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By Shae K. Kim

The aim of this study is to manufacture magnesium alloys with alkaline earth metal oxides (BeO, CaO, MgO or SrO) additions with the objectives of (1) ensuring safety during processing and applications by raising the ignition temperature and reducing oxidation, (2) protecting the environment by reducing or eliminating use of protective gases, (3) maintaining or improving elevated temperature properties with lower amount of Ca or Sr or rare earth metals when compared with conventionally developed high-temperature magnesium alloys, (4) developing cleaner strip casting and continuous casting processes without hot tearing and (5) obtaining all of these objectives without sacrificing mechanical properties or increasing the cost of magnesium alloys.

Jan 1, 2006

By Jeffrey R. Hill

To extend the life of the Merchants Railroad Bridge crossing the Mississippi River in St. Louis, MO, the owner implemented a rehabilitation and reconstruction project. The Merchants Bridge provides a key link in the transcontinental railroad system. The bridge is of local importance to the Terminal Railroad Association ? providing a link between St Louis and a rail switching yard in Venice, IL. The intent of the bridge rehabilitation is to keep the Merchants Bridge in service, even though the bridge was originally constructed in the 1890?s. The project involved replacing the East and West approach deck truss spans with new deck girder spans. The rehabilitation program required construction of new concrete piers to support the new spans. In order to reduce the track down time to two, ten day single track shutdowns, the specifications required that all foundation and substructure work be completed while leaving the existing spans in place. The preliminary bridge design specified rock-socketed drilled shaft foundations. Drilled shafts proved to be challenging due to working from beneath the existing bridge, a high water table, utilities, a flood wall, and existing rail way lines. The micropile alternative was technically appropriate given the access limitations, shortened the foundation rehabilitation schedule by several weeks, and realized a significant cost savings to the Owner.

Jan 1, 2006

By Mark W. Sajewycz

Creating technology, securing patent rights, and managing a patent portfolio are time-sensitive and dynamic activities. Agreements should be in place with technology partners (employees, contractors, joint venture partners), prior to embarking on research and development projects, so as to mitigate future disputes over patent rights. Technology partners should be educated on patent law basics so as to be mindful of patent bar triggering events. Accurate records must be maintained to capture information relevant for preparation and filing of patent application, including subject matter, names of inventors, and invention date. Developed inventions should be evaluated for whether to file for patent protection, delay patenting until technology is further developed, maintain trade secrecy, or effect deliberate public disclosure. Once decision is made to file for patent protection, time is of the essence, and application for patent protection should be filed as soon as possible, as many countries award patents on a "first-to file" basis. Decisions on where to file are made having regard to potential competitive advantages versus cost considerations, and can be delayed by taking advantage of priority rights recognized in patent legislation of most countries. Once patents are granted, competitors must be policed for potential patent infringement, and legal action may be necessary to prevent patent infringement.

Jan 1, 2006

By Cole A. Wist

?Twowinters ago, what had been a mediocre safety record at West Virginia?s Sago Mine grew dramatically worse. Over 23 months beginning in February 2004, two dozen miners were hurt in a string of accidents, some of them caused by rock chunks falling from the mine ceiling. Federal safety inspectors slapped the mine with citations 273 times, or an average of once every 2 ½ days. Despite this record, the price paid by Sago?s operators was light. Government regulators never publicly discussed shutting down themine and never sought criminal sanctions. The biggest single fine was $440, about 0.0004 percent of the $110 million net profit reported last year by the mine?s current owner.? -Washington Post, January 8, 2006

