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By Boris J. Kochanowsky

In the mobile crushing unit system trucks are replaced by a conveyor resulting in a "continuous" almost "fully-automated" operation with all its attendant advantages. In consequence, overall operating costs are greatly reduced. Because of the new designs of large mobile crushing units that have been brought on-to the market, the use of these plants has increased significantly during the last three years. This paper describes the designs of new mobile crushing units, and emphasizes the advantages that such plants offer to the rock products and mining industries. It examines operating costs, and indicates the conditions in which the application of these plants is most profitable.

Jan 1, 1968

By M. J. Laurila

Elemental analysis of slurry streams using X-ray fluorescence (XRF) has long been employed. However, detector technology has limited the application of XRF devices. Using detector technology employed on NASA's Mars Pathfinder to analyze soil samples, Process Control, Inc. has developed an on-line analyzer to mount on a sampling system. The prototype XRF elemental analyzer was installed at Detroit Edison's Monroe Power Plant in January, 1998 and has been employed to monitor feedstock quality. A slurry system has been developed for flotation control. This paper describes the testing of the analyzer using the new, draft ISO standard for evaluating the performance of on-line analyzers (ISO/DIS 15239).

Jan 1, 1999

By R. C. Jr. Babcock, V. S. Znamensky

The Pyke asbestos deposits were discovered by Kennecott Explorations (Australia) Pty. Ltd. in 1969 during the course of base metal exploration on the South Island of New Zealand. Extensive occurrences of chrysotile asbestos were found associated with the Red Mountain ultramafics in the headwaters of the Pyke River, and to the north and south along the ultramafic belt for a distance of 70 km. Surface evaluation and drilling by Kennecott in 1970 and 1971 identified numerous small deposits of good grade fiber in the Little Red Hills between the Pyke and Barrier Rivers. Additional drilling and three adits have been completed by other companies since that time. The property is presently held by Lime and Marble, Ltd., of Nelson, New Zealand, and Kennecott Explorations (Australia) Pty. Ltd. This chapter presents the regional and local setting of the asbestos deposits, including the geology and nature of mineralization. In addition, the exploration methods used by Kennecott in the discovery and evaluation of these deposits are outlined. Subsequent work by other companies is mentioned, but not de- scribed in detail. This subsequent work did not alter Kennecott's conclusions or produce any serious changes in the interpretation of geology and mineralization. The author acknowledges the contribution of the many employees of Kennecott Explorations (Australia) Pty. Ltd. who have been involved in the project. In particular, thanks go to Ramon Farmer, N.G. Corner, and A.W. McConie, who were responsible for completion of field work and reporting on the project. The responsibility for the conclusions and interpretations of this chapter are solely that of the author and result from his involvement in the discovery of the deposits and management of the exploration program. REGIONAL SETTING Ultramafic rocks on the South Island of New Zealand are thought to be Permian in age and occur between crystaIline and metamorphic continental rocks of Precambrian through Cretaceous age in the west, are thought to have once been part of the Antarctic subcontinent, and the extensive geosynclinal graywacke deposits of the Mesozoic New Zealand geosyncline in the east. They consist of the Dun Mountain ultramafics, a 130 km long segment of ultramafic rocks located at the north end of the South Island, and the Red Mountain ul- tramafics that occur in a zone 200 km long in the south half of the South Island as shown in Fig. 1. These two belts, once contiguous, have been offset a distance of 560 km by the still active Al- pine fault, which is analogous in character and offset to the San Andreas fault of the United States. The ultramafic rocks occur within a sequence of Permotriassic volcanic and sedimentary rocks that probably formed at the eastern margin of the continental plate. The ultramafics appear to be tectonically emplaced between Permian lithologies in the Dun Mountain belt (Coleman, 1966), and at the base of or between Permian volcanics and sediments in the Red Mountain belt. The Permotriassic ultramafic volcanic sequence of the Red Mountain ultramafic belt appears to be a typical ophiolite sequence. Ultramafic rocks, mixed mafic intrusive rocks and volcanics, volcanic rocks, and volcanoclastic sediments occur in apparent superposition from east to west in the area of Red Mountain. Farther south, ultramafic rocks are associated with basaltic volcanic rocks and some sediments, and still farther south are emplaced entirely in sediments. These structural compIications of the normal ophiolite sequence have resulted from the coincidence of Permian subduction, early Mesozoic extension and sedimentation, and Cretaceous subduction along the same plate margin (Landis and Bishop, 1972). The general geology in the area of the Red

