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By Arthur R. Still, Paul A. Bailly

5.1-PURPOSE, PROCEDURE, METHODS, MANAGEMENT Exploration can be technologically defined, with regard to the discovery of new mineral deposits, as all the activities and evaluations necessary before an intelligent decision can be made establishing size, initial flowsheet and annual output of new extractive operations. The purpose of mineral exploration is the discovery and acquisition of new mineral deposits amenable to economic extractive operations now or in the future. A prime objective of mineral exploration, however, is to find and acquire a maximum number of such mineral deposits at a minimum cost and within a minimum time. Immediately upon the heels of a successful ''exploration" discovery follow activities called, first, development, then operation. Under U.S. Internal Revenue Code regulations (Secs. 1.615.1 and 1.616.1) in effect at the time of this writing, which state that the "development stage" has been reached when "deposits of ore or other minerals are shown to exist in sufficient quantity and quality to reasonably justify commercial exploitation by the taxpayer," exploration in the technological sense may well continue after a mineral property has entered the "development stage" as defined for tax purposes. In many instances continued exploration, after reaching the tax defined "development stage," has disclosed additional reserves which justify a much larger, more efficient and more profitable operation than that which would constitute the minimum feasible. Even after a mine goes into production, continued ore search generally will increase the reserves, either justifying expansions in plant capacity or prolonging the life of the operation, but this work (actually "exploration") is normally considered, for bookkeeping and tax purposes, a part of mine development. Each exploration entity defines its own objectives in terms of acceptable mini- mum rate of return on investment for any deposit found and retained, and in terms of which commodities, and markets, are to be involved. For these reasons, exploration programs, and aims, will vary over a wide range, although all have the common objective of endeavouring to create new profit centers for the future. 5.1.2-EXPLORATION METHODS Exploration has evolved in the past several decades into a highly sophisticated and expensive endeavor in which large corporate entities, or subsidaries, normally are directed and staffed by highly trained exploration specialists. In some instances consultants, with expertise in a given field, are utilized to the benefit of such corporate groups. The "grasshopper" approach to exploration-searching only for outcropping minerals and/or investigating only mineral prospects offered by the discoverers of such outcrops has given us most of the past and present mines in the US., but this method is rapidly approaching the point of diminishing returns in areas that have been thoroughly prospected for currently marketable commodities. With

Jan 1, 1973

By Keith G. Wallace, K. M. (Chris) Chmura, Kirk H. McDaniel

The Waste Isolation Pilot Plant (WIPP) performed a feasibility analysis for the purpose of either modifying, supplementing, or replacing its two main mine fans. The WIPP, located near Carlsbad, New Mexico, is a U.S. Department of Energy (DOE) fa¬cility designed to demonstrate the permanent, safe disposal of U.S. defense-generated transuranic waste in a deep bedded salt deposit. Since the centrifugal fans were installed in 1988, multiple op¬erational and performance concerns have been identified. A com¬prehensive engineering study was conducted in 1995 to: 1) Qualify and quantify operational concerns, 2) Evaluate possible alternatives, and 3) Recommend an optimum solution. Multiple system modification and/or replacement scenarios were evaluated with associated cost estimates developed. The study considered replacement with either centrifugal or axial fans. Multiple fan duties are required at the WIPP. Therefore, Variable Frequency Drives and Inlet Vane Controls (IVC) were investigated for centrifugal fans. In-flight adjustable blades were investigated for axial fans. The study indicated that replacing the existing system with two double-width, double-inlet centrifugal fans equipped with IVCs was the best choice. This alternative provided the most desirable combination of: 1) ensuring the required operational readiness, and 2) improving system performance. The WIPP is currently planning to replace the first fan in 1997.

Jan 1, 1997

By R. Michael Craig

The flood basalts of the Columbia Plateau in eastern Washington State are under investigation for suitability in siting a deep geologic repository for high-level radioactive waste. To support safety and feasibility evaluations of the proposed repository construction and operation, an assessment is necessary of the potential for inflow of groundwater to the repository excavations from the surrounding saturated rock. Preliminary estimates of inflow are presented using simple models appropriate to the current understanding of available data. Both normal and bounding analyses are presented.