Jan 1, 2006

By W. G. Pariseau

Introduction Caverns of 50 m in linear dimension at depths below 2300 m with a life of more than 25 years are proposed for the next generation of water-filled neutrino detectors. Little precedent exists for excavations in such an extreme environment, although some guidance is available from mining experience at great depths, for example, in South Africa, in Canada and at the former Homestake Mine in the U.S.A. Unlike mining for ore, there are choices available in the construction of such caverns that may mean the difference between success and failure. These choices should be informed by rock engineering principles. Recently proposed guidelines for orientation of brick-shaped caverns where the long dimension is a small multiple of the short dimension indicate that the most favorable orientation is with the long and short dimensions parallel to major and minor preexcavation principal stresses (Pariseau, 2005). Numerical analyses at reduced strength indicate some yielding at cavern walls should be expected but that an equilibrium state is quite possible and is aided by arching the back into a spherical dome when the cavern is an empty cylinder (Tesarik and others, 2002). The same indications of stability occur with brick-shaped caverns. However, the most dangerous situation occurs during the excavation sequence to final cavern dimensions. There are any number of excavation sequences that lead to the same final cavern shape, so there is an opportunity to partially optimize the sequence with construction guidelines that minimize peak stress concentrations during construction. This contribution discusses three practical excavation sequences that lead to the same brick-shaped cavern in the strong, massive Yates formation at the Homestake Mine where considerable rock mechanics data has accumulated through the years(e.g., Pariseau, 1985, Pariseau and others, 1995) and where actual mining on the 8000 Level indicates a strong possibility of successful investment in the next generation of large, deep neutrino detectors. The main results are: (1) a favorable brick-shape is one with dimensions in the same proportion as the preexcavation principal stresses (compressionpositive), and (2) favorable orientation of the most extreme but temporary shape of excavation is also best for the construction sequence. Analysis results from a mix of Homestake Mine data and possible excavation geometry illustrate the advantages of these guidelines.

Jan 1, 2006

By Maria de Campos

The pre-reduction behaviour of chromite particles in methane-argon and methane-hydrogen gas mixtures was investigated between 1050°C and 1250°C. Loose bed of chromite particles were reacted in a vertical tube furnace under a pre-set gas mixture predetermined time intervals. Metallization results were obtained for the Cr and Fe components by chemically analyzing the reaction products. SEM-EDAX techniques and X-ray diffraction were employed to elucidate the reduction mechanism. It was found that higher reduction kinetics and higher Cr:Fe ratios in the metal phase would be achieved when hydrocarbon gas was used in comparison to classical carbothermic reduction at a given temperature. The reduction rate was generally bulk gas mass transfer controlled to the reaction site for initial stages which then was followed by ionic diffusion rate control. It is proposed that methane did not partake directly in the reduction but cracked, presenting the reaction site with hydrogen gas and atomic carbon, which was able to immediately react at the immediate area of reduction regeneration CO and H2 and thus maintaining a low partial pressure of oxygen at the reaction site.

Jan 1, 2006

Your assessment of the minerals business. I would first like to express our profound sadness and sincere condolences to the families of the miners who lost their lives in recent mine mishaps particularly in West Virginia, and other locations. Any loss is unacceptable. It is time to review and, if required, re-establish a rigorous health and safety agenda in the mines. It must involve a review of health and safety regulations. And innovative training methods for sensing, awareness and mitigation of health and safety hazards must be developed. As far as the minerals business is concerned, I am excited about the outlook for mining. Over the last 20 years, global demand for minerals has closely mirrored the growth of the gross domestic product. Minerals re-main a major part of the world’s economic foundation. And that will continue to be the case. It is no surprise that the fortunes of the mining industry rise and fall with general economic trends. Globally, mining has been strong — thanks to the explosive economic growth in Asia. The U.S. mining industry has performed reasonably well, with notable strength in the metals, coal and construction and aggregate areas and with some softness in the industrial minerals sector.

Jan 1, 2006

By G. Adel, J. M. Richardson

Mine-to-mill optimization is a holistic approach to the optimization of mining and processing operations. Developed at the Julius Kruttschnitt Mineral Research Centre, it attempts to minimize energy consumption through the optimization of the particle size reduction process. The approach involves sampling and modeling of blasting and processing, computer simulation to optimize the operation and develop alternatives, implementation of the most promising alternatives, and sampling to quantify energy savings. The primary objective of the present effort is to adapt mine-to-mill technology to the aggregates industry. This paper presents an update of work being conducted at quarries operated by the Luck Stone Corporation of Richmond, Virginia.

Jan 1, 2006

By Jason Laumb

Regional Energy Production ?Energy is a globally traded commodity and is influenced by regional and national needs as well as international trends. We can greatly expand energy export from the region. ?Significant opportunities exist for increased coal-based energy production.

