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By Gary S. Brierley, James R. Lambrechts, Andrew F. McKown

Various innovative Ground Improvement techniques have been proposed and applied to facilitate construction of the Central Artery/Tunnel Project in Boston. Given in this paper are discussions of the extensive use of deep soil mixing and jet grouting, and passive construction dewatering applications that are associated with the Design Sections D009A, D007A, and D019E.

Jan 1, 1999

By Anthony J. Ranalli, Florentino B. Maestas, Katherine Walton-Day, Richard W. Healy

Water movement and water chemistry were monitored in the unsaturated zone at two sites in fluvial tailings deposits along the Arkansas River near Leadville, Colorado. One of the sites was remediated by the incorporation of lime and biosolids into the soil. Preliminary results, based on data collected during the 11 months following remediation, indicate that differences between the two sites can largely be attributed to heterogeneity of the deposits. Remediation has increased the alkalinity in the upper soil zone, but as of yet, there is no indication that soils at depths greater than 30 cm have been affected.

Jan 1, 2000

By X. Wu, M. Karfakis, E. Topuz

The generalized ventilation network problems encompassing both natural and controlled splitting networks, is formulated using a nonlinear nonconvex programming model, which has not yet been solved satisfactorily. This paper presents a methodology which can deal with the problem. The proposed methodology converts the nonlinear problem into a linear problem, by using special ordered sets of variables, and optimizes it by a modified branch and bound technique. The global optimality of the methodology and its applicability to different cases are investigated

Jan 1, 1991

By R. Debkowski

The current underground infrastructure of an old monumental salt mine along with using it as a tourist, museum, nature, resort, conference and cultural events place is presented in the paper. At present, mainly in the monumental part of mine, only a small part of the historical chambers, which together with galleries form a tourist route available to visitors. Moreover, the essential activities aimed to make the tourist route more attractive and to change the decor of the underground sites are discussed.

Jan 1, 2006

By Bruce A. Brown

Construction aggregate is the most important nonmetallic-mineral commodity in quantity and value that is produced in Wisconsin. Crushed stone is produced from the Precambrian crystalline rocks and the Ordovician and Silurian carbonates, and sand and gravel is extracted from Quaternary glacial deposits. Dimension stone is quarried from both the Precambrian crystalline rocks and Paleozoic carbonate rocks. Other nonmetallic minerals include industrial sand, lime, roofing granules, terrazzo aggregate, and peat.

Jan 1, 1999

By J. A. Finch, Zhenghe Xu, Z. A. Zhou

The generation of microscopic bubbles by cavitation may enhance particle-bubble attachment and improve flotation performance. It is shown in this paper that tiny bubbles or cavities can be generated by strong shear and turbulence in high speed liquid flows. These conditions create the necessary pressure fluctuations in the bulk water to cause the local pressure to drop below a critical value. The formation of bubbles is favored by high dissolved gas contents to promote gas diffusion into the cavities, and by the presence of surfactants to provide some mechanical strength due to the adsorbed film. Experimental results on bubble formation by cavitation and consequent flotation of fine silica (d50 = 1.6 µm) are presented.

Jan 1, 1995

By J. D. Raulerson, R. P. Farias, G. A. Gruber

A flotation process has been developed to successfully treat ore from the Santo Domingo phosphate deposit in Baja California Sur. The ore contained less than 4% P2O5 with quartz, silicates, and carbonates as gangue minerals. Flotation of the low- grade feed in seawater required that the conventional Crago process, comprising direct anionic flotation, deoiling, and inverse cationic flotation, be augmented by an anionic cleaner flotation step, phosphate depression, and a calcite flotation step.

Jan 1, 1988

By E. Yuksel

Noted as one of the 20 major economies of the world, Turkey is a semi-arid plateau between the Eurasian and the African continents. With its surface area of 780 thousand sq km, it supports a population of 70 million people. While the mining history of Turkey can be traced back as far as 7 000 B.C., mining currently generates only 2% of Turkey’s gross national product. Turkey has 77 of the 90 principal minerals that are mined world-wide. Currently, some 5 000 mine occurrences including copper, lead, zinc, iron, gold-silver, chromite, sepiolite, mercury, and coal deposits, soda ash, marble, zeolite, feldspar, magnesite deposits, as well as the world’s largest known borate deposits, have been discovered and partially explored.

