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By A. Dolatmoradi

Nanocrystalline structure formations produced by severe plastic deformation in Fe-0.15C with initial ferritic-pearlitic and IF steel with ferritic microstructures have been studied through microstructural observation and microhardness measurements. It was found that the nanocrystalline region first forms near the surface of samples due to localized severe deformation. It was also observed that the nanocrystallization rate of Fe-0.15C and IF steels and the deformed layer thickness in these two materials are different with similar milling conditions. The crystallite size and structural evolution of the samples during milling was studied by employing XRD and SEM.

Jan 1, 2010

By C. Lapointe

"IntroductionTen years ago, when nuclear fission became practical, the element uranium, until then a not very desirable by-.product of the radium industry, became overnight the strategic material par excellence. One of the several important problems that had to be solved at that time was the rapid and precise determination of uranium in ores and concentrates.GeneralThe chemical analysis of uranium ores is a long and difficult business and is complicated by the presence in most ores of a large number of interfering elements. True, much progress has been made, during the past few years, toward simplification of the analytical methods, but the chemical determination still remains the job of a skilled operator. For this reason, the chemical method has been replaced, whenever possible, by a physical determination based on the measurement of the radiations emitted by the elements of the uranium family. There are several types of instruments suitable for these measurements, but of all the radiation detectors known to the physicist, such as ionization chambers, crystal detectors, scintillation, proportional counters, and the like, the Geiger-Mueller counters have proved to be the most satisfactory for routine determinations, because of their simplicity.The Geiger-Mueller counter is a very versatile instrument; it can be constructed to detect any type of radiation, corpuscular -0r electromagnetic. Here, however, we are interested in these counters because of their ability to detect the beta and the gamma radiations, both emitted by some members of the uranium family. The beta radiation is corpuscular, and is composed of fast electrons, while the gamma radiation is electromagnetic."

Jan 1, 1950

By T. Robson

"A multi-seam underground mining operation employing mechanized room-and-pillar methods provides 35 per cent of Smoky River's annual ROM coal production (2 million tonnes) from the Smoky River coal field. Surface mines provide the balance. Tectonic activity, which has resulted in deformed coal seams and a rugged relief to the area, has provided natural boundaries to discrete mining areas. Coal transportation to the central preparation plant incorporates a 3 km long underground conveying system. The company is committed to efficient resource recovery and a safe and healthy working environment. Introduction The Smoky River Coal operations (SRC) are centered in the Smoky River coal field located in west central Alberta, some 360 km west of Edmonton and 20 km from the Town of Grande Cache (Fig. 1). Combined mining operations produce 2 million tonnes per year run-of-mine coal from which 1.65 million tonnes of high quality, low volatile, coking coal are obtained. The underground mining operation, employing mechanized room-and-pillar methods, provides 35 per cent of SRC's annual ROM coal production (2 million tonnes). Surface mines provide the balance. Tectonic activity has resulted in deformed coal seams and a rugged relief in the area. This has provided natural boundaries to discrete mining areas. Background Exploration of the Smoky River coal field took place over four decades commencing in 1926. McIntyre Mines Limited (parent to Smoky River Coal Ltd.}, commenced development of the property in 1968 having secured a long-term contract for the delivery of coal to Japan. Production of underground coal at Smoky River commenced toward the end of 1969 and has been continuous on the property since that time. Originally, two underground mines were opened. Original planning envisaged the use of room-and-pillar techniques to develop blocks of coal for subsequent extraction by longwall retreat mining. Following initial development, two longwall units were established, the first in November 1970 in No. 5 Mine and the second in February 1971 in No. 2 Mine. Difficulties were experienced on both units, and production commitments could not be achieved. The longwalls were discontinued, and mechanized room-and-pillar was subsequently used for all underground mining."

