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By J. R. Walls

The United States potash industry had its beginning in the early Colonial days. Potash was initially manufactured by leaching of hardwood ashes in large iron pots. Production of potash was recorded as early as 1631 in New Hampshire, and in Maine a few years later. According to the census of 1850, the production of potash was America's most thriving chemical industry and, at that time, 569 plants were reported producing potash from wood ashes. Interest in potash was so great prior to the 1800's that the very first United States patent, signed by George Washing- ton, was granted for the production of potash on July 31, 1790. A new era for the production of potash began when potash was discovered by the analysis from a brine well in 1839 near Stassfurt, Germany while exploring for salt. The predominant use of potash at that time was in the chemical industry rather than agriculture. The discovery, by Justice von Liebig in about 1858, that potash salt contributed greatly to the essential plant food in soil opened up an enormous potential market for a suitable potash material.

Jan 1, 1985

By J. Wyn Prior

The seismic refraction technique is probably the most popular geophysical method of bedrock profiling in geotechnical site investigations but is somewhat restricted by the inherent assumptions in the method. This paper describes how Hales' method of profile interpretation is modified to overcome the assumptions of increasing velocity and layer thickness with depth when only first arrival data is available. A further expansion of Hales method enables presentation of refraction data in a form whereby bedrock features, such as changes in velocity, relief and dip in particular, are more readily recognized. Characteristic curves of the more common bedrock features are presented as an aid to bedrock feature recognition.

Jan 1, 1976

By J. Richard Kyle

Salt domes, their cap rocks, and the adjacent sedimentary strata represent a major economic resource in the Gulf of Mexico basin. Gulf Coast salt diapirs formed in response to sediment loading of the "mother" Louann evaporite sequence of middle Jurassic age, an effect that is caused by the buoyant nature of the lower density salt. Halokinesis progresses from nonpenetrative deformation that creates broad "pillow" structures into discrete high-amplitude diapirs. Because of its buoyancy, the top of the salt diapir remains near the land surface or the seafloor during much of its history as the basin floor subsides. The salt within the Gulf Coast diapirs is deformed complexly and commonly shows subvertical banding that represents modified sedimentary layers with different contents of nonhalite components. The most abundant impurity is anhydrite, which occurs as individual millimeter-scale crystals or as deformed clasts that generally form about 5% of most salt stocks. Many mature salt diapirs are mantled by a "cap rock" that consists of a lower anhydrite zone and an upper calcite zone, commonly separated by a discontinuous gypsum-bearing zone. The anhydrite zone forms as accreted layers of anhydrite grains and clasts that are left after episodes of halite dissolution. The calcite zone is a product related to petroleum destruction accompanying bacterial reduction of aqueous sulfate. Calcite-cemented siliciclastic strata occur above or alongside diapirs. The mineral resources of the salt-dome setting are remarkably diverse. Major economic products of the salt-dome environment are salt and cap-rock-hosted native-sulfur deposits, as well as petroleum resources that occur on the dome flanks and in the cap rock. Native sulfur forms as a result of bacterial sulfate reduction accompanying petroleum destruction to form hydrogen sulfide, which is subsequently oxidized to elemental sulfur, major amounts of which have been produced by the Frasch process from Gulf Coast salt-dome cap rocks. Some cap rocks have produced limestone, gypsum, and anhydrite for a variety of construction uses. Although traditional industrial-mineral resource production from Gulf Coast salt domes is shrinking, some cap rocks host potentially commercial concentrations of celestite and barite, as well as the metals Zn, Pb, and Ag. Furthermore, caverns, excavated within the salt stocks, serve as major storage facilities for crude oil (including the Strategic Petroleum Reserve), liquefied petroleum gas, and natural gas. These resources are products of fundamental geologic processes that are integral to the evolution of the Gulf of Mexico basin. Whereas production of some industrial-mineral resources, such as elemental sulfur, has declined in recent years, ample reserves of salt will allow production to continue into the foreseeable future. Further, there is potential for other mineral-resource production from cap rocks under favorable economic circumstances. Expanded use of caverns, excavated in the salt masses for material storage and disposal, is likely to continue into the next century.