Jan 1, 2004

By A. Cavero, M. Diaz

The annual rainfall at Minera Yanacocha's gold mining operations in northern Peru averages 1.2 meters. The influx of water into the operations is higher than losses to evaporation and by ore absorption which results in a positive water balance. To minimize water intake and maintain a balance, some special operating procedures are required, and a system involving diversion ditches, storm ponds, heap skirting and detoxification and treatment of excess water is practiced. An operation background is also reviewed at the beginning of the paper.

Jan 1, 1998

By J. Mark Richardson

Modern mining operations are increasingly affected by complex economic factors. Broad and rapid fluctuations in metal prices, rising operating costs, socio-political trends and the inherent technical difficulties encountered in most operations, all can combine to quickly change once-profitable ventures into money-losing propositions. Accurate knowledge of metal inventories during all phases of an operation has become essential to wise management decision-making. This paper reviews key elements of metallurgical accounting: sampling theory, measurement technology and computerized data adjustment. Application of current technology to the reconciliation of a hypothetical operation is discussed.

Jan 1, 1991

By R. A. Metz, James W. Clark, William C. Dixon, Kevin L. Wiley, Thomas R. Couzens

This paper is a description of certain geologic aspects of the Inspiration mining operation. It is not a geologic description of the Inspiration deposit nor an exposition of all the geologic work involved in the development and exploitation of the deposit. A few specific examples of the application of geology and geostatistics to the mining process are given to illustrate the progress that has been made in making the Inspiration Mine more efficient and cost effective, and a statement of the philosophy of geologic applications is offered.

Jan 1, 1992

By Steven J. Schatzel

A study was made of frictional ignitions in the underground coal mining industry from 1980 to 1992. The population of frictional ignitions was correlated to a variety of potential contributing factors including the mined coalbed, geographic location, mine production, methane gas emissions, and the type of mining equipment in use. The number of frictional ignitions reported in 1991 and 1992 surpassed the annual totals in all previous years included in the study. Most frictional ignitions occur during cutting operations at a coal face by a continuous miner. The average coal production of mines experiencing frictional ignitions is greater than the average of all underground coal mines throughout the survey period. Methane drainage may have produced a drop in the ratio of gas emissions to coal production (E/P) in mines experiencing frictional ignitions.

Jan 1, 1995

By Peter A. Burger

The Greenvale Orebody comprises a series of contiguous lateriteprofiles developed terrace-like during the Cainozoic over a serpentinized harzburgite intrusive emplaced within Proterozoic schists. Each terrace displays individual characteristics of metal distribution. Topographically higher (older) profiles have been partially eroded and metal concentrations reworked. Within the laterite profile, metals have been concentrated or depleted according to their relative solubilities. At tropical temperatures, acidic meteoric waters have progressively depleted the ultrabasic parent rock of Si and Mg, leaving A1 and Fe to form a surface duricrust. Ni, Co, Mn and Cr have accumulated in the lower and middle levels of the weathering mantle. Only Ni and Co have accumulated to exploitable grades. Lateritization has evidently proceeded over a considerable portion of the Cainozoic and may be still continuing.

Jan 1, 1979

By D. R. Nagaraj

The practice of nonsulfide minerals flotation can be best characterized as an evolutionary blend of scientific theory and art. Although extensive fundamental studies have been carried out in the past several decades, and significant theoretical aspects have been developed, plant practice has developed the art form, often ahead of the theory, which is somewhat in contrast to sulfide minerals flotation. Several excellent review articles have been published in the past highlighting both the theoretical aspects and plant practice. An overview of nonsulfide flotation is presented here. Major differences in sulfide and nonsulfide flotation are highlighted. An assessment of the state of nonsulfide flotation, recent advances made in flotation processing, and industry needs are also given.

Jan 1, 1999

By Sukumar Bandopadhyay

In recent years planning of surface mines in general and reclamation and post-mining land uses in particular have become very complex. Due to the lack of suitable techniques, land use plans are rarely based upon structured decisions. Data collection may be conducted in a rigorous manner and certain analyses may be performed on the data; the decision to put the land to a specific use, however, is finally based upon the intuitive judgment of one or several individuals. This paper demonstrates how techniques from fuzzy set theory can be used in order to select an optimum post-mining land use plan. The various land use planning alternatives have been characterized according to both qualitative information and quantitative factors and the "fuzzy" aspects of the collected information are incorporated into the analyses. In a practical application, the methodology is used to obtain the most reasonable solution to a post-mining land use planning problem in Interior Alaska.