Jan 1, 1986

By Martin Wehrli, Oliver Schneider

"MOTIVATION Tunnel construction companies must keep costs low, finish projects in less time and still meet the high quality and safety standards. Therefore, their main goal is always to optimize the tunnel excavation process. Traditional geodetical methods are used since more than 100 years to ensure an exact breakthrough of a tunnel. Evolving sensors, sensor fusion and increasing computation resources opened new fields of application for geodetic solutions in tunneling. These solutions offer new ways to reduce costs and risks in tunneling. INTRODUCTION Nowadays in tunneling, geodetical measurement methods are not only used for guidance, but also for various other applications. This paper gives an overview about where geodetical measurements are used today and highlights their benefits for safety and costs aspects. Furthermore, advanced solutions are introduced. In progressive projects, they have already become state of the art technology and are in use daily. STANDARD GEODETICAL MEASUREMENT APPLICATIONS In drill & blast tunnel construction processes, there are many standard geodetical applications used in the different construction phases, each having different requirements regarding accuracy. In the excavation construction stage, guidance tasks and setting-out of various positions is done by the foremen. Thanks to simplified measurement tools, the foremen are enabled to carry out these measurement tasks themselves without requiring deep surveying knowledge. In contrast, deformation analysis and network measurement campaigns need sophisticated planning and a profound education in surveying. Therefore, these tasks are carried out by surveyors. Profile control and as-built documentation is required in each construction phase. Depending on the requirements of the project, this task can be carried out either by the foremen or a specialized surveyor. Table 1 provides an overview over typical surveying tasks in an underground project including information about who is doing the job and the according accuracy requirements. The listed tasks are described in more detail below."

Jan 1, 2016

By K. R. Weller

In recent years, a variety of new or substantially modified grinding machines have been offered to the mining industry with claims of improved performance relative to standard grinding machines especially rod and ball mills. The incentive for developing such new machines is high, because costs associated with grinding are a very substantial part of the total costs of processing run-of-mine ore, and gold ores are no exception in this regard. The incentive is also high because of the very low conversion of input energy to comminution energy in most tumbling mills. If the most energy-efficient means of mechanical size reduction is slow compression of single particles, then this energy amounts to only about 3% of that used in tumbling mills. It would seem, therefore, that there is a huge potential to do better. This paper examines three types of grinding machine for which claims of higher energy utilisation ( amongst other beneficial claims) have been made, namely the high pressure grinding rolls, the vibrating drum mill and various styles of stirred mill. It presents evidence concerning the claims, examines the range of particle size and particle size reduction over which benefits might reasonably be expected to accrue, discusses the major issues in contention and briefly describes the research the CSIRO Division of Minerals has in progress, both independently and collaboratively, the latter mainly with the Julius Kruttschnitt Mineral Research Centre (JKMRC) via the Cooperative Research Centre for Mining Technology and Equipment (CMTE) and the Australian Mineral Industries Research Association (AMIRA). There are many criteria which may be chosen to assess relative performance of grinding machines. Those used below are:

Jan 1, 1995

By Anna Marabini

This paper provides a summary of the studies performed over a period of more than fifteen years by the Italian National Research Council's Mineral Processing Institute in Rome to develop applications for the use of chelating reagents in the flotation of metallic minerals. A description is given of the various phases through which the studied progressed, starting with the combined use of commercial chelating reagents and a neutral oil and then moving on to the synthesis of new long-chain chelate collectors for the flotation of sulphide and oxidized Pb, Zn and Cu minerals. After a series of preliminary tests which confirmed the possibility of floating various metallic minerals with commercial reagents containing chelating groups exerting specific action on given cations, the studies were addressed to the development of a theoretical method of choosing chelating groups that exert selective action on one metallic mineral rather than others. The theoretical approach was based on thermodynamic data concerning the chemical equilibria in solution. The validity of the method has been proved in numerous cases by flotation tests on pure minerals. Subsequently the research was directed towards the design and synthesis of reagents with a mixed aliphatic-aromatic structure containing chelating groups for Pb and Zn and an alcoxyl chain of various length, position and configuration. The flotation results obtained on oxidized and mixed Zn-Pb ores provided interesting pointers for designing the nonpolar portion. The structural criteria identified via these studies were interpreted on the basis of chemical and steric considerations. A description is given of a new synthetic chelate collector which is effective in the selective flotation of Cu minerals from complex sulphides. The fact that this reagents is more selective than xanthate is demonstrated by comparative flotation tests on actual ores.