Jan 1, 1999

By Wenhua Wan, Jan M. Mutmansky

Many concerns have been expressed worldwide regarding the use of diesel equipment in underground mines due to the potential health risks associated with diesel particulate matter (DPM). In assessing the risk to the health of miners and designing control strategies for DPM, it is important to know the concentration of DPM in the working areas of a mine. In some mines, significant stratification occurs due to the characteristics of the diesel exhaust, affecting exposure and the ability to measure DPM concentrations accurately. This study outlines some of the concentration profile data obtained during sampling at three mines where diesels were employed. Mine #1 (a gold mine) employed large openings in which a diesel-powered roof bolter was used. Mines #2 and #3 are both room-and-pillar operations with varying conditions. Mine #2 is an experimental mine where two stationary diesels were utilized for sampling purposes, while Mine #3 is a traditional evaporite operation using two mobile diesel vehicles for section haulage. These field studies indicated that some level of stratification occurred in all the mines, but the stratification was not as pronounced in the case of Mine #2 due to the complex pattern of exhaust emissions generated by the vehicles. The stratification seemed to depend on the distance from the vehicle, the mine air velocity, whether the vehicles were moving or stationary, and whether the exhaust was diluted by equipment design features. The concentration of DPM was generally higher at samplers located near the roof and lower at samplers located near the floor. However, this was not found in all cases. This paper provides conclusions on how knowledge of stratification patterns can be utilized in sampling and control of DPM in mine atmospheres.

Jan 1, 1997

By John A. Breslin

The U.S. Bureau of Mines develops technology to help ensure that the Nation has an adequate and dependable. supply of minerals at reasonable economic, human, and environmental cost. Our research programs seek improvements for almost every aspect of the mineral production cycle--from evaluating the availability of minerals, removing the ore from the earth, to enhancing the performance of mineral materials. The health and safety of the men and women who work in the Nation's mines and minerals processing plants and the environmental impact of mining and mineral processing are major Bureau research concerns. In recent years, the U.S. mineral industry has found it increasingly difficult to compete for a share of world markets. Many foreign producers benefit from lower production costs and higher grade deposits. Some foreign governments subsidize their mineral industries and impose fewer restrictions with respect to environmental controls and health and safety regulations. If the United States is to compete in world mineral markets, innovative technology must be found to lower the cost of recovering and processing minerals. Mining and mineral processing research by the Bureau identifies ways to help the country maintain a sound, competitive industry and a dependable mineral supply, so vital to economic growth and the national security. This work includes efforts to improve existing techniques and procedures; but more and more of the Bureau's resources are being focused on long-term, high-risk research directed at developing new approaches to mining and mineral activities--approaches like in situ mining. Bureau scientists are studying the mining applications of computer assisted mining and investigating a variety of "high tech" approaches to extractive metallurgy. Such cutting-edge research will be necessary if major advances in health and safety, environmental quality, strategic and critical minerals availability, and overall U.S. competitiveness are to be achieved. It is just such high-risk research that the industry cannot afford to conduct itself, but--in the long run--cannot afford to be without. It is this type of research that will help us arrive at a revolutionary breakthrough rather than small incremental changes in health and safety technology as well as recovery methods. Our mining and mineral processing research is also directed at reducing the Nation's dependence on imports of minerals that have key defense and industrial uses. Some of these strategic and critical minerals are particularly vulnerable to supply disruptions. We are working on technologies that would allow the United States to take advantage of domestic sources of these minerals--sources consisting primarily of deep or low-grade ores, ores with complex mineralogy we do not yet know how to process, and small deposits that are now uneconomical to mine and process. Other research activities focus on ways to reduce the Nation"s consumption of key minerals and increase the recycling of these minerals. The opportunities in this area include coal. The current middle eastern crisis reinforces the need for a stable energy supply--preferably a domestic supply. The extensive reserves of coal in this country are well documented. Perhaps what is not as well recognized is the impact that the price of coal can have on its competitive position both for domestic fuel selection considerations as well as for the ability of this country to compete in the coal export market. Today, the role to the United States is as a reliable, but high-cost exporter of high-quality coal. U.S. export coal competes with supplies from other major suppliers, including Australia, Canada, Poland. If U.S. mining costs were lowered by at least $8 per ton in the year 2000, then coal exports would surge by a projected 46 percent, and U.S steam coal displaces significant quantities of foreign coal imports in Europe. Further cost reductions would make