Jan 1, 1986

By W. A. Steingraber

This paper discusses the application of deep well disposal techniques to the problem of disposing of large volumes of low level radioactive wastewaters generated by the in situ uranium mining industry in Seth Texas. Data is presented on wastewater composition and volumes, geologic and hydrologic parameters of the disposal reservoirs, tell construction techniques, well operation, well monitoring requirements, and critical factors in evaluating the Safety and environmental impact of a deep injection well system.

Jan 1, 1980

By K. Morsy, S. S. Peng

This paper deals with the causes and mechanisms of massive pillar failure in a room-and-pillar mine that employed nine-entry panel system using supersection technique under a cover ranging from 91 to 168 m (300 to 550 ft). Chain pillar squeeze and large roof-to-floor convergence were first observed at the belt transfer point on the very inby side of the main entries. It propagated outby quickly and within 24 hours it had covered an area approximately 1,250 m long by 762 m wide (4,100 x 2,500 ft). The failure was caught and stopped by a solid barrier pillar. Using computer modeling, the study indicated that the massive failure was initiated due to a combination of undersized chain pillars in some panels and weak immediate floor. Also, the study shows that the massive pillar failure expanded to a large area because of no barrier pillars between some panels and between mains and panels. Based on the computer modeling, alternative mine plans have been proposed to avoid such problems.

Jan 1, 2000

By M. G. Karfakis

This paper examines the chimney occurrences in the Hanna Coal Field, Wyoming. Chimney caving is defined, previously proposed mechanisms involved in the development of a chimney are critically reviewed, and factors controlling chimney cave are identified. The main portion of this paper deals with the identification and characterization of chimney subsidence due to underground coal mining in the Hanna Mining District. In an attempt to characterize the subsidence, sink-hole occurrences are correlated with the depth of coal, thickness of mined-out beds, mining methods, nature of overburden, structural geology, and hydrology. Most sinkholes in the Hanna Basin appear to be conical in profile, with the apex upward. The average diameter is 15 meters (50 feet), with an average depth of 11 feet. Most have developed above an overburden of less than 61 meters (200 feet). The average mining height to width ratio is 5. Much of the chimney development is governed by the thickness and character of the overburden, the width and height of the mine opening, and the in situ state of stress.

Jan 1, 1986

By A. J. Sinclair

Los métodos de desmuestre para estudios de viabilidad dependen de las características geológicas del yacimiento que ha de ser evaluado. Se requiere un estudio geoestadístico preliminar, teniendo en cuenta los aspectos de autocorrelación de las variables sometidas a estudio, con objeto de que el plan de diseño de muestras pueda ser optimizado para producir las estimaciones de ley y tonelaje dentro de los límites de errores establecidos. En general, debe de tenderse a una distribución regular de muestras para ello, y longitudes regulares de las mis¬mas (a partir de los testigos o cortes, por ejemplo) son preferidas con objeto de facilitar los análisis estadísticos. Los planes de desmuestre son modificados y mejorados (bien técnica o económicamente) a medida que avanza el programa y es obtenida información adicional. Las muestras a granel para pruebas metalúrgicas pueden ser evaluadas en término de va¬riaciones señaladas por todas estas muestras en un depósito y la variabilidad de la ley dentro de las mismas. Una atención adecuada sobre estas fuentes de variabilidad asegurará una evaluación adecuada de los resultados de las pruebas piloto de las muestras a granel. Por otro la¬do, un estudio mineralógico general del yacimiento es un requerimiento importante, a veces ignorado, en una evaluación más general pero semicuantitativa de la representatividad de una muestra a granel; y, además, proporciona una información muy útil para optimizar el diseño de la planta.

Jan 1, 1982

By W. E. Cobb

Mining companies, as developers of natural resources, are being forced to deal with the potential long-term liabilities of past, present, and future mining operations. As discussed in a previous paper (Cobb, et al., 1987), these liabilities can include solid waste disposal corrective action programs (state or federal actions), Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), (Superfund) (state or federal actions), or natural resource damage claims (typically filed by state agencies and provisions specified in CERCLA). These potential liabilities are very real, and should dramatically impact the way a company views its exploration and development programs, and operating mines.

Jan 1, 1988