Jan 1, 1994

By Kerry Spickelmier

With the dissolution of the former USSR and a welcoming of foreign, minerals expertise by a host of developing countries, a "new," more international, world of minerals is open to the mining industry. However, even in the new frontier, the old laws of nature still apply. For those attendees of the 98th annual Northwest Mining convention, the adage "survival of the fittest" commanded particular attention. Miners, engineers, geologists and other unique species traveled to Spokane in December to learn of adaptations they can make to assure, or at least prolong, their place in the mineral industry's land of the living. You have heard the tales of the spotted owl and the desert tortoise, but add to this endangered list the North American mining industry. During a session on international investment criteria, D. Silver of Balfour Holdings (Littleton, CO) blamed excessive environmental regulation, 1872 Mining Law revision and the anti-mining-and-business attitude of our government for migrations from and extinctions within the domestic mining population. "We've been on a death curve for some time," Silver said, "with a lower birth rate and a higher death rate. In the last four years, we've lost 60% of the gold producers in North America, and we're down to 110 companies. The entire industry has lost about 400 companies and is now down to 2800." Unreasonable regulation founded on emotion rather than scientific fact has been the chief cause of death, according to many of the convention speakers. B.J. Kennedy, president and chief operating officer of FMC Gold (Reno, NV), emphasized, "We have accepted a regulatory environment - but we oppose being strangled to death by unreasonable regulations."

Jan 1, 1993

By Michael C. Stanley

The set of discoveries for a mining district or camp is a reflection of the exploration history. In the western Abitibi greenstone belt of Ontario, future exploration can be guided by a study of statistical trends of known gold deposits. In this area simple trends indicate a strong decrease in the contained quantity of gold discovered through time. Much of this decrease is attributed not to falling mining grades but to smaller tonnages of ore. A plot of the largest discovery in each ten year time period suggests that deposit discoverability is following a size-biased sampling model. Cumulative ounces of discovered gold indicate that an asymptotic value has been reached where exploration is not expected to add significantly to known reserves. This is substantiated by a downward trend in the exploration success ratio of the number of new deposits discovered versus the number of new mineral prospects. The set of discovered deposits reflects a non-random sampling process where size- biased modeling suggests that the largest deposits will be discovered early in the exploration effort. It is the exceptionally large deposit contributing to the observed size-biased distribution. Although this pattern is observed for the western Abitibi the model is complicated by recent, large reserve additions that are attributed to the original discovery. There is present in this area a subtle learning process in exploration leading up to the largest discovery. For comparison a learning model was estimated using cumulative size of discovery per unit of time. This model yielded results consistent with the statistical trends and is thought to be a superior forecast of future discoveries in this region.

Jan 1, 1992

By H. Hinds

Plant testing of DuPont's Activator Technology in the vat leach circuit of the Homestake mine shows increased gold recoveries of 3-5%. Activators are catalysts of gold dissolution in cyanide solution. DuPont received the patent for this technology in January, 1996. The test was run in the west sand plant alternating control and activated vats to reduce the variability in head grade and cyanide consumption. Activated vats had gold in the preg solutions earlier, higher gold recovery, and lower gold residuals. Activator addition did not adversely affect mill operations or the environment. Optimization of the technology continues.

Jan 1, 1997

By George Biro, Christoph Mueller

A number autonomous operations is in place in several, mainly in fenced areas, where safety is assured by locking off the entire area for other traffic. However autonomy can be brought much further if functional safety is assured and a real mixed traffic of autonomous and manually operated vehicles is possible. MobileTronics has created a modular software and control framework for autonomous machines. The paper covers application examples in which the deterministic object recognition in combination with probabilistic algorithms and sensors is used as a basis for functional safe certification of mixed traffic autonomy.

Jun 25, 2023

By Paul W. Patton, Christopher Scott Smith

The use of ceramic-in-rubber pulley lagging on bulk material belt conveyors is increasing. Many of the applications have been on pulleys originally installed with rubber lagging. There is a consensus that the fiction characteristics of the ceramic material are significantly better but the factors quoted vary, possibly because the more complex traction mechanism of the dimpled ceramic elements on the belt is not well understood. In this paper we will report and evaluate field data from a number of field installations to provide a study of actual friction characteristics in successful applications for those who desire reliable data for using ceramic-in-rubber lagging in new conveyor designs.

