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By Bruce Regensburg

As trucks become larger and larger, haul roads take on a more significant role in mining costs and economics. The School of Mining at the University of Alberta has compiled a design manual for haul roads using both empirical and theoretical information. One section of this manual deals with the economics of haul road construction. While many mines look only at the construction costs of haul roads, this paper looks at all associated parameters including construction costs, removal costs, timing, truck productivity and width implications. The authors demonstrate the method to determine the most appropriate quality of road for different road conditions and life spans.

May 1, 2001

By E. Eccleston, E. Gardner, F. Letarte, R. Schonewille

"In 2005, after nearly a decade of process development and feasibility work, the commercialization of the Falconbridge Nickel Smelting Technology (NST) began in earnest with the design and construction of a grassroots ferronickel plant at Koniambo Nickel in New Caledonia. The NST process was developed as an alternative to the conventional Rotary Kiln-Electric Furnace (RKEF) process for production of ferronickel from saprolitic nickel laterite ores. The NST process promised environmental and energy efficiency advantages over the conventional route. A key step of the NST process involves fluidized bed pre-reduction of calcined laterite ore using direct injection of pulverized coal as the reductant. Two parallel fluidized bed reduction roasters (FBRs) were installed at Koniambo Nickel, each designed for a maximum capacity of 4,200 MTPD of calcined nickel laterite ore. This paper describes the process development and scale-up of the fluidized bed pre-reduction process, the design challenges associated with the prototype commercial units, and the current status of the FBR operation at Konaimbo.INTRODUCTION In the mid-1990s, Falconbridge began to develop a new flowsheet for production of ferronickel from nickel laterite ores. The process that developed came to be known as the Falconbridge Nickel Smelting Technology (NST). The flowsheet, which is particularly appropriate for saprolitic ores, involves several major unit operations, including: drying in a hammer mill-flash dryer, calcination and preheating in a flash calciner, pre-reduction in a fluidized bed reactor, and smelting in a DC arc furnace to produce the ferronickel product. This paper focuses on the fluidized bed pre-reduction step of the process and provides an overview of the process chemistry, laboratory and pilot plant development work, scale-up and commercialization of the pre-reduction step, and the results obtained in the prototype commercial units."

Jan 1, 2017

By M. P. Davies

"Risk, the product of probability and consequence, is an integral part of mining. Whether evaluating exploration priorities, determining property acquisition potential, reviewing the components of an operating mine or assessing environmental/closure issues, the concept of minimizing risk is central to economic and technically appropriate decision making.Until recently, risk evaluations have tended toward a strongly mathematical basis. With this previous trend, it was essential to establish precise probability density functions to all assessed components or issues where often little information was available. The combined effect of the seemingly complex analyses with corresponding insufficient data often resulted in either a poorly executed risk evaluation or no evaluation whatsoever; either result not acceptable for optimal decision making. This paper presents a simple and practical procedure to carry out risk assessments for the mining industry. Although simplistic in nature, the power and usefulness of the technique is immense. The basis for the procedure involves combining deterministic assessments (often “gut feel”) with appropriate probabilistic descriptors. The resulting procedure, termed Potential Problem Analyses, or PPA, can be used anywhere an evaluation of risk will assist in optimizing technical and/or economic decisions. As will be shown, a key element of the PPA procedure is the multi-disciplinary input the framework allows which makes the method ideal for a teamwork approach to decision making."

Jan 1, 1997

By F. H. Samuel, J. E. Gruzleski, S. Valtierra, H. W. Doty, F. J. Tavitas-Medrano

319-type cast Al-Si-Cu-Mg alloys are commercially important due to their popular use in automotive applications. Artificial aging heat treatments are commonly performed in these alloys to achieve precipitation hardening and, therefore, improve their mechanical properties. The present work was carried out to investigate the effect of conventional (at a constant temperature, as specified by the standard T6 heat treatment regime), and non-conventional multi-temperature and interrupted aging cycles on the hardness, tensile and impact properties of two 319-type alloys (with and without Sr+ Mg additions). The results show that certain multi-temperature aging cycles have a more favourable effect in improving some mechanical properties than conventional cycles.