Jan 1, 1986

By E. B. Fitch, D. A. Dahlstrom

Liquid-solids separation is common to practically all mineral and coal processing as the bulk of beneficiation plants employ water as the major processing vehicle. The growing usage of hydrometallurgy has increased the importance of liquid-solid separation as acidic and basic solutions result in greater amounts of colloidal solids, with their consequent greater difficulty of separation, the economic need for chemical recovery to minimize this operating cost, and the usual necessity of employing more costly construction materials. The three processing steps covered in this section have significant capital costs. Drying, particularly, has an important operating cost because of the obvious need for energy to evaporate the water or solvent. Several common factors influence all three liquid-solid separation steps. Particle Size and Size Distribution. In general, finer particles have slower settling and filtration rates. The specific surface area is increased, which means a lower solids concentration in the thickener underflow and discharged filter cake as well as a grater moisture content to be evaporated in the drying step. Therefore, overgrinding or excessive attrition should be avoided. Consideration should be given to optimum particle size consistent with entire plant operation performance and recovery. Solids Concentration. Increased feed solids concentration will generally minimize required equipment size and costs in all three liquid-solid separation steps. Most thickeners are designed on the basis of unit area required, expressed as square feet per short ton of dry solids per day (square meters per metric ton per day) which will usually decrease with increased feed solids concentration. Filtration rates also increase as the required flow through the capillaries of the filter cake decreases. Dryer capacity increases and less energy per ton of final product is required to evaporate the associated moisture. Particle Shape and Surface Characteristics. Generally, optimum shape is a spherical particle of zero porosity. As either of these factors degrade away from the desired state, difficulty increases. This is particularly true in drying, where porosity can decrease drying rate significantly if the moisture must first reach the particle surface by diffusion

Jan 1, 1985

By David J. Akers

INTRODUCTION The variety of uses of coal and the wide range of characteristics of coal combine to produce a need for a wide variety of laboratory analysis. Coal is used to heat homes, produce electricity, and make coke for steel manufacture. It can also be used to produce both gaseous and liquid fuels as well as a variety of chemical products. Various applications may require specialized analytical procedures. For example, some of the procedures developed for the coke industry, such as expansion or contraction during carbonization, have little value to the power generation industry. Even for a single application, the type of analysis needed can depend on the source and/or general nature of the coal. This section provides a general overview of the types of analytical procedures commonly applied to coal from the perspective of the user of this information, not the producer. The intent is not to detail laboratory procedures, but rather to discuss the application of commonly used laboratory tests in coal preparation. Accordingly, laboratory procedures are categorized by type of information produced. Gravimetric Analysis Procedures that produce weight-based information (parts per million, pounds per cubic foot, or weight percent). Such analyses can relate to the coal's physical, chemical, or mineralogical characteristics. Volumetric Analysis Procedures that produce volume-based information (amount of a mineral present as a volume percent). The primary source of volumetric information is from petrographic analysis. Application Tests Procedures that measure some characteristic of coal that has been empirically related to some application or handling or processing step. Typically, these procedures attempt to duplicate some aspect of the commercial application at laboratory scale and may produce information in the form of an index. Applications procedures do not measure a single component of the coal but infer the combined effect of multiple components. Each class of information is discussed in the order listed. References are provided as a source of more detailed information. The American Society for Testing and Materials (ASTM) publishes the most inclusive reference to analytical procedures. This publication,16 which is revised annually, provides extensive information concerning generally accepted methods of laboratory analysis. ASTM also provides standards for sampling and some information concerning sample handling.

Jan 1, 1991

By B. Stewart

Recent ore pass failures have underlined the need for improved designs, standards, structural monitoring methods, and better hang up prevention and removal techniques. Researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) are investigating methods to improve safety during transport of ore in ore passes. Design criteria and hang-up prevention and remediation strategies involve studies of the effects of static and dynamic ore and waste rock loads on chutes, walls, gates, and support structures. Particle flow analysis methods were used to simulate the response of various ore pass designs to a wide range of ore loading conditions. A full-scale mock-up of actual ore pass and chute assemblies was duplicated and tested for load response. Data from a particle flow code and the mock-ups were com-pared. Loads on an active ore pass chute were measured.