Jan 1, 1985

By A. R. MacPherson

"This paper considers four aspects of autogenous grinding. Part 1 discusses statements on power efficiency of autogenous grinding compared to conventional crushing and grinding systems. It also demonstrates how high-power efficiency can be obtained from autogenous grinding systems. Part 2 considers a simple method of testing ores to determine the type of autogenous plant which can treat these ores on a commercial basis. A comparison of testing for simple small plants vs large plants or complex ores is included. Part 3 considers important aspects which have to be considered in proper design of an autogenous grinding system. Part 4 discusses problem ores and how they can be treated in an autogenous system. INTRODUCTIONAfter about 35 years of using autogenous grinding plants in the mining industry, it is perhaps time to review where we are with this, by now, relatively old development. Autogenous grinding in this paper means grinding run-of-mine ore by fully autogenous means or by using a ball charge to assist the grinding (semi-autogenous). Also, autogenous grinding can be eitherby dry or wet.The use of autogenous grinding in the fifties was making its slow start, and it was not until the sixties that more of the mining industry would consider its use . By the seventies, most builders of new plants would have considered autogenous grinding, whether they used it or not, in the final design.In the eighties, most large plants use autogenous mills and to reduce over-all operating costs, many older conventional plants are now looking and actually retrofitting these old plants with autogenous grinding mills.It is evident that many misconceptions concerning autogenous grinding are still current. Some come from improperly designed plants which result from poor test work. There are many considerations in the proper design of autogenous plants. Some ores have been found to give problems even in a well designed plant. These ore types are beginning to be classified and recognition in the test stage allows steps to be taken in the design so that these ores can be efficiently handled in autogenous grinding plants.Therefore, this paper will address the following aspects of autogenous grinding:1. Misconceptions regarding autogenous grinding.2. Testing of ores to ensure a well designed commercial plant.3. Important considerations in mill design.4. Difficult ores, their recognition and types of design to handle such ores."

Jan 1, 1989

By P. Radziszewski

Industrial practice in mineral processing shows that an important problem in understanding and monitoring in-mill parameters is due to the lack of fundamental knowledge and appropriate sensors. With the development and growing use of DEM charge motion simulators for mill optimisation and design, it is possible to describe the fundamentals of grinding mill behaviour, in improving the understanding of internal grinding mill dynamics and in developing solutions to industrial practice. The main challenge to bringing this DEM technology to the mill operator however was the need for substantial computing power and time. However, what about a simplified DEM charge motion model running in real-time? What about the use of sensor technologies to correct any possible drift in simulator prediction? Could such a technological system be used to predict mill performance and eventually be used for mill control and optimisation? Some of these questions are answered with the development of an "on-line" DEM charge motion simulator package (SAGTools?) along with that of a number of sensor technologies (liner wear, acoustic, instrumented ball) that can contribute to simulator precision. With the objective of bringing this modelling and sensor technology into the concentrator control room to assist operators, this paper aims to describe the main elements of this emerging and developing technology and discuss how it can lead to online mill performance prediction and eventual control.

Jan 1, 2007

By E. Burdukova

Long-chain primary amines are utilized as collectors in potash ore flotation. Krafft temperature of long-chain amines in brine is about 100 °C, and this makes such amines practically insoluble in brine at room temperature. When dodecylamine, melted at 70 °C and dispersed in hydrochloric acid (or acetic acid) aqueous solution, is added to a KCl-NaCl saturated brine at room temperature, the amine precipitates. The experimental results demonstrate that the precipitating amine hydrochloride particles are selectively abstracted by KCl particles, but not by NaCl particles.

Jan 1, 2009

By J. Dubinski

This paper describes the key circumstances of the underground coal gasification (UCG) process, which is planned to be carried out in the Polish hard coal mine ?Wieczorek?. The construction and field tests of a UCG pilot plant have key issues that need to be addressed to realize the research project goal: the elaboration of a highly effective technology of fuel and electricity production. The project will conduct several monthly tests of gasification in the pilot geo-reactor, which will be constructed based on the results of laboratory tests. The realization of the process requires numerous appropriately prepared actions adjusted to natural conditions in the hard coal deposit. Based on scientific principles, it is necessary to elaborate the procedures related to the location of the UCG installation (including its legal and safety aspects), and to perform a technical risk analysis. In addition, it is necessary to determine the required mining, geological, technical, economic and organizational circumstances, while at the same time considering the real but constantly changing process conditions.

