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By Jakub Nalaskowski, Vamsi K. Paruchuri, Marcin Niewiadomski, Jan D. Miller

Spherical oxide particles can be used as mineral fillers, paint pigments, polishing materials and catalysts. They can be prepared using various techniques involving precipitation and spray drying. Melting of particles in a high-temperature flame is a simple technique which produces particles with a high degree of sphericity and high smoothness from non-spherical feed material. In current research the preparation of alumina particles by melting the feed material in a hydrogen- oxygen flame is described. The spherical particles obtained were characterized using scanning electron microscopy, atomic force microscopy, energy dispersive spectroscopy, X-ray difiaction, Fourier transform infrared spectroscopy and electrokinetic measurements. The particles pre- pared exhibit a high degree of sphericity and a low level of roughness. The chemical composition of the material after preparation is unchanged, however the crystallographic structure is different. It is suggested that alumina changes from pure a-alumina to a mixture of different transitional forms. Changes in the electrokinetic behavior were also observed for alumina which can be attributed to the strong dehydration of the oxide surface and/or change in the crystallographic structure. Also, the possible accommodation of trace amount of impurities in the surface zone during melting cannot be ignored.

Jan 1, 2003

By Robert A. Jankowski, Ellsworth R. Spencer, Jay F. Colinet

Longwall mining is the most productive method of under- ground coal mining in the United States (US.), and record levels of production have been reached in recent years. These ever-improving production levels have the potential to generate significantly higher quantities of respirable dust. Consequently, the longwall industry continues to struggle with controlling dust liberation and maintaining compliance with the federally-mandated respirable dust standard. In response, longwall operators have in- creased the application of primary dust controls, airflow and water flow, in an effort to improve respirable dust control and reduce worker exposure. Pittsburgh Research Center (PRC) personnel conducted dust surveys at 13 longwalls operating throughout the U.S. and collected information to: identify current operating practices on these longwalls, identify the types of dust controls in use, document the levels at which these controls are being applied, and measure the respirable dust levels present. This data was analyzed to quantify the dust levels generated by the major sources on the longwall section and to evaluate the relative effectiveness of the control technologies in use.

Jan 1, 1997

By R. H. Grau

This Bureau of Mines report describes methane liberation trends from all U.S. coal mines liberating over 100 Mcfd (100,000 cfd) (2.8 Mm3/d). Detailed are results from the latest Bureau survey performed in 1985 and shown are mine and company name, location, coalbed and methane liberation quantity. The report shows that in 1985, there were 180 mines producing more than 100 Mcfd (2.8 Mm3/d) and the total quantity of methane liberated by these mines was 303,900 Mcfd (8,605 Mm3/d). This data is compared with previous studies performed in 1971 , 1973, 1975, and 1980. From 1971 to 1985, there was a 10% decrease in the number of mines liberating at least 100 Mcfd (2.8 Mm3/d) but there was a dramatic 34% increase of liberations from these mines. The increase seems to be caused by new mines being developed in deeper, gassier coalbeds, particularly in Alabama. Likewise, in comparing the ten highest liberating mines in 1975, 1980, and 1985, an increase in methane liberations each year was experienced. The report classifies mines by three levels of liberations: greater than 100 Mcfd but less than 500 Mcfd (2.8 to 14 Mm3/d); 500 Mcfd to 1 ,000 Mcfd (1 4 to 28 Mm3/d); and greater than 1,000 Mcfd (>28 Mm3/d). It was found that 87% of liberations were from mines producing over 1,000 Mcfd but these accounted for only 38% of all the mines in the study.

Jan 1, 1987

By D. U. Deere, T. R. Harrell

Factors such as rock cover, rock type and rock quality can exert a dominate influence on the behavior of a concrete tunnel lining. This paper will present and discuss the investigation, evaluation and use of such factors at the Rocky Mountain Pumped Storage Project in the design of the 10.67m (35 foot) diameter concrete tunnel lining. A plane strain, finite element analysis was performed on the concrete/rock system. The finite element model consisted of a concrete lining zone and three (3) rock zones; a highly destressed rock zone, a transitional rock zone and an intact rock zone. Zones were differentiated from one another by varying the modulus for each zone. Results of this study yielded a concrete lining strain from radial expansion which was used in the crack control calculations for the concrete tunnel lining. After the tunnel excavation was performed, plate jacking tests and additional seismic surveys were run on the tunnel walls. This testing served to confirm the rock modulus values used in the preliminary analysis. However, results were observed which indicated that a two zone rock model would more accurately represent in-situ rock conditions than the three-zone rock model used in the preliminary analysis. This revision to the concrete/rock model was made and a final concrete tunnel lining analysis was performed.