Jan 1, 2006

By S. R. McCutcheon

"The regional stratigraphy of the Lower Carboniferous Windsor Group in the Moncton Subbasin indicates that evaporites could be present in the Marysville Subbasin, part of what was formerly called the Central New Brunswick Platform. The Windsor Group consists of basement-fringing, algal build-ups (Gays River Formation), in places with intercalated siliciclastics (Parleeville), which are laterally equivalent to deeper-water, very thin to thinly bedded, euxinic limestone (Macumber). The Macumber is overlain by stratiform, nodular to mosaic anhydrite (Upperton) that is hosted by carbonate or calcareous siliciclastics. The sulphate also is equivalent, in part, to the algal buildups. Deep-water salts (Cassidy Lake) which overlie and in places are laterally equivalent to Upperton rocks have a basincentre distribution. The Windsor Group is overlain by shallow water evaporites and mudstones (Clover Hill) or by greenish grey mudstone (""transitional beds""). The paleogeographic distribution of these rocks provide important clues that help predict where deposits of salt and potash can occur.IntroductionCurrently there are three known potash deposits in southern New Brunswick (2, 3 and 4, in Fig. I). All three deposits occur in the Windsor Group of the Moncton Subbasin, but until recently their exact stratigraphic position within the group was not known.The Windsor Group is a cyclic sequence of carbonates, evaporites and red beds that is up to 1.0 km in thickness (Schenk 1969, p. 1038). It is Late Mississippian (Visean) in age and the type area is near Windsor, Nova Scotia. The group was named by Dawson (1873) but the rocks were described earlier by Hartt (1867). Dawson (ibid.) was the first to assign rocks in southern New Brunswick to the Windsor Group."

Jan 1, 1983

By R. V. Fox, L. K. Sinclair, D. L. Baek

"In this study, rare earth elements were recovered from bastnasite concentrate and waste fluorescent lamp phosphors using supercritical carbon dioxide extraction with a nitric acid/tributyl phosphate adduct. Several pretreatment methods were used to alter the crystal structure of the source materials, and thus improve rare earth element recovery. Pretreatment methods included 1) dry roasting of the source material at 730oC, 2) decomposition with 50% sodium hydroxide solution at 150oC for 4 hours, and 3) decomposition with 12 M sulfuric acid at 300oC for 4 hours. Treated and untreated samples underwent supercritical extraction at 24 MPa and 65oC for 1 hour. Untreated bastnasite and phosphor samples showed <10% rare earth element recovery, but sodium hydroxide digestion resulted in >60% recovery for most rare earth elements. Dry roasting of the bastnasite concentrate was also effective, resulting in >60% recovery for cerium.INTRODUCTIONRare earth elements (REEs) consist of the 15 lanthanides, scandium, and yttrium. Scandium and yttrium are included because they are in the same group as lanthanum, appear in many of the same ore deposits as the rest of the lanthanides, and exhibit many similar chemical properties. REEs are used in a wide array of applications including electronics, magnets, catalysts, glass, and solid-state lighting (Xie, Zhang, Dreisinger, & Doyle, 2014). Because of China’s continued dominance of worldwide REE production, the United States Department of Energy has sought to diversify domestic supplies of REEs (United States Department of Energy, 2011). A key part of this strategy is the development of improved extraction methods for both ores and recycled sources.Supercritical fluid extraction (SFE) is a promising technology for extraction and separation of rare earth elements. Contact with an acid adduct dissolved in supercritical carbon dioxide allows for the rapid extraction of REEs from solid matrices. Supercritical CO2 has several potentially useful properties as a solvent, including high diffusivity and the ability to tune solvation properties by adjusting pressure. Such tunability may have applications in separating the REEs once they have been extracted from the solid phase. Tributyl phosphate/nitric acid adducts (TBP:HNO3) are a particularly promising class of adducts for SFE extraction of rare earth elements. Using TBP:HNO3 adducts in supercritical CO2, several researchers have successfully extracted REEs from their oxides (Wuhua, Pijia, & Yongjun, 2010; Zhu, Duan, Xu, & Zhu, 2009). However, there is a complication in applying this technique to many types of ores and recycled sources: REEs are often locked in refractory minerals which are resistant to acid attack, resulting in limited recovery in supercritical extraction."

