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By Shahriar Vahdani, Andy Herlache, Andrew Bro, Wei-Yu Chen

"The Presidio Parkway Project will reconstruct approximately 1.6 miles of highway, including seven bridges, three cut-and-cover tunnels, and an undercrossing connecting the Golden Gate Bridge to the City of San Francisco, California. The project site is approximately 5.6 miles from the San Andreas Fault, which is capable of producing magnitude 8 earthquakes. Seismic hazards include strong ground shaking, soil liquefaction, ground settlement, and lateral spreading. At the Tennessee Hollow bridge section up to 30 feet of loose sands and soft clays are present. Concerns are raised that standalone drilled piers will experience excessive lateral soil loads from liquefaction-induced lateral spreading pressure resulting in excessive pier head displacement of up to 8 inches. Ground improvement by Cement Deep Soil Mixing (CDSM) is proposed to provide additional foundation stiffness. This paper presents the methodology to: 1) assess the effectiveness of the ground improvement in resisting lateral spreading, and 2) optimize ground improvement design at individual bridge bents based on local site condition. A series of 3-D numerical analyses are conducted and the results show that drilled piers with CDSM ground improvement are capable of withstanding seismic demands from lateral spreading and the lateral pier head displacement is reduced to less than 2 inches. The adopted analytical approach is efficient at modifying design for individual bents and can be considered for future pier foundation design in seismically active areas. IntroductionThe Tennessee Hollow bridge section (Low Viaduct) is an integral component of the Presidio Parkway project which will replace the existing facility with a new multi-lane roadway between the Golden Gate Bridge and the City of San Francisco. As shown on Figure 1, the project site is located about 5.6 miles east of the San Andreas Fault and 12.5 miles west of the Hayward Fault. The Low Viaduct will span over a future wetland habitat subject to tidal fluctuations and potential scouring."

Jan 1, 2014

By L. Chunpongtong

The mining limit in oil sands is regulated by the ratio of total mining volume (ore, interburden, and overburden) one has to mine per volume of bitumen in place (TV/BIP). This paper presents a mathematical solution for creating the most economical pit outline where the TV/BIP ratio upper limit is 12, by combining mining economic theory and the Lerchs-Grossmann (LG) algorithm.

Jan 1, 2014

By D. Sprott, P. A. Kirsch, J. Harris, D. Cliff

This paper details the work of RISKGATE, the largest Australian Coal Association Research Program (ACARP) occupational health and safety initiative to date. The program is an interactive online risk management system developed to maximize health and safety performance in the coal mining industry by implementing continuous improvement in managing major unwanted events. The comprehensive knowledge base covers tires, collisions, fires, isolation, strata control underground, ground control open cut, explosions, explosives, manual tasks, and slips/trips/falls. All major Australian coal mining companies contributed topic experts to this broad industry initiative: nine coal mining companies, more than 80 experts, and more than 400 days of individual time for knowledge-capture workshops.

Jan 1, 2014

By A. Galley, R. Tosdal, F. Robert

The Canada Mining Innovation Council (CMIC) Exploration Innovation Consortium developed a 10-year business case for developing new discovery criteria, exploration techniques, and better data management and analysis to improve exploration success in deep, remote, and covered terrains. Within this context, the CMIC devised a five-year project proposal to create improved multiparameter exploration tools to detect ore systems and more efficient vectoring toward high-grade mineralized cores. The Footprints project was approved March 2013. More than CAD$13 million funding was provided through the CMIC-led joint sponsorship from 30 companies and the Natural Sciences and Engineering Research Council. Consistent industry leadership and integration of dedicated industry and academic expertise has the project on track for reaching its well-defined objectives.

Jan 1, 2014

By B. R. Conard

Copper refining at Vale Canada (previously known as Inco) has been associated with Ni production. Because Cu and Ni carry risks for adverse health endpoints through inhalation exposure, it is critical that their aerosol levels, and the metallurgical processes through which they enter the air, are understood. Because certain Ni substances have been linked to respiratory cancers, it is also important to characterize the amounts and types of Ni compounds in occupational settings. This paper describes electrorefining and electrowinning operations near Sudbury, Ontario (1930–present), and gives aerosol measurements (1978–present).