Jan 1, 1986

By Nestor M. Fillip

INTRODUCTION The Advisory Conference on Tunneling held in Washington, D.C. in 1970 under the auspices of the organization for Economic Cooperation and Development (OECD) forecast that $54 billion would be expended by member countries on underground construction in the 1970s. Construction activity since the Conference indicates the forecast may have been conservative. Statistics in the report indicated a vast increase in tunneling projects for mass transit, hydro-electric development, railroad tunnels, sewer and sewage retention reservoirs and water tunnels. Development of equipment is required to meet the demands for high speed excavation and provide tunnel driving systems with maximum efficiency and capability to sustain high speed advance rates. BORING MACHINE CAPABILITY During the last decade, use of Tunnel Boring Machines (TBMs) has increased. Where ground conditions and limits of machine design criteria permit, circular tunnel sections are either the only section , or an alternate sections specified in the documents: a TBM is either required or is an acceptable alternate means of tunneling. The evolution and acceptance of the TBM has had an impact on the construction and to a lesser degree on the mining industry. The traditional drill-blast-muck or "hand" mine

Jan 1, 1974

By S. M. Jarrett, W. B. Schmidt

Within the last year, the Nation has been shocked by two major tunneling disasters. Almost exactly a year ago 17 men died in the San Fernando Tunnel in an explosion attributed to gas. A few months later another 21 men died in an explosion laid to the same cause at Port Huron, Michigan. The analysis of the causes of these accidents is still continuing. While it appears that they differ substantially from each other in their specifics, they share the common trait that, like most industrial accidents, they might well have been prevented. Gas explosions in tunneling are neither new nor particularly unusual. Forty years ago, Assistant Director Jarrett was hired as a safety engineer on the Hetch Hetchy Aqueduct in California after an explosion that killed 12 men. Prior to 1946, in California alone, the Bureau of Mines had recorded 27 gas explosions incidental to hard rock mining and tunneling. The purpose of this paper is to review the status of the principal regulations affecting tunneling and to indicate some ways in which safer and more healthful conditions can be obtained. The Bureau of Mines was established by an Act of Congress of May 16, 1910. Since that time the Bureau has been making investigations and compiling and publishing health and safety data relating to mining and to tunneling. If any benefit is to come from an anaylsis of tunneling accidents, it must be the knowledge needed to prevent their repetition. The Bureau of Mines has also had informal discussions with the Department of Labor regarding the possibility of the Bureau's assuming that agency's responsibility for tunnel inspections.

Jan 1, 1997

By Murat Budakoglu

Albite (NaA1Si308) is one of the important raw materials for the rapidly developing Turkish ceramic and glass industry. Prior to 1980, development of the ceramic industry in terms of raw material was dependent upon small-scale mining operations; in the last decade, these efforts have increased substantially. The aim of this study is to investigate the geochemical properties and distribution of albite occurrences in the Kocayayla district, which is about 12 km northeast of the town of Milas, about 50 km west of the city of Mugla in southwestern Anatolia. Kocayayla is also well known for its famous ancient city, Labranda. The field area is located in the Menderes Massif, which was formed by major tectonic events during the Late Proterozoic and subsequent periods. The target area was studied to prepare a detailed geological map (scale, 1:10,000), and to determine the formation of albite-mica-schist-quartzite borders in the host rock gneiss. To do this, systematic sampling of albite was done in the two main areas, the Sarikaya and Yumruta? regions. In the study area, albite zones are scattered within an area of about 20 km2, and they extend in a northeast-southwest direction; mica-schists and quartzite veins accompany these units. Mineralogical observations show that quartz is the main mineral associated with albite. In the ceramic industry, the albite + quartz assemblage is well known and is classified as "standard" or "super type," depending upon the content of TiO2 and Fe203. In this study, the Sarikaya albites (profile I) exhibit remarkably lower TiO2 (0.15% on the average) values contrasted to that of Yumruta? (profile 11; 0.24% on the average), whereas Fe203 values vary slightly from 0.076% to 0.085% in both regions.