Jan 1, 1991

By V. S. Znamensky, R. V. Stewart

This chrysotile asbestos ore body is located near the northern tip of the Province of Quebec, Canada. It is some 1818 km (1130 miles) north of Montreal, 480 km (300 miles) north of the tree line, and is situated within the zone of continuous permafrost. The open pit ore zone is approximately 0.4 km (1% mile) in length, some 61 m (2OO ft) in width and plunges at 25o to 30 o below surface to a vertical depth of at least 610 m (2000 ft). The ore body was originally evaluated by programs of surface mapping, diamond drilling, and bulk sampling. The fiber is semicrude, possesses excellent strength, and good fiber length distribution. GEOLOGICAL SETTING, LOCATION, AND DISCOVERY The chrysotile asbestos mineralization at the Asbestos Hill mine occurs in serpentinized ultrabasic rocks of Precambrian age. These intrusive rocks are found in older volcanic sedimentary rocks known as the Cape Smith-Wakeham Bay belt and are shown in Fig. 1. The rocks comprising this belt overlie older basement rocks composed of granite and granite gneiss. This belt has a width of 32 to 64 km (20 to 40 miles), and trends in a general east- west direction, a distance of about 370 km (230 miles) from Wakeham Bay on the east coast of the Ungava Peninsula to Cape Smith, located on the east side of Hudson Bay. Two sequences of rock have been recognized in this belt. The lower (oldest) rocks are known as the Povungnituk group, and consist principally of massive lavas and sediments. The upper (younger) rocks are known as the Chukotat group, and are composed of pillowed lavas with interbedded sedimentary rocks. Sills of ultrabasic rocks exist in both younger and older rocks, but are more often found in the Povungnituk group. Concentrations of chrysotile asbestos, as well as nickel and copper minerals are found at or near the base of ultrabasic sills, and are most common where a change in dip occurs. The mine is situated about 1818 km (1130 miles) north of Montreal, approximately 1126 km (700 miles) north of the start of continuous permafrost, and about 482 km (300 miles) north of the tree line. The depth of permafrost at the mine site has been calculated to be approximately 549 m (1800 ft). This rich deposit of asbestos was discovered in 1957 during extensive exploration for nickel in the Ungava nickel belt. During that year, traverses conducted by Murray Watts spotted interesting looking ultrabasic rocks, and followup ground examination disclosed rich surface showings of asbestos mineralization near the present open pit. In 1958, a two-man prospecting party returned to the discovery site and a mineral exploration license was granted to Fig. 1. Location map Keewa Quebec Mines Ltd., a wholly owned

Jan 1, 1986

By M. Fornaro

A small size quarrying activity (3 different quarries with an overall production in blocks less than 10.000 m3/year) has been exploiting for a long time the ?Tonalite? deposit of Adamello-Presanella. In 1967, given the outstanding natural beauty of the area, a natural park has been established with the aim of preserving environmental quality and, at the same time, of providing a sustainable development to the area. Because of the potential impacts of a mining activity in such a context, a specific study has been recently carried out in order to define if and how the quarries could co-exist with the park, beyond the ?administrative results? of a classic environmental impact assessment. The paper deals with the process that drove to the conclusion that the activities are not ?a priori? incompatible with the aims of the park. In the opinion of the authors, a responsible quarry management, which must take inspiration from the care given to environment by traditional alpine productive activities (e.g. the use of water, of wood, and of the stone itself), and take advantage of modern technologies in terms of emissions and safety, can be considered not only compatible with the protected area, but even able to positively contribute to the protection of the land and environment (Barisone et al., 2001). A series of specific prescriptions, which have been adopted by the Park Authorities after this study, are also discussed in the paper: only the definition of suitable spatial and temporal limits, the adoption of effective technical practices and a strict control are considered to be able to drive this ?exceptional? activity towards the final goal of real sustainability.