Jan 1, 2016

By Jae-sang Ahn

As the amount of construction information used in the growing construction field increases, the importance of efficient construction field management has been growing. Therefore, construction industry have been tried to introduce and conjugate various software and IT technology such as PMIS, Web Camera, RFID, GPS, PDA. However, existing IT technology especially PMIS have not been performed systematically because of difficulty of real time information collection and decision-making from the insufficient handy equipment. These problems make construction manager cannot efficiently respond to diverse condition occur in construction sites. In addition, after the completion, individual who use PMIS have to move another site and use another system so than cannot use information from previous sites. On the other hand, development of IT technology transmute PDA phone for text-based work like schedule management, internet research to smart phone for network based multimedia service. In other words, smart phone is not just IT equipment but new way for overall industry and it can satisfy the demand IT technology on construction sites. Therefore, the purpose of this study is introduce mobile based individual unit PMIS system using cloud computing and SNS which is in development progress. It is expected to be possible to collect and record the real-time information that occur at the site and make rapid decisions based on the recorded information, by converting the office works that are managed based on the site PC or Web, if the site management system that is based on the smart phones and Cloud computing that will be constructed through this research are utilized. After this study, it is necessary to research about interwork with project unit PMIS system and test on real construction site.

Aug 1, 2013

By Tom Shumka

INTRODUCTION ?The Electro-Magnetic Crack Detection (EMCD) technique is an electromagnetic inspection method used for detecting and sizing surface breaking flaws. ?It works well on structural material or welds, ferrous or non-ferrous metals. ?EMCD?s rapid scanning is achieved using a hand-held probe. ?EMCD provides reliable crack detection and sizing (length and depth). Cracks can be sized accurately. ?EMCD dramatically reduces most cleaning requirements as there is no need to clean to bare metal. ?EMCD is capable of inspection through thin metallic coatings, or through non-conducting coatings up to 10mm thick. ?EMCD allows full data storage for back-up, off-line view and audit purposes.

Oct 1, 2010

By C. D. Smith

Numerous studies have shown the potential of air rate profiling to significantly improve the flotation performance of a bank of cells. To date many profiles have been implemented; balanced, increasing, decreasing and combinations of these. Previous work has typically shown using an increasing air rate profile, where the air rates are increased proportionally to each cell down the bank, yields a higher grade for a given recovery compared to other profiles. Air rate profiling can then be thought of as having two distinct components; determining the correct distribution of a given volume of air and, perhaps more importantly determining the correct total volume of air to add to the bank. To date no method for this second component has been established. In an alternative technique the air rate to each cell is adjusted in order to optimise the air recovery from that cell. Air recovery is the fraction of the inlet air which overflows the weir of a cell as unburst bubbles. The peak in air recovery (PAR) is a robust measurement that indicates optimal performance for the operating conditions in the cell, and sets the PAR air rate. By doing this for each cell in the bank, the optimal total air rate to the bank and the optimal distribution of that air can be simultaneously determined. In this study plant trials evaluated different air rate profiles, and profiling based on PAR. The total air rates to the bank for all profiles tested were approximately equal, allowing direct comparison. The results showed that the highest cumulative mineral recovery was achieved by operating at air rates which gave the PAR for each cell down the bank. Different distributions of the same total air rate to the bank gave the same cumulative upgrade ratio, but lower cumulative recoveries. In this study, the increase in cumulative mineral recovery, at the same upgrade ratio, was more than 33%. Peak in air recovery (PAR) based optimisation of air rates to banks of cells and to the individual cells has been shown to significantly improve flotation performance as it simultaneously determines the optimal air rate to the bank, and the optimal distribution of that air.

