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By M. Kavvadas

Geotechnical design using Factors of Safety recommended by Codes of Practice is based on largely unknown ?margins of safety?, usually without consideration for the importance of the project (i.e., potential consequences of failure) directly or explicitly. On the contrary, probabilistic modelling can be a useful tool in risk management as it provides the means to measure the risk to be managed. This is achieved by calculating the probability of failure associated with a specific design, i.e., by relating the classical factors of safety with the corresponding probability of failure and by using a cost optimization procedure to achieve ?optimal? designs, accounting for the expected costs in case of catastrophic failure. This paper describes the methods used to calculate the probability of failure and its correlation with the classical Factor of Safety using sampling techniques and a simplified method based on the moments of the factor of safety considered as a random variable. These procedures are illustrated in an example which investigates the stability of a slope.

Jan 1, 2005

By R. J. Matetic, Peter G. Kovalchik, Jeffrey Shawn Peterson

The National Institute for Occupational Safety and Health (NIOSH) has initiated a study of a roof bolter to reduce noise exposure to mine roof bolter operators. An important segment of this research entails determining the affect of various drilling configurations on the performance (penetration rate) and sound power emissions when drilling into granite. Test conditions included various combinations of rotational speeds and thrusts; hex and round drill steels of one inch (1.) and one and three-eighths inch (1 3/8.) diameters; vacuum and wet conditions; and using drill media of differing compressive strengths. This paper will detail the affects of each of these on the performance and sound power level emission. When drilling into granite, it was found that wet drilling generated lower sound power levels and performed better than vacuum drilling.

Jan 1, 2005

By Donald W. Stever

In 1995 I was asked to participate in a litigation matter between a corporation and its insurance carriers concerning insurance coverage for remedial costs at a large, environmentally contaminated closed-down former industrial facility. One of the buildings on this site became known to the lawyers representing the company as “the infamous Building 8”. This building housed millions of documents retrieved from various locations at the facility while it was being shut down. It became apparent that the facility management had no document destruction policy, and thus Building 8 contained internal memoranda, notes, copies of correspondence, permits, operating records, inventory records, and the like from fifty years of operation. Needless to say, some of these documents, all of which were subject to discovery by the insurance companies in the litigation, contained material that was less than helpful to the company’s case. Of course, there were also a few helpful documents, but the overall usefulness of these records was outweighed by the negative impact they had on the conduct of the litigation. A second example involves e-mail. Several years ago, acting on an anonymous complaint that we later discovered was made by a disgruntled former employee who had been fired, a small army of federal environmental investigators descended on a client’s operating facility and, armed with a search warrant, literally commandeered the facility’s EH&S department. The investigators impounded the computers of the EH&S personnel and extracted all of the data from the hard drives of those PCs, as well as all EH&S related files from the hard drives of several servers used by the facility. These computers contained many years’ worth of stored e-mails, draft letters and memoranda, and other documents that provided grist for a four and one-half year criminal grand jury investigation of the facility and its EH&S staff. Both of these companies would have benefited from following a rigorous, enforceable, corporate records policy. Here is a third problem. My client had, during the 1960s, made a brief, and unprofitable foray into the nuclear fuel processing business. It ultimately sold the subsidiary, and was forced to give the purchasing company a broad indemnity against future liability. As might be expected, years later the facility was found to have considerable soil and ground water contamination both by chlorinated solvents and low-level radioactive material. Several years into the remediation program, my client discovered a tractor-trailer load of files, apparently removed from the subject facility, sitting in a parked trailer in a company-owned lot 300 miles away from the facility, where they had been for nearly thirty years. These documents were not helpful to the client, but had to be reviewed, at considerable cost, by paralegals. Moreover, several of the boxes turned out to have been mildly radioactive, setting off a chain of health and safety issues that consumed tens of thousands of dollars of legal expenses before they were resolved. Today, formal, enforceable corporate records management programs have become an extremely important element of overall corporate management. What was for most of the last century little more than a low level warehousing function is now a critical, actively managed, operating function that affects every level of corporate management. The rapid assimilation into corporate culture of electronic document management and the prevalence of e-email as the primary means of internal communication have created records management complexities the likes of which were not even conceived of fifteen years ago. Record preservation and destruction are no longer matters that can be handled on an ad-hoc decision making basis. Because of regulatory requirements affecting various classes of documents and the litigation consequences of ad hoc retention and destruction of corporate business records, and the need to have the ability to quickly retrieve documents in either a litigation or business negotiation context, a set of records management norms have evolved over time that have become the core elements of virtually every corporate records program. However, notwithstanding the existence of a set of norms (which are the basic elements of a

