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By D. Bessinger, J. M. A. Geldenhuis

High titania slag is produced from the smelting of ilmenite. These slags contain approximately 85 per cent TiO2 and consist mainly of a M3O5 solid-solution phase. During cooling the slag can decrepitate to a fine particulate material, which decreases the value of the product. Based on X-ray diffraction analyses of the decrepitated slag after cooling, it was found that the M3O5 phase had almost disappeared. The disappearance of the M3O5 phase was linked to oxidation of the slag. A M6O11 phase formed in the decrepitated slag. It is postulated that decrepitation of high titania slag is caused by volume changes due to the oxidation of the M3O5 phase in the slag.

Jan 1, 2005

By P. Venkatraman

Laboratory and pilot-scale test data have shown that the innovative feed presentation of the CrossFlow separator provides improved metallurgy when compared to traditional hindered-bed or teeter-bed classifiers. This design feature prevents excess water from entering the separation chamber and disrupting the overall fluidization flow rate within the teeter zone. Recent side-by-side industrial-scale evaluations have verified that this technology can improve overall efficiency, reduce the cut point of separation, and increase throughput capacity. This paper describes the important features that make this novel separator ideally suited for size classification and density concentration. Test data from heavy mineral, phosphate, and industrial mineral applications are also discussed.

Jan 1, 2005

By M. Morrongiello

The Kalgoorlie Consolidated Gold Mines Fimiston Open Pit is mining through a dense network of disused level workings and stopes of varied sizes and orientations. This study investigated the interaction between underground workings and the pit slope stability, in particular for the ultimate pit depth of over 600 metres. Parametric analyses were conducted on the structural and rock mass properties in order to provide realistic input. Several cases in both 2D and pseudo 3D using UDEC were modeled and analyzed to investigate the performance of the rock mass at various mining stages. The concept of equivalent property factor was also introduced to model the 3D behavior using 2D models. Based on the modelling results, the possible failure mechanisms and deformation of the pit walls were assessed. Factors of safety have been derived for the pit slope at different mining stages using the strength reduction technique. The modelling results agree well with pit performance monitoring results to date. The concept and results presented in this paper could be a useful reference for operations with similar circumstances and stress regimes.

Jan 1, 2005

By Shimi Tzobery, Jay Davenport, Raymond Henn, Sam Bandimere

Over the past several decades, the use of cement-based grouts using ultra fine cement as a replacement for portland cement has begun to gain acceptance as an alternative to chemical solution grouts used in permeation grouting. The amount of information currently available on grouts made with ultrafine cement is limited. The authors used a previously developed field testing program to perform additional tests to evaluate the permeation performance of portland and ultrafine cement-based grouts. For the first time, the 2003 testing program included an attempt to determine the 28 day compressive strength of the sand permeated by the grout.

Jan 1, 2005

By D. B. Spears

The sillimanite group includes the aluminosilicate minerals sillimanite, kyanite and and alusite, all of which have the same chemical composition (Al2SiO5). This discussion also includes the closely related mineral, mullite(about Al6Si3O15), which, although rare in nature, is produced artificially for industrial use. All of the minerals in this group have a low coefficient of thermal expansion and high corrosion resistance. This makes them desirable for refractory applications, especially in the steel and foundry industries. Other uses include electrical insulators, abrasives and household ceramic products. The minerals in the sillimanite group decompose with an irreversible expansion at temperatures between 1,300° C and 1,600° C (2,372° F and 2,912° F). Sillimanite and and alusite have relatively small expansion on decomposition (4 percent to 6 percent) and, therefore, can be used as aggregates in refractory products. Kyanite’s expansion on decomposition is large (18 percent). So it is sometimes used to balance shrinkage of other materials such as clays in refractory mixtures. For applications requiring high-temperature volume stability, mullite is more desirable. As an additive, mullite improves resistance to creep and corrosion, and imparts thermal and electrical insulating properties.