Jan 1, 2004

By Juan L. Yarmuch, Hyam Rubinstein

Open-pit mine planning is a key process in the definition of mineral reserves and their efficient removal. Ore in open-pit mines is extracted bymining sequential pits called pushbacks. Pushbacks need to satisfy complex geometrical constraints to ensure the efficient usage of equipment. To date, no algorithms that both account for those constraints and maximizeNPV, are commercially available. Therefore, pushback design is done by engineers relying on their expertise to incorporate practical features intothe output of commercial tools. In this article, we present a new algorithm that produces close to optimal practical pushbacks and we illustrate its performance in real mines.

Jun 25, 2023

By C. Timothy Shaw

Traditionally, only the large mining companies have maintained specialist departments in such areas as Rock Mechanics, Ventilation and Safety. To the small companies this has been a luxury that they could ill afford. Any work required by such companies in these areas, more complex than could be handled by the existing staff, was done by consultants. This situation is changing though and there is a need arising for many specialist departments. These changes are partly being brought about by the effects of inflation as the ever increasing costs are causing more and more operators to increase the size of their operations in search of economies of scale. In addition though the plethora of new laws and regulations are creating a need for many more specialists in all areas of mining in order to ensure compliance. The abovementioned factors, added to the existing Pattern of mines endeavoring to improve the working environment for their labor force, both for reasons of practical labor relations and also due to further legislative pressures, have thus created a climate where, in the near future, departments such as Rock Mechanics, Safety, Ventilation, Environmental Engineering and Subsidence Control will be commonplace in mining companies. It will no longer be practical to function without such services. Many mining companies already maintain such departments and this has particularly been true of the big mining groups of South Africa. From the experience gained by many of these large companies with specialist departments, it is clear that the maintenance of a cadre of experienced, competent professionals in such a department has not always been easy. It would seem from the experience gained that one can generalise and state that graduate mining engineers tend not to view specilisation as an optimum direction for their career development. It is of course true that many professionals, especially those with higher than a bachelors degree, do view these areas as valid career options, but even here experience shows that wastage is high. The time therefore seems to be ripe to take a look at this area in some detail to see whether reasons for the problems can be isolated. Working from that some suggestions can be made as to directions in which improvements might be made. If the challenge of the demands of the new regulations are to be met then such improvements must be made.

Jan 1, 1980

By N. Dahmen

The Robbins Mobile miner has been in development for more than ten years. Two machines have been trialed in mining environments. While day to day performance to date has fallen short of the levels anticipated, instantaneous performance has been impressive for given rock conditions and continues to encourage further development. The Pasminco mobile miner has been committed for a 1.8km main decline extension at Broken Hill. M.I.M. Holdings, parent company of Mount Isa Mines, owner of the first mobile miner, are considering a new machine for McArthur River. Robbins, Pasminco, and The Centre for Mining Technology and Construction have, joined forces to accelerate development of .mechanical rock cutting techniques in general, and of the Mobile Miner in particular.

