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By E. S. Peterson, M. K. Harrup, K. A. Dolbeare, J. E. Wey

Efficient methods for removal of copper from heap leach solutions without mobile organic phases are a current mining industry need. To satisfy this need a selective, high-capacity, durable solid material is required. The INEEL has developed a set of materials based upon current solvent extraction chelates that provide selective copper concentration in the presence of high concentrations of iron. In contrast to conventional solvent extractions, our strategy anchors the chelators to a non-polymeric solid substrate through the use of a custom designed linker molecule. The fundamental synthetic routes to these materials have already been established and attachment to the solid surfaces achieved in an efficient manner. Our continuing research is focused on the optimization of the synthetic pathways to these solid materials and the evaluation of their copper capturing capabilities.

Jan 1, 2002

By Knezicek Zeljko, Knezicek Tihomir

Lignite open cast mine "Dubrave" is the largest lignite mine in Bosnia and Herzegovina. The open cast mine was designed with two external waste dumps. Waste dump "West" is the major dump, while "Cajici" dump is used for dumping waste taken from leveling the terrain. The major waste dump contains 14.6 million cu.m. of waste, while the side waste dump contains 3 million cu.m. of waste. Existing situation with available sites for depositing the waste shows that additional space for dumping the waste must be provided. Three options can be taken into consideration. The fact is that none of the three options are suitable for the current production situation. This article deals with the optimization process for obtaining the optimal variant where a waste dump can be located and selection of the most valuable option.

Jan 1, 2002

By N. T. Rempe

The underground voids that result from mining provide opportunities for deep geologic waste disposal (DGWD). Such disposal could solve many environmental problems. DGWD takes careful planning, technology transfer and true partnership between waste generators and mine/repository operators. The US government is now planning on using specially mined excavations to dispose of radiotoxic and mixed waste. Using the experience gained from the domestic projects that are now in preparation and from foreign repositories that are now in operation, US mines can claim their rightful share of the growing market for DGWD.

Jan 1, 1997

By Terry A. Ring

Sand bed filters are used to remove large and small particles from liquid streams. The large particles are removed by the straining action of the filter bed and the small particles are removed by particle deposition on the surface of the bed particles. Particle deposition, while being essential for the filtering action of colloidal particles, is not the only process that occurs in the filter bed. Other processes that occur are (1) the substrate becomes filled with particles limiting further deposition, and (2) some deposited particles are resuspended. The sum total of all these processes determine the performance of a filter bed.

Jan 1, 1982

By A. K. Sheik, W. G. Pariseau

A small underground mine in northern Idaho was used as an experimental facility for studying the role of water in the analysis of mine opening stability. Laboratory test data, borehole measurements and geological mapping assisted in constructing a coupled finite element model of the rock mass. The model was used to make quantitative estimates of: 1) rock stress, strain and displacement changes, and 2) water pressure and flow velocity changes that occurred during historical mining. Stope cuts and wet fills were included in the analysis. Stability of crown pillars between stopes was of particular interest. The relatively low effective stress and high rock mass strength showed that water pressure changes were of no great consequence in agreement with experience. The computational tools used in the analysis may be applied to other wet mines with appropriate changes to site-specific input data.

Jan 1, 1999

By K. Nagata, T. Kawashima, S. Tejima

The expanding volume of maritime coal transportation is intensifying the problems concerning large vessel service, port construction, trans-shipment, and environmental control. The major problem is the shipment of coal. Customary methods for bulk transfer must be improved and new systems developed. Slurry unloading has a key role in the new systems. This report reviews progress in slurry transportation research that has been done in Japan since the 1960s, when large-scale experiments for domestic transportation were done. Experiments on the effects of vibration on the slurry cargo and on reslurrying are focused on.

Jan 1, 1987

By Slobodan Vujic, Goran Cirovic, Dragan Radojevic

Mine production systems (MPS) are characterized, more or less, by the following properties: uncertainty, subjectivity, impreciseness, polysemy, instability, indefiniteness and lack of data. From modern study aspect these MPS mathematically belong to the class of fuzzy systems. With this in mind, the usage of fuzzy sets is recommended as a methodology that treats impreciseness, indefiniteness and complexity of mine production systems in a satisfactory manner. Fuzzy modelling, discussed in this pa- per, is applied as a mathematical implement. The objective of the paper was to show production optimization in practice on the ex- ample of bauxite open pits where fuzzy linear programming (FLP) was used following the criterion per income. The variables in criterion function are linguistic variables while both variables and variable restrictions are presented by triangular fuzzy numbers (TFN). The term "satisfactory income" presented through triangle fuzzy numbers was introduced instead of "maximizing the income". sensitivity of the obtained solutions has been analysed

