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By W. C. Zhu, C. H. Wei, L. L. Niu

With an increase of mining depth, a series of mining-induced hazards such as rockburst, coal and gas outburst, roof collapse, and water burst are getting more serious and more frequent. The intrinsic mechanism responsible for the occurrence of mining-induced hazards is the damage and unstable failure of rockmass or coal seam. The most distinct difference between deep and shallow levels is the so-called three ‘high’ (H3) conditions, i.e. high geo-stress, high fluid pressure and high geo-temperature. Therefore, the response of rock or coal to the deep mining operation is a phenomenon involving thermal (T), hydraulic (H), and mechanical (M) processes. Most importantly, mining excavation may vary the rock stress condition greatly, which may be a key factor to trigger the mining-induced hazards such as rockburst. In this regard, it is of great significance to clarify the damage and failure mechanism of rock and coal under coupled THM conditions, in order to clarify the rock failure mechanism responsible for the occurrence of mining-induced hazards. Thereafter, the mining-induced hazards cannot be predicted with confidence by considering each process independently. Of course, the requirement to include coupling of these processes depends on the specifics of the mining-induced hazards under consideration. For example, the water inrush is considered as a coupled hydro-mechanical (HM) process, in which the unstable failure of rockmass occurs under the combined contribution of geo-stress and water pressure. As for the coal mining at depth, in addition to high geo-stress and gas pressure in coal seam, the high geo-thermal condition that may greatly change the adsorption / desorption of gas and gas flow should be taken into account. Firstly, a general-purpose mathematical model for rock damage and failure process under coupled THM conditions is formulated based on damage mechanics principle, and it is solved by finite element method (FEM). In this model, the deformation and damage of rock, fluid flow and thermal transfer in rock would interact with each other, one process affects and initiation and progress of another. Then, the model is used to predict the mining-induced water outburst, where it is simulated as coupled hydro-mechanical (HM) problems. Based on the numerical simulation, the dimension of water-proof pillar is designed. Finally, the gas drainage from deep coal seam is numerically evaluated, where the coupled coal-gas interaction considering the effect of gas adsorption/desorption, gas flow in coal seam and geo-stress and geotemperature, is comprehensively taken into account. The proposed model could be used for clarifying the mechanism of mining-induced hazards in deep-level mining.

Jan 1, 2015

By N. Manopulo, J. Maier, L. Tong, C. Becker, P. Hora

The contribution presents a new finite element approach in which the common updated Lagrangian formulation is replaced by a spatial flow formulation applying a special arbitrary Lagrangian-Eulerian for-mulation (ALE). The description separates spatially the process in a die inside zone and in a profile zone. For the description of the inside zone, where the filling process occurs, a special Euler time independent mesh is applied. By this formulation the mesh has to be generated only once, which simplifies the generation of spatially optimized meshes. For mapping of the material flow during the filling process the method uses a flow surface traction method as applied in casting simulations. A further strength of the new method is the computational efficiency which allows the modelling of extrusion process with the highest complexity with a response time of 12 hours, which is important for the industrial optimization process.

Jan 1, 2015

By Krishna Parameswaran

In this paper, we attempt to answer an often asked question, how can metal mining be compatible with the principles of sustainable development. Starting with the classic Brundtland Commission definition of sustainable development as "development that meets the needs of the present without compromising the ability of future generations to meet their own needs," we make the case that mining is or should be sustainable, using examples of sustainable practices at ASARCO LLC, an integrated U.S primary copper producer. These examples cover the entire mining cycle starting with exploration, mining, beneficiation, smelting, refining, closure and post-closure and post-mining land use. It is hoped that the presentation will challenge the mining industry to even greater innovation as future mineral development projects are planned.

Jan 1, 2015

By Y. Q. Li, Z. C. Shen, C. H. Zhao

The dynamic properties of the KYF-320 flotation machine which is one of the biggest flotation machines in the world were tested and then verified by the computational fluid dynamics (CFD) simulation. Aeration rate testing results suggest that he effect of circulation holes on the fluid state in the flotation cell becomes gradually smaller when the impeller speed is greater than 107 r/min. The dispersion degree of air increases with the increasing impeller speed and decreases with the increasing aeration rate, and it increases slightly when the impeller speed is greater than 107 r/min. The air holdup increases and then decreases with the increasing impeller speeds and aeration rates, and a maximum value of air holdup is shown at impeller speed of 107 r/min with a value of 12.28%. CFD simulation results are in good agreement with these testing results. Industrial-scale test was carried out using this 320 m3 flotation machine for the flotation of Cu ores. The results show that Cu content increases from 0.06% of crude ore to 1.26% of concentrate, and the S content increases from 0.39% of crude ore to 24.83% of concentrate. Moreover, using this flotation machine 5.88% of power is saved compared to other type of large flotation machine.