Jan 1, 2014

By A. Sokolov, E. Hasikova, V. Gostilo, V. Titov

Introducing online X-ray fluorescence (XRF) analyzers in the mining and processing industries can lower costs and improve the representativeness and speed of analysis. The applicability of the CON-XTM industrial conveyor XRF analyzer for continuous measurement of potassium content in process materials was demonstrated at various stages of potassium muriate (MOP) production. The CON-X analyzer produced reliable and accurate results for sylvinite ore (27–36% KCl), MOP cake after flotation (88–97% KCl), and NaCl residue (1.5–5% KCl). Tests of the analyzer at an MOP-producing plant showed a < 0.5% difference between online and laboratory results.

Jan 1, 2014

By A. M. Ramadan

The composition of phosphate rocks, mainly used in manufacturing fertilizers, varies among deposits; therefore, phosphate rocks from different sources are expected to behave differently in acidulation processes. This paper examines the effect of preconcentration of phosphate ore from El-Sebaiya East, Egypt, using flotation on uranium leaching. A high-grade ore sample (27.3% P2O5, 168 mg/kg U) supplied by the Al-Nasr Mining Company, was subjected to reverse single-stage flotation to separate carbonate from the phosphate sample. Subsequently, P2O5 and U concentrations were 32.2% (92.1% recovery) and 225 mg/kg, respectively. After the leach process, the U concentration in the liquor was 319 mg/L.

Jan 1, 2014

By Ri McCrindle

"Analytical Chemistry is moving rapidly towards a concept where technicians have to do no more than press a button and print the result from an instrument that is a featureless ""black box"". In this environment we must ask how much traditional &apos;&apos;wet chemistry"" is still required for undergraduate students.Methods that can be fully automated will become increasingly important. An example of such a method is that of the slurry nebulisation and ICP-OES analysis of precious metal concentrate. Grinding the sample and adding Triton X100 as dispersant, complete analysis time is in the order of 90 min as apposed to the traditional Carius tube method which could take as long as 24 h. For most of the elements studied, the results using ""in-house"" reference material for calibration and as samples as well were within the 95% confidence level. Elements of low concentration in the sample (As, Bi and Se) were not within that level."

Jan 1, 2014

By Yasuhiro Konishi, Norizoh Saitoh

"We have developed new recycling technologies, based upon an eco-friendly biotechnology, in order to extract precious and rare metals sourced from post-consumer products. Recently we have been focusing on the metal ion-reducing bacteria, Shewanella algae and Shewanella oneidensis, which are able to reduce and deposit the precious metal ions (gold (III), platinum (IV), palladium (II), and rhodium (Ill)) into metal nanoparticles at room temperature within 120 min. When targeting the leachates from printed circuit boards, the Shewanella bacteria were able to allow selective reduction and deposition of gold (III) ions under acidic conditions in the presence of heavy metal ions, proposing a new bio-recovery system for gold. We also found that the Shewanella bacteria can separate and concentrate soluble rare metal ions (dysprosium (III), indium (Ill), and gallium (Ill)) from dilute solutions. Using this biomass adsorbent, the effectiveness of system for the novel recovery of indium from the leachate of used LCD (liquid crystal display) panels has been demonstrated.IntroductionMany high-tech manufacturing industries are highly dependent upon the use of critical raw materials that are the rare metals (e.g. rare earth elements/indium) and precious metals (e.g. gold/platinum group metals). There are now serious global concerns over the short term and long term availability of critical raw materials for high-tech manufacturing. This highlights the paramount importance of sustainable component reuse and material recycling technologies for recovery of critical raw materials. We believe that the most important domestic source of precious metals is through more recycling, and this will require more research and further development for the recycling of precious and rare metals. In general, chemical/thermal recycling is deemed to be the most appropriate means to extract the precious and rare metals from postconsumer products. However, there are issues related to the heavy use of toxic and hazardous chemicals, and the release of toxic emissions.Biological recovery methods provide an attractive alternative strategy and use microorganisms to separate and concentrate soluble precious and rare metals from dilute solutions into microbial cells via biosorption [1-3] and biomineralization [ 4, 5]. Biological systems generally operate at ambient temperature and near-neutral pH. Consequently, microbial recovery of metals would be an environmentally friendly method for recycling precious and rare metals from end-of-use products."