Jan 1, 2007

By T. A. Griffin

Gentlemen: The subject of this paper is: ADVANCED APPLICATIONS OF BUCKET WHEEL EXCAVATORS AND RECLAIMERS. Against an urgent world wide energy crisis, the role of bucket wheel excavators and reclaimers in the surface mining of fossil fuels and other ores has been raised to new prominence. This paper will review the reasons for the expanded application of bucket wheel technology, its unique contributions, and other factors relative to volume, cost, versatility, and efficiency. Today, surface mining is faced with the twin challenge of (1), accelerating the rate of removal of massive quantities of overburden and ore, and (2), replacing comparable high volumes of overburden back into the mined-out portion of the pit. Optimum quantitites for - a single electrical power plant now range from 5 to 15 million tons of coal per year. The use of bucket wheels offers the best method for meeting this challenge at lowest possible cost. For example, an advanced application that also satisfies environmental concerns involves the simultaneous functioning of two bucket wheel excavators during surface mining operations. Working at spaced intervals and different levels in conjunction with a transfer conveyor and stacker, one excavator removes the ore while the other one transfers overburden to a stacker that replaces it back into the open pit. The result of this continuously operating cycle is: (1) removal of ore and replacement of overburden back into the pit in massive quantities, (2) at accelerated volume and extreme low cost that cannot be matched by conventional loading machines of any size, and (3) fulfills a basic environmental requirement which is to

Jan 1, 1974

By D. Tepavac, S. Simmonds

"The high virgin horizontal in situ stress field in the Sydney Basin and its impact on civil engineering projects is a well-known and accepted phenomenon found in significant literature (e.g., Pells, 2013). The prevailing high-stress effects depend on many factors — rock quality, tunnel orientation, proximity of geological features to tunnel crown, size and shape of opening, depth of excavation and stress magnitude. The behavior of the rock mass under high in situ stress conditions can cause stress fracturing and consequent dilation of the tunnel periphery, resulting in rock spalling at the tunnel crown/ invert or raveling of rock blocks on the tunnel sidewall. This type of failure is of a brittle nature and may create construction and safety risks during tunnel excavation, if it occurs behind the excavation face where ground support has already been installed. Therefore, the associated risks need to be managed during construction. This paper presents the design strategy adopted to mitigate these adverse tunneling conditions for the WestConnex Project to-date. Overview of the WestConnex M4 East and new M5 tunnel projectsWestConnex is one of the New South Wales government’s key infrastructure projects. This 33 km (20.5 mile) project aims to ease congestion and connect communities and is the largest integrated transport and urban revitalization project in Australia. It was a key recommendation of the State Infrastructure Strategy released in October 2012. It brings together a number of important road projects, which, together, form a vital link in Sydney’s Orbital Network. These road projects include a widening of the M4 east of Parramatta, a duplication of the M5 East, and new sections of motorway to provide a connection between these two key corridors. The WestConnex project includes a number of stages: Stage 1a: M4 Widening; Stage 1b: M4 East; Stage 2: New M5; and Stage 3: M4–M5 Link. The tunnel design referenced in this paper relates to Stage 1b and Stage 2 of the WestConnex Project (Fig. 1)."

