XPS have collaborated over the last 3 years in developing a patented (Winter) processing alternative to the traditional smelting operation in which all processing takes place in the solid state at temperatures many hundreds of degrees lower than those required for liquid processing. Amongst the attractions of the process are much lower capital costs, as well as reduced operating costs, particularly of energy.A techno-economic study on the new process identifies a reduction in overall energy consumption of 70% against conventional processing and approximately 40% lower than the current best practice. By utilising more natural gas than coal based energy sources, the KWG process is able to show an overall 50% reduction in greenhouse gas emissions compared with the most energy efficient current practice. The impact of the new process on future processing is therefore regarded as highly significant, with global energy reductions equivalent to the effect of completely eliminating energy demand from a country the size of Italy.The study concluded that the potential for this process to completely revolutionise the global ferrochrome industry should not be underestimated. Its impact reaches far beyond exploitation of a regional natural resource."

Jan 1, 2015

By D. S. Speakman

The copper-zinc orebody at Sherritt Gordon's Ruttan Mine occurs in a structurally complex area of the Rusty Lake greenstone belt in northern Manitoba. Problems in interpreting drill results indicated a large deviation, and the structural complexity an erratic deviation, of drill holes. This was confirmed when a surface hole was intersected 420 feet to the left of line on the 800 level. This problem acted as a catalyst in promoting a search for a suitable down-hole survey method. The instruments investigated included magnetic multishot and gyroscopic units as well as the ABEM Reflex-Fotobor. Only the Fotobor came close to meeting the company's needs of simplicity, reliability, accuracy and ownership. In this paper, the methods of operating this instrument, as well as the data extraction and reduction techniques, are described. Data on the accuracy and repeatability of the instrument are presented, and a tabular presentation of the results of surveying on 86 holes totalling 64,000 feet of drilling is made. Preliminary statements of the results of ongoing research on causes of hole deviation are presented and recommendations for minimizing deviation are given. The use of the survey device is recommended in areas of structural complexity, for very steep or backsight holes and where expected ore intersections are missing.

Jan 1, 1978