Jan 1, 1996

By P. Verhoeven, G. Hefter, P. M. May

The dissociation (ionisation) constant of hydrogen cyanide, pKa(HCN), has been measured by high precision glass electrode potentiometric titrations in saline solutions containing up to 5 mol/L sodium chloride. The dissociation constant of water that is necessary for the calculation of pKa(HCN) has also been measured. In saline solution, and in contrast to literature values, pKa(HCN) changes considerably at both high and low ionic strengths as a result of changes in activity coefficients. In addition an equation is presented, using literature data, that describes the variation of pKa(HCN) with temperature up to 150°C. The significance of the changes in pKa(HCN) for optimising the pH of alkaline cyanide gold recovery streams is briefly discussed.

Jan 1, 1991

By Drupad B. Desai, Alexander Rosenbaum

In recent years, there has been an increasing use of two-pass tunnel lining system consisting of segmental unbolted expandable precast concrete initial lining and cast-in¬place concrete final lining in the United States. Used so far in soft ground tunneling performed under free air, it often includes a waterproofing or gasproofing membrane placed between the initial and final linings. This paper describes the utilization of this two-pass system for an extension of the Baltimore Metro, constructed in part under compressed air. It offers a description of the extension project, known as Section C; addresses the tunnel lining selection process and the design of the lining elements; examines the effect of the adopted lining system and tunneling technique on the design of the project's major structural components; and describes design modification instructions in order to accommodate constantly changing field conditions.

Jan 1, 1993

By Noel C. Joughin, Orrie Fenn, Brian E. Protheroe

Work has shown that the use of high-pressure water jets enhances the performance of mechanical cutting in very hard rock. To assess the potential of this approach for use in conjunction with free rolling cutters, a series of tests has been conducted using both disc and button type cutters, to determine the relative effects, on cutter performance, of variations in relevant jet and cutting parameters. In these tests it was found that water jet assistance can result in reductions in the forces on a free rolling cutter typically of the order of 40%.

Jan 1, 1985

By R. D. Begley, A. W. Khair

This paper presents an assessment of modeling techniques in predicting subsidence over longwall areas. Extensive instrumentation has been made, both at the surface and subsurface, at three longwall mines in northern West Virginia. Ground movements were monitored during a three- year period until subsidence ceased in these areas. A comparative analysis of empirical subsidence prediction techniques including graphical (NCB), profile function, influence functions (USBM, Bals', Knothe's, and zone area) will he presented. A brief geologic and topographic description of each site, along with the instrumentation and monitoring program, will also he presented.

Jan 1, 1990

By D. S. Choi, H. D. Dahl, D. L. McCain

The paper examines current room and pillar mining practice in the U.S.A. from the standpoint of rock mechanics. Consideration is given to the deformation characteristics of the roof formation and the coal seam as determined in the laboratory as well as in the field. The results can be utilized by the practicing mining engineer to improve current mine design practice.

Jan 1, 1982

By C. Y. Kao, Roger Y. Cheng, C. S. Hsieh

The mushroom-shaped Minghu power cavern located in central Taiwan is 21.2 m (W) by 40.5 m (H) by 127.2 m (L) and is designed to house 4 units of power generating-pumping equipment with a total capacity of 1,000 MW. This paper presents an introduction to the geological conditions at the cavern site; the rock mechanical tests undertaken; the design approach adopted; the construction method and sequence followed; and the instrumentation provided in the roof arch to monitor the behavior of the surrounding rocks. The measured data collected from the embedded instruments will be compared with those obtained from theoretical analyses and presented in this paper. Several technical problems encountered during the construction stage are covered and the solutions of these problems are also described therein.

Jan 1, 1983

By Yoginder P. Chugh

About 65% of the U.S. coal production (835 n tons was surface mined. A similar proportion of the Illinois basin's production (112 m tons) is also surface mined. The state of Illinois is the third largest producer of surface mined coal in the United States, after Wyoming and Kentucky. The Illinois coal basin encompasses Illinois, southwestern Indiana, and western Kentucky, as shown in Figure 1 (dotted lines). The estimated surface mineable coal resources in the basin amount to about 27 billion tons, and about 69 m. tons of coal is surface mined annually (Tab1e I).