Aug 1, 2013

By M. Wittke

"In the course of the extension of the railway network in Israel, currently the two 4.6 km long tubes of the Gilon Tunnels on the line from Akko to Carmiel are being constructed. The tunnels run through the limestones of the Bina- and Yirka-formations, which locally are karstified. The maximum overburden amounts to 160 m.The limestones are mostly horizontally bedded and vertically jointed. Occasionally also inclined joints exist. The tunnels cross various fault zones, which mostly strike at an acute angle to the tunnel axis and are steeply inclined. The karstic cavities which were encountered during tunneling have partially been filled by clay. In the vicinity of the fault zones, the rock has often been strongly jointed and weathered respectively. The two single-track tubes have a cross section with vertical walls and an open invert. The tubes are connected by cross cuts with a spacing of approx. 250 m.During the tender phase, WBI has elaborated the tender design for a joint venture of a Chinese and an Israeli construction company. After the joint venture had been awarded the contract, the preliminary and the detailed design have been elaborated by WBI and the construction works have been guided. On the basis of the geological description, rock mechanical models have been elaborated, followed by stability analyses on the basis of the Finite Element method. The tunnels have been excavated according to the shotcrete method. The support in most areas only consisted of a very thin shotcrete lining and radial bolts in the area of the roof. Depending on the degree of jointing and weathering, locally advancing support by means of spiles has been applied.The internal lining of reinforced concrete has been constructed in parallel to the heading of the tubes. Mucking and delivery of materials was carried out through the cross cuts.The breakthrough was achieved in April 2014 and thus within schedule. The predicted distribution of the excavation and support classes along the tunnel has been in good agreement with reality."

Jan 1, 2015

By Song (Bruce) Li

This paper presents a three-tier web-based GIS application that uses Java Server Page (JSP), Java Servlet and relational database to manage performance monitoring and reporting in the oil sands mining industry. It is a real-time Earth Structure Performance Monitoring System (ESPMS), which allows the user to record and store instrumentation monitoring readings as well as technical observations and instrumentation installation documentations into a complete relational database. The ESPMS introduces the advantages of precise field record keeping, due diligence, security, consistency and completeness while at the same time simplifying the task of reporting. ESPMS combines web-based Geographic Information System (GIS) mapping and data management to facilitate the collection, organization, retrieval, reporting and communication of the vast amounts of monitoring data related to mining and tailings engineering associated with site investigation and construction information. ESPMS utilizes web-based GIS technology to incorporate referenced aerial photographs, Energy, Mines and Resources (EMR) maps or AutoCAD drawings as a base map for the monitoring site. It dynamically creates and administers all instrumentation monitoring locations and reading frequencies. It enables the user to collect and manage the data associated with an unlimited number of reading events. It provides the designer with real-time monitoring data (what, why, when, how), thereby allowing them to make early adjustments to design protocols or procedures, or to take remedial action(s) regarding the subject earth structure under construction or after completion. It provides more cost-effective reporting and data sharing through the Internet. It improves security on data entry and eliminates unauthorized data changes. It allows better integration of graphics and illustrations with numerical data files. It is capable of managing the continually expanding workload resulting from new and larger structures in the oil sands or other mineral mining industries. The ESPMS facilitates easier data gathering for preparation of as-built and after-built or regulatory reports, etc. It enables quick location of the interested instruments and summarization of the performance of the instruments. It enables one to visualize performance data and QA/QC construction test results spatially on any given cross-section. Data can be exported to MS Excel for detailed analysis and to evaluate the stability of the earth structures.

May 1, 2004

By Ernest A. Hodgson

WHEN excavations are made, at depth, in hard brittle rock structures, as in certain mines in India, in South Africa, and in Ontario, the pressure due to overburden, together perhaps with inherent geologic strain, tends to become concentrated in the walls of some of these openings and the rock bursts, often closing the adjacent drifts and scopes and presenting a serious menace to the miners. Where the rock is much fractured and faulted, the danger is greater, since the pressures tend to shift without warning from point to point, sometimes within a few hours. Attempts have been repeatedly made to find some physical property of the rock which will change with pressure, which can be measured for rock 'in place' in the mine, and which will give an indication of the state of strain, thus warning of an approach to bursting conditions. Some of the properties tested have been the speed of propagation of elastic waves in the suspect rock, variations in temperature due to pressure changes, rate of closure of openings or shifts along fault planes, strain gauge measures, and others. Each of these has proved unsatisfactory for the purpose. The most promising method so far proposed has been the study of the very faint, sub-audible snaps (microseismims) which are produced in rocks under pressure. Such a study has been in progress at Lake Shore Mines since May, 1942. Instruments designed to pick up, amplify, and record the microseismims were perfected and a programme of observing, using the microseismic method, has been carried through with persistent diligence and at considerable expense. In 1943, experience with the method in a pillar section on the west side of the Lake Shore mine gave much promise of predicting bursts. A very heavy burst on January 29th of that year occurred in the exact section of the mine covered by the instruments, and the records indicated a measure of prediction. In response to repeated requests for information, a number of reports were given out, among others a radio talk by the writer over CJKL (Kirkland Lake), which was reported in full in the Northern News . Also, a detailed account of the occurrence was given in an illustrated paper by the writer (l).