Jan 1, 1995

By G. Robert Frey

INTRODUCTION This chapter on underground rotary drills briefly describes the equipment features, selection or applica¬tion criteria, safety features, and relative costs of both face and roof drills. After a brief description of the basic components, the application, safety, and cost con¬siderations will be explored. ROTARY DRILL COMPONENTS As illustrated in Fig. 1, an underground rotary drill consists of five basic components. These components are the energy system, chassis, boom, feed assembly, and operator's station. Energy System The energy system of a typical underground drill con¬sists of an electric motor, driving a hydraulic pump or pumps. Usually, the drill is equipped with a cable reel to store the trailing power cable from the portable power center in the mine. A simple control box is supplied to house electrical switchgear and protective devices. In addition to the pump, the hydraulic portion of the energy system includes the hydraulic cylinders, hydraulic tram motors, relief valves, control valves, etc., necessary to actuate the various machine functions. Chassis The chassis provides the frame or support structure for the other four basic components of the drill. Fre¬quently, it incorporates an oil reservoir for the hydraulic system. The chasis provides the support for the trans¬mission, which drives rubber tires or, in the case of some foreign machines, the crawler tracks. The steering link¬age and steering tires also may be considered as parts of the chassis. Boom The boom is the structure that supports the feed assembly; it is either hinged or pivoted on the front of the chassis. Hydraulic cylinders on the boom are used to lift or swing the boom relative to the chassis and to swivel or "roll" the feed assembly. Feed Assembly The feed assembly is made up of the support struc¬ture with an integral thrust mechanism, a rotation unit, centralizers to stabilize the auger, and a hose handling arrangement. In addition, most drills have an extension frame with a tilt device to aid in positioning the feed. Operator's Station The operator's station is the area from which the miner operates the drill. UNDERGROUND ROTARY DRILL APPLICATIONS Underground Face Drills Underground face drills are used in mining opera¬tions that utilize the conventional mining system. The face drill is used to drill holes in the exposed face of the material, and the face is then "shot" by means of explo¬sives or high pressure air. The loose material then is ready for loading and transporting from the face to the preparation plant. Typical specifications for under¬ground face drills are listed in Table 1. Certain parameters should be established as to where the drill is to be used and what is expected of it. To create an awareness of some of the considerations that too often are overlooked, some questions are listed that should be asked in conjunction with the selection or application of the proposed drills. Energy System: Can the drill be supplied with the proper voltage to match the available or proposed elec¬trical power system of the mine? Is the system 250, 460, 500, 550, or 950 v; dc or ac; 3-phase; 60 or 50 Hz? Is the drill equipped with an adequate electric motor to handle the proposed duty cycle? Typical motor power on a single-boom drill would range from 25 to 40 kW (35 to 50 hp); the nominal power for a dual-boom

Jan 1, 1982

By John C. Braithwaite

Gold production commenced in New Zealand during the gold rush of 1861, and recovery to date is over 900 tonnes, almost 60% of which was alluvial. New Zealand pioneered development of bucket line dredges during the 1880's. The advent of the modern hydraulic excavator and increased gold price led to a resurgence in alluvial production with about one hundred plants in operation in 1988. The processing plants are mainly floating, with throughputs of 50-100m3/hr fed by backhoes of 20-40 tonne operating weight. Some larger plants with more sophisticated recovery systems have commenced over the last few years, with the largest using a 180 tonne backhoe.

Jan 1, 1989

By A. M. Marabini, V. Alesse, Belardi. G.

An alternative flowsheet was designed for the flotation treatment of a complex sulfide ore from the Sotiel Mine in Spain. The ore contains 0.71% Cu, 2.24% Pb and 5.63% Zn. Two specially developed synthetic collectors, methyl-mercapto-benzoxazole (MMBO) and 6n-propoxy-mercapto-benzo-thiazole (PMBT), were examined. MMBO exerts a specific action on copper and zinc minerals after treatment with copper sulfate, and PMBT exerts a specific action on Pb minerals. Flotation operating variables (pH, frother type, frother quantity and feed particle size) were examined by means of rougher flotation tests to determine the optimum conditions for the new collectors. Once the optimum conditions were determined, a series of open flotation circuits were run on feeds of various particle sizes (obtained by different types of grinding). The objective was to obtain high-grade Cu and Zn concentrates. The results of the open-circuit tests demonstrated that a Cu concentrate grading from 18% to 23% Cu and a Zn concentrate grading from 40% to 48% Zn can be produced.

Jan 1, 1996

By P. D. Lafleur

A concerted effort to determine the quantities and effects of trace elements in the environment requires the application of a number of different analytical techniques in the same or in different laboratories. The interpretation of analytical data is often difficult because of differing results between analysts or even by the same analyst at different times. Standard Reference Materials (SRM), which are certified for their trace element content and are in a matrix similar to the one of interest, can greatly increase the accuracy of analysis and the reproducibility between laboratories. The United States National Bureau of Standards (NBS) has developed a number of SRMs applicable to the determination of trace elements in environmental materials. Two of these, SRM-1571, Orchard Leaves, and SRM-1577. Bovine Liver, are excellent for biological tissue analyses. Several new standards are of value for fossil-fuel analyses. These are: SRM-1632. Trace Elements in Coal; SM-1633, Trace Elements in Fly Ash; SM-1634, Trace Elements in Residual Fuel Oil: and SRM-1635, Trace Elements in Gasoline. In cooperation with the US Environmental Protection Agency, the NBS has recently concluded an interlaboratory comparison involving analyses by more than 60 laboratories on these fossil-fuel materials. The resulu of this intercomparison and the broad range experience with the biological materials will be presented showing both intratechnique and intertechnique variations, and the sensitivities and comparisons with the values certified by NBS.