Jan 1, 2015

By K. Thuro, H. Käsling, F. Menschik

"With increasing data volume, due to enhancing requirements for ground investigation programs for large construction projects, the demand for more efficient filing systems is more and more growing. Depending on the project we also have to use flexible systems to cope with varying data out of different lab and field tests.The chair for Engineering Geology at TUM is developing a web-based database solution to handle all project relevant data in a more appropriate way. We aim to optimize our data management to achieve a fast and easy way of collecting, documenting and analyzing our gained data. The second objective is to provide an easy access to our data for project partners across broadly distributed locations.This Database system consists of a PHP web interface and a MySQL database core. The current setup allows an online access via Internet (www). We are able to grant and constrain access to all data or only arrays of data with our user management system to guarantee the safety of project data and respect all rights and proprietorship. The database system is of modular design and consists of the following three base modules: module of general project data, module of laboratory data and user management module. At the current stage we are able to save and work with all usually generated specific values from unconfined compressive strength tests, brazilian tensile strength tests, point load tests, CERCHAR and LCPC abrasivity tests and ultrasonic tests. The user is able to perform a simple statistical analysis within our database (e.g. average calculation of one sample) and export data as csv or xls files for further analysis.For specific questions within projects we are able to deploy and integrate further modules in our database system. At this moment, we are developing an add on to use this database for different drill test analyses. One of the tools correlates drilling performance and drill head wear measured in the field with rock mechanical properties, and extrapolates the data to estimate the performance and wear in new projects. Today we are managing 90 projects with 550 samples and almost 1350 lab tests with the base module.In our contribution we aim to demonstrate an efficient way of data structuring using a relational database for laboratory and field testing data."

Jan 1, 2015

By S. Noh, T. K. Kim, B. O. Lee

Future nuclear reactor systems such as a sodium-cooled fast reactor are being designed under severe conditions in terms of operating temperature and irradiation fluence compared to current commercial reactors. For realization of such systems, it is necessary to develop an advanced structural material having both high strength and irradiation resistance at high temperatures. Oxide dispersion strengthened (ODS) steel is considered as one of the most promising structural material because of its excellent creep and irradiation resistance on the basis of uniformly distributed nano-oxide particles with a high density. Up to now, ODS steels have been intensively studied and developed to apply these materials to the in-core structural component of future nuclear systems. Several advanced ODS steels were designed and fabricated by a mechanical alloying, hot isostatic pressing and hot extrusion processes. This study focuses on the effects of heat treatment parameters during the fabrication process parameters on the microstructures of ODS steels for future nuclear system applications.

Jan 1, 2015

By Zorigtkhuu Davaanyam, Bern Klein, Stefan Nadolski, Amit Kumar

"The High Pressure Grinding Rolls (HPGR) is a relatively new comminution technology that has been shown to be more energy efficient compared to semi-autogeneous (SAG) mills. Full and fair consideration cannot be given to HPGR-based comminution circuits in early stage projects, because presently pilot scale testing is required for assessing and sizing; pilot scale testing requires bulk samples weighing more than one tonne. A CAMIRO research program was conducted at the University of British Columbia to develop bench scale tests that would reduce the quantity of sample required to assess HPGR.Three test procedures were developed.1. The Direct Calibration Methodology calibrates piston press test results to pilot scale test results such that piston press tests can then be used to determine the energy–size reduction relationship for a range of ore types.2. The Database Calibrated Methodology, which is similar to the Direct Calibration Methodology except that it calibrates piston press tests against a database of pilot scale and piston press tests.3. The Semi-Mechanistic Methodology was developed to use piston press test results as an input for an HPGR based energy-size reduction performance model.Through utilization of these methodologies, the energy–size reduction performance of an HPGR can be predicted with minimal sample requirement. In addition, piston press testing is far more cost effective, faster, and accessible than pilot-scale HPGR testing.IntroductionOne could argue that in the future, decisions regarding selection of comminution circuits will be made primarily on the basis of energy consumption. The following facts and predictions support the argument:"