Jan 1, 2009

By Richardson A. H.

"IntroductionSafety and training in the mineral industry will always be issues that are hotly debated and discussed.The nature of the mining industry, where people and equipment work in close quarters deep below the earth's surface, attracts a great deal of public attention and concern, especially in the areas of safety and related training activities. This concern has been carried over into the mineral processingsector which is, of course, a vital part of the mining industry.It is therefore imperative that mining people closely examine the policies, procedures and programs presently in place to determine if they meet the needs of the industry and its employees. Everyone stands to benefit: the companies, employees and the mineral industry as an important segment of the Canadian economy.Phrases such as ""Safety First"", ""Safety is Number One"", have a role to play in industrial safety programs but in reality are a shallow approach to the magnitude of the challenge. An industry must produce its products in a cost-effective way, with good employee relations. None of these objectives can be successfully achieved unless accompanied by good safety performance. Accidents both on and off the job result in very poor efficiency, high costs and poor employee relations.This chapter, Safety and Training, outlines those major areas that the author believes are necessary components for an industrial safety, health and training program, but are not all inclusive. More will surely be added as additional problem areas requiring attention are identified. The major sections discussed are: Development and Implementation of a Safety Program; Occupational Health; Training; and Audit Procedures.The author has drawn on his experience as both a mill superintendent, mine manager and superintendent of safety, health and training. The approach developed at loco Metals Manitoba Division is frequently used in this paper with examples and excerpts to better illustrate the subject, but does not represent the full scope of programs in place in the Division."

Jan 1, 1989

By H. W. Fleming

In 1955, the results of a regional, geological interpretation of the northern portion of New Brunswick were used as a basis for selecting, for intensive exploration, three areas in which structural and stratigraphic conditions were believed to be favourable. Airborne electromagnetic work, in one of these areas, provided the justification for acquiring the Murray group. Even though the initial results were discouraging, this geological interpretation, combined with the fortuitous discovery of cop• per-bearing float, was sufficient reason for carrying out further work using geochemical methods. This work finally resulted in the discovery of the Murray massive-sulphide deposit, after about eighteen months of coordinated exploration on the property. While this deposit is a typical New Brunswick-type base-metal occurrence, extensive leaching has produced a fossil gossan that rendered it an elusive target for exploration techniques of limited penetration Full credit for localizing the target area is given to the geochemical techniques, but geophysical surveys were needed to provide the necessary

Jan 1, 1961

By C. Bourgoin

"The limited development and application of new technologies to narrow-vein mining is currently impeding progress in the industry to a point where productivity, working conditions and operating costs have reached a critical stage in many Canadian mines.In an effort to foster the emergence and application of new technologies, Université Laval, together with other organizations, has carried out a R&D project focussed on the need of identifying new development pos5ibilities and of facilitating the transfer of technology in matters related to underground mining methods and machinery.The first phase of the study consisted of an in-depth assessment of current practices and problems in narrow-vein mining. The second phase was a state-of-the-art survey of mining methods and equipment, together with proposed modifications and innovations. The third phase of the project concerns the experimental development as well as the principal application of various proposed technologies.This paper presents an overview of the organizational, technical and strategic considerations which guided the University group and it serves as well to introduce a newly-published brochure, entitled ""Underground Mining Techniques of Vein Deposits"", which summarizes such work to date. More specifically, a perspective of technological developments applicable to narrow-vein mining is presented."