Jan 1, 2014

By A. van As, J. McGaughey, M. J. Mol, R. Tosen

Geotechnical monitoring is a key element of the successful management of a block cave mine. The interrelationships between production and various monitoring datasets are often not realized due to a lack of data integration and appropriate 3D visualization. Timely delivery of information to ensure best cave management practices is only possible with an integrated cave management system. At Rio Tinto, a state-of-the-art cave management system (CaveCAD) has been designed and developed in cooperation with Mira Geoscience to integrate and analyze vast datasets and report this as instructive information regarding the current \u201cstatus\u201d of the cave.

Jan 1, 2014

By D. Chakravarty, B. Samanta, D. Ghosh

Autonomous robots are useful for 3D underground mine mapping to avoid human exposure to hazardous spaces. To prepare a precise mine map, a self-navigating robot must navigate an arduous path, avoiding obstacles and sensing the environment. A prototype laboratory-scale robot was built and evaluated through a mock-up in a test mine gallery. It was outfitted with a 2D laser scanner, a stereo camera for obstacle avoidance, and a high-precision, laser-based imaging and digitizing system for collecting 3D point cloud data. Various algorithms were used for scan matching to facilitate simultaneous localization of the robot for mapping.

Jan 1, 2014

By L. Chunpongtong

The Athabasca oil sands mineable resource is located in northeastern Alberta, Canada. In oil sands mining, the ore zone is regulated to have a minimum mining thickness of 3 m and a cutoff grade of 7 wt.%. The current algorithm that is widely used to flag ore zones and waste zones tends to overestimate oil reserves and causes low-grade ore to be processed. This paper presents the development of a more complex algorithm that is more representative of the actual oil found during operations and that can prevent low-grade ore from being sent for processing.

Jan 1, 2014

By N. R. Thote, J. L. Porathur, C. P. Verma

Highwall mining is a highly mechanized coal mining method associated with several advantages, such as a very high production rate (approximately 3,000 t/d) and low production costs. There is no requirement for underground support, ventilation, or blasting. Production leads to added recovery, which is otherwise lost in the ultimate pit. The use of highwall mining can bridge the gap that exists between supply and demand in the energy sector. This paper presents a brief review of highwall mining technology, including current status, analysis tools, and design techniques. In addition, it identifies important parameters from the analysis of failure case studies.

Jan 1, 2014

By C. V. Deutsch, O. Babak, J. G. Manchuk

High levels of geological heterogeneity occurring over relatively short distances pose a challenge to the unconventional open-pit techniques used in oil sands mining. There is strong motivation to mine selectively and minimize dilution and loss; however, the large equipment and high mining rate used to meet production targets tend to reduce selectivity. A numerical model is developed to account for geological complexity, mining equipment, regulatory criteria, and other operational parameters. This framework is used for more accurate forecasts, optimization of equipment, and other operational decisions. An example demonstrates the approach in light of Alberta Energy Regulator criteria.

Jan 1, 2014

By A. Vervoort, A. Govaerts

Geostatistical concepts are often difficult for students to understand, even those with a strong mathematical background. One of the main problems is the link between the variation of the parameter value in space or time and the calculated experimental semivariogram. Another challenge is differentiating between directional and omnidirectional semivariograms and their interpretation. For these reasons, interactive tools were developed based on the free public domain software R. The use of these interactive tools is limited to educational situations only (i.e., to visualize basic concepts). The interactive modules can be accessed at www.bwk.kuleuven.be/geostatistics.