Jan 1, 2015

By E. J. Haas, K. A. Rost

"This study sought to identify changes in continuous mining machine (CMM) operators’ risk perception and risk behaviors as a result of adding a proximity detection system (PDS) into their environment. To accomplish this research task, 9 CMM operators from 5 locations were interviewed. Interviews were thematically analyzed for constructs including patterns in risk perception and behavior before and after PDS integration and the process of adapting to the PDS. Operators discussed standing in the red zone less than they did before using the PDS; however, they also discussed other risky decisions they made while learning how to operate their CMM with the PDS technology such as “cheating” the technology and working faster to meet production goals. The process of relearning job tasks with technology and unintended behaviors as a result of that relearning process need to be taken into account when introducing new technology into the mine environment. The study results show an in-depth view of mine workers’ perspectives and how their job tasks and environment could be or are affected when learning how to use new technology that are relevant to companies and mine operators when introducing new technology into the mine environment. INTRODUCTION Established “red zones” can help prevent striking and pinning incidents by providing guidance to continuous mining machine (CMM) operators about where they should stand and not stand while operating a CMM. Although red zones influence operator placement positions, these guidelines are not foolproof safety mechanisms. Depending on the job task and circumstances of the mine environment, a CMM operator may unintentionally or intentionally stand in a red zone. For example, CMM operators may work in close proximity to their CMM for better visual attention cues and the ability to work at a higher rate of production [1-3]. To further enhance protection and prevent collisions between vehicles and mine workers, a proximity detection system (PDS) was developed for the industry. The PDS determines an individual’s position relative to a specific piece of machinery, issues visual and/or audible warnings to the mine worker to change positions, and, if necessary, disables machine motion [4]. The introduction of new technology within other sectors has been identified as a factor that influences work decisions. Specifically, previous research demonstrates that when technology debuts there can be an initial intrinsic risk perceived among users about how the technology will interact with their current environment and behaviors; however, these ambiguities, including the possible risks and benefits, are seldom studied [5]. Some research suggests that the constant presence of technology can disrupt situation awareness and decision-making capabilities by increasing worker responsibilities and worker cognitive demands [6-8]. Further, if workers’ perceived risks both with and without technology are misjudged, unsafe decisions that result in human error and injury may be more likely [9-11]. Although these statements are provided within a broad contextual framework, they support the need to study how technology is perceived among end users in their own environment. Because research about technological impact on worker behaviors has suggested both positive and negative consequences of technology, this issue is worth addressing in the mining industry. Specifically, research has not determined whether CMM operators view their placement choices in the red zone as safe or risky and what effect PDS technology has, if any, on risk perception and subsequent risk behavior."

Jan 1, 2015

By F. Cihangir, A. Kesimal, K. Karaman, B. Ercikdi

Uniaxial compressive strength (UCS) and shear strength parameters(cohesion and angle of internal friction, Cand F) of rocks are important parameters needed for various engineering projects such as tunnelling and slope stability. However, direct determination of these parameters is difficult and requires high-quality core samples for tests. Therefore, this study aimed to explore the applicability of the Brazilian test (BT) - a simple, less sophisticated and inexpensive method for both specimen preparation and testing - to estimate the UCS and shear strength parameters of rocks. Thirty-seven rock types were sampled and tested, 24of which were volcanic, 8 were metamorphic, and 5 were sedimentary. Statistical equations were derived to estimate the UCS and shear strength parameters of rocks using the BT. The validity of the statistically derived equations was confirmed using predictive analytics software (PASW Statistics 18). A strong linear relation was found between BT and UCS values. BT and UCS values exhibited prominent linear correlations withthe cohesion values of rocks. The Mohr envelope was also used to determine the cohesion and friction angle of rocks using BT and UCS values. It is deduced from the current study that the BT values can be used to estimate the UCS and cohesion. However, no relation was observed between the angle of internal friction values and the UCS and BT for all rock types. Therefore, different approaches are suggested for the estimation of the internal angle of friction for application in the preliminary design of projects.