Jan 1, 1998

By Hans Hamrin, Bruce Kennedy

Once an ore body has been probed and outlined, and sufficient information has been collected to warrant further analysis, the important process of selecting the most appropriate method or methods for mining can begin. At this stage, the selection is preliminary only, serving as the basis for a project layout and feasibility study. Later, it may be found necessary to revise the details, but the basic principles for the ore extraction should remain a part of the final layout. With respect to the basic principles employed, relatively few mining methods are used today. For the purposes of this presentation, the principles are classified as follows: 1) For naturally supported stopes, the available methods are room-and-pillar mining and sublevel stoping. 2) For artificially supported stopes, the available methods are shrinkage stoping, cut-and-fill mining, square-set mining, and longwall mining. 3) For caving methods, the available techniques are sublevel caving and block caving. Due to the uniqueness of each ore deposit, the variations on each of these methods are nearly limitless. It is impossible to include even the major variations in this chapter; the goal of this chapter is to present the principles as a guide to the mining engineer in adapting the general methods to specific needs. The selection process described herein is intended to supply the techniques by which the candidate methods available for a given ore body can be reduced to one or two feasible approaches. The feasible approaches then can be evaluated in detail, and the particular modifications can be investigated. In describing costs and economic factors, all values herein are expressed in terms of 1978 US dollars.

Jan 1, 1982

By Mohamed A. Younis, Robert J. F. Goodfellow

This paper investigates the design approaches taken and the philosophy employed during the construction of the Metropolitan Airport Commission (MAC) storm tunnels, part of the Phase 4 Segment of the MAC Trunk Storm Sewer Project at Minneapolis St.-Paul International Airport, located in Minneapolis, Minnesota. URS Corporation was retained to provide a design and Construction Management (CM)services for the MAC Trunk Storm Sewer Project. A case history of the design and construction challenges of the project is presented. The MAC storm tunnels consisted of the construction of twin 10-foot inside diameter (I.D.) tunnels within 7 feet of an existing 72-inch I.D. storm pipe at the base of a 70-foot high highway embankment. The analysis required during the design stage of the project is discussed. This analysis and our design approach provided a defensible framework and justification to make design decisions on relevant issues including: allowable spacing of new and existing structures; preferred order of construction; expected ground deformation behavior; response of lining types to adjacent construction; and effects of proposed changes to design at the submittal stage and during construction.

Jan 1, 2003

By N. Economou

Temporary local seismic networks were installed in western Crete, in central Crete, and on Gavdos, an island south of western Crete, in order to image shallow seismically active zones of the Hellenic subduction zone. Data acquisition was divided in four campaigns through the years 1996 to 2001. More than 4000 events in the magnitude range between 0.5 and 4.8 were detected and localized. The resulting hypocenter distribution allows the localization of seismically active zones in the area of central Crete from the Mediterranean Ridge to the Cretan Sea. The comparison of the hypocenter distribution and the structure has allowed intraplate and interplate seismicity to be distinguished. A southwards dipping zone of high seismicity within the Aegean lithosphere is found south of central Crete in the region of the Ptolemy trench. Between 20 and 40 km depth beneath central Crete, the Aegean lithosphere appears to be seismically inactive. Especially for the year 2001, 1560 events were localized, by the seismic network installed on Messara, central Crete. Most of the seismic events were located, as expected, in the South region of central Crete. National Observatory of Athens (NOA) maintains a permanent seismic network in Greece. In this work a comparison of the earthquake epicenters obtained from both the NOA network and the BOCHUM-TUC network is presented.