Jan 1, 1994

By J. D. Galloway

The mining industry of British Columbia continues to grow steadily in importance. The gross value of the production in 1925, sixty-two and a half million dollars, was a record, and ali indications point to the 1926 output registering a still higher figure. In an industry such as mining, where production means the depletion of known ore reserves, the discovery and development of new &apos;ore-deposits is of the utmost importance. To maintain and increase production, steady development is essential. In this respect, the record of the last three years in British Columbia mining is most satisfactory, as in this period more real development has been carried on than in any similar period in the history of mining in the Province. Prospecting, or the search for new ore-bodies, has also been fairly active, but comparatively few important new discoveries have been reported in the past few years. The mineral output of British Columbia consists of Iode minerals, coat and coke, and building materials. In 1925 the value of the output of these three classes of products was, respectively, about 46, 13, and 3 million dollars. The industry as a whole embraces the mining of these materials, and the treatment and manufacturing processes involved in preparing the various products for the market.

Jan 1, 1926

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. Chung, W. Petruk, D. Doyle

"A series of tests was conducted on Carol Lake iron ore, which contains about 38 wt % hematite and 19 wt % magnetite, to establish a flowsheet for high weight yield by spirals. A pilot plant was run in parallel with the IOC concentrator to simultaneously test two flowsheets on the same feed material. The IOC concentrator processes the ore by treating it directly in a spiral circuit, whereas the pilot plant used a laconite flowsheet which had a low intensity magnetic separator (LIMS) at the front of the circuit. The LIMS produced a non-magnetic (hematite-rich) product and a magnetic (magnetite-rich) product prior to treating the ore in two separate spiral circuits. The results from about 150 tests were evaluated by chemical assays and materials balancing techniques, and a selected test was evaluated by the image analysis and materials balancing technique.The image analysis and materials balancing evaluation showed that a higher hematite recovery was obtained by the hematite spiral circuit than by the IOC concentrator spiral circuit, and a slightly lower magnetite recovery by the magnetite spiral circuit than by the IOC concentrator spiral circuit. Furthermore the hematite recovery by hematite spirals was higher than the magnetite recovery by magnetite spirals. The better hematite recovery was achieved because a higher liberation is obtained for hematite than for magnetite, and the hematite in the Carol Lake ore has a narrower grain size range than magnetite. Consequently, better spiral control can be maintained when processing a hematite-rich spiral feed, than when processing a magnetite-rich spiral feed. Since the feed to the IOC concentrator spiral is a mixture of hematite and magnetite, an intermediate hematite recovery is obtained by the IOC concentrator. INTRODUCTIONA study of characteristics that affect recoveries of hematite and magnetite from the Carol Lake ores of the Iron Ore Company of Canada (IOC), was carried out in connection with a project on designing a flowsheet for maximum weight yields. A pilot plant using a taconite flowsheet was run in parallel with the existing IOC concentrator which uses a classical iron ore flowsheet. About 150 tests were run to compare iron recoveries and weight yields by the spirals in the two flowsheets. Better iron recoveries were indicated for the taconite flowsheet, but the results were not consistent and the reasons for the observed differences were not apparent. The material from one test (Test 61), which gave better iron recoveries for the taconite flowsheet, was evaluated by the image analysis and materials balancing technique. A suite of samples was taken from 5 points in the IOC concentrator and from 8 points in a pilot plant (taconite flowsheet). The samples were analyzed to compare the behaviours of the Carol Lake hematite and magnetite in the spirals of the two flowsheets. The results provided a sound basis for further tests in designing a high weight yield flow sheet."