Jan 1, 1999

By R. A. Hodge, J. W. Murray

By an order of the Executive Council of the Provincial Government dated January 18, 1979, a Royal Commission was established under the Public Inquiries Act to: 1) Examine the adequacy of existing Federal and Provincial requirements for the protection of the health and safety of workers associated with exploration, mining and milling of uranium in B.C. and for the protection of the environment and of the public. 2) Receive public input on these matters. 3) Make recommendations for setting and maintaining standards for worker and public safety and for the protection of the environment as a result of the exploration for the mining and milling of uranium ores. At that time,and at the present time in British Columbia, no uranium mines were, or are, in operation. Exploration at a number of sites was under way and one deposit, the Blizzard deposit, with estimated reserves of 1.92 million tonnes containing approximately 4.74 million kilograms of U308 was at an advanced stage of exploration. With our Terms of Reference, and because of the diverse geology of the western Cordillera which could potentially host a broad variety of uranium, deposit types, the Commission was faced with the task of considering environmental and health protection necessary for the potential development of [any] kind of uranium mineralogy situated in [any] of the environments found in British Columbia. Over the past 17 months since that time, much has transpired, culminating in the February 27, 1980 Provincial Government announcement of a seven year moratorium on exploration, mining and processing of uranium coupled with the termination of our Inquiry before completion of the hearings. The Government sebsequently modified its decision to terminate the Commission completely, deciding instead to stop the hearing but allow time for the Commission to gather in the work that had been initiated

Jan 1, 1980

By Gail B. Knight

INTRODUCTION In May 1984, The Canadian Pacific Railway awarded to the Joint Venture of Foundation of Canada, Ltd. of Toronto, Atlas Construction Co. of Montreal, and S. A. Healy Co. of Chicago the contract for the construction of 27,000 ft of tunnel starting from the east portal. Selkirk contractors, the Joint Venture of Foundation, Atlas and Healy, which had successfully completed for CPR in 1983 the construction of both portal structures for this tunnel, studied several different alternative proposals before presenting its bid pooling each individual company's technical resources and experiences. (Foundation had just completed in association with other companies a similar tunnel project in British Columbia, and the S. A. Healy Co. could provide its experience of more than 40 miles of tunnels excavated by full face boring machines.) Among the alternatives investigated there was a fully circular tunnel to be excavated by a 30 ft diameter TBM, a full section drill and shoot proposal, and a mixed alternative, the "key hole" proposal, consisting of a TBM driven circular top heading followed by benching to design size. Technical, geological and economical considerations determined the alternative that was eventually proposed to CPR. HISTORICAL NOTES The tunnel construction parallels an existing tunnel through the Selkirk mountains that was excavated in 1885. In order to reduce the grade to 1% on the heavily loaded west bound trains, the new tunnel was at a lower elevation and lengthened to almost 9 miles. GEOTECHNICAL INFORMATION CP Rail site investigations began in 1978. The surface rocks in the tunnel construction area are metamorphosed Cambrian and Pre-Cambrian sediments; the underlying formation contains fine and coarse grained rocks presenting different degrees of metamorphism. The

Jan 1, 1987

By Severn P. Brown

Cement plants in the central Hudson River valley utilize limestones of the Helder-bergian Series of the Lower Devonian. Chiefly calcilutites, calcarenites, and cherty calcisiltites, these rocks represent progressively deeper environments, from lagoonal to neritic, with scattered reef deposits. Stratigraphic continuity is marked, and a layer-by- layer analysis shows strikingly constant chemical compositions. The structural picture varies from flat-lying and relatively unfaulted beds on the northwest, through gently folded and faulted beds on the north, to complex overturned beds with closely spaced imbricate faults on the south. Operating techniques are simpler in the north, where grade control is effected chiefly by the initial layout of the faces. In the south, grade control requires flexibility and frequent adjustment of faces or scheduling. A system of quarrying along strike has been developed, grade being computed from a cumulative foot-per cent graph of the critical oxides in each mappable layer. Balancing shovel production among the many faces is simplified by comparing production requirement ratios with ratios of the various types of rock in each face. Drilling and blasting limits are geologically controlled if warranted, or large blasts embracing several rock types are shot and the resulting pile of broken rock is staked along shovel limits.

