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By T. Nomura, N. Saitoh, K. Tamaoki, Y. Konishi

We have developed new recycling technologies, based upon an eco-friendly biotechnology, in order to extract precious and rare metals sourced from end-of-life products and electronics. We have been focusing on the metal ion-reducing bacteria, Shewanella algae and Shewanella oneidensis, that are able to reduce and deposit gold ions (Au(III)) or PGMs ions (Pd(II), Pt(IV) and Rh(III)) into metal nanoparticles at room temperature within 120 min. When processing the aqua regia leachate of printed circuit boards, Shewanella bacteria were able to rapidly and selectively collect gold ions under acidic conditions in the presence of heavy metal ions, proposing a new bio-recovery system for gold. This biotechnological procedure also has the potential to allow the recovery of PGMs from the leachate of automotive catalysts. Shewanella bacteria were also able to successfully perform the complete reduction and deposition of the PGM ions. The ability to collect the PGM ions suggests that this represents a new process for the biorecovery of PGMs from used automotive catalysts. Our proposed biological method enables the rapid and highly efficient recovery of precious and rare metals via separation and concentration utilizing microbial reactions at room temperature.

Jan 1, 2014

By K. Murase

Potentiostatic electrodeposition behavior of dendritic copper from acidic copper(I) chloride (cuprous chloride) baths containing sodium chloride and sodium bromide was investigated. The morphology, or appearance, of copper dendrite and the sodium content in the dendrite as an impurity were both influenced by deposition potential (0 to ?150 mV vs. SHE) and bath temperature (R.T. to 60 C), while the current efficiency for the deposition was 99% or more irrespective of the deposition conditions examined. The bath pH did not affect the deposition behavior in the pH range of 0 to 2. Bath temperature was found to be the most important factor influencing the deposition current. The current density of the dendrite deposition on a titanium cathode was lower than that onto a copper cathode with the same substrate surface area. The reproducibility of the current for the dendrite deposition was poorer when an as-polished titanium cathode was used, although it was improved by surface treatment of the cathode with an HF-HNO3-H3PO4 solution before electrodeposition. The deposition behaviors were discussed with the potential-pH diagram of the Cu-Cl-H2O system.

Jan 1, 2007

By Daniel B. Leznoff

The cyanoaurate anions [Au(CN)2]- and [Au(CN)4]- are shown to be useful building blocks for synthesizing supramolecular coordination polymers. For the gold(I) unit, aurophilic interactions often increase the structural dimensionality of the system and can impart increased thermal stability to the metal-polymers produced. A series of polymers of the form M[Au(CN)2]2(Ligand)x have also been prepared and show large colour changes upon changing the ligand, thus illustrating a sensor-type application. Both building blocks can mediate significant antiferromagnetic and ferromagnetic interactions between transition-metal centres in the polymers. For the gold(III) unit, no metal-metal interactions are observed, although weak Au-N(cyano) interactions control the intermolecular packing. Several structural examples of cyanoaurate-based coordination polymers are presented, including 2-D and 3-D arrays and a supramolecular square.

Oct 1, 2003

By X. Wu, W. R. Chen, J-G. Legoux, B. R. Marple, E. Irissou

Cold gas dynamic spray (CGDS) has been considered a potential technique to produce the metallic bond coat for TBC applications, because of its fast deposition rate and low deposition temperature. This paper presents the influence of spray processes for bond coat, including air plasma spray, high velocity oxy-fuel, and in particular CGDS, on the oxidation performance of TBCs with a Co-32Ni-21Cr- 8Al-0.5Y (wt.%) bond coat. Oxidation behaviour of the TBCs was evaluated by examining the coating microstructural evolution, TGO growth behaviour, and crack propagation during thermal exposure at 1050°C. The relationship between the TGO growth and crack propagation will be discussed.