Jan 1, 2014

By L. X. Li

Coking coal producers often encounter variations in clean coal quality when mining multiseam deposits containing coals with different washability and coking properties. This paper describes how, for a single coal property, an initial clean coal specification with an ash content of 8.5% on an air-dried basis (ADB) and a free swelling index (FSI) of 5.5 can be improved to a specification with 7.5% ash content ADB and an FSI of 6. This is accomplished by sorting coal seams into two groups for processing and blending. A preliminary economic model demonstrates how this improvement enhances economic returns through a beneficial factor.

Jan 1, 2014

By A. Rodriguez-Prado, P. Kuschk, R. L. Legge, W. C. Lennox

Using constructed wetlands to chemically reduce hexavalent chromium Cr(VI) to Cr(III) from industrial and mining wastewater has proven to be feasible and efficient. Applying first-order kinetics to describe the process is simple, but in some cases a more accurate model is required to reflect the process. This paper studies the feasibility of using non–first-order kinetics to describe the reduction process. Results indicate that half- and second-order kinetics adequately described Cr(VI) reduction in laboratory wetland mesocosms. The organic carbon content played a relevant role, whether it was built up by plant growth or spiked into the feed water.

Jan 1, 2014

By Chonghe Li, Xionggang Lu, Wei Xiao, Xingli Zou, Weizhong Ding

The reduction degree and rate of the initial ilmenite concentrate and pre-oxidation samples by hydrogen were investigated by using thermogravimetric analysis system. H2-TPR was used to detected reduction properties of the pre-oxidation products which were oxidized at different temperatures. The phase transformations and micromorphology changes during pre-oxidation and hydrogen reduction were identified by XRD and SEM. The FeTiO3 was decomposed into TiO2 and Fe2O3 at the temperature below 900 oC. With the temperature rising, Fe2TiO5 was the only stable phase in high temperatures. The reduction of pre-oxidation ilmenite concentrate was faster than the natural sample, which was attributed to the micropores generated on the surface of ilmenite concentrate during oxidation. The main phases of the reduction product were metallic iron, ferrous pseuodbrookite.

Jan 1, 2014

By Ramana. G. Reddy, Haoxing Yang

The electrodeposition of zinc from zinc oxide using urea and choline chloride mixture in a molar ratio 2:1 is investigated in different experimental variables, namely, the concentration of added [BMIM]HSO4, temperature, and applied cell voltage. The additive, [BMIM]HSO4, was determined to have beneficial effect on the current efficiency, energy consumed in the process and surface morphology of the deposits. The highest current efficiency (92.6%) and lowest energy consumption (2.92kWh/kg) was obtained for solution with 20mg/mL [BMIM]HSO4. The morphology showed the formation of absorbed additive layer on the cathode at higher concentration of additives. Experiments were conducted at different temperatures between 343K and 388K and at various applied cell voltages between 2.7V to 3.6V to determine the best experimental conditions. By varying temperature, highest current efficiency (91.3%) and lowest energy consumption (2.69 kWh/kg) was obtained at 373K. The electrodeposition process is enhanced between the applied voltage 3.0-3.3V by achieving lower energy consumption (2.75~3.06kWh/kg) and higher current efficiency (88.4~89.7%). SEM images showed grain size is significantly increased in higher applied voltages. While at higher temperatures, it seemed to generate particle growth as clusters at the outer deposit layer.

Jan 1, 2014

By Wang Shuchan, Zhang Zimu, Zhang Dianhua, Liu Yan, Zhang Ting-an, Zhao Qiuyue, Lv Chao

Rare earth extraction tank has many adverse effects like big floor space and high production accumulation during industrial production. Current researches usually focus on changing the device structure without making a breakthrough towards gravity clarification. This paper attempts to achieve this goal by using both the action of clarification by gravity and clarification by stirring. Because many physical parameters affect the clarification and separation rates, the density, viscosity and surface tension of the two phases were determined at different temperatures and different concentration of aqueous solution. The innovation of this research involves adopting the Karl-Fischer method to investigate water content in oil phase during the stirred separation process. In this paper, the separation effect of different physical parameters was studied and the dimensional equation between water content and the physical parameters was established by combining with the experimental data.

Jan 1, 2014