Jan 1, 2005

By Kelvin K. Wu, George H. Gardner

On July 24, 2002, a nonfatal entrapment accident occurred at the Quecreek #1 Mine, Black Wolf Coal Company, when an active mining section inadvertently cut into a flooded abandoned mine. This incident, and the dramatic rescue which ensued, brought national attention to a common problem in the coal mining industry. Since 1995, there have been more than 100 inundations at coal mines in the United States. Unavailable, inaccurate, or incomplete mapping of older abandoned mines is typically responsible. Serious problems associated with accidental discharges of fluid mine waste material (slurry) and water from coal refuse disposal facilities have resulted from similar causes. Recent problems related to the inaccurate location of old abandoned mine works have increased the interest in the use of conventional and emerging drilling and geophysical techniques for detection of air-filled and water-filled cavities. The United States Congress has committed significant funding toward investigating the applicability of these technologies. MSHA actively promotes the use of the best available technology to minimize the significant adverse safety and environmental consequences associated with unplanned breakthroughs and inundations. This paper provides background information and a general summary of the MSHA-sponsored field demonstration projects which are currently in progress. Potential benefits and limitations are discussed. The need for field verification/ground-truthing is emphasized. Under appropriate conditions, geophysical methods can be effectively integrated into a comprehensive field exploration program.

Jan 1, 2005

By Lars A. Stålberg

"This paper will touch several of the topics covered by SDIMI 2005, including,• Sustainability indicators for the minerals industry, • Best practice of sustainable development in the minerals industry, • Social contributions,The complex issues of a company’s "sphere of influence" and "complicity" are important to every discussion of business and Human Rights. The paper will argue that to protect and promote Human Rights needs to be regarded as an integral part of sustainable development policies for the minerals industry. This implies a need for explicit inclusion of Human Rights indicators among the indicators to be applied by the minerals industry."

Jan 1, 2005

By Ch. Arvanitidis

This paper presents the design solution for an actual case of settlement tanks, for a wastewater treatment plant under construction, actually founded on swelling clay (the nature of which had not been appreciated beforehand) and suffering considerable damage as a result. Two points of interest prompted the use of a numerical model as an alternative approach to the traditional method of analysis: First, the desire to compare the in situ measured deformation and displacement of the tanks with the figures calculated by the numerical model. Second the need to check the validity of the suggested solution as a remedy, i.e. the replacement of a certain thickness of clay by graded material.

Jan 1, 2005

By R. K. McLimans, C. Knudsen, S. Bernstein, D. Frei

Computer Controlled Scanning Electron Microscopy (CCSEM) is used to analyze indivdual mineral fractions in heavy mineral sands. CCSEM is a fully automated particle analysis technique for the determination of physical and chemical properties of a large number of individual particles. CCSEM enables the precise and accurate determination of the modal abundances of individual mineral fractions (e.g. ilmenite, rutile, zircon, or garnet), their average chemical composition (and compositional variation), as well as their physical properties such as size (e.g. diameter and perimeter length) and shape (aspect ratio and circularity). A unique sample preparation procedure is used to produce representative polished sections from cylinders of raw sand samples such that thousands of grains are present in a polished cross section, but grains are not touching. The combination of this sample preparation technique with CCSEM enables the fully automated analysis of individual grains without the application of de-agglomeration or erosion steps to separate touching particles. Hence, CCSEM yields information representative of the entire area of analyzed grains without systematic bias due to neglect of rim areas by de-agglomeration or erosion steps. Therefore, the resulting data are determined with high accuracy, precision and statistical validity. Because the sample preparation is relatively straightforward, using raw sand samples, and all chemical and physical properties are determined in one analytical session per sample, CCSEM is a powerful cost and time efficient tool for characterizing chemical and physical properties of minerals in heavy mineral sand deposits.

Jan 1, 2005

By E. Giama, A. Macridis, A. M. Papadopoulos

ISO 14031 is an international standard that describes a process for measuring environmental performance evaluation by setting quantitative indicators and providing a structured approach for organizations to follow, independent of location, size, complexity and type of activity. It is not a standard for certification as ISO 14001 is, but it fits into the ISO 14000 series of standards and is intended to assist organizations to apply environmental management systems and obtain environmental evaluation. This case study’s main objective is to identify the interaction between ISO 14031 and ISO 14040-42. ISO 14040-42 is referring to Life Cycle Analysis (LCA) methodology. More specific, LCA is applied (based on the ISO 14040-42 standard) to stone wool’s production, the market dominating thermal insulation material, produced by bauxite and amphibolite. LCA is used as a decision making tool for the development of environmental indicators (based on ISO 14031 guidelines) and for environmental performance evaluation.