Jan 1, 2006

By W. F. Moll

Absorbent clays are products, usually in the form of granules, that can absorb and hold approximately their own weight of liquids while essentially maintaining their size and integrity. They always contain in abundance at least one of three materials: montmorillonite, attapulgite and diatomite. The first two are complex silicates; the last is amorphous silica of biogenic origin. Not all montmorillonites provide the base for an absorbent clay, however. Nevertheless, the silicates in particular, and the diatomite to a lesser degree, have certain molecular properties that give rise to the useful physical properties. Uses Use of absorbent clays is as old as civilization. Numerous references to "fuller's earth" appear in ancient writings, including the Bible. Fuller's earth originally connated a clay that could absorb oil and grease from wool to facilitate cleaning. Robertson (1986) covers the fascinating history in interesting detail. In the modern sense, absorbent clays find application in three principal areas, and a host of minor ones. Industrial floor absorbents, cat litter and agricultural carriers comprise the major uses.

Jan 1, 1986

By Roger Holmberg

INTRODUCTION The driving of drifts is a very important aspect of underground mining. It is not unusual for the percent¬age of rock broken during development in a mine using sublevel caving, for example, to be as much as 25% of the total. If one also considers the amount broken for transport, ventilation, and exploration drifts, one can easily understand that the planning and excavation of drifts play a major part in the total economics of the mine (Fig. 1). Increasing mechanization in mining demands larger tunnel areas for transport and mining equipment. With modern machines the hard work involved in using hand¬held pushers is gone, and a better environment is achieved. More rational methods could be used, but much of the experience the working man acquired by working close to the rock face (such as utilizing the natural weak planes in the rock when he placed the drill¬ing holes) has unfortunately been lost. By having sepa¬rate shifts for drilling, loading, and hauling, more atten¬tion has to be placed upon a well-designed drilling pattern. Some reduction in the number of holes required can be achieved with mechanized drilling because of the larger holes that can be produced. On the other hand, it is probably not possible to achieve the same precision as with pneumatic pushers, and it is difficult to utilize the larger holes because these cause more damage to the re¬maining rock. Recently, however, the precision has be¬come very good with the parallel booms and automatic devices for setting the lookout angle (Fig. 2). A larger arch of the drift roof requires a more carefully executed blasting procedure than before in order to prevent rock fall and to insure a sufficiently long stand-up time. In this chapter, empirical relationships that can be used to design an economic and optimal drift blasting design will be presented. The principles of the calcula¬tion method are based upon the earlier work of Langefors and Kihlström (1963) and Gustafsson (1973). COMPARISON OF EXPLOSIVES To provide for the use of various explosives it is necessary to have a basis of comparison. Several meth¬ods have been developed to characterize the strength of an explosive. Some examples are comparison of values given by (1) calculated explosion energies; (2) the ballistic mortar test; (3) the Trauzl lead block test; (4) the brisance test; (5) the weight strength concept; and (6) the underwater test. However, most of these meth¬ods should be used carefully when stating the breaking

Jan 1, 1982

By R. A. Burns

The production of kaolin and calcium carbonate in North America exceeds 13 million tons sold into higher value market segments. With a few exceptions, the markets supplied exhibit mature growth rates. In some market sectors, technology changes have and continue to occur shifting pigment-type consumption and growth. New sources of supply will impact current businesses. New product and process developments for kaolin and calcium carbonates are continuing. Each of these issues is examined in developing a view of the future for kaolin and calcium carbonate in North America.

Jan 1, 1997

By Brenda B. Mehnert

Long-term monitoring is necessary to successfully develop predictive subsidence models. Thus, the Illinois Mine Subsidence Research Program (IMSRP) has documented subsidence over a longwall mine in south-central Illinois throughout a 3-year period. No monitoring results of this duration have been previously published for longwall mining in Illinois. To study the effects of surface subsidence and the rate of subsidence, precise level surveying was conducted at the site two or three times a year. Level surveys were conducted at approximately the same time of year using a WILD NA-2 level with a micrometer. Second-Order, Class-I, closure errors were obtained in each survey. Survey monuments were designed to minimize frost-induced movements. At this particular site in southern Illinois, subsidence over chain pillars and the panel centerline continued 3 years after mining. Since mining in 1988, 6.67 feet of subsidence or 70% of the extracted height has been documented over the panel centerline, with almost 0.30 feet in the last two years. The area over the chain pillars has subsided a total of 1.44 feet, with 0.44 feet occurring within the last 2 years. Monitoring over the chain pillars and at the centerline shows the residual subsidence to be fairly uniform. Monitoring is continuing over both of these areas. Long-term monitoring data can be used to improve evaluation of subsidence effects on land and structures. However, coal companies will time mitigation activities depending on other factors including the threshold of structural damage, type of repair needed, and maintenance of landowner and company relations.