Jan 1, 2005

By Phil Pennington, D. Jack Adams

Mining and processing of minerals, metals, and fossil fuels can release selenium and arsenic into wastewaters. Both selenium and arsenic are difficult to remove to levels that meet current drinking water and discharge criteria. These metalloids can be used as electron acceptors by microorganisms transforming them back to reduced states, thus removing or stabilizing them. Bioremediation cost effectiveness will be discussed in terms of site information required, microbial populations, co-contaminants, pH, redox, and nutrients. Full-scale, economical ex situ and in situ biotreatments are possible and can produce 1,000’s of times less sludge than conventional precipitation technologies.

Jan 1, 2005

By Trevor R. Ellis

The extractive industries addition to the International Valuation Standards (IVS) is scheduled for publication in the next edition of the IVS book in January 2005. This will provide guidance for valuation of minerals and petroleum industry assets of all types for all appraisal uses. It will provide asset valuation support to the International Financial Reporting Standards for the stock markets of the world, and a global umbrella standard which can be supplemented for local needs by institutes and regulators. This paper discusses implementation of the IVS within the minerals industry and important issues that the industry should confront.

Jan 1, 2005

By J. Yuan

Ground calcium carbonate (GCC) and chemically precipitated calcium carbonate (PCC) have become important mineral-based commodities in recent years. GCC manufacturing generally requires high purity and high brightness deposits of marble, chalk or limestone as the stone source. PCC usually uses limes made from lesser quality limestone deposits. GCC products have a wide span of particle size, with a d50 size ranging from sub micrometers to as large as several inches such as those used in landscaping. PCC products are typically limited to less than 10 µm (1,250 mesh). Each PCC product has a narrowly distributed size range. GCC and PCC products tend to have higher levels of whiteness com-pared with other traditional filler and extenders, such as kaolin and talc. Published statistics of GCC production volume often vary due to the exclusion of certain size range GCC products. According to Roskill’s latest estimate, world GCC capacity was believed to exceed 56 Mt (62 millionst) during 2004 for all grades.

Jan 1, 2005

By Bekta? Uz

In this research, geological characteristics of sand quarries around the village, Kemerburgaz Akpinar, are studied and the mineralogical, petrographical, chemical and technological characteristics (such as sieve analysis, relative density, water absorbtion etc.) of the sand samples, obtained from the area are explained. In the general area sand' quarries, being in lacustrine formations belonging to Neogen, the stratigraphic location of the sand occurences take place at high levels of these formations, geologically. All of this pattern, being under 1 mm with a ,particle dimension, it ranges from 0,5 mm in the quantity of 99 % to 0,25 mm in the quantity of 15 relative density is 2,65 g/cm3 ; water absorbtion is 0,9%. Mineralogically, the sand samples contain Quartz (84%), Feldspar (3%), Calcite + Aragonite (10%), Pyroxen+Amphibole (1-2%), Garnet+Tourmaline (0.5%), Olivine (0.1-0.5%). Besides, sand samples contain SiO2 with the quantity of above 90%. Containing Quartz at high levels for mineralogical, petrographical and chemical characteristics, Akpinar sand will be evaluated as silica sand when the carbonate mineral is removed with the method of ore preparation such as leaching.

