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By Franc Runovc

The service hoisting plant in the mining transportation is an installation serving for the vertical transport of material and persons. An adequate mathematical model is presented for simple evaluation of the project parameters where different plant designs and the ways of transport are take into consideration. The technical and economical optimization procedure is added to the basic mathematical model of the project. This approach enables on one hand the optimization of the reconstruction of the multi-purpose hoisting plants in order to suppress possible bottle necks, while on the other hand it enables the determination of such values of the parameters of the choice and of the operation that the sum of total expenses per a transport unit' becomes the lowest. The optimization procedure is designed in such a way that all numerical data of the optimum hoisting plant are printed out together with the graphical representation of dependencies of the fundamental parameters in broader optimization region.

Jan 1, 1992

By D. W. Tedder

Several bauxite feeds and residue sands and muds, produced by Bayer plants in the US and over-seas, were fractionated using dry and wet magnetic separators. The magnetic sand fractions typically contained about 50 to 60 wt % Fe2O3 and the bulk of the radioactivity in the sands. The muds are more difficult to process, but some fractionation is possible using a combination of classification and magnetic separation techniques. Among the mud samples, higher radiation levels are often associated with the less magnetic fractions. Bauxite is more easily fractionated using dry magnetic separation. Much of the radioactivity in bauxite appears to concentrate in the sand and mud residuals.

Jan 1, 1987

By R. F. Kovar, R. N. Torbin

Foster-Miller has recently developed a new concept for a highly specialized shaft lining system. This innovative shaft lining system uses a continuous slip forming placement technique, lining the shaft from the bottom up such as in a raised bored shaft. Although this part is not unique, the concept is designed to use polyurethane foam instead of concrete for the liner material. Furthermore, the concept is designed to attain rates of advance of 30 m/h (98 fph). The polyurethane foam liner is designed to be thinner (100 mm or 4 in.) than a conventional concrete liner (300 mm or 12 in.). It will eliminate the high cost associated with the erection and operation of an on-site concrete batch plant. The system will be designed to operate remotely, requiring few personnel for its operation. This system (or parts of it) may be appropriate where fast construction speed is required or where a jointless liner is needed.

Jan 1, 1990

By J. P. Golightly

The nickeliferous laterites of Soroako are described in their setting in the huge Cretaceous ultramafic complexes of central Sulawesi, Indonesia. The ore bodies occur on spurs, ridges and hill flanks beneath remnants of extensive erosional surfaces. Weathering pro- files that have developed on unserpentinized harzburgite and on strongly serpentinized lherzolites show distinctive laterite structures, mineralogy and chemistry. The former are unique to the Soroako area and permit an unusual degree of upgrading by rejection of unserpentinized peridotite boulders. A mass balance calculated for a selection of profiles indicates that in situ leaching of a column of peridotite 20-50 meters thick has taken place with only minor lateral migration of nickel in solution.

Jan 1, 1979

By P. H. Williams

Experiences gained using computers in the mining and geological environment have shown that it is quite rare for a system or the data it stores to be truly stand alone. Just as the mining enterprise aims to have a smooth integration of operations from exploration through mining and extraction to sales, so it should develop all its information systems within an overall framework or architecture which covers the applications and data as well as the computer hardware and communications. This paper discusses methods of achieving such an architecture, and describes some of the benefits it can have on the development and implementation of information systems. The key aspects are the identification of the business functions and the data that they use, and ensuring that the IS plan supports the overall objectives of the enterprise. Hardware and communications policies should be based on the plans for the applications and data, rather than the reverse.

Jan 1, 1986

By S. W. Asihene, K. Osseo-Asare

The leaching and solution treatment operations used in the ammoniacal treatment of laterites depend on the ability to establish and maintain close stability relations between soluble metal ammine complexes and solid phases such as oxides, hydroxides, basic carbonates, sulfides and ammonium double salts. This paper presents a quantitative treatment of heterogeneous equilibria in ammonia/laterite hydrometallurgical systems, by means of several.types of hydrometallurgical phasedia- grams (e.g., Eh-pH, log [NH3 + NH4+] - pH, log [C02] - pH, log SO42-] - pH, log [Metal] - pH). Dissolution/precipitation phenomena associated with nickel and cobalt recovery and with magnesium scaling are discussed in the context of the phase diagrams.