Jan 1, 1986

By C. McDonald, S. Slottee

Deep "paste" thickeners have been used in the alumina industry for several decades to improve chemical recovery and allow “stacking” of the red mud for disposal. These paste systems have eliminated many traditional tailings ponds in addition to providing better tails washing and better water recovery. This technology is not widely used or understood in other mineral processing applications. However, there is growing worldwide recognition of the advantages of concentrating mill tailings to a “paste”, i.e. a solid suspension that does not settle or segregate. This technology offers several alternatives to the traditional tailings pond such as “stacking” or mine backfill. More water recovery is possible than with high rate thickeners. Process benefits come in the form of better chemical and metals recovery through better washing in counter current decantation (CCD) applications. Obtaining a true paste (non-segregating suspension which exhibits a yield stress) and understanding the handling characteristics for applications outside alumina, are recent developments. Achieving all of the benefits available from a paste system requires careful design that takes into account the specific requirements of the disposal application along with the peculiar difficulties in producing and handling paste. In fact, design of a paste system is markedly different from a conventional system. Project design usually requires the cooperation of experts in several interrelated specialties including geotechnical, thickener design, pumping and discharge design and controls. A successful project must coordinate all activities to ensure that the overall objectives for the project are achieved. This paper describes the properties of paste, reviews the applications, and discusses the design of a complete paste deposition system.

Jan 1, 2003

By John W. Brauns

18.1-RAILROAD JOHN W. BRAUNS Conventional railroad haulage can be employed at both open-pit or strip and underground mines-in the latter case, largely for transfer of ore from distant openings to processing plants, or processed material to loading points or docks, using standard hopper cars for bottom unloading or gondolas for rotary dumping. The major application, however, is in surface mining for moving ore and/or waste out of the pit to a crushing plant or dump. Consequently, the following will deal largely with this phase of railroad operation, though the conclusions apply equally, for the most part, to other rail-type surface haulage. In surface mining, trains consisting of a locomotive and gondola or side-dump cars suitable for loading by power shovels are used. Gondolas are restricted to hauling ore as a rotary dumper is required. Side-dump cars are more versatile, carrying both ore and waste, but because of their additional dumping mechanism they are likely to be more expensive to maintain.' Also they weigh up to twice a flat-bottom car of the same capacity and. therefore, fewer" cars can be hauled per train. Standard-gage track is most commonly used. Track systems incorporate low-quality temporary track where moves are frequent and permanent high-quality track on main lines. Rail haulage can be used alone, or in combination with other surface haulage methods, thus permitting a selection best adapted to the peculiar requirements of each mining project. 18.1.1---GENERAL APPLICABILITY, CONTROLLING PHYSICAL CONDITIONS For handling rough rock, the shovel-train system is unexcelled.' The ideal applica¬tion is in a large, but not excessively deep, open pit mine from which the coarsely blasted ore and waste must be transported over 3 mi. If. in addition, a high production rate is to he maintained, railroad haulage probably will afford a lower cost per ton transported. Grade must he relatively gentle-usually 3% uphill and 4% downhill. The greater the differences in elevation involved, the greater are the track grade space requirements; for example, a 3 c ramp out of a pit only 300 ft deep is almost 2 mi long. Main-line track locations should he selected carefully so that the number of moves during the life of the mining operation can he kept to a minimum. This applies both to the ore haulageway and that for waste. Such moves are not only expensive, but are difficult to execute without adversely affecting production rates. The large mine affords greater opportunities for judicious location of semipermanent trackage. Figs. 18-1 and 18-2 illustrate typical track layouts. The effect of terrain in considering railroad haulage is confined chiefly to the initial cost of the installation. Grade construction in mountainous territory is ap¬preciably more expensive. However, if that expense can be borne, the subsequent maintenance cost of trackage will not he much higher than in areas of low relief.