Jan 1, 2006

By M. Galetakis

This paper proposes a new approach for calibration of dual gamma-energy transmission (DU-ET) ash analyser for improved online analysis of run-of-mine lignite. An adaptive neuro-fuzzy inference system (ANFIS) was developed to model the relationship between the intensities measured by the scintillation counter of the analyzer and the measured ash. Samples collected from Megalopolis lignite mines were measured for their ash content by using standard laboratory methods as well as by DUET. Obtained data was divided into training, testing and validation sets. A first order Sugeno type ANFIS was used in conjunction with early stop training. The calibration performance obtained by this approach was significantly better compared with that obtained by standard calibration methods based on multiple linear regression analysis.

Jan 1, 2006

By A. Ansari

Standard depressants used in the selective separation of copper and molybdenum sulfides by flotation pose environmental and health hazards. In this investigation, the floatability of chalcopyrite and molybdenite in the presence of six well-characterized lignosulfonates was studied through Hallimond tube flotation and adsorption tests. The results define the physicochemical conditions (lignosulfonate type and dosage, pH, presence of ions) for possible selective separation of molybdenite from chalcopyrite. Dissolved polyvalent cations, especially calcium, appear to serve as "activators" for lignosulfonate adsorption on both minerals. From this point of view, the use of lime as a pH modifier is not always appropriate for optimum selectivity since high dosages of lime to produce high pH tend to indiscriminately depress both sulfides.

Jan 1, 2006

By Jin Li

The tensile properties and microstructure of AZ91 Mg alloy before and after equal channel angular extrusion (ECAE), and the fracture behavior during tensile testing for as-extrusion and ECAE AZ91 were investigated. The alloy was performed ECAE from one to eight passes at 498K. The elongation decreased with the pass number increasing after ECAE. Grains were refined, partial coarse ß-Mg17Al12 phase fell to pieces, fine ß-Mg17Al12 precipitated in the AZ91 Mg alloy after ECAE. During tensile test the a-Mg/ ß-Mg17Al12, a-Mg/Al8Mn5 interface and the grain boundaries in a-Mg matrix acted as the crack initiation sources. The frequency of micro-cracks at the a-Mg/ß-Mg17Al12 interfaces and grain boundaries increased after ECAE, which accelerated the growth and coalescence of the micro-cracks during tensile test and resulted in the decrease of elongation of AZ91 Mg alloy by ECAE.

Jan 1, 2006

By R J. Worland, D Bowyer, J L. Mauk

The TerraSpec is a compact field portable mineral analyser that uses non-destructive reflectance spectroscopy for mineral identification. The instrument uses and measures infrared and visible light that is absorbed by certain covalent and molecular bonds (AlOH, FeOH, MgOH, CO32-, OH, H2O and NH4) within the lattice of a mineral at specific wavelengths producing an absorption spectral profile. A variety of minerals can be detected including clays, micas, carbonates, and hydroxides as well as some sulfates and silicates. However, not all minerals are detectable, such as quartz and feldspar. Alteration minerals replacing volcanic rocks have been studied for several epithermal prospects in the lower Waitekauri Valley (Sovereign, Jubilee, Scotia and Jasper Creek) and a geothermal field in the Taupo Volcanic Zone. At the Sovereign, Jubilee, Scotia and Jasper Creek prospects previous XRD investigations determined well developed clay mineral zonation with illite in the west (Sovereign and Jubilee) grading into interstratified illite-smectite (Scotia) and smectite (Jasper Creek) to the east. Although the percent of illite within interstratified illite-smectite could not be determined and some illite-rich illite-smectite (>90 per cent illite) and some smectite-rich illite-smectite (>90 per cent smectite) could be misidentified as illite or smectite respectively, the TerraSpec survey determined the same zonation of illite to illite-smectite and smectite. Common chlorite, rare calcite and local kaolinite were also detected. At the geothermal field, the TerraSpec was primarily used to determine the occurrence of kaolinite, dickite and alunite, which form in acid conditions. Widely spaced (every 50 to 100 m) XRD results are in excellent agreement with closely spaced (every 5 to 10 m) TerraSpec results that further determined the occurrence of these minerals in previously unrecognised intervals. It also determined the occurrence of zoned smectite, illite-smectite, illite, and chlorite alteration. Overall, the TerraSpec is a rapid mineral identification technique that is very useful in delineating the occurrence and distribution of certain minerals in both epithermal deposits and geothermal fields. Although the TerraSpec cannot detect as many minerals as XRD, the TerraSpec allows data collection at a sampling scale and speed (real time) that is not practical by XRD.