Jan 1, 2005

By J. Villeneuve, M. A. Reute, E. Verhoe

The objective of EU waste policy is to reintroduce used materials into the economic cycle, especially by recycling, or to return them to the environment in a useful state or at least a harmless state. To support decision-making in complex systems, the standardised ISO 14040 life cycle assessment (LCA) method can be used to quantify and to interpret the environmental repercussions of (changes in) a product system from cradle to crave related to a functional service unit. The use of the standardised LCA method at European level can be characterised as a damage-oriented or top-down method, which is often used in product design. Winning, extraction and processing of metals are part of the interconnected worldwide metals production system linked to product design, manufacture and recycling. This complexity cannot be dealt with using LCA. This paper will discuss a dynamic model that deals with this complexity, at the same time providing detailed bottom-up insight into the complex web of materials referred to as Metal Ecology. An example on the replacement on lead in solders will be discussed to illustrate this.

Jan 1, 2005

By R. Bleischwitz, R. Delzeit

"Tantalum, a heavy metal with characteristics such as superconductivity and high terminal resistance, nowadays is the most efficient material for production of capacitors, which are essential for production of small electronic applications like notebooks and cell-phones. It is one of the strategic resources for information societies. With supply extracted from Central Africa (Congo / DRC), China, Australia, and Canada, it can serve as an example for sustainability efforts in the management of non-renewable resources in Developing Countries, Newly Industrializing Countries and Industrialized Countries alike. The paper analyzes the life cycle of tantalum in its environmental, social, and economic dimensions. The first section highlights the importance of tantalum, showing a demand-driven market. The second section analyzes current and future supply. The third section tackles environmental and social impacts of tantalum mining in different legislations. The fourth section especially deals with the Case of the Democratic Republic of Congo since companies have been accused of participating in a civil ‘resource war’. Section five will draw conclusions for sustainable resource management. Written in an interdisciplinary manner, the article has a bearing on economics, especially on resource economics and new institutional economics, as well as on geography. It deals with questions such as security implications of physical scarcity in rapidly growing markets. In doing so it can, firstly, be shown that information exchange in combination with reputational risks lead to a shift in extraction activities from a Developing Country (DRC) to an Industrialized Country (Australia); i.e. a ‘race to the bottom’ does not take place. This, however, does not mean that market mechanisms work properly since information exchange (especially with China) is incomplete, moral hazard still prevails, and inadequate institutions hamper development processes in an exporting country like Congo. Any sustainable resource management for tantalum not only should foster gathering and exchanging better information on environmental and social impacts, but also incentives for upstream metal recycling in industry as well as support for governance processes in Developing Countries"

Jan 1, 2005

By Daniel Saint Don, Jacques Dumouchel

QIT Madagascar Minerals (QMM)’s heavy mineral sand deposit located near the Village of Fort Dauphin, Madagascar was recently drilled using Boart Longyear Company’s Mini-Sonic drill. Continuous sand core samples were obtained to a depth of up to 30 meters for analysis and compared with the existing drilling data. Results were used as part of a validation process of the resource estimate, based on approximately 1,500 exploration holes drilled to date.

Jan 1, 2005

By Jerry C. Tien

Mining in China dates back at least 4,000 years. Today, with no less than 103,000 metal/nonmetal mines and between 40,000 to 80,000 coal mines, China’s mining industry is undoubtedly the largest in the world. Despite improvements in recent decades, seemingly endless mining accidents continue to make the news. Official coal mining deaths were 6,702 in 2003, and 6,027 miners died in 2004; actual figures may be much higher. Added to these were the 2,699 deaths in the metal and nonmetal industries. Most of these accidents were due to CH4 (methane gas) explosions and fires as a result of inadequate mine ventilation de-sign or practices. A good portion of these accidents occur in small, privately run and often technically illegal mines. During the past 10 years, the Chinese government has attempted to crack down on small and often technically illegal mines without much success. The number of accidents and associated fatalities has not significantly reduced. However, there appears to be a new urgency in China’s efforts to step up mine safety in the country. After its worst reported mine disaster in more than a half century, the government quickly paid reparations to families, suspended high-level officials in charge and announced additonal reforms. One of those was the elevation of the central government’s work safety office to cabinet-level status. There has been increased transparency in reporting and investigation of mine accidents and disasters in recent years. There has also been an increase in public criticism by labor leaders concerning the neglect of mine workersafety.1 This article examines the causes of China’s many mining accidents, current legal and enforcement structures, respective mining health and safety related laws and regulations, recent mining industry developments and the latest effort to curtail small mining operations.