Jan 1, 1975

By S. D. Thompson, L. Adler

J.R. Sturgul Thompson and Adler (1988) present a new simulator for use in designing conveyor belt systems for underground mines. Their model uses a large Fortran program to do a Monte Carlo simulation. Their approach is similar to that done by other researchers, such as Stanford (1965) and Newhart (1977). All Fortran based simulation models use an imaginary clock that is advanced a time increment. At each advance of time increment the program has to determine what is to take place in the system. Since many things can take place at different places in the system, this approach requires that a large amount of logic is needed at each step of the program. This, then, necessitates a great amount of jumping between different portions of the program. In fact, the Fortran program, CMBCS, takes up to 15 to 20 minutes to run on the mainframe and several hours for the PC. Such execution times are typical of Fortran based simulation studies. There have been other examples of Fortran based simulation studies in mining. Cross and Williamson (1969) presented a model of a working open-pit copper mine. Fosinato (1982) presented a model of the bucketwheel excavators for the large open-pit mines in Southern Victoria in Australia. These excavators discharge into a complex conveyor system, which can be thought of as being similar, but more complicated than the one modeled by CMBCS. All previous simulation studies using Fortran as the source code have several things in common: they all are very lengthy, often being of the order of 10,000 lines of code and take a great deal of CPU time to execute. The program of Fosinato takes more than 4.5 hours to run on a large mainframe. Also not mentioned by Thompson and Adler is the actual time it took to write the Fortran code. This, too, can be considerable, as Fosinato's program took several man years to write and de-bug. In order to change it, as the parameters change or as the mine increases, further large amount of time is needed. An alternate to such Fortran based programs is provided by using a special computer language known as General Purpose Simulation System (GPSS). This language is designed to solve a wide variety of discrete event simulation problems and appears to be particularly suited for mining situations as shown by Sturgul and Yi (1987). Although GPSS was introduced as far back as 1961, it has not been used in mining to any great extent. However, the original form was quite crude and inefficient compared to modern versions. Perhaps with the increasing popularity and availability of these recent versions, this will change. Two such versions are GPSS/H for the mainframe and GPSS/PC for the personal computer. GPSS/H allows for interactive usage, such as allowing input data to be entered via a menu. GPSS/PC has excellent graphical capabilities and one can actually view the simulation in progress. In addition, one can halt the simulation and change values of various parameters. If a particular portion of the simulation is in progress via a concept known as "microwindows." These new versions have greatly increased the potential for using the language for mining situations. Mining applications of GPSS have been given by Sturgul and Yi (1987), Sturgul and Harrison (1987), Sturgul (1987), and Sturgul and Singhal (1988). Schriber (1987) presents a summary of the recent advances in GPSS.

Jan 12, 1988

By Michael G. Li

Prediction of acid rock drainage (ARD) for low-sulphide, low-neutralisation potential (LSLNP) mine wastes is methodologically different from that for normal sulphidic mining wastes. In this paper. LSLNP wastes are conveniently defined as those with S2 < 1% and ABA-NP2 < 20 kg CaCO3 eq/t. The distinctiveness of ARD prediction for LSLNP materials originates from their frequently low oxidation rates and is mainly attributable to two reasons. First, the utilisation efficiency of available carbonate neutralisation potential (CNP2) rapidly deteriorates when the sulphide oxidation rate per unit mass of waste drops below a certain level. Reducing the flushing rate of a waste has the same effect as increasing the oxidation rate. Second, silicate neutralisation becomes increasingly important as oxidation rates diminish, and can no longer be ignored in LSLNP materials as it often is for normal sulphidic mine wastes. In this paper, the effects of oxidation rate, pore gas CO2 partial pressure, and flushing rate on ARD prediction for LSLNP materials are theoretically demonstrated with the help of modelling using the computer program MINTEQA2. A new methodology for ARD prediction for LSLNP materials is presented in terms of a prediction procedure. Finally, a case study is given to validate some of theoretical aspects discussed and to illustrate the use of the newly proposed ARD prediction procedure.

Jan 1, 2000