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By Yutaro Fukase

Various types of service robots have recently been developed for guarding facilities, caring for the elderly, carrying objects, and cleaning buildings. As barrier-free facilities improve and their use expands, these robots have more space within which to move inside buildings. Yet robots that move autonomously rely on position-detection systems. Though improving rapidly, these systems are far from perfect in determining positions in certain situations, especially when robots navigate large areas or cross various locations. Our group is working to solve this problem by developing a position-detection system using random-dot patterns on a floor. First, we construct a floor with a random-dot pattern and register the positions of all of the dots into a database. As the robot moves across the floor, a camera on the robot captures an image of the floor beneath it and crops the dot pattern in the image. The cropped dot pattern is matched to the dot patterns in the database to determine the position of the robot and the direction in which the robot is facing or moving. In this paper we propose a self-localization system and matching algorithms derived from a space technology and present the results of several experiments.

Aug 1, 2013

? A BARGE WILL BE INSTALLED IN THE BOTTOM OF A COMPLETED PIT. ? THE PROVEN BAUER CUTTER TECHNOLOGY WILL BE INSTALLED ON THE BARGE AND A DEWATERING PLANT WILL BE INSTALLED NEAR THE BASE OF THE PIT RAMP. ? THE WATER LEVEL IN THE PIT WILL BE RAISED BY 20- 40 METRES AND REMAIN CONSTANT OVER DURATION OF MINING. ? THE CUTTER WILL BE LOWERED TO MINE 10 METRE DEEP BENCHES ON A CHECKERBOARD PATTERN TO AN ULTIMATE DEPTH OF 200 METRES. ? THE 5? MINUS CUTTINGS WILL BE PUMPED TO THE DEWATERING PLANT, DEWATERED, AND TRUCKED TO SURFACE.

May 1, 2003

By N. W. Xu, M. D. Wei, F. Dai, B. Li

"Chevron notched samples achieve general acceptance for measuring the Mode-I (opening mode) fracture toughness of rocks. The cracked chevron notched semi-circular bending (CCNSCB) sample, which is developed from the International Society of Rock Mechanics suggested the cracked chevron notched Brazilian disc method, has recently received much attention. However, these chevron notched methods have not been fully mastered, some ideal assumptions based by their theories and formulas, such as the straight-through crack assumption (STCA), have not been verified detailedly. Fractures of CCNSCB specimens were numerically simulated considering different heterogeneities, geometrical and mechanical parameters. The results show that, the real fractures of CCNSCB specimens are never satisfied with the STCA. In fact, micro fractures not only occur in the notch tip but also the two chevron edges. Consequently, the crack front features prominently in a shape of parabolic curve, far from being straightthrough. Moreover, curvature of the crack front is only affected by shape of the chevron ligament. Cracks usually start from two sides of the notch tips rather than center of the notch width, and propagate deviating from the postulated fracture routes. These fracture mechanisms induce errors with the measurements, and thus more attentions should be paid to the real fractures of the chevron notched samples for measuring fracture toughness more accurately. INTRODUCTIONWith the increasing requirement of people for resources and energies, frequent rock engineering activities have been conducting, such as underground excavation, oil exploration and deep burial of nuclear waste. Many problems appear in rock fracture. Consequently, there are more and more attentions paid in rock fracture mechanics due to its broad application prospects for solving these engineering problems. Since Mode-I (opening mode) fracture is the most common failure mode in rocks, Mode-I fracture toughness is a primary parameter to predict rock mechanical properties in actual engineering, and thus its accurate values are necessary to the researches of rockburst, rock mass slope stability, rock cutting, hydraulic fracturing, tunneling, et al. Therefore, it is thus significant to evaluate and study relevant methods to obtain the reliable value."