Jan 1, 2015

By E. V. Konopleva, H. J. McQueen

Steels in high variety have been providing strength and ductility for more than a century mainly through complex heat treatments following hot shaping. The economical and sustainable goal was a steel with the two operations combined through applying knowledge of dislocations and strengthening mechanisms aided by new mechanical and microstructural techniques. Primary hot reversing-mill rolling produced static recrystallization (SRX) between every pass to significantly finer grain size. Hot torsion showed that with lay-on temperature and rate of reduction suited to gradual precipitation of minor additions of Nb, the austenite grains would become highly pancaked; the existence of very fine subgrains along the grain boundaries (GB) could be deduced from tests on stainless austenite. The HSLA strip had to be water-jet cooled immediately to prevent SRX at austenite GB and ensuring complete transformation to ferrite avoiding grain growth after coiling. Confirmation on old mills and successful product led to the design of more flexible mills for wider range of compositions and products. A significant one was auto bumpers that reduced crash damage. More crack-resisting compositions were developed for strip welding into line pipe for arctic oil transport. Lower metal consumption and easier fabrication has resulted in more sustainable welded bridging.

Jan 1, 2015

By P. K. Kaiser, C. D. Martin, F. Amann

"This article focuses on the uniaxial compressive strength (UCS) of homogeneous and heterogeneous rocks. Critical factors impacting the UCS of rocks are reviewed and then separate assessments of UCS data from homogeneous and heterogeneous rocks are presented. The variability (coefficient of variation) of UCS test results for homogeneous rocks is found to be generally <25% while for heterogeneous rocks the variability is >35%. Failure mode variation is found to be the cause of the variability of UCS test results in heterogeneous rocks. Empirical engineering design methods that use UCS as an input parameter are discussed and suggestions are provided for selecting appropriate UCS values.INTRODUCTIONThe UCS is one of the most commonly used rock engineering parameters whether for rock mass classification or for strength determination. The mean UCS and its variability are often assumed to represent a reliable rock material property. For the reasons discussed in this article, UCS is rarely representative of the intact rock UCS. The UCS test simply records the collapse load during uniaxial loading of a cylindrical specimen. As suggested by many, the UCS is an index rather than a unique engineering parameter. The UCS is thus a proxy for rock strength which depends on the loading rate (e.g., Bieniawski 1967), specimen geometry (e.g., Hudson et al., 1971), specimen size (e.g., Bieniawski 1968), and many other factors. Furthermore, the UCS is not the same as the Hoek-Brown strength criterion parameter sci.There are differences in opinion on what is commonly considered to be ‘intact rock’. When sampling ‘intact’ pieces of core from drillholes crossing blocks of rock bound by block forming discontinuities, samples will be ‘intact’ but some samples will be veined, others will be damaged, and others will be neither. According to Hoek (1983), intact rock pieces are “the unfractured blocks occurring between structural discontinuities in a typical rock mass” and the sci parameter for intact rock is determined using the fitting procedure proposed by Hoek and Brown (1997) based on the data requirements outlined by Hoek (1983). Studies (e.g., Bewick and Kaiser 2014; Kaiser and Kim 2014) have shown that independently determined UCS and sci values for the same rock type are not equivalent. Thus, UCS data cannot be used as a replacement for sci."

