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By E. H. Ahrens

This paper deals with the daily work of operating geologists and should be of interest to recent graduates. Working with development and production is quite different from exploration and many of the required skills and techniques must be learned on the job. Try to obtain your first position at a mine where good geological work is being done because it is important that you establish a solid foundation by learning valid techniques. Many do not! Those who desire to work in exploration are well advised to spend the initial two or three years at an operating mine where they will deal daily with an orebody during development and mining. Attempt to understand the controls of ore deposition and be interested in all phases of the operation. Learn something about factors which can adversely affect profitability and you will be a better explorationist.

Jan 1, 1983

By R. Q. Honaker, D. Tao, D. Taulbee, B. K. Parekh

A significant amount of energy exists in the waste generated by the coal and timber industries. In the coal industry, the energy loss is mainly due to the discharge of fine coal to the waste impoundment. Despite the fact that the fine coal has the greatest cleaning potential, dewatering, handling and transportation concerns prevent its use as product in many cases. Likewise, the sawdust generated from wood production has energy value and is used as industrial boiler fuel when the transportation distance is relative short. However, wood waste is often discarded into cumbersome landfills due to uneconomical transportation alternatives. Recent research found that these two waste materials can be combined to provide a high energy fuel of around 13000 btu/lb that can be easily handled and transported to end users.

Jan 1, 2004

By Y. C. Kim

An alternate development drilling strategy to the one currently in use at the nine was investigated using geostatistics for a portion of the pit. The study area consisted of 4,000' x 5,000' in plan and 1,080' in elevation. The massive orebody, the three-dimensional nature of the problem, and the location of ultimate pit limit in the study area all created some unique problems in devising the development drilling strategy, as compared to the two-dimensional tabular deposits such as coal deposits. Rather than using the confidence interval of the global reserve estimate as the main criterion for development drilling, the confidence interval of short and medium range mine planning blocks was used as the objective. Based on somewhat arbitrarily selected level of confidence, the results from this study showed that a total of 50 DDHs rather than the planned 62 DDHs is sufficient in the study area, if the selected confidence levels are acceptable to the management. This paper also emphasizes the importance of the particular objectives being used in development drilling and how they influence the "optimai" place- ment of the development drill holes.

Jan 1, 1981

By Fernando Pendás, Jorge Loredo, Alumudena Ordóñez

Water derived from mine-tailings typically contains high concentrations of H+, SO4, Fe and other metals, and it frequently suffers a decline in pH and the development of acidic mine drainage (AMD). A paper describing the results of a series of laboratory experiments with real AMD and a subsequent field trial with a in situ pilot system to assess a potential method for remediating tailings-derived water is presented here. After testing different organic substrates, residence times and flow conditions during two years to determine the most appropriate treatment for a polluted Spanish AMD, a pilot scale system combining SAPS, ALD, oxidation/sedimentation ponds and an anaerobic wetland was designed. Preliminary analyses of effluent samples indicate acidity and metal removal is occurring within the system, although sulphate removal is not complete. The results of this small-scale field trial suggest a potential cheap, long-term alternative for remediation of acid mine drainage.

Jan 1, 2000

By Hemendra N. Kalia

The target to double the coal production by 1995 presents a formidable challenge to the coal mining industry. The mines of future, probably will be located in relatively difficult geological environment because of the exhaustion of the well defined bedded and easily minable deposits. To compound the problems of mining industry will be the reliance of power plants need for coal. The coal must reach the power plants on schedule to avoid expensive blackouts and brown¬outs. It will be imperative that the mines operate without interruptions and at designed capacities. The parameters which have been traditionally responsible for the interrup¬tions of production are: breakdown of production machinery, labor management relations and geological anomalies. Of these three problems, solutions for the first two can be arrived at by developing procedures to correct the situation. A planned maintenance and preventive maintenance program will go a long way in minimizing the equipment breakdowns. Labor relations will eventually improve as the miners begin to enjoy long-term employment. However, with the geological problems, the situation will probably continue to deteriorate and would require careful planning to minimize the impact of geological problems on production and safety. Some of the geological aspects which interfere with production are: faults, washouts, slips and slickensides, water bearing overlying strata, impuri¬ties in the coal seam, and presence of expansive clays in the coal floor. The design of large capacity mines will have to incorporate the geological distur¬bances and mine through them it may become very uneconomical to abandon producing sections because of the presence of the geological anomalies. This paper discus¬ses the geological aspects of coal mining which should receive consideration from the inception of the mining ventures. Pertinent geological aspects are discussed to develop the data base which will aid in evolving safe and efficient mine layouts.