Jan 1, 1945

By A. Abadías Llamas, N. Bartie, M. Stelter

Evaluating the economic viability as well as the sustainability of the Circular Economy (CE) system requires a deep understanding of the distribution of all elements, compounds, alloys, materials etc. in flows. In this paper, the circularity of the copper value chain, including primary and secondary processing, is rigorously evaluated. The studied system comprises the metallic copper production from primary sources (from mineral to metal), copper-containing commodity production (copper is mixed with other metals) and copper recycling through secondary smelting to close the loop. This is linked to photovoltaic (PV) panels and battery storage. A simulation model of this system is created using HSC Sim, considering more than 30 elements (and its various compounds), 180 unit operations and 800 flows. From the mass and energy balances obtained through the simulation, an exergy analysis is conducted to evaluate the resource consumption from a second law (entropy) perspective. Additionally, these results are complemented through a Life Cycle Assessment (LCA), the recovery of technology elements and by-products is discussed, while quantifying the losses through the value chain. Through the digitalization of the complete system, a better CAPEX and OPEX understanding of the metal recovery and losses can be obtained, as well as the associated resource consumption and environmental impacts. New flowsheets and technologies can be evaluated. Several scenarios show how the resource consumption and the environmental impacts are affected by the recovery of different materials to produce different products. INTRODUCTION A key challenge of the circular economy (CE) is the linkage and optimization of both resource and energy efficiency of the (renewable) energy infrastructure and the resource cycle depicted by Figure 1 simultaneously. In addition, the CE requires the linkage of all stakeholders as shown by Figure 1. This has been discussed in some detail by Reuter and Bartie (2019) and Reuter et al. (2019). Copper and all its associated technology elements is one of the key enabling metals that is an economical copper colored thread through CE society (Reuter & Kojo, 2014). The Metal Wheel (Figure 2) shows the linkage of and recovery of various elements associated with copper and other carrier metals. This reveals that copper acts as an important carrier metal because of its properties i.e. the wealth of technology elements it carries from geological ores, but also its capacity to act as solvent of valuable elements and thence a key closer of various complexly connected element and material cycles when these technology elements are released during copper refining. The same applies to all other carrier metals of modern CE society as shown for example recently in a lead policy brief (Blanpain, Reuter & Malfliet, 2019).

Jan 1, 2019

By M. Choy, A. Kadiayi, E. Magdzinski

"Design of engineering controls to limit occupational noise exposure rely on accurate calculation inputs. Sound in mines can carry considerable distances. Mine ventilation engineers rely on noise propagation calculations to estimate silencer performance criteria for key mine fan installations that are often in proximity to occupied areas of a mine and can remain in service for decades. The blasted and rockbolted walls of hard rock mining tunnels have unique acoustical properties. Underground testing in an operating metal mine in Sudbury, Canada was performed and results processed to characterize noise propagation in mines, with the goal of improving the accuracy of noise calculations.INTRODUCTIONAs mine operators continue to improve and promote workplace safety, addressing noise at fixed infrastructure locations is observed as increasingly common. Underground fans are important to consider in this context, as they are typically loud, in proximity to occupied and sensitive workplaces, and operate nearly continuously. Predicting noise propagation from ventilation fans within underground mines has long been a challenge, with few available resources documenting acoustical properties as calculation inputs. Other factors in addition to rock face absorption properties include tunnel geometry and distance from the fan, which play critical roles in characterizing the noise level at any given point away from the fan. By understanding and establishing methods to better predict noise dissipation along underground mining tunnels, engineers can design noise controls with a greater degree of precision and confidence to effectively protect workers from over exposure to noise.This paper investigates classical methods of predicting reverberant room and direct field noise propagation. These prediction methods are then compared to noise measurements taken within the Fraser Mine of Glencore’s Sudbury Integrated Nickel Operations (Sudbury INO) Measurements were taken at a depth of ~881 m (2,889 ft), along an ~300 m (984 ft) long blasted hard rock mining tunnel. The noise along the mine tunnel resulted from the intakes of two 900 kW (1,200 hp) ventilation fans with a combined exhaust capacity of 300 m3/s (630,000 cfm)."