Jan 1, 2010

By Timothy D. Dreger

In the spring of 2009, Suncor Energy Inc. technical personnel saw an opportunity to improve planning 0and mining of overburden material in order to address aggressive construction goals and increased mining complexity. By tying together current and historical equipment performance, geological model information, and material observation in the field new operating elevations for the shovels were developed. At the same time, methodology of recording and reporting overburden movement through the Modular Mining DISPATCH system was changed. The result of this first stage of improvements was an increase in construction-grade material available at the face. The personnel involved realized that other opportunities were available to build on the initial successes and establish processes that would stand up to attrition and experience levels. A cross-functional technical team was assembled to identify ways of further improving workflows around overburden mining. Some of the opportunities realized include greater alignment between planning, reporting and operations as well as development of reporting tools that help steward Mine Operations to the plan. All of which have resulted in Suncor meeting or beating its forecast overburden targets. The cross-functional technical team continues to seek out new and better ways of doing business so Suncor can continue to deliver on its commitment of outstanding performance and results.

May 1, 2011

By J. H. Baek, S. Alexandrovskii, D. W. Lee, B. K. Kim

Nano-phase titanium carbide was synthesized by Mg-thermal reduction process using a novel route of Mg-thermal reduction. The processes are based on I) feeding of TiC14+CxC14 x = 1, 2 ) solution into liquid magnesium, 2) Mg-reduction of metal chlorides, 3) TiC formation by the reaction of released Ti and C atoms, and 4) vacuum separation of residual liquid phases of Mg and MgCl2. In this study, the process for titanium carbide production with composition close to stoichiometry and the minimum content of impurities was optimized with the various process parameters such as concentration of initial solution, its feeding rate and reaction temperature, as well as a kinetic study.

Jan 1, 2004

By Y. Mitsuda, Y. Kayanuma, T. H. Okabe, M. Miyake

A new process to recover platinum group metals (PGMs) from automotive catalyst scrap using metal vapor was developed. To improve the efficiency of the acid dissolution process of PGMs, metal vapor of reactive elements such as magnesium or calcium were contacted with spent automotive catalyst. It was expected that metal vapor would react with metal selectively and form intermetallic compounds. The specimen of the spent catalyst was treated at 1173 K for 3 h, and it was then dissolved in aqua regia for 1 h to recover PGMs. After the reactive metal treatment, 88% of Pt, 81% of Pd, and 72% of Rh in the catalyst scrap was dissolved, while only 77% of Pt, 69% of Pd, and 38% of Rh was dissolved from untreated scraps.

Jan 1, 2004

By C. L. Belyk

There are fifteen accepted types of uranium ore deposits and at least forty subtypes readily identified around the world. Each deposit type has a unique geological model which may also have unique processing implications. Primary uranium production in the past decade has come from a handful of these deposit types: unconformity, sandstone, calcrete, intrusive, breccia complex and volcanic. Processing implications for each of the fifteen deposit types can vary widely between and within different geological models. Some key characteristics of uranium deposits that may have processing implications include: ore grade, uranium and gangue mineralogy ? including clay and carbonate species and content, hardness, porosity, uranium mineral morphology, and carbon content. Processing roadblocks may occur as a result of one or more of these characteristics for any of the fifteen deposit types. Future technological advances and innovative thinking around uranium ore processing could provide avenues for roadblock removal setting the stage for additional and economically-viable uranium production from traditional and non-traditional uranium ore deposits.

Aug 1, 2010

By J. Fournier

A novel sol ? gel (SG) synthesis procedure utilizing varying ratios of glycine and ethylene glycol to total metal cations has been developed to create high purity nanometer sized La0.65Sr3.5MnO3 powders. X-ray powder diffraction (XRD), transmission and scanning electron microscopy (TEM, SEM), and dynamic light scattering (DLS) have confirmed that the crystallite sizes of such powders are ~ 20 nm, and the aggregate particle sizes vary between 100 to 300 nm. Mixing varying weight percents of SG LSM powders with commercially available Praxair LSM in a composite LSM/YSZ functionally graded cathode has been shown, through the use of electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), to exhibit enhanced oxygen reduction kinetics vs. at conventional cathode materials.