Jan 1, 1979

By D. Bizier, B. H. Gardner, Y. P. Wang, S. Serata

As part of an ongoing effort to develop more cost-effective and “user friendly” hardware for geomechanical measurements required for underground mine design, Serata Geomechanics, Inc. (SGI) has investigated the potential of borehole pressure cells (WCs) for in situ measurement of stress states and continuous monitoring of changes in ground stress. In particular, because of certain advantages gained thereby, WCs utilizing an elastomer, instead of metal (e.g., copper), for the skin of the pressure cell have been developed. A data analysis technique for determining ground stress state directly from BPC data has been developed. This technique has been tested for salt ground through both in situ applications and computer simulation analysis of the BPC/borehole boundary interaction. This paper discusses the data analysis technique, the results of field and computer simulation testing of its validity, and evaluates the advantages of elastomeric BPCs in relation thereto. It utilizes field data from recent elastomeric BPC applications in the salt mine at Goderich, Ontario operated by the Sifto Division of Damtarn Inc.

Jan 1, 1986

By L. R. Shotwell, C. F. Voss, R. J. Bastian

Pacific Northwest Laboratory (PNL) currently supports the U.S. Department of Energy's Office of Civilian Radioactive Waste Management in developing and evaluating analytical methods for assessing the suitability of sites for geologic disposal of high-level radioactive waste. The research includes consideration of hydrological, geomechanical , geochemical , and waste package components and the evaluation of the degree of coupling that can occur between two or more of these components. The PNL effort and those of other research groups investing potential waste sites in the U.S. and abroad are producing a suite of computer codes to analyze the long-term performace of the proposed repository sites. This paper summarizes the ongoing research in rock mechanics at PNL involving flow through jointed rock. The objective of this research is to develop a methodology for modeling the coupled mechanical-hydrological process of flow through joints and then attempt to validate a "simple" model using small -scale laboratory test data as a basis for judging whether the approach has merit. This paper discusses the laboratory tests being conducted to develop s joint behavioral constitutive model for the numerical method under development and the modeling approach being considered.

Jan 1, 1986

By Richardo Montoya

Radomiro Tomic, the new CODELCO division, is a copper deposit located at 3000 m a.s.l. and 40 Km from Calama in northern Chile. It has total oxide reserves of 802,000,000 tonnes with an average grade of 0.59% total Cu (using a cut-off grade of 0.4% total Cu). The copper oxide ore is mainly atacamite and chrysocolla. Startup is expected to commence in December 1997 of 150,000 t/y of Cu cathodes. Future expansion to 250,000 t/a of Cu cathodes is currently being planned. The process consists of an open-pit mine, a two-stage crushing system, agglomeration with sulphuric acid and emplacement on a heap leach pad for a 45-day leaching cycle. Solvent extraction and electrowinning will produce LME "A grade cathode. A number of significant technology innovations have been incorporated into the project.

Jan 1, 1998

By Edward L. Mooney

In the, West, walking draglines often offer the least cost method of uncovering coal for surface mines. However, with each of these machines costing millions of dollars, a good deal of analysis can be justified by the potenial savings or, conversely, costs associated with the choice of a machine. This has resulted in the recent development of a number of computerized models for dragline selection and pit design. One of the earliest reported models for this purpose was developed by Dunlap and Jacobs (1). Later, Rumfeldt described the computer approach to sizing stripping draglines given the required production rate and mine site parameters (2). This basic approach is probably still the most widely used with models for more complicated mining methods reported by Stefanko, Tomica, Finch, as well as others (3,4,5). furthermore, detailed simulation models useful in this regard have been developed by McDonnell Douglas and Fluor, Utah (6,7)

Jan 1, 1982

In his keynote address at the 18th International Minerals Processing Conference (IMPC), R.P. King, director of the University of Utah Comminution Center, said "it will be the application of very fundamental physical principles that is likely to bring major advances in comminution technology (IMPC, pp. 39-45)." It is evident from the literature published in 1993 that many of these fundamental studies, particularly as they relate to single-particle fracture mechanics and mineral liberation, are starting to bear fruit. The beginnings of fundamental mathematical models for design, scale-up and control of comminution systems are now taking shape. Modeling/fundamentals Population balance models (PBM) have been used to describe grinding systems for 20 to 30 years. However, Williams and Meloy (IMPC, pp. 73-79) pointed out some of the inherent problems with this modeling approach and that there is no unique solution for the unconstrained PBM for grinding. Many of the current constraints used to back-fit selection and breakage functions were also shown to have problems. The need for a more fundamental means of determining these parameters was indicated.