Jan 1, 2005

By Tracy Braun, Dan Lampshire

Over the past decade, heap leaching at Cortez has evolved from a rather small operation producing around 30,000 ounces per year of gold to an operation scheduled to produce over 400,000 ounces in 2004. Evolution and expansions in the heap leach operations are discussed including plant design criteria and some of the design features in the various facilities. Operating parameters and production forecasting are also discussed.

Jan 1, 2005

By Jaroslaw Drelich

This report briefly reviews the measurements and interpretation of adhesion forces measured between microscopic probes and substrates having micro- and nanoscaled roughness characteristics that were recently conducted at Michigan Tech using atomic force microscopy. The laboratory study concentrated on both rigid and deformable materials, with the probes larger than the size of roughness features of interacting surfaces. For such systems, a detailed surface characterization in terms of roughness parameters, asperity size and shape, and spacing between asperities, as well as analysis of deformation of materials is required. Analysis of the experimental data can be done with theoretical models, which are suitable for rough surfaces and therefore allows to normalize the measured forces. Alternatively, loading of the probe during adhesion force measurements can be managed properly to control deformations of the nano-scaled surface irregularities. Controlling the deformation reduces and even eliminates the effects of nano-roughness on the probesubstrate contact area, promoting conditions described by the contact mechanics models for the sphere-smooth substrate system.

Jan 1, 2005

By C. Pieper, J. B. Pateiro Fernandez, S. Möllerherm

"Since the United Nations conference on "environment and development" in Rio de Janeiro in 1992, the term "sustainable development" or short "sustainability" is used more and more in social-political discussions. Agenda 21 calls on the countries on national level as well as governmental and non-governmental organisations on international level to develop a concept of sustainability indicators to measure the progress towards sustainability. This paper deals with the development of an evaluation system for sustainability in the minerals extraction. By their application, aspects of sustainable development in the raw minerals industry are to be systematically conceived and assessed. This project has been carried out on behalf of the German Federal Ministry of Economics and Labour."

Jan 1, 2005

By Claude Deveau, Stephen R. Young

Introduction Tanco History Tanco is sometimes known as the Bernic Lake Mine. It is located about 180 km east-northeast of Winnipeg close to the Manitoba-Ontario boundary. Tanco operates an underground mine employing ramp access, room and pillar mining and shaft hoisting for the production of tantalum, lithium and cesium minerals. Tantalum recovery employs conventional gravity and centrifugal concentration methods along with a flotation process which recovers ultra-fine tantalum. All tantalum concentrates are shipped to Cabot Supermetals, Boyertown, Pa., for the production of tantalum chemicals and metals. Tanco also produces lithium products from spodumene ore. The lithium concentrates from Tanco are shipped worldwide for use in ceramics, specialty glass and mold powders. Cesium processing involves the dry grinding of pollucite as feed stock to the on-site chemical plant dedicated to the production of cesium formate, a high density drilling fluid. Tantalum milling operations commenced in 1969. In the early years of the operation, feed grades were three to four times as high as they are today. Coarse-grained tantalum mineralization with complete tantalum liberation at sizes of 300 µm allowed for easy recovery with conventional equipment such as spirals and shaking tables. Over the years, the process and feed material to the plant have drastically changed. Due to drastically reduced liberation sizes, efforts have been made to try to recover as much of the liberated particles as possible in order to maintain acceptable recoveries.