Jan 1, 2005

By J. Fournier

A novel sol ? gel (SG) synthesis procedure utilizing varying ratios of glycine and ethylene glycol to total metal cations has been developed to create high purity nanometer sized La0.65Sr3.5MnO3 powders. X-ray powder diffraction (XRD), transmission and scanning electron microscopy (TEM, SEM), and dynamic light scattering (DLS) have confirmed that the crystallite sizes of such powders are ~ 20 nm, and the aggregate particle sizes vary between 100 to 300 nm. Mixing varying weight percents of SG LSM powders with commercially available Praxair LSM in a composite LSM/YSZ functionally graded cathode has been shown, through the use of electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), to exhibit enhanced oxygen reduction kinetics vs. at conventional cathode materials.

Jan 1, 2005

By Robert C. Lo

As tailings dams grow in physical size, their impact on public safety and the environment also increases in severity. Over the last three decades, tailings dam engineering has evolved from largely "trial-and-error" methods to a mature, multi-disciplinary engineering endeavour. This paper reviews the current practice of tailings disposal, and the evolution of tailings dam engineering. Key factors affecting dam integrity and examples of dam failures are then highlighted. Finally, the paper reviews some of the recent trends that lead to new challenges to the mining industry. These challenges include: coping with heightened public concern about dam safety; balancing potential conflict between seismic and environmental requirements; and addressing issues introduced by globalization of the mining industry. Institutional responses and technological tools available to meet these challenges are also outlined.

May 1, 2001

By J. Gao

We present results from our investigation of the concept and practice of using surface-charged latex nanoparticles as building blocks for conductive membranes. Nanoparticles were synthesized by free-radical co-polymerization of two hydrophobic monomers, butyl acrylate (BA) and methyl methacrylate (MMA), a crosslinker, N, N'- methylenebisacrylamide (BIS), and a charged monomer, sulfonate styrene sodium salt (NaSS), in water. The resultant nanospheres were characterized with static and dynamic laser light scattering. Thin films were cast from concentrated particle dispersions, followed by incubation at ?110 °C. Conductivity, water uptake and final charge content were measured. The membranes have higher conductivities than both amorphous films cast from sulfonated BA-MMA-Styrene copolymer chains and BA-BIS-MMA-NaSS gel films. TEM images and neutron scattering spectra confirm the particulate structure of the membranes.

Jan 1, 2005

By Didier Fohlen

Three Policy Shifts to enhance IFC?s Accountability ? Comprehensive and dynamic treatment of social, health, safety and environmental risks ?Covers a range of risks encountered by clients in emerging markets ?Framework to anticipate risks and to address them as they arise ?Includes community development, biodiversity, human rights ... ? Effective principles to guide an outcomes-based approach ?By clients and IFC ?Focus on broad community support and value-added sustainable development initiatives Enhanced governance, transparency and disclosure

May 1, 2006

By Davis Myers

OVERVIEW ?A summary of population demographics data ?Potential impact of Baby-Boomer, Generation X, Millennial demographics in the mining workforce ?Planning with constrained resources Age Cohorts ?Baby Boomers: born 1946 -1965 ?Booming economy, TV, cold war, JFK, Vietnam ?Generation X: born 1965-1980 ?There was always space travel ?PC?s, Black Monday, Challenger, Desert Storm, fall of Berlin Wall ?Millennials: born 1980-2000 ?There was always the internet ?IM, Facebook, Sept 11, Columbine

Nov 1, 2011

By M. Leijd, K. S. Forrester, M. Saxon, M. Oczlon

This paper provides an introduction to wet high intensity magnetic separation (WHIMS) and its successful application to the beneficiation of rare earth element (REE) enriched eudialyte. The analysis includes an in-depth reporting of the deportment of key elements as well as a statistical interpretation of the relative importance of operational parameters including magnetic field intensity, flow velocity, and matrix loading density. Conclusions are drawn on the relative success of the technology, potential areas for process improvement, and the research direction that continues to be investigated. Three original equipment manufacturer (OEM) technologies were subjected to a series of screening and characterization tests to identify the optimal operating parameter set to magnetically beneficiate eudialyte from Norra Kärr, Sweden. Upon the completion of the characterization test it was apparent that the Metso HGMS technology was superior with respect to REE recovery and gangue rejection for the Norra Kärr composite. The Metso HGMS was then subjected to a series of verification tests to confirm the repeatability and reproducibility of the system.