Jan 1, 1993

By A. C. Hitchins, C. N. Orssich

The Eagle zone is a gold-bearing, sheeted, quartz vein porphyry deposit hosted by the Cretaceous Dublin Gulch biotite granodiorite stock, located in central Yukon, 50 km north of Mayo. The deposit occurs at the western end of the stock and has been drill tested over a 1000 m by 500 m area, to a depth of 150m. Mineralization consists of 1 cm to 2 Cm wide, parallel, grey and white quartz veins with accessory gold, arsenopyrite, pyrite, pyrrhotite, chalcopyrite, native bismuth, bismuthinite, and scheelite. Vein densities range from two to fifteen veins per metre and average approximately five per metre. The majority of the veins have potassic and or phyllic alteration envelopes. Alteration of the granodiorite becomes pervasive as vein densities increase. Mineralization outside of the Eagle zone, but spatially related to the Dublin Gulch stock, includes: (i) scheelite bearing sheeted quartz vein zones within the east-central portion of the stock; (ii) a swarm of gold-bearing quartz-sulphide veins up to a metre wide in a zone along the northern contact of the stock and extending 7 km further west; (iii) the Mar scheelite skarn located on the south side of the stock; and (iv) cassiterite-bearing breccias located 2 km north of the stock. A geological potential resource of 64.5 Mt tonnes at a grade of 1.03 g/t Au has been estimated for the Eagle zone from widely spaced core and reverse circulation drill holes. Mineralization is open at depth, on strike to the west and beneath the hornfels to the north.

Jan 1, 1995

"These standards were developed by the CIM for use with the value or worth of a Mineral Property as opposed to “evaluation” where the key objective is an economic assessment or determination of the economic merit of a propertyP1 .0 BACKGROUNDPl.1 There are at present no comprehensive standards for valuation of Mineral Properties in the Canadian mining industry. The Mining Standards Task Force (MSTF) of the Toronto Stock Exchange and the Ontario Securities Commission in its Final Report (January 1999) specifically recommended that the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) form a committee of valuation practitioners to review and advise on approaches to valuation of Mineral Properties.Pl.2 On May 5, 1999 at the Calgary Annual General Meeting, CIM Council approved the formation of a Special Committee on Valuation of Mineral Properties (CIMV al) to be co-chaired by Keith Spence (Chairman of the CIM Mineral Economics Society) and Dr. William Roscoe (Roscoe Postle Associates Inc.).Pl.3 The mandate of CIMVal is to recommend Standards and Guidelines for Valuation of Mineral Properties to be used by the mining industry in general and to be adopted by Canadian securities regulators and Canadian stock exchanges.Pl.4 The members of CIMVal represent of a mix of professional disciplines and experience in the field of Mineral Property valuation:Keith N. Spence (Co-chair), Alliance Pacific Resources Inc., TorontoWilliam E. Roscoe (Co-chair), Roscoe Postle Associates Inc., TorontoMichael J. Bourassa (Secretary), Aird & Berlis LLP, TorontoChristopher R. Lattanzi, Micon International Limited, TorontoRoss D. Lawrence, Watts, Griffis and McOuat Limited, TorontoPaul E. Lunney, Noranda Inc., TorontoCraig A. Roberts, Pacific International Securities, VancouverDavid A. Scott, CIBC World Markets, TorontoIan S. Thompson, Derry, Michener, Booth & Wahl Consultants Ltd., VancouverWilloughby A. Trythall, retired Placer Dome executive and consultant, Vancouver"