Jan 1, 2005

By K. N. Panigrahi

India bestowed with 6000km of the coastal belt, contains some of the richest and largest placer deposits with a mixture of heavy minerals like ilmenite, rutile, leucoxene, zircon, monazite, sillimanite and garnet. Each of the minerals is having economic value due to its inherent characteristics for industrial use in fields of paints, metallurgy, refractory, abrasive and so on. The reserves of titanium bearing minerals (ilmenite, leucoxene, and rutile) in the country is around 378 million tonnes. More than 90% of the titanium based minerals produced worldwide are utilised for making value added products in the pigment industries. Approximately 8 million tonnes of monazite reserves are available in the country from which several rare earth elements like cerium, neodymium, lanthanum, yttrium etc. can be extracted for use in several industries. The country contains a deposit of about 20 million tonnes of zircon, which is used in foundries, refractories, ceramics and chemicals. India has a reserve of 107 million tonnes of garnet and 131 million tonnes of sillimanite required for the abrasive and refractory industries respectively. Keeping in view the multifarious uses, the beach sand minerals are being exploited to have the economic growth of the nation. Although the process adopted for the separations are simple, the equipment involved are specially designed because of the nature of the material of construction. Starting from the spirals to magnetic separators, all equipments are manufactured outside India, which is not only costly, but the availability also takes much time for fulfilling the import formalities. Unlike open cast mining, beach sand mining is a environment friendly mining because dredging is implemented to cut and pump the loose sand through a slurry pump causing less damage to the surface topography as both mining and backfilling takes place simultaneously. Therefore all out efforts are made to explore the beach sand placer deposits in an economic manner to emerge as a leader in the global mineral industries.

Jan 1, 2005

By Murali M. Gadde, Syd S. Peng, C. T. Holland

Cutter roof failure is one of the most common ground control problems affecting the safety and economy of an underground coal mine operation. Several attempts were made in the past to understand the processes responsible for cutter development and to devise mitigating measures. Yet, many cutter failures still happen and their advance prediction remains as elusive as before. One of the reasons for the impasse in predicting cutters lies in the limitations of the current numerical modeling technologies. The development and propagation of cutters is a progressive phenomenon and continuum models can only approximate this process. Since the discontinuum modeling is severely restricted by the lack of reliable input data, alternatives must be sought to better understand cutter failures using the continuum models. This paper proposes one approach using strain-softening material model to simulate the cutter initiation and propagation process. An attempt has also been made to provide some insights into the reasons for the change in cutter location at different parts of a development layout.

Jan 1, 2005

By J. O. Voigt

No major changes took place in the salt industry during 2004. No new uses of salt appeared and only localized supply disruptions occurred. Many salt producers reported slightly increased salt sales and profits for the year. In the United States, about half of the salt supply is produced as brine, by solution mining, and is used by the chemicals industry. One-third of U.S. salt is produced as rock salt by 14 underground mines. The remaining two production techniques, each with less than 10 percent of the total tonnage, are vacuum-pan-evaporation for refined, food-grade salt, and solar pond crystallized salt.

Jan 1, 2005

By Keith E. Meyers

Condition monitoring is a viable troubleshooting practice among many industries to extend equipment performance, minimize unplanned downtime, reduce maintenance and repair time and costs, and increase related aspects of plant safety. But obstacles abound for mining, mineral-processing and cement operations striving to implement the technologies. Harsh machine environments can muddy efforts. High vibration in machinery can interfere with wide-spread rollout. Staff expertise or skills may be lacking. And costs may be prohibitive. Fault detection has emerged as a practical and cost-effective solution to identify process and machinery faults before failure interrupts productivity or jeopardizes worker safety. Fault detection can be a stand-alone system or connected to plant automation.

Jan 1, 2005

By Didem Maral

Olivine is a name of a mineral group that has a chemical formula of: (Mg, Fe), SiO4. The most important rock for the olivine group minerals is dunite, which can contain olivine up to 95-99%. Dunite can be obtained from chrome enrichment as a by-product. As a result of alteration of the olivine group minerals, several kinds of different minerals can occur. Main consumption areas of olivine are steel and iron industry. Also olivine is used in not only casting and refractory industries but also production of radiator, ballast material and abrasive. North of Bursa-Orhaneli has got more than 5 billion tons reserves in ultrabasic massifs. M.T.A found that olivine has got high quality of using in refractory and casting industry.

Jan 1, 2005