Jan 1, 1976

By G. B. Walker

The success of Heavy Media Separation, the static sink-float process, is evidenced by the operation of an estimated 300 installations treating many millions of tons per year of a wide variety of mineral products ranging in value from gravel to diamonds. The static heavy media process is usually limited to the treatment of plus 1/4 inch material. Mr. Victor Rakowsky, who was largely instrumental in the development and application of heavy media separation, recognized the need for a new apparatus and process which would extend the application of heavy media into the finer size range without placing a restrictive limit on the top size of the feed. He recognized the requirement for the application of centrifugal force to augment the force of gravity in separating fines by sink-float techniques.

Jan 1, 1966

By D. Loy LeRoy

As we are all aware, the impacts of the 1977 Surface Mining Act and the implementing OSM Regulations require application of new, as well as existing, equipment and technologies. Our firm recently completed (June, 1979) a study for the Department of Energy titled "Analysis of the Impact of Public Law 95-87 on Mining Performance." The objective of the study was to analyze the impact of the Act and its regulations on mining performance in order to provide recommendations to alleviate the impacts identified, including identification of research needs. This paper presents some of the highlights of that report: projected cost increases; additional equipment needed for compliance; review of methods currently practiced or those which can be modified; and will focus particulary on equipment and technology applications.

Jan 1, 1980

By B. K. Parekh

Silicon carbide (SiC) can be produced by heating rice hulls to elevated temperature, The product is a mixture of beta crystalline silicon carbide whiskers, particles and unreacted carbon. The silicon carbide whiskers are 0.5 micron in diameter and 50 to 100 micron in length and have been found useful for reinforcing metal and other composite materials. The carbon can be removed by combustion, but this makes separation of the silicon carbide whiskers from particles difficult and a high grade whisker product cannot be made. However, a clean high grade Sic whiskers product can be obtained from the pre-burned converted rice hulls using physical separation processes that are based on differential wetting. Recovery of Sic whiskers from the pre-burned material was found to exceed 90 percent. A modification of the froth flotation process developed during this study is now being used commercially to separate silicon carbide whiskers and particles and to recover a high grade whisker product.

Jan 1, 1985

By John A. Patterson

There are certain data handling techniques used by statisticans that can help one to calculate the size of an orebody and to develop some of the relationships between size, cutoff grade, average grade, mining cost, and profit. Knowing the relationships amongst these factors can help determine the most desirable operating conditions. A statistical technique that we will use is data grouping. This allows us to work with relatively few groups instead of many samples, If we were able to segregate the ore in an orebody into grade groups, add the amounts in each group, and plot the sums as a curve, we would get something like Figure 1. A smooth curve develops when the grade classes are small enough, otherwise a "stair step? histogram results. The area under the curve, being the sum of the tonnages in all of the grade classes, is proportional to the total number of tons in the orebody. If we take the data of a distribution such as Figure 1 and add the tonnages above a specific grade we have in effect a cutoff grade

Jan 1, 1958

By D. W. Alberter

I consider it a great pleasure and distinction to be invited to appear before your organization to discuss our experiences with a comparatively new system of what is known as a "Full Dimension" extensible conveyor system. One of these systems has been operating in our Diamond Smokeless Mine, Boltz, Pennsylvania, since 1959 servicing a continuous mining machines For those of you who are not familiar with this method of transportation, I would like to offer an explanation.

Jan 1, 1962

By B. V. Driga

The paper presents the evaluation method of the thermal power potential of the salt lakes developed in collapsed salt mines in Romania. It is well-known that the hydro-chemical stratification of these lakes favors warmer internal layers. The degree of heat varies during the year, but, taking into account the large number of genetic lakes of this type, it can be used as a local utilizable power source. The authors analyze the correlations between the physico-chemical parameters of the water and the degree of heat stored as a function of the morphological parameters of the lakes, as well as the technical parameters for capitalizing on this power.

Jan 1, 2008

Room-and-pillar mining at White Pine started in 1953 from a sub-outcropping orebody that gently dips to 1000 m depths in a distance of about 6 km. High horizontal stresses were recognized in the mid-1960s which had obvious stability impacts when viewed in combination with the increased overburden stresses. Modifications in conventional room-and-pillar design were introduced through the years on a trial-and-error basis to help overcome stability and resource recovery problems. These modifications were based on pressure arch concepts using pillar yielding and/or pillar recovery, and on mine layout orientation to minimize stress impacts. While some of these modifications were successfully applied in some areas, they failed in others. Through the years, visual observations played a major role in panel design with contributions from stress measurements and analyses. However, the down slide in the copper economy during the 1970s and early 1980s resulted in a loss of interest in the application of these concepts. This paper reviews ground control problems and presents the results of recent stress measurements and computer analyses. They shed light on the importance of using yield pillars and mine layout orientation to control stresses at depth.