Jan 1, 1966

By Dan Plazak

Discussion by Dan Plazak The authors are to be congratulated for presenting a simple and practical tool for quick estimates of ground water flow rates. At the risk of detracting from the simplicity of the method, I would like to suggest a slight refinement to the equation as presented. As the authors noted, the Jacob-Lohman equation (1952) assumes confined-aquifer conditions. To use confined-aquifer equations in water-table aquifers, Jacob (1963) presented a correction to convert water-table aquifer drawdowns [Ahw] to equivalent confined aquifer drawdowns [Ah,: 2] [Ah Ah = Ah - w(1) Cw 2H where: Ah, = Drawdown in confined aquifer: Ahw = Drawdown in water-table aquifer and H = Original saturated thickness of aquifer] Substituting the above in equation ( I) of Hanna. Azrag and Atkinson [4nT Ah - 2H ) Qj2.25 T t(2) 1 nr2 S W] Since the above expression predicts lower pump rates, it causes the Jacob-Lohman equation to agree more closely with appropriate analytical and numerical models. Figure 1, adapted from Fig. 5 of Hanna. Azrag and Atkinson, illustrates the closer agreement of the modified equation to their numerical model, as reflected in Qm/QJL ratios closer to unity. The agreement improves particularly as drawdown [Ah] becomes large in relation to aquifer thickness H. An additional advantage of the modified equation is that Hanna, Azrag and Atkinson's correction factor C is much more stable as pit depth increases. Assuming, as did Hanna, Azrag and Atkinson, that their numerical model is an accurate predictor, it is clear that the modification incorporated in equation (2) improves the accuracy of preliminary estimates of ground water flow to a pit.[ ] References Jacob, C.E and Lohman. S. W.. 1952, "Nonsteady flow to a well of constant drawdown in an extensive aquifer." Transactions, American Geophysical Union. Vol, 33, No. 4. pp. 559-569. Jacob. C. E.. 1963, `Determining the permeability of water-table aquifers,' USGS Water-Supply Paper 1536-1, pp. 245-271

Jan 1, 1995

By Stephen J. Klein, Fernando Orduz, Randall J. Essex

INTRODUCTION The Keystone Tunnel project consists of widening an existing 7.3 m-wide (24 ft) highway tunnel to a width of 13.7 m (45 ft) to provide a three-lane, two-directional highway tunnel. The 13.7 m-wide tunnel was excavated in a staged drill-and-blast sequence through foliated schist, and was supported using pattern rock reinforcement and shotcrete. Notable project features are: the low vertical cover over the tunnel is less than the span of the opening; the project is the second instance where the Federal Highway Administration (FHWA) has accepted rock reinforcement as a permanent support element; and the project is the first instance where the FHWA is accepting shotcrete as the final interior surface of the tunnel. This paper covers the design and construction phases of the project. PROJECT DESCRIPTION The South Dakota Department of Transportation (SDDOT) retained Woodward-Clyde Consultants (WCC) to evaluate the feasibility, prepare construction plans and specifications, and provide construction management services for the widening of the Keystone Tunnel. The tunnel is located in the Black Hills National Forest area of South Dakota near the southwest corner of the state. The Keystone Tunnel is on U.S. Highway 16A, about 0.8 km (1/2 mile) north of Keystone which is approximately 32 km (20 miles) south of Rapid City (Figure 1). Highway 16A serves as an important transportation link between Rapid City and the Mount Rushmore National Monument which is located about 2 miles west of Keystone. The road through the tunnel consisted of two lanes about 7.3 m (24 ft) wide, and is being widened [ ]

Jan 1, 1989

By R. Hiebert, M. Canty, S. Beckman

An innovative biological process is described for the treatment of cyanide-, metals- and nitrate-contaminated mine process water. The technology was tested for its ability to detoxify cyanide and nitrate and to immobilize metals in wastewater from agitation cyanide leaching. A pilot-scale demonstration is described in which a pilot plant was constructed to demonstrate the technology on a mine process-waste stream at a mine in Nevada. The demonstration was performed jointly under the Mine Waste Technology Program (MWTP), funded by the US Environmental Protection Agency (EPA) and jointly administered by the US De¬partment of Energy's (DOE) Western Environmental Technology Office (WETO) under Interagency Agree¬ment Number DW89938513-01-0. The Superfund Innovative Technology Evaluation (SITE) demonstration program was also involved in the project. MSE Technology Applications Inc. (MSE), Butte, MT, was the contractor responsible for conducting the project, and Pintail Systems Inc., Aurora, CO, was the technology provider. The pilot-scale unit was field-tested at Echo Bay's McCoy/Cove Mine southwest of Battle Mountain, NV. The biotreatment process was considered successful in destroying cyanide in the mine process water. The process was also determined to be effective in removing metals. The pH was consistently neutralized and nitrates were successfully removed from the mine process water. From the results of these pilot-scale tests, it was concluded that the biotreatment process potentially of¬fers an innovative, cost-effective alternative for the treatment of mining wastewaters.