Jan 1, 2014

By Raj Thamburaj, Li. Ping, Prakash C. Patnaik

"An effective prognosis system for aircraft engines may involve the application of a wide range of technologies and methodologies, which may include: - On-line, real-time and in-situ non-destructive inspection/detection/sensoring - Aircraft/engine instrumentation - Airborne data recording system - Advanced signal filtration - Data compression technologies - On-line engine health monitoring technologies - On-line engine component life usage monitoring technologies - Mission severity analysis algorithm based on life prediction and damage tolerance analysis models - Life assessment methodologies - Optimized repair/overhaul/maintenance planning - Optimization of mission assignment and homogeneous life usage - Web-enabled information delivery and sharing system - Decision making logistics This paper will demonstrate some efforts that Orenda has accomplished over the last decade in collaboration with the Institute for Aerospace Research of National Research Council Canada and the Department of National Defense. The presentation will focus on the following projects:"

Jan 1, 2004

By Philip Peck

Mine closure issues ?Narrow issues: ?Environmental focus; ?Broad issues: ?Social issues and sustainability; ?Continued importance of mining; ?Historical legacies from closed mines; ?Barriers to development; ?Migration [ir]reversibility Dealing with closure issues ?A matter of choice ?Option 1: Engagein solving closure problems as best possible; ?Option 2: Exit, leaving the playing field to firms not interested in solving problems ?Option 3: Delay, till better time to enter or until early entry [by others] fails and pick property up cheap [?].

May 1, 2006

By B. Farabi Khoshmehr

In the present study the effect of Silicate Sodium oxidation agent concentration and Plasma Electrolytic Oxidation (PEO) treatment time were investigated on properties of oxide layer on Aluminum alloy. The phase composition and surface morphology of PEO films were evaluated through x-ray diffraction (XRD) and scanning electron microscopy (SEM). Pin on Plate abrasive machine were used to investigate of were resistance of coating. The results showed that oxide layer which formed on Aluminum surface consist of high temperature a- Al?O? and ?- Al?O? phases. The diffraction peak intensity and percentage of these phases were increased by increasing silicate sodium concentration. Microscopic studies revealed a porous surface for PEO coating. This was affected by silicate sodium concentration and oxidation time. The wear test results showed that the weight loss of PEO coating was reduced due to improvement of their wear resistance.

Oct 1, 2011

By Michael Samis

NOFLEX valuation results ? CF deviations and net CF risk discount factors ??Cash flow deviations indicate average cash flow variability. ??Net cash flow riskdiscount factors (NCFRDFs) indicate the size of the risk adjustment applied to a cash flow. NCFRDFs profile should change with variations in cash flow uncertainty since the risk adjustments applied to the project cash flow reflect investor sensitivity to uncertainty.?DCF and RO will often produce different NCFRDFs for the same project since they use different methods of risk-adjustment.

May 1, 2006

By Steve Forgeron, Brendan MacKenzie, Kevin MacPherson

"The geological composition of strata immediately adjacent to coal seams has a significant effect on the safe and efficient extraction of coal from underground mines of the Sydney coalfield. Geological features such as paleo-sandstone river channels, seam splits, floor rolls, paleo-soils and stone-filled rupture features can rapidly alter the competency of immediate roof and floor strata, significantly reduce the height of the coal seam, cause rapid variations in seam gradient and influence the in situ and run-of-mine quality of the coal.The impact of these features on the over-all mining operation can be significantly reduced if mine management can be for-warned of their impending occurrence. Using the information acquired from boreholes, geological mapping, x-ray diffraction analyses, microscopic studies, geophysical logs and seismic surveys, sedimentary models have been constructed which enable the mine geologist to predict, with increasing accuracy, the future occurrence of deleterious geological features ahead of the working face."

Jan 1, 1986