Jan 1, 2015

By D. R. Schmitt, Q. Jia, R. Kofman

"Tests were carried out on clear glass blocks containing borehole aligned with and at an angle to applied principal stress states in order to study the growth of drilling induced tensile fractures. The samples were illuminated such that photoelastic fringes could be video recorded during the measurements; this was useful in assessing states of stress and in determining fracture initiation. Axial drilling induced fractures were observed at the azimuths of the applied uniaxial stress as would be expected from the concentrated stresses. En echelon fractures were observed from the borehole deviated at 45° to the direction of the compression. These preliminary and currently qualitative results show that glass blocks serve as a useful test medium for studies of stress concentration and drilling induced fracture creation. INTRODUCTIONWith the increasing exploitation of unconventional oil/gas reservoirs using deviated drilling in recent years, the effects of the in-situ stress on the success of energy production have become more critical than ever before. Knowledge of the state of stress in the earth enables us to determine well trajectories, well locations, hydraulic fracturing design and production rates, but knowing the crustal stress is always challenging. Strictly, it can only be obtained to varying quantitative degrees by accessing the earth through drilling. Failure of the rock at the borehole wall produces borehole breakouts (e.g., Bell & Gough, 1979; Haimson & Herrick, 1986; Zoback et al., 1985) and drilling-induced tensile fractures (DITF) (e.g., Aadnoy, 1990; Aadnoy & Bell, 1998; Barton et al., 1997; Brudy & Zoback, 1999; Davatzes & Hickman, 2010; Peska & Zoback, 1995). Thus, it is important to understand the failure mechanism of the rock in the vicinity of the borehole. A number of closed-form expressions have been developed that allow the stress concentrations to be calculated in the vicinity of a borehole including Kirsch’s (1898) 2-D plane strain solution and 3D formulae for elastically isotropic (Hiramatsu and Oka, 1962) and anisotropic (Lekhnitskii, 1981; Amadei, 1983) continua. These solutions have been applied in numerous studies (e.g., Ong, 1994; Ong & Roegiers, 1996; Vahid & Ghassemi, 2011; Jia & Schmitt, 2014; Ito et al., 2001) to analyze the failure mechanisms of drilling-induced tensile fractures (DITF) on the borehole wall."

Jan 1, 2015

By X. X. Wu, Q. Zhang, R. H. Fan, Y. J. Feng, J. D. Liu, P. Z. Zhao

In the present study, AA6016 automotive sheets with different grain size were fabricated through changing fabricating parameters, and the effects of grain size on the bendability were studied by bending test and optical microscopy. The results showed that the sheet with coarse grains exhibited poor bendability, and some micro-cracks were revealed at the surface of the bending samples. While the sheet with fine grains exhibited good bendability, and the bending samples showed smooth surface. Shear bands on the cross section of bending samples were observed. It was found that samples with coarse grains had more shear bands. These shear bands distributed in bundles, which facilitated the formation of continuous neckings and micro-cracks. However samples with fine grains had less shear bands, which distributed uniformly. The decrease of grain size could not only hinder the formation of shear bands, but also improve the homogeneity of its distribution during bending. On the other hand, refining grains could increase the amount of grain boundaries, which impede the propagation of shear bands. Hence the decrease of grain size could hinder the formation of continuous neckings and micro-cracks during bending, resulting in the significant improvement of the bendability.

Jan 1, 2015

By Q. Chen, J. H. Zhang, M. Zhang, F. M. Zheng, Y. J. Zhang

The characteristics of air bubbles and gas dispersion in KYF flotation cell are studied using the method of the point conductivity probe and CFD simulation. With increasing of speed, the velocities of air bubbles increase slowly and the distribution of diameters exhibits little change. With increasing of aeration rate, the gas holdup is increased. However, the velocities and diameters of bubbles have no great change. The CFD predictions on gas holdup have good agreement with the experiment results. The gas holdup distribution in the center section is revealed. The gas dispersion in the middle and upper part of flotation cell is uniform. It would be helpful for bubbles and solid particles collision. The gas holdup of the lower part of flotation cell is scarce, and it agrees with the observation in experiment. The gas would accumulate at the suction side of impeller blades, and it would decrease the power consumption. The rotating speed and aeration rate have great effect on gas dispersion. With increasing of aeration rate, the gas holdup of flotation cell will increase. The increasing of speed would improve gas dispersion. The results are expected to help to optimize the performances of KYF flotation cell.

Jan 1, 2015

By A. Koster, V. Maurel, S. Dezecot, Szmytka. F.

The aim of this work is to clarify the role of microstructure heterogeneity in the initiation and growth of cracks in a lost foam cast A319 for low cycle fatigue (LCF) loading condition. Because 2D analysis fail to establish the scenario of damage events, this study is based on 3D in situ analysis using synchrotron X-ray tomography during LCF test performed at 200°C. If X-ray tomography is now an established technique to study damage development in 3D, its application for relatively high temperature cyclic tests has never been done so far. Initial 3D observations of damage show that the cracks that lead to fracture initiate near large pores and propagate into the hard particles 3D network of the eutectic regions.