Jan 1, 1993

By Donald L. Gaughenbaugh

Under the terms of the 1970 amendments to the Clean Air Act, the EPA established national ambient air quality standards for a number of pollutants. Sulfur dioxide (SO2) was one of these pollutants. These ambient air quality standards have had perhaps their biggest impact on the power utilities. In an effort to meet the air quality standards set forth by the EPA, utilities using high sulfur fuels have been forced to install flue gas desulfurization (FGD) systems. The majority of FGD systems in operation today are nonregenerable systems, that is the by-product of the system is disposed of, usually into settling ponds. Limestone slurry is the most common reagent used to remove SO from the flue gases. The calcium carbonate (limestone) slurry interacts with the flue gas, absorbing the SO2 and forming a by-product of calcium sulfate/sulfite which is disposed of.

Jan 1, 1986

By R. K. Mehta

An electrochemical coal oxidation model involving heterogeneous kinetics is presented. This model was tested by collecting current transient data on three coals assaying different ash content under varying operating conditions such as particle size, temperature, and % solids. In all cases, the model fitted the data very satisfactorily. Three intrinsic rate constants, namely mass transfer coefficient of Fe(II) Ions diffusing from solution to the anode (kma), mass transfer coefficient of Fe(II) Ions diffusing from solution to the coal surface (kmc), and chemical rate constant for coal oxidation with respect to Fe(III) at coal surface (k), were calculated. It was interesting to note that in this system, the mass transfer at anode was as important as the chemical reaction at the coal surface. The validity of this model was further demonstrated through a comparison of the activation energy of coal oxidation: firstly, by utilizing calculated chemical rate constant and assuming Arrhenius' type of relationship: secondly, by utilizing conventional approach using limiting current values. The comparison revealed that agreement was quite close. This kinetic analysis is useful because such a model can be used in predicting the intrinsic rate constants so that the relative importance of mass transport can be rationally analyzed.

Jan 1, 1991

By Robert C. Freas, Donald D. Carr, Lawrence F. Rooney

Perhaps no other mineral commodities in this volume have as many uses as limestone and dolomite. These carbonate rocks are the basic building blocks of the construction industry, the material from which aggregate, cement, lime, and building stone are made. Carbonate rocks, and their derived products, are used as aggregates, fluxes, glass raw material, refractories, fillers, reactive agents in sulfur-oxide removal, abrasives, soil conditioners, ingredients in a host of chemical processes, and much more. Although the use of limestone and dolomite goes back before recorded history, new uses and products are continually being found. Carbonate rocks form about 15% of the earth's sedimentary crust and are widely available for exploitation. Found extensively on all continents, they are quarried and mined from formations that range in age from Precambrian to Holocene. Reserves of carbonate rock are large and will last indefinitely, although high-purity deposits may be absent or have limited availability in certain areas. Limestone and dolomite are so useful and so abundant that in 1989 about 798 Mt were produced in the United States. In fact, about 75% of all stone quarried or mined in the United States was carbonate rock. Sand and gravel was the only mineral commodity produced in greater quantity. In this chapter we have sought to provide the general reader an overview of carbonate rocks, their composition, distribution, production, and uses. The literature on the limestone and dolomite resources of the United States and Canada is so vast and diverse that one can easily become mired in print. We tried to list those references that are easily accessible and that provide the economic geologist with a starting point for more intensive study. The table listing selected references on limestone and dolomite resources in Canada and the United States reflects our attempt to be selective rather than exhaustive and to direct the reader to the best sources of detailed information.

Jan 1, 1994

By Jan E. Stache

Commercial software programs are being utilized to create and maintain a mine subsidence database in conjunction with the U.S. Bureau of mines research on mine subsidence in Illinois. A three-year survey net of monitored structures in an Illinois subdivision was entered as textual information (attributes), on an existing AutoCAD drawing. These attributes can be optionally displayed on the corresponding drawing or extracted as a text file for import to a database program. The database program, dBASEIV, allows combinations of multiple database files for extensive querying capabilities. Subsurface database files can be merged with surface database files to enhance the effectiveness of surface response analyses in mine subsidence research. The geographic information system (GIS), pcARC/INFO, was chosen to integrate existing AutoCAD drawings and dBASEIV database files into a relational database with a graphical representation. The relational database allows users to update either the graphical representation or the database, with the changes being reflected automatically in its alternate format. The increased capacity, through use of a GIS, to query combinations of database files and have the results reflected graphically has significant potential for expediting mine subsidence research.