Jan 1, 2015

By E. Rosseland

Glencore Nikkelverk is operating its Chlorine Leach Process in Kristiansand, Norway, producing nickel, copper and cobalt metals by electrowinning. The copper tankhouse, with an annual capacity of 40 000 tons, is based on traditional technology with copper starting sheets and cast lead anodes. Due to the integration of this copper sulphate process in a nickel chloride refinery, operating conditions are unique. In recent years, operating costs have escalated, and health, safety and environment are top priorities. Test work on a new copper process involving permanent cathodes was therefore initiated in 2007, and a pilot plant was started up in 2012. The objective was to introduce innovative technologies and tailor these to be robust in the Nikkelverk process, to form a basis for a new sustainable copper tankhouse with a high degree of automation. Key learnings from more than 10 years of R&D work is presented, focusing on cathode materials and copper metal deposition including product quality, robotic stripping, coated titanium anodes, electrode contacts and alignment, electrode current monitoring with Hatch HELM tracker technology and acid mist capture using cell hoods with off-gas scrubbing. The new copper tankhouse project was approved in December 2018, and commissioning is planned in 2022. INTRODUCTION The Kristiansand nickel refinery was started up in 1910, processing nickel-copper matte originating from Norwegian mines. It was the first industrial plant in the world to produce nickel by electrolysis using the Hybinette electrorefining process. After roasting to burn off sulphur in the matte, copper was leached and recovered as cathodes by electrowinning with lead anodes. In the first years, the copper cathodes were fire- refined and cast into ingots for sale (Thonstad Sandvik, 2004). The Nikkelverk refinery was acquired by Falconbridge Ltd. in 1929, and since then matte from Sudbury, Canada has been the main feed source. The Hybinette process was in operation until 1975 when conversion to the newly developed Chlorine Leach Process was started (Stensholt, Zachariasen, & Lund, 1986). In this process still used today, nickel and part of the copper in the matte is leached using chlorine gas generated on dimensionally stable anodes in the nickel and cobalt electrowinning tankhouses, as illustrated in Figure 1. The presence of dissolved copper ions in the strong chloride leach solution is essential for effective chlorine absorption and nickel dissolution. To improve copper-nickel separation, slurry from the atmospheric leach is pumped to autoclaves and then to cementation tanks for precipitation of copper as copper sulphide, which is collected in filter presses. The leach residue, also containing the precious metals, goes through a 3-stage wash to remove chlorides before being introduced as a slurry to fluid-bed roasters for sulphur removal. The resulting calcine is then leached in spent electrolyte from the copper electrowinning tankhouse, to dissolve most of the copper and also some nickel, cobalt and other elements. After separation of the leach residue, elements like Bi, Te, As and Ag are removed from the strong copper sulphate solution by reaction with metallic copper in three columns in series filled with cut copper cathodes. The purified solution then passes polishing filters before being mixed with spent electrolyte and returned to the electrowinning cells.

Jan 1, 2019

CSIRO Minerals, in association with the AJ Parker CRC for Hydrometallurgy, has an active program of hydrometallurgical research in which physical and computational modelling are used to better understand and improve a range of different unit operations. The modelling is based on flow simulation (Computational Fluid Dynamics or CFD), but incorporates other physical and chemical phenomena of importance, such as droplet break-up and coalescence, species transport and reaction. This paper reviews some of the major projects that have been undertaken at CSIRO Minerals and will illustrate the critical importance of hydrodynamics to the performance of unit operations and the improvements that can be made to performance using such modelling techniques. Unit operations that are discussed include solvent-extraction, gravity thickeners, flotation cells, bio-heap leaching and stirred tanks.

Jan 1, 2005

By T. S. Li, D. Ilievski, I. Livk

Micromixing of the fluid and the particulate phases in a continuous gibbsite precipitator was investigated for three different micromixing states, namely maximum mixedness (MM), complete segregation (CS), and maximum mixedness of the fluid but complete segregation of the particulates (MMF-CSP). The influence of the micromixing on continuous precipitation of gibbsite was studied at different precipitation conditions via simulation. Three different cases were considered with respect to the precipitation kinetics: (1) gibbsite secondary nucleation is favoured with slow crystal growth and agglomeration rates; (2) gibbsite crystal agglomeration and growth are dominant mechanisms with secondary nucleation suppressed; and (3) gibbsite crystal growth is the only relevant phenomenon. Simulation results for the cases (1) and (3) showed that the crystalline products for both the MM and MMF-CSP micromixing states were very similar, but the product obtained from the CS micromixing state was considerably different. This indicates that at those precipitation conditions the fluid micomixing has the dominant effect on the product properties, and the particulates micromixing effect is insignificant. However, when operated under the conditions of fast crystal growth and agglomeration kinetics, i.e. case (2), both the fluid and the particulates micromixing were found to affect the precipitation process, resulting in a significantly different product. Computational Analysis in Hydrometallurgy 35th Annual Hydrometallurgy Meeting held in conjunction with the 44th Annual Conference of Metallurgists ofCIM Calgary, Alberta, Canada Edited by