Jan 1, 2019

"“Developed by the CIM Sub-Committee, these guidelines are an addition to Guidelines Specific to Particular Commodities which are appended to the CIM Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines.Rock Hosted DiamondsJennifer Burgess, Consultant, Sechelt, BCNeil Buxton, WWW International Diamond Consultants Ltd.Darren Dyck, BHP Billiton Diamonds Inc., Kelowna, BCMartinus Oosterveld, (De Beers retired), Plettenberg Bay, South AfricaRichard Routledge, Scott Wilson Roscoe Postle Associates Inc., Toronto, ONMalcom Thurston, De Beers Canada, Toronto, ONPreambleDiamonds are produced commercially from intrusive rock, consisting of kimberlite and lamproite, and from alluvial and marine placer deposits. These guidelines apply to rock deposits; the term ""diamonds"" herein refers to natural diamonds; ""diamond deposits"" refers to diamonds hosted in kimberlite and lamproite rocks; and ""diamonds"" and ""stones"" are interchangeable.The CIM Best Practices General Guidelines for other commodities are also applicable to diamond deposits, however, because of diamond's distinguishing aspects, additional guidelines are appropriate as published in the CIM Guidelines for the Reporting of Diamond Exploration Results and these Best Practice Guidelines for estimating Mineral Resources and Mineral Reserves (MRMR).Diamonds differ from other minerals. Firstly, they occur as discrete particles in concentrations as low as parts per billion. Secondly, the release of diamonds from the kimberlite or lamproite host rock is a function of the excavation and treatment process. Thirdly, the value of diamonds varies from deposit to deposit and varies with stone size within a given deposit. These aspects must be considered when sampling, evaluating the resource and establishing the reserve of a depositThe product from metallic mineral mines is generally quite liquid in terms of number of potential buyers, and the commodity prices and price structure are published daily. In contrast, most diamonds are valued in the overall market context only 10 times a year in ""sights"" and the marketing of diamonds is dominated by a small number of organizations. Diamond valuation is more akin to industrial minerals valuation in that process recovery is important at the ""assay stage"", the impact on price of new goods arriving on the market must be evaluated, and product quality must be acceptable to potential buyers."

Jan 1, 2003

By L. Dufourm

This paper presents a review of plant layout considerations incorporated into recent designs of SAG/Ball mill circuits for two medium sized concentrators. The plant layouts presented and the design concepts discussed, relate to smaller SAG circuits, but can equally apply to larger milling circuits. Included are design concepts and ideas introduced by the various project teams, and the focus is on the primary factors of any layout design which are safety, constructability, operability, and capital cost.

Jan 1, 2012

By H. Helmstaedt, P. Thurston, R. Harrap

"Evolution of the continental lithosphere over Earth’s 4.6 billion year history is one of the fundamental questions of geoscience. Much of the Earth’s present-day continental crust formed during the first 2 billion years, the Archean eon, of the planet’s lifetime and thus, Archean processes of lithospheric formation must be studied in order to address this question. Until recently, the processes of Archean lithospheric evolution were thought to be fundamentally different from present-day plate tectonic processes. However, subsequent evidence suggests that the growth of Archean continents may be explained in terms of modern tectonic accretionary tectonics similar to those presently operating in the southwest Pacific region. The evidence supporting this hypothesis was compiled largely by Canadian geoscientists working in the Superior Province of the Canadian Shield in northwestern Ontario, over the past 15 years. Study of Archean rocks is also economically important because the Archean rocks of the world, although comprising only a relatively small fraction of the exposed continental crust, contain much of the world’s mineral wealth, including more than half of the world’s gold, as well as significant base metal reserves. Furthermore, the vast majority of primary economic diamond deposits are derived from the lithospheric roots beneath Archean cratons.The LITHOPROBE Western Superior Transect is located within the western part of the Superior Province in northwestern Ontario (Fig. 1). The Superior Province is the largest and best exposed Archean crustal block in the world and forms the nucleus of the North American continent. The internal structure of the Superior Province records a history of the processes that formed the earliest lithospheric elements of the Earth into cratons, thus providing an ideal laboratory for investigating early crustal evolution. The Western Superior Province is characterized by a regional pattern of alternating, 100 km to 200 km wide geological belts (Fig. 2). The observed geologic relationships between and within these subprovinces have been explained in terms of a modern tectonic model of terrane accretion. Oceanic floor, volcanic island arcs, oceanic sediments and continental fragments were accreted successively from north to south against the southern margin of a cratonic nucleus (North Caribou terrane, Fig. 2) which grew steadily in size with the arrival of new terranes through geologic time. If this model is correct, it suggests that the tectonic processes operating today have been active without major variation over the past 3 billion years."