Jan 1, 1986

By M. R. Smith

Barrick Goldstrike Inc.'s Betze/Post Open Pit is located at the north end of the Carlin Trend, in Eureka County, Nevada, U.S.A. (see location Map, Figure 1). About ten open pit gold mines exist on the trend, which strikes northwesterly, through the north end of Eureka County and into Elko County. The final Betze/Post Pit configuration is shown in Figure 2, Pit Configuration. The final pit will be about 2450m long by 1550m wide, elongate in a west-northwesterly direction. The pit straddles the Barrick/Newmont property boundary. The highest elevation of the pit perimeter is 1800m at the south wall, with the east end pit bottom elevation at 1200m.

Jan 1, 1993

By Z. Yu

Dewatering of a -0.5 mm fine coal has been studied extensively. Deep cleaning requires however fine grinding, and dewatering of such ultrafine products presents a great challenge. Several coal samples finely ground and characterized by different wettabilities have b.een used in the filtration tests. Vacuum and press filters have been employed. In this paper only the results obtained with different flocculants (totally hydrophobic. semi-hydrophobic and hydrophilic polymers) are included. The results reveal the effect of coal surface properties and flocculant type on filtration of ultrafine coal.

Jan 1, 1994

By S. S. Sephton

The La Perla Mine, owned by Altos Hornos de Mexico, S.A., is located approximately 100 miles east of the City of Chihuahua in the State of Chihuahua, Mexico. The mine began operations in 1958. Existing ore beneficiating facilities, consisting of heavy media and jig plants, upgrade the ore prior to shipment by rail to the Altos Hornos steelmaking complex in Monclova. Sizable reserves of two distinct ore types, which were not amenable to treatment in the existing beneficiating plant, or usable in the blast furnaces, have been mined and stockpiled in order to uncover the treatable ores. One of these ore types has been labeled "Diseminado" ore, and is low grade containing approximately 42% Fe with sulphurs ranging from 1 to 2%. The other ore type has been labeled "Pulverulento" ore, and is high grade containing approximately 65% Fe and 0.1% S, but at 80% minus 325 mesh, is too fine grained for efficient sintering. Late in 1968, Arthur G. McKee & Company became involved with the problem of improving the above ores for their efficient and economical use in Altos Hornos' blast furnaces. Early in 1969 representative samples of Diseminado ore were obtained for laboratory bench-scale testing at the University of Minnesota, Mineral Resources Research Center. Concentration tests incorporating magnetic roasting, wet magnetic separation, high intensity separation, high tension magnetic separation, anionic flotation of apatite, cationic flotation of silica and oleic acid flotation of iron were performed. Laboratory testing was concurrently carried on at La Perla Laboratory, which resulted in plans to construct a 10 TPD pilot plant. The pilot plant was operational in September, 1969. Analyzing laboratory results as well as pilot plant results, Altos Hornos and Arthur G. McKee & Company metallurgists agreed that the most promising flowsheet for the low grade Diseminado ores entailed wet magnetic cobbing, desliming, and oleic acid flotation of the non-magnetic fraction. A combined concentrate of

Jan 1, 1972

By M. Kawulak

The necessity to protect the environment can limit mining activities and make some areas less attractive for the prospecting and exploration of mineral deposits. In Poland, the main environmental factors that restrain Irumng are: 1. Regional A Protection of the landscape B. Protection of ground water from contamination and depletion 2. Local A Conservation of fertile soils B. Conservation of forest resources C. Preservation of natural, cultural, and historical monuments The regional factors listed above that can limit mining are presented on a map of Poland. These data, combined with maps of known and potential mineral deposits, make it possible to delineate general levels of limitation for various mining-related activities varying from "no existing environmental limitations" to "no allowed industrial activity" As an example, a compilation of such data is presented for lignite exploration and mining in Poland. Lignite deposits occur within Upper Paleocene to Upper Miocene clastic strata at depths ranging from a few to 300 m. The thickness of the lignite is generally a few meters, but can locally reach over 100 m within grabens. As a result, the overburden-to-lignite thickness ratio varies from less than 1 to over 20. Within the same Tertiary strata, and within overlying Quaternary strata, several aquifers exist that produce good quality water that may be contaminated or depleted during lignite mining. The protection of these ground waters is the main factor limiting lignite mining and should be addressed in mining and environmental policy and planning.

Jan 1, 1996