Jan 1, 2005

By W. R. Bruce, G. W. Hodgson, K. A. Clark

"IntroductionANY PLANT processing mined Athabaska oil •sand for the recovery of oil produces, as a waste material, about one ton of sand for every barrel of oil recovered. A disposal problem of major proportions is thus indicated. For a 100,000-barrel per day plant, provision must be made for moving .about 4,000 tons of sand per hour on a continuous basis to a tailings dump at least several thousand feet removed from the plant site.Of the many known ways of conveying solids on .a large scale, the hydraulic pipeline transfer method is becoming increasingly important because of convenience and economy of operation. It has been in use for many years in mill operations at metalliferrous mines for the disposal of tailings and as such was a natural outgrowth of •hydraulic sluicing (3). Pipeline transportation of mill concentrates has been adopted recently ( 1), wherein high-density solids are moved several miles by hydraulic pipeline. The flotation power of the water suspending the solids may be increased 'by addition of magnetite for the handling of ore in pipelines (8). Low-density solids such as coal have received considerable study for low-cost pipe-lining (2) and a successful operation with coal has been carried out in England with indications of considerable savings over other methods of transportation (9). Dredge operations are based on pipeline transportation for the dredged sol-ids, and the scale of pipelining there .has involved pipe sizes as large as 32-inch (6). However, the tendency has been to regard the pumping of solids in water merely as a simple method of transportation and little consideration has been given in the published literature to study of the most economical modes of operating .a pipeline."

Jan 1, 1952

By J. P. Harrison, R. Roostaei

"In this paper we investigate the consequences of using conventional triaxial peak strength criteria in the polyaxial stress conditions that occur around the end of a long circular underground opening. A series of 3d boundary element analyses were performed using Examine3D to determine the stresses induced around the tunnel in different in-situ stress conditions. To discuss the applicability of a triaxial strength criterion in failure prediction, strength factors were computed for both the Ottosen polyaxial strength criterion and the triaxial Hoek-Brown criterion. Assuming that the Ottosen criterion is an accurate indicator of strength factor, the discrepancy from this value due to the Hoek-Brown criterion is the error in prediction.In order to simultaneously show the error in prediction and actual strength factor, a quantitative bivariate colour scheme is used to visualize the results. This allows rapid identification of regions with large error, and where either unsafe or overly conservative conditions occur. We show how the inappropriate use of triaxial criteria rather than polyaxial criteria leads to an under- or over-estimation of strength factor, and can result in uneconomic or unsafe design. Extending the analysis to different in situ stress regimes shows how the in situ stress conditions affect the assessment."

Jan 1, 2015

By Vladislava A. Ignatkina, Victor D. Samyguin

"Within the limits of two-phase approach, considering mass transfer with pulp and air streams was shown that each bubble appears to be an elementary carrier, transporting particles from the collection zone into the froth. The kinetics of flotation was described by the exponential equation in which first order flotation speed constant has to be replaced with two-phased coefficient of a mass transfer. Criteria of selectivity of two ore fractions separation, based on determination of optimum time at which maximum difference between extractions and components content in separated fractions were offered. An interrelation between optimum time of pulp residence in a flowing chamber of a flotation machine, time of bubbles mineralization and an optimum airflow has been ascertained. Cumulative criterion of mass transfer efficiency of flotation process has been ascertained to be a form of the spectrum and its position on axis of three-phase coefficient of a mass transfer.INTRODUCTIONRegularities of a mass transfer of three bearing streams: pulp stream, air stream and froth stream underlie theory of mineral complexes flotation (Samygin, Filippov, & Shekhirev, 2003)However, only description of mass transfer in pulp stream by means of kinetic equations that were simple and convenient for practical use, has gained a full distribution (Tykhonov, 2009;Rubinstein&Filippov, 1980; Saleh, 2010).Within the limits of a single-phase approach, the role of gas stream in increase of speed and selectivity of flotation, was associated with an improvement of hydrodynamic mode. An influence of particles and bubbles sizes (Rubinstein&Filippov, 1980; Rubinstein&Samygin, 1998, Samygin et al., 2003; Dai, Fornasiero,& Ralston, 2000), of pulpflow and airflow (Finch& Dobby, 1990) and turbulent energy intensity (Shubert, 1979; Massinaei, 2007) on the flotation process has been studied. It was stated that flotation selectivity is increasing by means of gradual airflow increase from first to final cameras of the impeller flotation machine (Aslan&Boz,2010; Finch, 2011) and by means of using a multizone flotation machine (Samyguin, Filippov, Matinin, Lekhatinov, &Tertyshnikov, 2013)."