Jan 1, 2006

By S. Kurama

Incorporation of de-watering sieve waste of borax (TSW) from Etibor Kirka Borax Company (Turkey) on the mechanical and physical properties of a commercial floor tile composition was investigated. In order to achieve this aim, TSW was partially employed in place of feldspar in the standard composition up to 20 wt %. The formulated compositions were wet milled, dried, shaped and then fired at 1190C for a total firing time of 38 minutes (from cold to cold) under industrial conditions. It was found that using of TSW up to 15 wt % improved the physical and mechanical properties of final product. The results indicated a good prospect for TSW as a co-flux in floor tile formulations.

Jan 1, 2006

By A. V. Tarasov

The nonferrous metals industry has been a sector with one of the highest growth rates during the recent years. The prospects for the Russian metals industry during the period until 2010 are associated first of all with a growing domestic demand for its products. The technological level of the metallurgical operations in Russia is relatively low in comparison with industrially developed countries: the average energy requirement is higher by 20% to 30%; the amount of generated waste in the process of rolled products manufacture is twice as high; the average labor productivity is lower by 2.5 to 3.0 times; the overall negative environmental impact is twice as high. Improvement of the technological level of the nonferrous metals production under the conditions of market economy is possible by application of innovative technologies for the development of this sector. The main trends for development of the nonferrous metals sector are: - meeting of more stringent requirements to the quality of concentrates; - more complete recovery of associated elements as commercial-grade products; - development of continuous process lines based on autogenous, resource-saving and environmentally safe processes; - use of combined technologies, including pyrometallurgical, hydrometallurgical and upgrading processes; - expansion of the fields of application for nonferrous metals and their alloys.

Jan 1, 2006

By Dennis R. Dolinar

Screen material in the form of welded wire mesh and geogrids are used in underground coal mines to prevent the fall of small pieces of rock from the roof between roof bolts. Further, if the screen is installed during the production cycle, roof fall injuries can be reduced significantly. Therefore, the National Institute for Occupational Safety and Health (NIOSH), because of the safety implications, conducted an evaluation of screen materials commonly used in U.S. coal mines to determine their support characteristics and identify the parameters that could affect their performance with respect to controlling the fall of rock from the roof surface. To evaluate the load and stiffness characteristics of the screen, a test frame was designed and installed in the Mine Roof Simulator (MRS) at the NIOSH Pittsburgh Research Laboratory (PRL). With this test set up, the screen is bolted at four corners of the frame and a center load is applied. The test set up allows for up to 20 in of screen deflection while the load and screen defection are continuously recorded. A series of tests were conducted to evaluate the effects of various parameters such as bolt tension, the type of load bearing surface and the size of bearing plates on welded screen performance. The most common screen material used in U. S. coal mines is an 8-gauge wire welded in a 4-by-4-in spacing or aperture. The peak screen load was normally limited by wire breakage. The conditions at the bearing plate influence the nature of the wire breakage. However, the screen stiffness was controlled by slippage at the bearing plates, and by weld and wire failure. The size of the bearing plate had a significant effect on the performance of the welded screen. Therefore, the design capacity of the 8-gauge screen is evaluated based on plate size. For a 6-by-6-in bearing plate the average peak load is 2,900 lb with a stiffness of 250 lb/in. For an 8-by-8-in bearing plate, the average peak load is 4,500 lb with a stiffness of 430 lb/in. These test results are based on a 4-by-4-ft bolt spacing. A geogrid mesh was also tested.