Dec 1, 2018

By K. S. Venkataraman

The physical properties of clay-water systems depend on the complicated system of forces between the clay particles themselves, and between the clay particles and the ions in the liquid phase. The kind and distribution of ions in, on, and between the clay particles and the size and the shape of the particles are the basic factors determining the macroscopic behavior of clay-water systems. Understanding the system requires a knowledge of the nature of the clay particles, their size, structure, composition, and surface properties, and of the manner in which they interact with ions [and molecules] in the surrounding liquid [or other medium]. The validity of Professor Brindley's words (Brindley, 1958), written three decades ago in the context of making pottery, whitewares, and electrical porcelains, transcends time, and the basic message is perhaps all the more important in the considerably expanded use of ceramics for structural, thermal, tribological, electronic, and other applications. Silicon carbide, silicon nitride, and sialons have been studied in the last two decades for high- temperature structural and tribological applications, particularly for using in internal combustion engines. Titanates, zirconates and niobates of barium, strontium and lead, have high dielectric constants, and are extensively used in the formulations for making capacitors. Hexagonal ferrites (molecular formula MO.6Fe2O3) are in use for making permanent magnets for fabricating miniature motors, and for assembling loud speakers, particle accelerators etc. Cubic ferrites such as magnesium-zinc ferrite and nickel-zinc ferrite are used as transformer cores, and for other high-frequency applications. In this context, Richerson's recent book (Richerson, 1984) on the general scope of traditional and technical ceramics is a good starting point for an overview of contemporary ceramics technology. Glasses are a whole class of amorphous materials used widely as sintering aids, and for making glass-bonded ceramics and glass-ceramic composites. Composites are yet another burgeoning field where two or more particulate components are used for improving the performance of ceramics. For all these applications, the inorganic starting materials are almost always submicron and near-micron powders. Understanding the powders' physicochemical properties, and their surface chemical interactions with the surrounding liquid/gaseous medium is-necessary for making reliable ceramic parts at competitive prices. Even though ceramics science and engineering has attained its separate identity in universities and the industry, ceramists themselves would concede that ceramics science is a cross-disciplinary field, having incorporated and assimilated within itself many principles from several apparently disjointed disciplines. Principles of material science, graduate-level physics and chemistry, polymer science, surface and colloid chemistry, transport phenomena, particle technology, unit operations commonly used in chemical engineering and mineral processing, and statistics and applied mathematics are integral part of any ceramics curriculum in universities. Added to this is the fact that all bench-scale successes in making ceramic parts are to be scaled-up for larger throughput operations. Understanding and applying process engineering principles of comminution, classification, drying, calcination, etc. then becomes essential. CERAMIC FORMING: Despite the diversity of the materials and processes, conceptually, the steps involved in making ceramic parts have remained the same over several decades: The different components for making the pan (usually one or more powders plus other forming and sintering additives) are proportioned and mixed thoroughly, and the well-mixed formulations are consolidated into desirable shapes known as "green bodies." Usually binders such as wax, clay, organic polymers and surfactants, whether dispersed or dissolved in a suitable liquid are used during mixing the batch for giving strength for the green bodies. In the dried green state, the inorganic powders typically occupy only 55 to 60% of the bulk volume of the body, depending on the particle size distributions of the powders and the forming history, with mostly inter- particle voids accounting for the rest of the void volume. SINTERING: The formed bodies are then fired in high- temperatures kilns/furnaces during which the parts are exposed to a predetermined temperature profile, and "soaked" for a certain duration at the final high temperatures, typically between 1200 K and 1900 K, and then cooled to room temperature. The gaseous atmosphere in the furnace is controlled (oxidizing, reducing, or inert) when necessary. During the initial stages of firing, volatile liquids evaporate, and during the intermediate temperatures between 400 and 600 K, the the organic polymeric additives pyrolize and oxidize into water vapor, CO, C02, and other gases. At still high temperature, the glasses, when present, soften, and simultaneously, the ceramic particles rearrange into a network of grains with definite grain boundaries so as to reduce the total interfacial free