Jan 1, 2016

By C. O. Campbell

THE recognition by C. W. McKee, field engineer for Springer Sturgeon Gold Mines, Limited, in the fall of 1940, of the economic possibilities of a small outcrop of baryres near Pembroke, in Hants county, Nova Scotia, followed by aggressive exploration and development by the Company, has placed Canada for the first time in its history in the position of becoming a major producer of barytes and its products. In past years, production of this mineral in Canada has been unimportant. Thus the coral output from 1885 ro 1933, inclusive, amounted to only 41,027 short tons, following which there was no production until 1939. Deposits in Nova Scotia, and particularly in the Lake Ainslie district, Cape Breton, have been the main source of supply, with a production between 1866 and 1925 of 31,689 tons. Following the examination of the outcrop of baryres near Pembroke by Mr. C. W. McKee in October, 1940, the area surrounding it was trenched, and, as this work gave encouraging results, a diamond drilling programme was commenced. A grid system was laid our and sixteen holes aggregating 2809.3 feet were put down, spaced at 100-foot intervals, the deepest hole being 300 feet. This drilling outlined a body of high-grade baryres over 600 feet long and 200 to 250 feet wide, with an average depth of 120 feet and estimated to contain well over one million tons of ore. The limits of the body were reached on the west, north, and southwest, but the drilling was suspended before the eastern limit was determined. Quarrying operations, and construction of a 100-ton mill, were commenced in February, 1941. The mill was placed in operation on May 29th, and on June 15th, eight months after the initial discovery, the first shipment of 2,500 long rons of milled baryres was made to Trinidad, British West Indies.

Jan 1, 1942

By Mel Owen, Bob Tipman

"A number of studies have identified the presence of heavy minerals in the Athabasca oil sands. A 1996 Mineral Development Agreement study into the recovery of Co-Products identified low operating costs, a simple flowsheet and access to market as key drivers in advancing interest in a viable project.Commercial bitumen extraction processes recover 50% of the titanium heavy minerals and 85% of the zircon into froth containing 1 % of the feed solids. Froth treatment tailings grade is 11.5% Ti02 and 3.6% Zr02.Processing this high grade feed in a combination of flotation, roasting, screening, gravity concentration and magnetic separation, results in concentrates of rutile, leucoxene, ilmenite, zircon and rare earths of marketable quality.A combination of high grade feed and a simple process lead to operating costs among the lowest in the industry. Low cost heavy minerals and low energy costs indicate an intriguing potential for low cost pigment production in Alberta. The production of heavy minerals from oil sands remains one of the largest untapped resources in the Province of Alberta1.0 IntroductionThis paper describes the results of an investigation into the recovery of heavy minerals from tailings produced by the major oil sands plants. The study was carried out under a Canada-Alberta Mineral Development Agreement (Alberta Chamber of Resources 1996). The MDA Co-Products Study examined the potential for the economic recovery of heavy minerals from oil sands tailings."

Jan 1, 1998

By S Sokhanvaran

Electrodeposition of silicon from a cryolite based electrolyte at a relatively low temperature (1000°C) is a promising approach to generate high purity silicon. In order to obtain fundamental data pertaining to electrowinning of silicon from Cryolite?SiO2 melts, density and electrical conductivity measurements were made. A range of temperatures and SiO2 contents was studied for each property. It was found that while density has an inverse relationship with temperature, the dependence for electrical conductivity is direct. Increasing silica content up to the saturation limit (~ 5 wt%) increases the density whereas further increase in SiO2, lowers the melt density. On the other hand, the conductivity is lower for the melts with greater SiO2 content, at any temperature.