Jan 1, 2015

By Mark S. Greenleaf, Alec D. Smith, Mary Vittoria-Bertrand, Heather B. Scranton, Jean Louis Z. Locsin

"Rhode Island’s new $163.7 million, 2,265 ft (690 m) long, four-lane Sakonnet River Bridge sits just south of the existing bridge in Portsmouth/Tiverton. The bridge, a critical transportation system link between Massachusetts and Rhode Island, has a steel I-girder main span and concrete New England Bulb Tee approach spans. The foundation work was done between October 2009 and July 2010, and the bridge was completed in February 2014.Foundation design and construction challenges make the project noteworthy. There were thick layers of silty glacial soils with bedrock as deep as 400 ft (122 m) below the waterline, coupled with high foundation capacity demands at the river piers in 50 ft (15 m) of water. The Sakonnet was one of the first major bridge projects in the country to incorporate AASHTO Load and Resistance Factor Design (LRFD) guidelines for foundation design and construction. Because of these and other challenges, the engineers conducted two design-phase load test programs on several foundation elements. These programs were successful and allowed the engineers to adjust the final foundation design prior to the start of construction. During construction, the contractors drove thirty 6 ft (1.8 m) diameter steel pipe piles, each with a novel recessed steel plate insert, to depths of 130 to 200 ft (40 to 61 m) at the three river piers. The insert provided increased resistance of the steel pipe piles and saved about $9 million. Also, 457 14x117 en bearing or friction H-section piles were driven to between 50 and 190 ft (15 to 58 m) at five land piers. All piles were driven relatively close to the existing bridge, which remained in service during construction, due to the project team’s precautionary use of instrumentation and the installation of a jacking system.Area GeologyThe Sakonnet River is up to 60 ft (18 m) deep along the bridge alignment and is underlain by a deep bedrock valley. The bedrock valley is buried by at least 350 ft (107 m) of soil, which includes a complex sequence of interbedded glacial soils (glacial till, glaciolacustrine deposits and glaciofluvial deposits), overlain by geologically recent estuarine deposits. The soils having the greatest impact on the foundation resistance are the glaciolacustrine (fine sandy silt or silt) and glaciofluvial (silty sand with gravel, cobbles, and occasional boulders less than about 2.5 ft [0.8 m] in size). The soil overburden decreases toward the east and west banks of the river, as the bedrock surface rises."

Jan 1, 2015

By E. Ghali, W. Zhang, G. Gabra, N. Sorour, G. Houlachi

The additives polyacrylamide, 1-Butyl-3-methylimidazolium chloride, Tetra-butylammonium bromide, Benzalkonium chloride and chitin are evaluated during zinc electrolysis from synthetic acidic sulphate electrolyte containing Mn2+ ions, in absence and in presence of 0.0055 mg dm-3 of Sb3+ ions. Galvanostatic polarization tests for 2 hours at 50 mA cm-2 and 38oC were carried out to determine the cathodic and anodic potentials, and current efficiency of the deposited zinc. Potentiodynamic polarization and cyclic voltammetry tests have also been employed to study the electrochemical behavior of each additive on the zinc deposit on aluminum electrode. Results showed that, in presence of Sb3+, adding 1 to 3 mg of 1-Butyl-3-methylimidazolium chloride increases the cell voltage by ˜0-7 mV. Current efficiency is increased by ˜4.90-6.40%; power consumption is reduced by ˜147-173 kWh t-1 by adding 1-3 mg, respectively. However, in absence of Sb3+, cell voltage is decreased by ˜7-28 mV, current efficiency is increased by ˜0.70-1.50%; power consumption is reduced by ˜41-47 kWh t-1 by adding 1-3 mg. The effect of the other additives on cell voltage, current efficiency, lead content and morphology of zinc deposit has also been examined. Surface morphology and crystallographic orientation of the deposit was studied using scanning electron microscopic (SEM) and X-ray diffraction (XRD), respectively. The content of lead in the deposit has also been measured using inductively coupled plasma spectroscopy (ICP).