Jan 1, 2006

By Ephraim Jeya Kumari

The demand for the titanium dioxide pigments and the shortage of higher-grade titaniferous ores with low radioactivity and zircon sands worldwide has encouraged the development of new techniques for the beneficiation of lesser grade titaniferous ores. The inferior quality ores are invariably richer in radio-active and lanthanide oxides, which severely interfere with the fluidized bed chlorination reaction (FBCR), in which ultra-high purity titanium tetrachloride is distilled off for pigment manufacture. However the present beneficiation techniques require high quality ilmenite ores and are not suitable for upgrading lower grade ilmenite ores which do posses trace metals in the form of lanthanides and actinides as Al-phosphates and zirconium silicates, respectively. The presence of mineral hosts, zircon sand and monazite in ilmenite and anatase also increase in chlorine gas consumption in the FBCR and contribute to a larger volume of hazardous waste production, which must be neutralised at a significant cost before being disposed off safely. In view of the problems described for lanthanide (Ce, Nd etc) and actinide (Th, U) trace impurities in titaniferous ores, an alternative route, which is flexible and more accommodating for processing difficult ores, is discussed. In the new process, which may be used for richer grades of ores too, the ore is roasted in air with sodium carbonate below 950°C to promote the formation of water-soluble sodium ferrite and insoluble sodium titanate phases. In this investigation, the high-temperature roasting process and the ensuing hydrometallurgical leaching steps have been analysed in the context of selective separation of lanthanide and actinide minerals from the main titaniferous mineral structures. Evidences for the selective separation are presented based on the chemical (XRD, XRF, AA) and microstructural analysis (SEM, EDX, EPMA) of roasted mass and the leached product. The efficiency of selective separation is also reported based on the chemicals analysis and the particle size of the materials derived after leaching. The paper highlights the various thermodynamic aspects of reaction equilibrium in the Fe-Ti-O-Na system, and the effect of Eh-pH diagram in the determination of pH required for the better control of the removal of iron and sodium. Two different types of Ti ores, namely ilmenite and anatase, their crystal structure and the phase transformation will also be explained on the basis of wet chemical analysis, XRF, XRD, EPMA and SEM-EDX studies. The method developed examines the technological feasibility of the selective separation process.

Jan 1, 2006

By P. A. Olubambi

The leaching of zinc and copper from Nigerian bulk sulphide ore with sulphuric acid in the presence of hydrogen peroxide was studied. The aim of the study was to investigate the effectiveness of hydrogen peroxide as an oxidant for the sulphuric acid leaching of zinc and copper from a complex sulphide ore. Distribution of elementals within the various particle sizes was initially determined by ICP-OES and XRF to provide a basis for explaining the dissolution process. The effects of concentration of hydrogen peroxide, particle size, stirring speed, and leaching time at a constant temperature of 298K were studied. There were variations in elemental and mineralogical composition within the different sizes. The concentrations of zinc and copper reduced as particle size decreased while silica, sulphur, iron and lead contents increased. Dissolution results showed that the leaching rate of copper was lower than that of zinc. The highest recoveries of zinc and copper were obtained at a leaching time of 180 minutes, stirring speed of 160 rpm, particle size of 75 µm and a concentration of 1M H2SO4/1MH2O2. It was observed that the leaching rate of zinc and copper increased with increasing hydrogen peroxide concentration. Increased stirring speed had a negative leaching effect as it promotes hydrogen peroxide decomposition. Keywords: Nigerian sulphide ore, zinc, copper, hydrometallurgy, sulphuric acid, hydrogen peroxide.

Jan 1, 2006

By Rolf Schillinger

Blasting activities on the surface or underground necessarily involve the most sensitive aspect of environment remediation, human response or annoyance. Such effects are unavoidably characteristic of those activities. For this reason, blasting activities are governed by law and official regulations under surveillance of authorities, where companies and explosives engineers have to proceed within proper limits. Subject of the paper is a practical way of handling some necessary vibration standards being focused on blasting activities. The paper is based on the German Standard DIN 4150, Part 1 - 3, “Vibration in buildings”, Part 1: “Prediction of vibration parameters”, June 2001, Part 2: “Effects on persons in buildings”, June 1999 and Part 3: “Effects on structures”, February 1999.

Jan 1, 2006

By Leigh Freeman

This article provides an overview for a series of leadership development workshops offered through the SME Young Leaders Program. The first of these workshops, “Accelerated Development Plan,” will be held at the upcoming SME Annual Meeting in St. Louis, MO on Sunday, March 26. How does a foundation of technical competencies relate to the development of social competencies necessary for management and leadership roles in the resource sectors? Technical competencies provide the foundation for a successful career. Social competencies provide the framework on that foundation. Successful leaders will be those who develop competencies in all areas.

Jan 1, 2006