Jan 1, 1994

By D. C. Wilder

Deformations during heating and cooling of three drifts in granitic rock were influenced by the presence of faults and shear zones. Thermal deformations were significantly larger in sheared and faulted zones than where the rock was jointed. but neither sheared nor faulted. Furthermore. thermal deformations in faulted or sheared rock were not significantly recovered during subsequent cooling thus a permament deformation remained. This inelastic response is in contrast with elastic behavior identified in unfaulted and unsheared rock segments. A companion paper (Butkovich and Patrick, 1986a) indicates that deformations in un- sheared or unfaulted rock were effectively modeled as an elastic response. We conclude that permanent deformations occurred in fractures with crushed minerals and fracture filling or gouge materials. Potential mechanisms for this permanent deformation are asperity re-adjustments during thermal deformations. micro-shearing, asperity crushing and crushing of the secondary fracture filling minerals. Additionally, modulus differences in sheared or faulted rock as compared to more intact rock would result in greater deformations in response to the same thermal loads.

Jan 1, 1986

By R. D. Hansen, R. R. Klimpel

Previous papers by these authors on slurry rheology control grinding aids have emphasized the end-use results and application methodology involved. This paper emphasizes the chemical principles and the influence of various chemical structures behind slurry rheology control chemicals. Particular examples are shown which correlate chemical structure modifications to environmental factors involved in grinding such as pH, shear, ore type, water chemistry, and particle size.

Jan 1, 1990

By P. Venkatasubramanian

The selection of a mining method for a mineral deposit is a complex decision problem. Human judgment, based on experience with mineral deposits and geologic conditions, remains the single most important input of the decision-making technique. If the use of artificial intelligence, in particular the developments in expert systems, is taken to its logical conclusion, the experience of the domain experts could be incorporated into a decision-support expert system. A knowledge-based decision support system for mining method selection for ore deposits has been designed whereby the domain knowledge is represented as production rules and organized in a semantic tree representation. This model is written in the PROLOG language. While the verification difficulties of expert systems models are recognized, an example of the model's decision on the mining method for a given ore body is presented and shown to be consistent with the decision made by human experts. In addition, plans, for further verification of the model are delineated.

Jan 1, 1992

By A. Chamaret

Minerals extraction is related to complex sustainable development issues that are subject to international and local controversies. Debates must be based on objective and comparative elements. Defining strong indicators for assessing impacts and performances of mining sites thus appears necessary to inform and support the decision-making process for stakeholders. Recently, many indicator sets have been developed on an international level based on top-down approaches, but they commonly lack legitimacy for stakeholders and adequacy to specific site issues. They thus need to be complemented by the consultation of local actors concerned by such mining activity, in order to define indicators that are closer to the needs and contexts of the specific sites. The question raised by this kind of top-down/bottom-up approach is how to organize and reveal the plurality of values and concerns associated with mining. Based on the principle of representative diversity, the approach undertaken at the Arlit uranium mines in Niger aimed at defining indicators that are understood and accepted by all actors. The aim was to measure the impacts and performances of mining sites in the four sustainable development dimensions, and at local, regional and national scales.

Jan 1, 2007

By Brian Fulcher

The Fort Lawton Parallel Tunnel was built in 1990 - 1991 by Morrison Knudsen Corporation (MK) as an integral part of Seattle METRO's planned expansion of the Westpoint Treatment Plant. The project included a concrete lined 2542 m (8,340 ft) long tunnel bored in sands and clays under the presence of methane gas and over 27.4 m (90 ft) of ground water table. The tunnel roughly paral¬lels an existing and still operating 3.65 m (12 ft) diameter tunnel originally completed in 1909. The parallel tunnel was constructed using a Lovat 4.72 m (15 ft-6 in) earth pressure balanced TBM with ribs and timber lagging as primary support. The tunnel alignment crossed under as much as 91.4 m (300 ft) of overburden as well as twin mainline railway tracks; terminating in a shaft adja¬cent to the Seattle ship canal. The project was completed in June, 1991 after a final "wet-tap" tie-in to the existing brick-lined sewer; over five months ahead of the contract schedule. This paper will describe the construction methods, job site conditions and difficulties encoun¬tered on this very challenging and successful project.