Jan 1, 1990

Zirconium chloride is of great commercial importance as starting materials for production of ZrO2, Zirconium metal and other Zirconium compounds from its main resources (Zircon Sands). The present study concerns with preparation of pure ZrO2 from Zircon by direct chlorination technique. Different parameters affecting the chlorination process are studied viz. carbon, chlorine flow rate temperature and time. The chlorination extent is determined from the loss in weight and chemical analysis of reaction products. The maximum chlorination extent -92% are achieved at 1100°C for 30 min. Zirconium oxide is produced from the collected zirconium tetrachloride either by calcination at 900°C or by hydrolysis in water in presence of RCI with a purity = 99%. Evaluations of the products of the process are investigated microscopically and by X-ray diffraction. The apparent activation energy of the chlorination of Zircon is determined to equal 36 kJ/mole.

Jan 1, 1997

By G. Gillet

The conventional magnetic separators used in the mineral industry are equipped with traditional magnetic circuits or with permanent magnets (rare earth). However, when processing minerals with low magnetic susceptibilities or minerals of very small particle size, these separators are inefficient. In addition, a conventional magnetic circuit consumes considerable amounts of electricity to generate a relatively low magnetic field (~2 Tesla). The equipment is also heavy and bulky. Only a separator having a superconducting sole-noid can contribute in solving most of the problems, and only such a separator can produce high magnetic fields with low energy consumption. New developments and the experience acquired in using these superconducting magnets have resulted in new uses for magnetic separation, especially in the environmental area. This paper presents and describes a separation system that uses superconducting magnets that are completely automated and able to treat raw materials (concentration or purification) or liquid industrial effluents containing heavy metals in solution. Several industrial sectors, including the surface treatment, petroleum and chemical industries, are generating effluents containing heavy metal ions. The main metal ions found in such effluents include zinc, copper and vanadium. The purification of such effluents by magnetic separation is performed by adding a certain proportion of iron salts. The treated effluent passes through a superconducting separator where the flocs are retained in a matrix of steel wires. The efficiency of supraconducting high-gradient magnetic separation (HGMS) by this method exceeds 95%. Mineral separation and industrial-waste purification results are presented.

Jan 1, 2000

By C. Eddine

"Can we use data to make communication effective? How does one successfully tackle the challenge of solving cultural differences and harmonizing the needs of diverse stakeholders while developing and maintaining a strong and reliable corporate image? Is it possible to achieve better engagement and minimizing risks with data? This paper aims to explore human rights and business procedures, the promotion of shared prosperity in a sustainable manner and the use of metrics to guide decision-making process. Among the topics examined are: • the significance of stakeholder engagement in community development projects; • the use of grievance mechanisms to give a voice to First Nations and communities / populations in vulnerable positions (including children and elders); • the benefits of configuring and implementing a feedback system in partnership with the communities. This research is a preliminary initiative and has limitations on the extent of the material used. The author acknowledges there is a vast amount of work and publications available on this subject, as well, as a variety of examples that have not been included. The intention is to keep developing this research to assess and expand how data can be used to minimize risks and improve engagement, in addition to inspire others to continue advancing this topic. Natural resources consumption is a reality that will not disappear in a foreseeable future. Several developments and operations are located in remote areas where communities in vulnerable situation and Indigenous Peoples live. Feedback systems are being ratified as a tool to help tackling the challenges of harmonizing cultural differences and fulfilling the needs of diverse stakeholders. Integrating social, environmental, and economic values plays an imperative purpose in preserving a productive and trustworthy relationship with stakeholders. Positioning social standards next to environmental and economic principles shows inclusiveness and firm intention of integration. We add value to a positive image of our industry by embracing responsibility for corporate actions and promoting their beneficial impact on the environment. The social context within communities, groups and organizations is dynamic and presents new challenges as connections evolve. There are wildly diverse expectations which one may need to address during exploration, construction and operating phases. Disagreements are an inevitable consequence of interactions due to the different needs and requirements of the parts involved. Nevertheless, balancing differences and solving conflicts can offer remarkable opportunities for improvement."