Jan 1, 2011

By B. R. Rakishev

When transferring from the railway transport to the combined automobile-conveyor transport by stripping works at coal mines, it was proposed to form at the working zone a concentration horizon for reloading part of the stripping volumes at the railway transport. The procedure is adduced for substantiating parameters of bloc-panels, depending on the step of transferring of reloading points in interrelation with the intensity of the working zone?s development with observing the balanced movement of parts of the stripping zone relative to the temporary concentration level.

Aug 1, 2013

Proper water and thermal management is essential for obtaining high performance of Proton Exchange Membrane Fuel Cells (PEMFCs). A steady, two-dimensional water and thermal management model was developed, aiming at considering pressure drop, open circuit voltage variation with stack temperature, water vapor effects on membrane conductivity, which made the model physically more reasonable and more suitable for various operating conditions. The model could predict the distributions of a series of important parameters along the flow channel, and thus the effects of various operating and design parameters on the fuel cell performance could be investigated easily by numerical trial-and-error method. The modeling results compared well with the available experimental results from the literatures. The results also showed that the humidification is crucial for the performance of PEMFCs. The model could be a very useful engineering tool for the optimization of PEMFCs.

Jan 1, 2005

By E. Michelotti, M. Cardu

This paper presents the results of a new method that has been tested to recover metallic cobalt lost by diamond beads from rock cuttings. When dimension stones are cut using diamond wire saws, the beads become worn and, before the end of their cycle life, lose a certain amount of material; this material is prevalently made up of sintered metal and diamonds. The material is then washed away, together with rock debris, in a dilute pulp. In effect, this process involves the dispersion of economically valuable, but potentially polluting, materials (such as cobalt) that are used to confer indispensable technological features to the beads. This current research aims to develop a waste-processing pilot plant (High-gradient Magnetic Separator or HGMS) to recover metallic components from the pulp by means of a suitable separation. The research\u2019s purposes are two-fold: a. to remove the polluting components from the rock debris before their disposal and b. to start a recycling process of the valuable metals.

Jan 1, 2010

By P. G. Lazenby

This paper describes the latest instrumentation improvements in the INPUT Airborne E.M. System, particularly the new electronic signal-processing techniques. Several anomaly examples illustrating these techniques are shown.

Jan 1, 1973

By C. Chongo, L. Little, Q. Mclennan

Since commissioning in 2005, First Quantum Minerals’ Kansanshi Mine in Zambia has produced over three million tons of copper and 1.8 million ounces of gold from a deposit with highly varied copper mineralization. The processing plant is complex with three independent flotation circuits, gold gravity concentration, atmospheric and high pressure leaching, solvent extraction, and electro-winning. For the first ten years of operating the plant, copper mineralogy was inferred from total copper and acid soluble copper assays, and various misconceptions developed about the mineralogy which impacted operational strategy and project decisions. In 2015, an on-site mineralogy section was set up with an Automated Scanning Electron Microscope, the Zeiss MinScan. This instrument has provided detailed mineralogical data that have debunked some of the mineralogy myths that had developed, highlighting the key underlying issues affecting processing performance. This has enabled the development of projects targeting losses of specific copper minerals in defined size classes, unlocking significant value. This paper describes some of the early misconceptions around mineralogy at Kansanshi processing plant, outlining projects that have benefitted from understanding copper mineral distribution. Learnings from Kansanshi are to be applied at other FQM sites, with a similar mineralogy program being set up at the Cobre Panama project. INTRODUCTION The deposit Kansanshi Mine is located in the North Western Province of Zambia, and it has been the largest copper producer in Africa for over a decade. The deposit occurs within a broad northwest trending antiform that can be traced for 12 km, hosted in a zone of complicated faulting, abundant vein injection, breccia development and down-dropped rock units that lies within Kansanshi’s mining license. The copper mineralization within the deposit is predominantly vein-hosted, although some is strata-bound, occurring in thin bands and veinlets parallel to foliation, and some is disseminated associated with albite-carbonate alteration (Gray, 2015). Supergene enrichment has led to significant variety in the copper mineral speciation. This alteration is complex, and has not followed the text-book principles with a neat layer of supergene mineralization overlying fresh hypogene ore. Rather, the occurrence and extent of oxidation and supergene enrichment is highly irregular throughout the deposit, sometimes occurring at significant depth in localized pockets and along fault lines. Gold mineralization tends to follow the copper within the deposit, but it is dominated by coarse-grained, free-milling native gold. The extent of copper oxidation – measured as the fraction of total copper that assays as acid soluble – is used to classify ore into three main ore types, named Sulphide, Mixed, and Oxide, which are then fed to three different primary crushers for processing in independent circuits.