Jan 1, 1998

By D. D. Campbell

"The Port Radium mine of Eldorado Mining and Refining Limited lies on the western tip of a large peninsula midway up the east shore of McTavish Arm, Great Bear Lake, about 30 miles south of the Arctic Circle. The mine is serviced by air, 950 miles from Edmonton, and by water, 1,380 miles from Waterways, Alberta.The veins were found, and the copper and cobalt minerals in them reported, by J. MacJntosh Bell of the Geological Survey of Canada in 1899. The veins were investigated by Gilbert Labine and E. C. St. Paul in 1930, and as a result of their work the Eldorado mine was brought into production in 1934. It produced silver and radium ores until 1940, at which time, as the silver orebodies had been mined out and the market for radium was negligible, it closed down. Early in World War II the need for uranium for the Manhattan Project was emphasized, and the mine was reopened in 1942. As a security measure Eldorado Mining and Refining was created a Crown company in 1944. The Port Radium mine has continued to be one of Canada's principal producers of pitchblende concentrates, and to date has about 25 miles of underground workings developed on fourteen levels.Regional GeologyThe general geology of the McTavish Arm area was mapped by D. F. Kidd in 1932 on a scale of one inch to four miles. A great deal of more detailed work has since been done by geologists of the Geological Survey and of Eldorado. The entire area at the end of McTavish Arm lies within the Precambrian Shield immediately east of its western margin. Most of the area is underlain by granitic masses which have intruded a sequence of late Precambrian sediments, volcanics, and hypabyssal intrusives. The pre-granite rocks now occur in extensive, irregular patches and pendants within the granite. Pitchblende deposits have been found in the district in all rock types, but the most favourable host rocks are the cherty sediments of the lower Echo Bay group."

Jan 1, 1949

By J. Groppo, W. Zhang, R. Honaker

"The flotation of monazite is depressed when using hydroxamic acid as a collector in the presence of calcium ions which may exist due to the dissolution of minerals such as calcite. Minor dosages of sodium hexametaphosphate (SHMP) were found to effectively depress calcite, whereas the flotation of monazite was not impaired in single mineral flotation tests. However, in a mixed mineral flotation system, monazite flotation was depressed significantly. The mechanism of hydroxamate adsorption on monazite and calcite, the depression mechanism of calcite on monazite, as well as the depression mechanism of SHMP on calcite and monazite were studied using micro-flotation, electro-kinetic, and adsorption tests. Findings indicate that the adsorption of hydroxamate on monazite was due to chemisorption while adsorption on calcite was a result of physical interaction. SHMP significantly increased the negative charges of calcite surfaces which depressed the adsorption of the hydroxamate anions on the calcite surfaces due to an elevated electrostatic repulsion force. When calcium-rich minerals such as calcite are mixed with monazite, the calcium ions dissolved from the mineral surfaces specifically adsorb onto the phosphate oxygen sites on the monazite mineral surfaces thereby causing depressing effects. The addition of SHMP to suppress collector adsorption on the calcite surfaces interacts with the calcium species that were specifically adsorbed onto the monazite surface, which prevents hydroxamic acid adsorption onto the rare earth oxygen sites due steric hindrance and results in the flotation depression of monazite. INTRODUCTIONAs one of the commercial rare earth ores, monazite has been widely exploited to produce additives for catalysts, batteries, alloys, etc. Because of the complexity and the fine nature of some monazite ores, methods such as gravity, magnetic, and electrostatic separation to treat beach sand monazite fail to produce satisfactory concentrates, suggesting the use of floatation is warranted (Cheng, Holtham, & Tran, 1993). The primary associated minerals of monazite ores include ilmenite, quartz, zircon, rutile, sillimanite (Dixit & Biswas, 1969; Pavez a& Peres, 1994, 1993). Using sodium oleate as collector for monazite has been reported in many studies (Cheng et al., 1993; Dixit & Biswas, 1969; Pavez & Peres, 1994, 1993). Several investigations have reported maximum floatability of monazite occurring at pH values between 8 and 9 (Cheng et al., 1993; Dixit & Biswas, 1969). A study conducted by Pavez and Peres (1994) compared the use of hydroxamate and sodium oleate for the treatment of a monazite ore and found that hydroxamate significantly improved the grade of rougher concentrate."