Jan 1, 2016

By Pablo Hadzeriga

There are two places in the world where potash, trade name for potassium chloride, is economically recovered from naturally occuring brines by solar evaporation. One is at the Dead Sea and the other at Wendover, Utah. American Potash and Chemical at Trona, California recovers potash from natural brines, but uses fuel to accomplish evaporation. Under proper meteorological conditions the use of solar evaporation might be desirable from the economical standpoint. Of course, this may not be true when, if by artificial evaporation, a group of very valuable salts are recovered. This is the case of the American Potash operation at Trona. Solar evaporation has its limits. The working temperature is low. We may say, just to cover most areas of the world where solar evaporation may be practical, that it will take place between 18°C and perhaps around 45°C. In most cases the average working temperature expected will be around 25°C.

Jan 1, 1963

By C. J. Bise

Virtual reality (VR) is a concept in which the human experience of perceiving and interacting with a computer-modeled environment is achieved through the use of sensors and effectors. It is an advanced form of computer graphics. The images are generated based on where the user looks and how the user moves. As personal-computer-based (PC) instruction gains acceptance as an innovative approach to providing safety training, VR can provide a multisensory, rather than merely a multimedia, mode of presentation. New technology continues to be introduced into the mining industry to meet the productivity needs of coal and noncoal producers. There is also an increased need for more innovative training of mine workers. New technology and equipment designs often affect the basic causes of accidents. For example, the development of cabs and canopies for underground coal-mine equipment has reduced the number of accidents related to roof falls and rib rolls. However, safety-training specialists then had to focus on the machines themselves, because the modifications had the potential for causing "pinch-point" accidents. In fact, although the overall physical demands on mine workers have diminished, there has been an escalation in the concerns about trauma from repetitive physical activity. Thus, health-and-safety training specialists have shifted their atten¬tion to the recognition, evaluation and control of workplace hazards (Hancock and Hill, 1995). Recognizing that the spatial relationships of a workplace convey more information about hazards when experienced rather than described, trainers agree that simulation is the method of choice. Unfortunately, until recently, simulation systems were either simple software programs that did not come close to portraying the real experience or were complex hardware systems (such as flight simulators) that did, but at a cost of millions of dollars (Fritz, 1991). However, researchers and training specialists are excited about an emerging approach to work-force education based on virtual reality. VR is also described as cyberspace, immersive simulation, artificial reality, telepresence, virtual environment or virtual world (Meyer and Dunn-Roberts, 1992; Peterson, 1992). It represents a group of concurrent advances in computer and interface technologies. They enable an individual to interact in a multisensory way with a computer-generated environment. To achieve this, a typical VR system incorporates a computer that contains the necessary databases for producing realistic images and audio; a head-mounted display (HMD) or screen for viewing the images; and a three-dimensional controller, joystick or data glove for interacting with the computer-generated environment. If virtual reality is to become an effective tool for the safety training of mine workers, its attributes will have to be measured against other forms of delivery. Accordingly, Carr (1992) listed the following areas in which VR should be considered the method of choice: ? When training mistakes would be costly. ? When the necessary environment cannot be experienced in the real world. ? To build interfaces that are sensible and can be manipulated. ? To make training situations really "real." ?To make perceptible the imperceptible.

Jan 1, 1997

By James Sheridan

Risk can generally be defined as the possibility or chance of a loss corresponding to uncertainty. Analysis is the process for examining the components and relationships of a complex system in order to determine the impacts of its variables. Risk analysis is therefore a course of action taken to analyze multiple variables of a system that is subject to speculative outcome. When risk analysis is applied to mine development, it becomes the means for assessing and measuring those parameters that contribute to economic viability. Mining can be a risky business. It is composed of an assortment of factors that contribute to its financial outcome. Of these factors, the most consequential output is the net present value (NPV). Applying risk analysis in mine development can identify those factors having the most significant impacts and applying limits to those impacts. Mathematical computer modeling using Monte Carlo techniques is available and can be customized to suit specific mine development ventures. Essentially, those parameters that are not fixed values can have input variability. Rationally deduced engineering estimates should be the basis for determining the initial values applied as inputs in the models. Risk analysis therefore provides the user a means to identify, rationalize and assess the risks in mine development in an informed, calculated, and unbiased format for making economic decisions.