Jan 1, 2015

By R. R. Song, Q. Li, H. Xing, X. C. Wei

Geomechanical modelling of fault stability is an important part of CO2 capture and storage (CCS) research program to ensure its viability and long-term safety. Storage of CO2 in deep subsurface reservoirs requires estimates of sustainable fluid pressures that will not induce fracturing or fault reactivation which could cause fault slip. More importantly, fault slip gives rise to seismic waves, which inflict severe damage to the cap rock of the reservoirs and may result in leakage pathways for the buoyant plume and thus compromise the integrity of seal formations. In this study, we generated a numerical model tuned towards conditions usually encountered in the Shenhua CCS demonstration project in Ordos basin. In particular, with the purpose of evaluating the sensitivity of the parameters as well as their relationships with the moment magnitude of the seismicity, a variance-based sensitivity analysis was adopted for importance ranking of the uncertain input parameters of the given model. However, such flow models could involve one or several spatial inputs, for instance, fault dip, distance between fault and the injection well, friction angle of fault, permeability of fault, Young's Modulus of fault, injecting pore pressure and the stress field. Studying the sensitivity to each of these spatial inputs motivated the present work. The results led to the following conclusions: fault depth and fault dip significantly affect the behavior of the fault and the fault slip becomes violent with the fault depth increasing and fault dip decreasing. Furthermore, the results indicate that slip time increases with the fault dip decreasing and decreases with permeability of fault increasing. In addition, the calculation of seismic moment and moment magnitude of an earthquake demonstrates that it rises significantly with the decrease of fault dip and the increase of fault depth, and it decreases with the rising stress field. The results show that variations of the only controllable parameter injection pressure do not show great influence to the fault behavior compared with other geological factors, which imply site selection is extremely important for the CCS projects.

Jan 1, 2015

By P. Schmidt, M. Hopf

Water-cooled parts of submerged arc furnaces are potentially dangerous, especially if molten matte or slag contacts the water. Explosion hazards and metal run-outs generate high costs for production loss and repairs - not mentioning the possible loss of human life. This paper reports about practical results of wear measurement on intensive water-cooled tap-holes and spray-cooled side walls. On the one hand an embedding technology has been developed, that is used e.g. in water-cooled copper tap blocks or copper side wall coolers. Second the application of the sensor installation on the inner side of a water-cooled steel shell will be discussed. The fibre-optic sensor is fed through a specially arranged piping system and measures numerous temperatures over its entire length. By using the thermal conductivity of the installed refractory materials the lining thickness is calculated. The practical installation of the sensors will be discussed and the results of the wear measurement will be compared to the theoretical FEM calculations. The highly sensitive and accurate temperature measurement, as well as the recalculation of the impact of differences in the cooling water temperature, allows the exact determination of the remaining lining thickness. The discussed technologies offer efficient and safe monitoring of tap-holes, side walls and other endangered parts of pyro-metallurgical smelters.

Jan 1, 2015

By T. Ivankina, T. Lokajícek, H. Kern, T. Svitek

The knowledge of 3D velocity distribution of P- and S-waves in rocks is very important parameter for interpretation and understanding the nature of seismic anisotropy observed in the earth’s crust and upper mantle. A new high-pressure measuring head was designed and constructed to enable ultrasonic sounding of spherical rock samples in 132 independent directions under up to 60 MPa of acting hydrostatic pressure by means of simultaneous longitudinal and transversal sounding. New measuring system enables ultrasonic sounding of spherical rock samples by using a pair of P-wave sensors and two pairs of perpendicularly polarized S-wave sensors (TV and TH) see Fig.1. Shear wave sensors polarization is oriented according to rotation axis of the sample. Special shear wave gel was used to transfer shear waves between the sample and sensors under acting hydrostatic pressure. An isotropic glass sphere was used to check and calibrate the new measuring setup. A spherical sample of a biotite gneiss from the Outokumpu scientific drill hole was used for testing measurement. There is shown that both, P- and S-wave velocities, can be measured simultaneously up to 70 MPa, respectively. We report data of the 3D velocity distribution of P- and Swaves measured for the first time on a sample sphere of biotite gneiss. We rely, in particular, on the directional dependence of compressional and shear wave propagation and their relationship to the crystallographic (CPO) and shape preferred orientation (SPO) of major rock-forming minerals. The 3D seismic measurements revealed a strong foliation-related directional dependence (anisotropy) of P- and Swave velocities. Ultrasonic measurements were compared with 3D velocity calculations based on neutron diffraction measurements of crystallographic preferred orientation (CPO) of major minerals. Comparison of 3-D velocity distribution (P, S1, S2 and S1-S2) determined by two completely different methods ultrasonic sounding and neutron diffraction is presented. Measurements showed that the intrinsic bulk anisotropy is basically caused by the CPO of biotite constituting about 23 vol.% of the rock.

Jan 1, 2015