Jan 1, 1993

By R. K. Mehta, K. N. Han, P. B. Queneau, V. Dieudonne

A study based on a statistically designed sets of experiments (central composite design) was conducted to determine the optimum conditions for leaching a subbituminous coal (7.0 % ash) from the middle Wyodak seam in mild sulfuric acid solutions. The statistical analysis was conducted with the ash content and ash removal as the dependent variables and with the coal loading, acid concentration, ferric ion concentration, and temperature as the independent variables. Treatment of the experimental data via a simple genetic algorithm (GA) revealed that acid concentration and temperature are the two most critical variables. Unlike the case with bituminous coal, the ferric ions addition shows no beneficial effect. The optimum "macro response" predicted by GA was verified experimentally; the ash content was reduced to 2.7%, which is close to the value predicted by GA. The ash content was further reduced to 1.7% in a two-stage leaching process devised by incorporating the optimization results with that of leaching kinetic studies.

Jan 1, 1993

By W. J. Adamson

Strategic Data Planning (SDP) is an emerging technique for the analysis and design of information systems. This paper describes the use of strategic data planning in the formulation of a complete integrated set of mining technical systems for the Koolan Island iron ore mine. Applications covered include hydrogeology, geology, mine planning, surveying, quality control, laboratory and mine production recording. Koolan Island is 13 kilometres long and 5.5 kilometres wide at its widest point. Its sole industry is an open pit iron ore mine of 3 million tonnes annual capacity, owned and operated by BHP Minerals. Some of the production is used by BHP Steel International, but most is exported. The orebody is steeply dipping and is mined bench by bench. Outturn grades for run-of-mine product are iron 66.5%, silica 3.0%, alumina 1.0%. Computer systems are run on Data General equipment, currently an MV10000. Computer applications, which are shared across mine sites, are developed and maintained by BHP Information Systems in BHP's Melbourne Office.

Jan 1, 1986

By Kevork Chouzadjian, Gary Davis, Nicholas Katsikaros, Bruce Kelley, Mellie Mavatoi

A process has been developed to recover gold and copper from two waste materials at the Bougainville Copper Limited mine in Papua New Guinea. It involves the bioleaching, in reactors, of a pyrite concentrate to liberate refractory gold and generate sulphuric acid, ferric sulphate and biomass for bacterial leaching of a chalcopyritic waste rock dump. Gold is to be recovered by cyanide leaching and copper by solvent extraction/electrowinning. The reactor bioleaching was developed in continuously operated reactors of 1 m3 capacity by CRA Advanced Technical Development at Cockle Creek, while the dump leaching was developed in 750 kg columns on site at Bougainville Copper Limited. The process was to be piloted on site.

Jan 1, 1990

By R. K. Paramguru, K. Srinivasa Rao

This paper describes a new approach for examining the kinetics and mechanism of zinc dissolution from sphalerite concentrate in acidic ferric sulfate solution in the presence of manganese dioxide. A literature search was performed to access the possible action of the two oxidizing agents, i.e., ferric ion and manganese dioxide. The possibility of galvanic coupling between ZnS and MnO2 and the cyclic action of the redox couple, Fe2+/Fe3+, on these two minerals were theoretically examined based on corrosion principles. Expressions for the mixed potential (Em) and the mixed current (im) were derived for the relevant corrosion and galvanic couples. Leaching experiments were conducted to establish which of the above phenomena is operative during leaching. The results indicated that the dissolution mostly occurs by the action of ferric ion on ins producing ferrous ions. The presence of MnO2 enables a quick conversion of ferrous to ferric, which maintains the rate of in dissolution. The process has promising features for commercial exploitation.

Jan 1, 1999