Jan 1, 2002

By Michael E. Salovich

The U. S. Department of Interior, Bureau of Mines (Bureau) has developed a prototype version of a computer application that combines hydrologic analysis with object-oriented graphics. This software is unique in that it presents analytic element analysis within an object-oriented CAD environment. Its user interface employs mouse handling, scrolling windows, dialog boxes, palettes, and pulldown menus. It can import scanned images of maps and overlay these images within the same window. This application was developed using object-oriented programming techniques. Several programming issues concerning graphics had to be resolved during development of this system. These include (1) how to represent hydrologic elements as graphical objects, (2) how to translate screen coordinates to map coordinates, (3) how to implement ?zooming? (changing the magnification level of a window), (4) how to overlay layers of images, and (5) how to import scanned images of maps. An object library was used to implement graphical user interface features such as scrolling windows and pull-down menus. Algorithms for CAD features such as map coordinate translation, zooming, and the layering of images were developed by Bureau researchers. The application has a modular source code structure and can be modified for use in other research applications.

Jan 1, 1992

By Thornton L. Neathery

A small area in the Alabama Piedmont was studied to determine if metallic enrichment was associated with local magnetic anomalies. Cores from two holes in these magnetic anomalous areas have sulfide (pyrite, pyrrhotite, chalcopyrite) film on slicken-side and fracture surfaces. Two hundred and fifty soil samples were collected from the top of the "B" horizon on 1, 000 foot centers over the general trend of magnetic anomalies. Soil samples were leached with a 1:2. 7 mixture of HF and H2SO4 and the dilute filtrate analyzed for Cu, Pb, Zn, Ni, Co, Cr, Mo, and Cd, using atomic absorption methods. Concentration-value maps were prepared for each element. Small areas of anomalous concentrations were defined for Cu, Pb, Zn, Mo, and Ni. Some of these areas generally coincides with magnetic anomalies. Concentration values (ppm) range from: Cu 165.0 - 0. 5; Pb 265. 0 - 0.0; Zn 1386.0 - 43. 0; Ni 187.0 - 10.0; Co 207.0 - 6. 5; Cr 117.5 - 2.0; Mo 95.0 - 0.0; and Cd 32. 5 - 2.0. Studies of other magnetic anomalies appear warranted.

Jan 1, 1972

By Takashi Sakaguchi, Takehiko Tsuruta, Akira Nakajima

Some attempts were made to recover gold from aqueous systems using immobilized persimmon tannin. This adsorbent adsorbed gold from solutions containing hydrogen tetrachloroaurate (III) with high efficiency, whereas there was minimal adsorption from solutions containing gold (I) sodium thiomalate and sodium dicyanoaurate (I). The adsorption of gold was rapid, and was affected by the pH of the solution, temperature, external gold concentration and amount of adsorbent. Adsorbed gold was easily desorbed with 1 M thiourea solution, indicating that immobilized persimmon tannin can be repeatedly re-used for the recovery of gold using adsorption-desorption cycles.

Jan 1, 1995

By Y. C. Guan

The dissolution behavior of silver and copper form their elemental states and Ag/Cu alloys in ammoniacal solutions has been studied using rotating disc electrodes. The variables studied included concentration of ammonia, oxygen partial pressure and rotating speed of the disc. The results have been interpreted in terms of the mixed potential theory. The effect of local current resistance on the overall current has also been examined as a part of the governing theory of the dissolution. It was observed that the dissolution potential and the rate of dissolution were very much affected by the composition of the alloys.

Jan 1, 1995