Jan 1, 2005

By P. Magnani

Quarry environmental reclamation can be achieved with favorable economical advantages and high energy efficiency, using stabilized materials obtained by the treatment of organic fraction of municipal solid waste (MSW).

Jan 1, 2005

By Steve Kral

The upswing in prices for base and precious metals, industrial minerals and coal has allowed the global mining industry to ramp up production at existing mines and begin construction of proposed projects. In addition to satisfying shareholders, the industry is also providing good paying jobs and creating needed infra-structure in places that previously did not have either. However, the industry has learned that the prospect of jobs and infrastructure is not necessarily a guarantee that communities will allow mines to be built. The industry must maintain even higher environmental and reclamation standards. And mining companies must help communities plan for life after a mine is closed and the company moves out.

Jan 1, 2005

By J. Kulczycka

Poland in time of transition had been dealing with the remnants of the previous regime ? particularly in the field of environmental protection. The burden left was tremendous and there was a need for fast and effective tools for improving the environment. The idea of environmental protection had been supported by the introduction of a new environmental policy that underlined the importance of sustainable development in industry in the beginning of 1990s. This policy introduced high environmental fees and fines ? a concept not very popular in Europe in that time ? and good only for a country in transition to boost the protection of the environment. While this policy had its role to play, its role is now completed. It is time to move forward, especially when these environmental charges affect the international competitiveness of industries so much, and at the same time have virtually no influence on environmental protection investments any more.

Jan 1, 2005

By Mutombo Nombe, Avimanyu Das, Rick Honaker

Enhanced gravity separators (EGS) provide a more efficient separation than froth flotation when cleaning coal in the 150 x 25 µm particle size range. To improve the performance of an EGS unit, air bubbles were injected into the feed stream in an attempt to decrease the apparent density of the coal particles due to the formation of bubble-coal particle agglomerates. Air injection had a significant impact on operating characteristics and separation performance. Coal recovery was increased by 10 to 20 absolute percentage points while a 2 percentage point drop in the minimum product ash content was also achieved.

Jan 1, 2005

By Misra M., P. Grimes, Chen. S.

The combustion of petroleum products produces emissions which contain oxides of nitrogen (NOx), hydrocarbons (HC), and particulate matter (PM) which have adverse health and environmental effects. In recent years there has been increasing interest in the use of water-fie1 emulsions as a substitute for conventional fuels. Emulsified fuels are emulsions of water in fuel, which are typically made of 10 to 20 percent of water mired with certain additives and fuel. Studies have shown that the emulsified diesel can significantly reduce the emissions of NO, PM and car- bon monoxide and increase the fuel efficiency. In order to produce a stable diesel emulsion, the development of an effective surfactant additive is critical. The stability of diesel emulsions is influenced by many factors, including size distribution of the droplets, the viscosity of the continuous phase, the physical properties of the interfacial film, and temperature. This paper describes a method to produce emulsified diesel and combustion results obtained from various tests. It has been found that the diesel emulsion made with this additive package was stable during the test, and the emissions were lower in NO, CO, and PM compared to the baseline diesel.

Jan 1, 2005

By David M. Jurich, Randy J. Essex, Alex de Aboitiz

An Automated People Mover (APM) transit system is planned for the growing Phoenix Sky Harbor International Airport. The APM will improve passenger movements between the terminals, and provide a link to parking facilities, a new rental car facility, and the planned metro Light Rail. The underground works will include shallow twin bored tunnels, taxiway crossings, and underground stations constructed beneath critical airport facilities. Challenging soft ground conditions will require extensive underpinning and ground improvements. Design is underway, and construction is scheduled to begin in 2007 with project completion in 2015. The owner’s planned delivery method for the APM Project will be Construction Manager at Risk (CMAR) with a Guaranteed Maximum Price.