Jan 1, 2003

By T. Joseph, E. Zheng, M. Curley

"Hydraulic transportation efficiency and production optimization are considerations in the surface extraction of Athabasca oil sand deposits. To reduce the dependence on haul trucks, it is possible to extend the hydraulic transport system to production faces using a mobile at-face slurry system (AFSS). The flexible arrangement of connected pipelines transports slurried minerals from the mining face to the processing plant. An experimentally verified mathematical model indicates the friction loss of oil sand slurry associated with the AFSS. Laboratory-scale testing enables extended analyses for examining pipeline slurry transport in an oil sands environment.RÉSUMÉ L’optimisation de l’efficacité du transport hydraulique et de la production sont des considérations importantes dans le domaine de l’exploitation à ciel ouvert des gisements de sables bitumineux de l’Athabasca. Afin de réduire la dépendance envers les camions de transport, on envisage d’étendre le système de transport hydraulique aux fronts de taille à l’aide d’un système mobile de transport des matériaux sous forme de boue à partir du front de taille (AFSS, de l’anglais at-face slurry system). L’organisation flexible des conduites reliées permet le transport de minéraux à l’état de boue du front d’exploitation jusqu’à l’usine de traitement. Un modèle mathématique vérifié de manière expérimentale indique la perte de charge par frottement des schlamms provenant du traitement des sables bitumineux associée à l’utilisation de l’AFSS. Des essais en laboratoire permettent de mener des analyses approfondies portant sur le transport de boues dans des conduites dans un environnement de sables bitumineux. INTRODUCTIONObjectives and scope of studyThe at-face slurry system (AFSS) concept has become a competitive means for materials handling to optimize haulage system efficiency and cost. The mobile and flexible arrangement of the AFSS introduces a unique set of hydraulic transport problems. This paper will focus on developing the mathematical models governing the friction and head losses within the AFSS concept.Background of the problemLarge-capacity shovels and dump trucks are increasingly used for excavation, loading, and hauling in the operation of surface mining. Production cost and efficiency optimization are demanded during the Athabasca oil sands (Alberta, Canada) mining process to secure North America’s energy supply. Increasing haulage distances, rugged terrain, and a constrained mine environment are conditions that will reduce the effectiveness of the shovel-truck haulage system (Frimpong, Szymanski, & Changirwa, 2003). In such conditions, the tire heat index and weight, distance, and time limits for truck haulage can be exceeded, simultaneously creating extreme tire wear and high maintenance costs. In addition to low production cost and equipment effectiveness, a mining environment also requires efficient waste-material recycling and distribution. Waste materials need to be recycled from the processing plant to a new destination such as a tailings dam, or replaced in mined-out areas such as backfill. The Athabasca oil sands configuration and location characteristics result in a mining environment that would benefit from flexible pipelines for constant production and an efficient waste-material recycling process."

Jan 1, 2017

By D. G. Tisdale, W. Curlook, J. M. Toguri

"In this study, the vapour phase reduction of titanium tetrachloride conforms to the traditional Kroll chemistry, but employs argon as an inert carrier gas and requires a higher reaction temperature of 1150°C to 1250°C. A vapour phase reaction is advantageous because titanium is the only condensed phase present, and the metal can be collected free of magnesium or magnesium chloride, in marked contrast to the titanium sponge produced by the conventional Kroll process. The yield of metallic titanium from the reaction was determined as magnesium additions ranged from 36% to 168% of the stoichiometric requirement. Yields of over 99% were obtained when an excess of magnesium was present. Although the collection efficiency was low, metallic titanium was collected at the reaction site, where all other species were present as vapours. Magnesium and chlorine concentrations in the collected titanium were less than 0.3%.IntroductionA proposed method (Curlook, 1987) for titanium production has been investigated as an alternative to the conventional Kroll process (Kroll, 1940). The advantages of the new process include a simplified means of recovering the product metal, and a potential for lower overall energy consumption and greater product purity. A higher reaction temperature for the reduction of titanium tetrachloride results in a vapour phase reaction, rather than the conventional liquid phase reaction. This is the major conceptual difference between the proposed and the established (Kroll) processes.This study focussed on optimization of the process chemistry and briefly examined the issue of product deposition and collection. The reduction of titanium tetrachloride with magnesium, to produce metallic titanium and gaseous magnesium chloride:"

Jan 1, 1997

By H. M. Lima, L. A. Gomiero, C. A. de Morais

ABSTRACT The Caetité-Brazil uranium facility produces approximately 400 tonnes U3O8 per year from an ore averaging 0.29% U3O8. The process steps are ore crushing, heap leaching with sulphuric acid, uranium separation and purification by solvent extraction (SX) with a tertiary amine, followed by stripping with a sodium chloride solution, precipitation as ammonium diuranate (ADU), and product drying. A change in the milling process is being evaluated to increase production and uranium recovery. Heap leaching will be replaced by conventional agitated tank leaching of the –590 µm ground ore slurry in a sulphuric acid medium. Replacement of the stripping reagent is also being considered.

Jan 1, 2012