Jan 1, 2000

By P. K. Gbor

Over 2 million tonnes of smelter slags containing Co, Ni and Cu are produced and stockpiled in Canada each year. Smelters also produce SO2 an air pollutant. Recycling these materials will maximize the value of natural resources and minimize possible environmental impacts of industrial operations. The objectives of this research were to understand the characteristics of slag, the reaction of slag with SO2(aq) and to develop a novel method for extracting Co, Ni and Cu from slag using SO2. The properties of slags from different smelters were studied, with emphases on the form of Co, Ni, Cu and Fe. Leaching experiments were carried out in a batch reactor. The parameters investigated included concentration of SO2(aq), stirring speed, particle size, temperature and pH. O2 was introduced into the reactor to study its effect on the system. The amount of each of Co, Ni and Cu in all the slags was less than 1%, while Fe was between 30% and 45%. The form of Co and Fe was primarily oxide, however, significant portions of Ni and Cu were present as sulphides. SO2(aq) alone, was effective in leaching Co and Fe. Cu dissolution was negligible due to precipitation. The presence of O2 improved Cu and Ni extraction. SO2(aq) was found to be more effective in leaching slag than H2SO4 at the same pH. The leaching process was modelled using the shrinking core model. A scheme was proposed for the extraction of Co, Ni and Cu from slag using SO2(aq). The process makes efficient use of SO2, separates Co and Cu at an early stage, and minimizes the consumption of base during Fe separation.

Jan 1, 2003

By L. L. Gagné

The Churchill Falls Development will eventually be the largest source of hydroelectric power in North America. Churchill Falls was discovered in 1839, but until recent years it was not practical to begin development of this site to tap the 7 million horsepower available. This $1 billion project is located in Labrador, 700 miles northeast of Montreal and 650 miles northwest of St. Johns, Nfld. The construction will divert the Churchill River 5 miles upstream from the 245 foot Churchill Falls. Rapids above and below the Falls, together with the Falls proper, give a natural head of 1,040 feet. In contrast to the basic simplicity of the surface installations, the powerhouse labyrinth is astounding in size and complexity. The largest in the world, it consists of three major chambers - the powerhouse, 972 feet long by 81 feet wide and 154 feet high; the surge chamber, 763 feet long, 40 feet to 64 feet wide and 148 feet high; and the transformer gallery, 856 feet long by 50 feet wide and 39 feet high. Other major features include eleven inclined penstocks, each 1200 feet long and 20 feet in finished diameter; eleven draft tubes averaging 37 feet in finished diameter and 162 feet long; six vertical cable shafts each an average of 865 feet in length; a series of eleven short bus tunnels linking the powerhouse and the transformer gallery; a vertical power-

Jan 1, 1997

By Jeffrey J. Schwoebel, Jianliang Li, Daniel J. Brunner

A United Nations (UN) administered degasification technology transfer project, funded by the Global Environmental Fund (GEF) is underway at the Shihao Mine of the Songzao Coal Mining Ad- ministration in the province of Sichuan, Peoples Republic of China. This mine exploits multiple seams at depths ranging from 300 to 600 m below surface. In-seam boreholes and frequently spaced in-mine vertical boreholes, developed from underlying galleries constructed specifically for this purpose, currently degasify the seams in advance of mining at the Shihao Mine. Because of ventilation system constraints and the in-situ gas con- tent, longwall mining of the coals at this mine could not proceed without some form of pre-mining degasification. This paper presents a simulation based degasification plan of long, in-seam horizontal boreholes for the Shihao Mine. Simulations with a coalbed reservoir program assessed time dependent degasification characteristics of both vertical and in-seam horizontal boreholes. The simulations used input data from reservoir and desorption tests conducted at the mine site. The results produced system design nomograms to assist mine engineers in defining the appropriate borehole spacing necessary to degasify the seam in the time available for pre-mining drainage. The predicted effectiveness of the current vertical degasification scheme was compared with that for a horizontal borehole program and served as the basis for the recommended in-seam borehole configuration for the project at the Shihao Mine. The horizontal borehole degasification program requires substantially less gallery and borehole development than the present vertical degasification scheme.