Jan 1, 2005

By A. Subbotin

During developing the Ingulska mine at the Mi-churinske uranium deposit in the central part of Ukraine the radioactive rock dumps have been piled. A height of dumps reaches to 15-25m. They occupy a large territory and can be a source of covering with radioactive dust the area around the Ingulska mine. Uranium content exceeds 0,01% in all dump rocks samples while in the dust fraction samples it ranges from 0,01 to 0,06%. Uranium content in road dust at the dump?s foot reaches 0,137%. A new (for Ukraine) method of f-radiography of tree and bush leaves sampled at the territory about 100km2 has been used. It is based on fission of 235U nucleuses due to heat neutron influence in a nuclear reactor and on following study of the Lausan films with tracks drawn by the fractures of these nucleuses. Uranium content of the dif-fusion-disseminated dust type is (0.9-22.2)?10-6% while in the individual particles it can be considered much more because of burned holes in Lavsan above them. The dust content with uranium in Kirovograd reaches to 20-50 part/cm2 while near the dumps it ranges from 100 part/cm2 to 300 part/cm2 in the radius of 1,5-2km from the Ingulska mine.

Jan 1, 2005

By K. Bounou, K. Komnitsas

"Risk quantification may be used as a sustainable development index in the mining industry, since it encompasses both economic and social factors. In addition, it may assist in the development of a framework, which is also indirectly related to sustainable development, to prevent accidents and improve health and safety standards. However, risk quantification in the mineral sector involves diverse activities and is considered a very difficult task. Although statistical data report accident severity rates, incident rates and accident frequency rates, none of these allow for accurate risk calculations. In this paper, two risk calculation formulas, which may be used to quantify risk, as well as to identify hazardous activities in a workplace, are proposed. Numerical examples are given based on statistical data available through the MSHA database. Also a combination of a decision/fault/event tree that allows risk quantification is presented."

Jan 1, 2005

By Bekta? Uz

The study area is located between Orhangazi and Sapanca geographically known as Armutlu Peninsula (Figure 1). It is steep broken and mountainous with an area of 4000 km2. [ ] Economic marbles are investigated in regionally such as Orhangazi, Elmali, Menek?eyayla, Sapanca, Pamukova and they are seperated approximately 800 km2 (Figure 2). These marbles are massive, thick and dispersed as small sized outcrops in Armutlu Peninsula.

Jan 1, 2005

By Huayang Luo, Hui Li, Wei Zhou, Gang Chen, Scott Huang

Abundant beach and offshore resources of gold deposits are demonstrated along the coast of Alaska, and Nome is one of the richest places. Considerable amounts of mineral resources data were collected and stored in geodatabase of ArcGIS. In searching for the best model for the interpretation of the Nome offshore gold placer deposit and accurate estimation of the reserve, the data were processed and visualized using ArcGIS. The gold concentration data collected from the Nome offshore deposit are of characteristics such that: (1) near lognormal distribution of data, (2) high positive skewed distribution, (3) a small number of extreme values dominating the reserve estimation, and (4) apparent anisotropy of the variogram. These characteristics make the development of an interpolation model for the gold deposit a challenging task. In this study, it is determined that five geostatistical methods provided by ArcGIS with visualization capability, i.e., Inverse Distance Weighted (IDW), Ordinary Kriging (OK), Ordinary Kriging with lognormal transformation (OK-log), Simple Kriging (SK) and Indicator Kriging (IK) are suitable candidates for the development of an interpolation model. The five algorithms are evaluated and compared with each other in the study. Cross-validation technique is employed to examine the accuracy of the five approaches. It is determined that the OK and SK algorithms are not suitable for this dataset because of the difficulty of fitting the semivariogram model despite their lower RMSE (Root-mean-square error) and the higher RMSS (Root-mean-square Standardized). The OK-log algorithm does not provide satisfactory prediction either, because it places too much weight on the role of extreme values resulting in overestimation and extremely high RMSE. Reserve estimation of each blocks is conducted using each of the interpolation methods and compared with the reserve calculated using the conventional polygon method. The IWD and IK algorithm seem to provide estimations more agreeable with the conventional polygon method.

Jan 1, 2005