Jan 1, 2019

By Guoxiang Chi

The Cornwallis Fold Belt in the Canadian Arctic Archipelago contains numerous Mississippi Valley-type (MVT) Zn- Pb occurrences and the world-class Polaris deposit. The occurrences are mainly hosted by the dolostone in the Thumb Mountain Formation which spreads over 25000 km2. Success in exploration requires further understanding of the genesis of these occurrences and an assessment of their parentage with the giant Polaris deposit. Syn-sulfide dolomites in regional occurrences share C-O-Sr isotopic characteristics similar with Polaris dolomites, indicating warm basinal brines enriched in 87Sr. The dolomites and sphalerites contain fluid inclusions with ice-melting temperature between ?45° and ?25°C, which is significantly lower than for most MVT districts in the world (?30° and ?10°C). These characteristics indicate that all the Cornwallis occurrences were produced by fluids of the same sources and/or aquifers. The deposit size was largely controlled by the rate and duration of the metal-carrying fluid flow, and by the availability of reduced sulfur at the site of mineralization.

May 1, 2001

By D. Assmus, S. Daly

"Poor fragmentation, high toe areas, excessive shovel wear and tear and frequent re-drilling and blasting of certain tough waste rock zones in the Lomex pit in the early 1980snecessitateda better understanding of these zones.A combination of geotechnical mapping, penetration rate data, toe elevation contouring and observations on shovel and drill performance were used to determine the character and extent of these zones. This complementary information was brought together by the geotechnical mapper and the explosives supervisor.Distinct zones with particular geological characteristics were determined. A classification system with three types of blast and dig-ability was developed for the Lomex pit and later applied to the Valley pit, with considerable success. The three blast zone types are called ""poor"", ""f air"", and ""good"". This system will be described in detail.The explosives supervisor adjusted the blasting parameters to each zone, in particular, pattern spacing and burden. The resulting powder factors showed considerable variation between the poor, fair and good zones within each pit as well as between the two pits. Pattern geometry and length of collar were also adjusted to improve fragmentation. Cost savings resulted from less re-drilling and less wear and tear on drills and shovels in the poor zones and more efficient use of explosives in all the zones. An annual estimated cost savings of well in excess of $1,000,000 is realized at Highland Valley Copper. A by-product of the mapping was the determination of unstable structures and water flowing zones. Blasting was then adapted to this information for enhanced slope stability."

Jan 1, 1992

By Madaah Hosseini H. R., P. Abachi, S. Miraghaei

In this study, the effects of milling time, chemical composition and heat treatment on microstructure and magnetic properties of nanocrystalline Fe-Si (6.5-25 at.% Si) alloys prepared by mechanical alloying have been investigated. The results show that increasing the milling time or the Si content, decreases the lattice parameter and increases the internal microstrain. The prepared powders mainly consist of micron-sized particles with an average grain size of less than 20 nm. The specific saturation magnetization values are slightly less than those of single crystal or conventional Fe-Si alloys and decrease as Si content increases. The coercive force values of the nanocrystalline as-milled powders are much higher than those of corresponding Fe-Si bulk alloys with a minimum at 13.5 at.% Si. The values of coercive force decreased after annealing but it seams that the residual strain developed during milling is not the major contributing factor to the higher values of coercive force in the mechanically alloyed powders and nanocrystals behave as single-domain particles without exchange interaction between them.

Jan 1, 2006