Jan 1, 2016

By D. R. Schmitt, N. Ong, R. S. Kofman

Shales and mudstones comprise about 75% of all the sedimentary rocks. In, particular, organic rich shales are considered as a petroleum source rock and more recently with the advent of hydraulic fracturing technology to be a reservoir in their own right. In this sense, the aforesaid motivates our work with laboratory measurements of elastic properties of these geologic materials, which are known to be anisotropic. As such, assuming Vertical Transverse Isotropy (VTI) symmetry, the dynamic and static moduli of a series of cores from various geological formations in Alberta, Canada are simultaneously investigated as a function of confining pressure using the ultrasonic pulse transmission method and strain gages. Dynamic moduli were obtained from ultrasonic P- and S-wave velocities measured on a prism cut with faces perpendicular, parallel and oblique to the assumed vertical axis of symmetry. Static moduli were calculated from strain-stress curves obtained along the directions perpendicular and parallel to the assumed axis of symmetry as well. Velocity measurements show that samples are highly anisotropic, but that the pressure-dependent behaviour of the wave speeds differs. VP(90°) and VSH(90°) both with layer parallel propagation and polarizations change little with pressure while VP(0°) and VS(0°) (both with layer perpendicular propagation) display significant nonlinear responses particularly at pressures < 25 MPa. These characters transfer to the derived full set of elastic constants. In order to effect a proper comparison of the dynamic and static moduli, we convert the dynamic elastic constanst to linear compressibilities pependicular (Kdyn1) and parallel (Kdyn3) which are directly comparable to the static tangent compressibiities obtained by differentiation of the observed strains. Both sets highlight the anisotorpic nature of the material but most interestingly Kdyn1 _ Ksta1 but Kdyn3 > Ksta3 by nearly 40% for one of the samples. The other samples measured respond similarly suggesting that conceptually the structure of such materials could be considered to be constructed of alternating stiff or compliant layers. This finding has implications in the response of the formation to stress particularly during hydraulic fracturing and the interpreation of acoustic logs in providing appropriate measures of elastic properties for engineering purposes.

Jan 1, 2015

Overview of Presentation ?About MiHR ?Human Resources Challenges in the Minerals and Metals Industry ?Getting the Facts -Sector Study Project ?Key Findings ?Recommendations ?Conclusions ?MiHR?srole

May 1, 2006

By Charles "Chick" Rodgers, Anthony Sarion

"With declining feed grade and increased production targets, it became necessary to upgrade Key Lake's eight stage counter current decantation (CCD) circuit. Following laboratory trials, mill operations recognized that dilution of the feed slurry and buffering of the feed density variations would improve thickener throughput. Plant testing resulted in the installation of Outokumpu's Supaflo ""Floe-Miser"" system. The circuit's flowsheet, instrumentation and control strategy were also upgraded along with the thickener feedwell modifications. The paper will also discuss these modifications and the implementation of the current control strategy.IntroductionCameco Corporation's Key Lake operation is the largest single uranium producer in the world. Current production is fourteen million pounds of uranium oxide (U 308) per year. It is owned 2/3 by Cameco and 1/3 by Uranerz Exploration and Mining with Cameco as the operator.The mine is 570 kilometres north of Saskatoon on the southern edge of the Athabasca basin. Access to the mine is by an all-weather road and a private airstrip.Process DescriptionThe Key Lake milling process consists of five individual plants: crushing and grinding; leaching and counter current decantation (CCD); solvent extraction; yellowcake precipitation and ammonium sulphate crystallization; and bulk neutralization (Figure 1 -Simplified Mill Flowsheet). A detailed mill flowsheet can be found in the appendix."

Jan 1, 1998