Jan 1, 1981

By J. F. Peterman, M. C. Roberts

The success of any industrial mineral project requires an accurate forecast of the demand fir the material as well as accurate projections of costs and prices. This paper develops a general method of predicting mineral requirements and applies it to the case of graphite. The basic method is to explain graphite consumption in each of its major uses by the output and manufacturing technology of the using industry. Once these underlying factors are determined, they can he projected to establish future requirements. This forecast is critical to the evaluation of a new source of supply, such as the graphite resources of Upper Michigan.

Jan 1, 1990

By Robert L. Russell

Production at Freeport Indonesia's Ertsberg open pit copper-gold mine started in 1972 at a rate of 7.5 kt/d (8270 stpd). Mill throughput remained at that rate for several years until the discovery of the Ertsberg East (GBT) ore body. This discovery prompted three succes¬sive expansion stages from 1981 to 1988 that boosted production to 20 kt/d (22,000 stpd). In 1988, the discovery of the huge Grasberg porphyry copper deposit launched an era of much larger expansions. The first of these was the installation of a fourth primary mill in 1989 that increased throughput to 32 kt/d (35,270 stpd). That was followed by an expansion of the crushing and screening plant and in 1991 the addition of a new south concentrator to bring production to 57 kt/d (62,830 stpd). The addition of a primary ball mill and the changeout of the original Denver flotation cells in 1993 brought production to its current level of 66 kt/d (72,750 stpd).

Jan 1, 1994

By Yeonuk Choi, Patrick R. Taylor, Lyle Cunningham

Laboratory experiments have been performed to evaluate the potential for metal removal and recovery from river bed tailings by ferric chloride leaching. The lead, zinc, silver and other metals in the river bed occur due to the old method of dumping mill tailings into rivers. This was practiced prior to the introduction of tailings impoundments. The effects of the leaching method, leaching time, pulp density, ferric chloride concentration, and leaching temperature on the rates and recoveries of lead, zinc and silver were studied. The effects of pulp density and leaching temperature were significant on the extraction rates of lead, zinc and silver. The lead content in the leached tailing was reduced to 0.023 percent, when using an 353O K leaching temperature and 0.384 g of FeC13/1 g of sample.

Jan 1, 1992

By Rudolf E. Pfister

One of the Swiss transalpine highways includes two remarkable tunnels: the 16.3 km long Gotthard Road Tunnel and the 9.3 km long twin tube Seelisberg Tunnel, both presently under construction. Large diameter shafts up to 900 m long are required for ventilation. Excavation techniques for rock formations ranging from loose sedimentary rock to granite and very hard siliceous limestone were carefully evaluated. The methods finally applied include excavation of shafts in hard rock, conventional drilling and blasting, excavation by ripper-tooth excavator ("Big John") in marlstone, shield protected heading in loose material and soft rock, and tunnel and shaft lining, both by poured concrete and by prefabricated elements. A critical review of the success of these methods can now be made after a five year construction period.

Jan 1, 1976

By Toshio Fujiwara, Sumikichi Ito, Masao Kitamura

The Tennohji-Benten Giant Trunk Sewer Project has been under construction since 1974 in the eastern part of Osaka, the second largest city in Japan. The entire project is divided into 7 blocks, some of which have already been completed. This 8.8-km sewer tunnel, being driven through a densely populated area, was planned to be constructed by the shield tunneling method. This paper described shield tunneling performances and ground behaviors during the construction of Blocks 2 and 3. An earth pressure shield (dia., 6,750 mm) was employed in Block 3 tunneling. The ground was generally soft and the cover over the tunnel varied from 13 m to only 4.5 m, so that a considerable amount of chemicals was injected to stabilize the ground. A hand-digging type shield (dia., 7,250 mm) was used in Block 2 tunneling under compressed air. For 85 m of the total length of 1.6 km, the soil at the face was extremely soft, and therefore, the ground freezing method was additionally employed.

Jan 1, 1981

By Richard Louis Viner, William D. Leech, Walter A. Mergelsberg

With the construction management team established and a full funding agreement secured the Washington Metropolitan Area Transit Authority (WMATA) now has the manpower and the financial resources to continue Metrorail construction into the 1990's. This paper describes WMATA's new role as construction manager after the transition from Bechtel Associates and gaining the full funding agreement with the Urban Mass Transit Administration (UMTA) and regional governments to complete 84.7 Metrorail miles (136km). The authors review the most recent station and line tunneling projects. WMATA's contractors have employed the state of the art soft ground and hard rock tunneling equipment and methods - an earth pressure balance TBM, a closed face TBM, and the New Austrian Tunneling Method (NATM). In final, the paper previews future underground work to be let under the funding agreement.

Jan 1, 1987