Jan 1, 1997

By H. Polat, B. Mohal, S. Chander

Several nonionic surfactants and one anionic surfactant were tested to enhance the flotation response of a low-rank coal. The nonionic surfactants included an ethoxylated octylphenol and several polypropylene-polyethylene block copolymers, and the anionic surfactant was a dioctyl sulfosuccinate. All of the surfactants improved the yield significantly, but the influence on grade was complex. To elucidate the mechanisms involved, separate studies were conducted to determine the emulsification behavior of the surfactants. For the nonionic water soluble reagents, a correlation between the emulsifying power of the surfactant and the flotation response was observed. An increase in the number of droplets produced was considered to he the main reason for increases in the yield. However, a small amount of surfactant adsorption on coal is essential to promote adhesion of oil droplets. When the surfactant was introduced into the flotation pulp prior to addition of dodecane, the benefits of the surfactant decreased significantly. The decrease was attributed to both a decrease in hydrophobicity of coal through increased surfactant adsorption and a decrease in the surfactant available for emulsification. When a surfactant dispersed in oil was used, the transfer of surfactant to the aqueous phase was minimal, and a considerable increase in yield was observed.

Jan 1, 1995

By J. S. Long

A finite-difference model using a digital computer was constructed to assist in the water management of a proposed oil-shale mining operation in the Piceance Basin in Colorado. The presence of ground water is both a detriment and a benefit for development of the resource. On one hand, dewatering is required because permeable zones are present in and above the oil-shale sequence, and rich oil shale at the proposed mine is as much as 457 m (1500 ft) below the water table. On the other hand, ground water is the most feasible source of water for processing the oil shale. A ground- water model was constructed to simulate the development of an environmentally acceptable water-management system that will satisfy both the mine-dewatering requirements and the water-supply requirements for processing. The ground-water model discussed in this chapter was constructed for the Rio Blanco Oil Shale Co. (RBOSC) by International Engineering Co., Inc., a subsidiary of Morrison-Knudsen Co. The model was applied to evaluate dewatering and water control systems for several open-pit mining plans initially investigated to develop Federal Lease Tract C-a. A collateral application of the model analyses was to project effects of the proposed dewatering operation on the regional ground-water regime in connection with a permit acquisition program by RBOSC. Subsequently, RBOSC has completely changed its mine development plan and has adopted modeling and related techniques more suitable for study of that plan and dewatering operation. The authors of this chapter are solely responsible for the contents and conclusions.

Jan 1, 1979

By W. DR. Fritz

Technical progress depends on strategic objectives and a concept showing how to benefit from the effects of novel techniques in an innovation process and how to implement them creatively in harmony with manpower capabilities. With the invention of prime movers, it was initially power engineering which dominated the development of industrial history before it was replaced by production techniques resulting from the more widespread use of machines. With the advances in the field of data processing and with the introduction of novel communication techniques, it is information technology- which today is having an ever increasing impact on technological progress. The main objectives of information technology in this context are a positive influence on the ?time? factor as well as the provision of tools to handle the complexity governing many operational processes through a concentration of information for the decision-making process. The German hardcoal industry became aware of the chances inherent in these new technological possibilities for the optimization of operational sequences and of decision-making and planning processes as a potential for success at an early stage and it has worked out a purposeful concept for their implementation.

Jan 1, 1992

By Tom H. W. Loomis

The department of the Interior is a federation or holding company of several fiercely independent bureaus which have either jurisdiction or expertise - or both - in a wide range of environmental fields. Each bureau is an advocate for its own concerns and an enforcer of its own mandates. This can be confusing to the company operating in the field. I will try to explain our concerns, help you see where we are "coming from," and give you some insight as to how we can help you. Other speakers have stressed the environmental concerns and site selection factors for uranium wastes so I will focus on the concerns of the Department of the Interior and some of the assistance we can give you in this area People are more aware and more concerned about environmental factors now than they used to be. Thus the past decade has brought about an evolution in both siting and design of uranium mill tailings ponds. Site selection criteria used to be simple - find a tract of land as near to the ore supply as possible with enough space and suitable topography for the expected volume of wastes. Site selections in the past have left a legacy of problems to be corrected - radioactive wastes on stream banks and in floodplains, mill wastes in and near established communities, and unprotected wastes subject to constant erosion. This is no longer acceptable environmentally or socially to a newly aware and concerned public. (Series of 30-35 slides showing uranium mine and mill wastes in Western United States. These illustrate environmental problems, reclamation and environmentally acceptable sites. The first group of slides are aerial shots taken in Wyoming and shows a surface mine and mill area. In the various views the pit, overburden piles, mill, and tailings pond can be seen. The next series were taken in Wyoming and New Mexico. These show various views

Jan 1, 1980