Jan 1, 1973

By J. G. Groppo

Laboratory settling and filtration testing was conducted on wet processed fly ash in order to determine the applicability of conventional dewatering techniques to reduce the moisture content prior to drying. Settling tests showed that acceptable clarity (<1.5 g/l suspended solids) could be achieved after as little as 6 minutes of settling. After settling to a consistency of 40 weight % solids, continuous laboratory vacuum filtration testing produced a cake containing below 20% moisture with throughput exceeding 150 lb/ft2/hr.

Jan 1, 1997

By Don Opacic

The disposal of sludges and other similar industrial wastes is a major problem. Liquid wastes from industrial operations, when treated, produce significant volumes of sludge which are difficult to dispose of, because of the chemical and physical properties of the sludge. In the mining industry sludge is produced from various water treatment operations, in particular mine drainage neutralization. Waste water from coal preparation plants also produces a sludge however the sludge is in fact a slurry containing clays, coal fines and coal impurities. In many areas the disposal of these sludges is producing a serious problem. Mine drainage sludge consists of a variety of hydrous iron oxides, usually ferric oxides, contaminated with other neutralization products such as calcium sulfate. The volume of sludge from mine water or mine

Jan 1, 1973

By Thomas E. Newman

This paper is a case study using new laser-terrain-mapping technology by EagleScan, Inc., for creating topographic maps. Holnam, Inc., has used this technology to create maps and volumetric calculations of several mines in the United States. The information is superior to conventional methods through accuracy, manpower, time, and cost. Holnam, Inc., was the first cement manufacturer to use the Digital Airborne Topographic Imaging System (DATIS?). The technology uses the DATIS? to produce high-resolution terrain maps and volumetric assessments of any area. DATIS? is a mapping instrument that integrates (1) a Light Detection and Ranging (LIDAR) instrument to measure terrain elevation using laser light, (2) a large-format digital camera, (3) a relative position Global Positioning System (GPS) to measure aircraft position, and (4) an Inertial Measurement Unit (IMU) to measure aircraft attitude. The DATIS? can measure up to 220,000 elevation samples per mil. The system continually collects data on the aircraft&apos;s position and measures the time for each laser pulse transmission to return from the ground, giving each sample a GPS reference. The system can operate at night, in overcast sky, and during high-wind conditions and can measure terrain below vegetation cover, unlike standard aerial photography used for traditional surveying and mapping. Surveyed ground-control panels are no longer necessary with this new technology, and only one ground GPS base station located within 60 mi from the aircraft position is required. A computer elevation-point data file is created with the x, y, z coordinates of each laser elevation sample. With this file, CAD engineering programs can create topographic maps that rival products using conventional aerial mapping techniques. Volumetric measurements of stockpiles and pits are also available due to the high density of points collected from an area. This new technology radically changes the turnaround time for map users, giving a product in the format used by today&apos;s cartographers. The time line from flight to maps is measured in days instead of weeks.

Jan 1, 1999

The Northside Storage Tunnel Project in Sydney includes over 20 km of TBM driven tunnels, over three km of declines and major caverns and pump rooms. The paper describes methods used for design on the project. Emphasis is given to the refinement of the use of empirical rock mass classifications, and to the use of discontinuum numerical methods. The use of empirical rock mass classifications in Sydney sandstone has usually led to conservative design because the systems are based on a random orientation of joints in the rockmass. Because the joint sets are usually oriented in a way that is beneficial for tunnelling, limits must be placed on the parameters used in the classifications system. The paper discusses these limits and the derivation of the parameters. The use of numerical methods in Sydney sandstone is discussed. Continuum methods have their uses, but discontinuum methods are preferred. The use of UDEC has been validated against a previous project, the New Southern Railway. Recommendations are given for UDEC models. In Sydney&apos;s geology, so advantageous for tunnelling, the challenges of this project have been to make the best use of the good conditions, while maintaining safety for the workforce and the future operators of the project.

Jan 1, 1999

The Waste Isolation Pilot Plant (WIPP) is adding a third fan to operate in parallel with, and supplement, its two existing main fans. An engineering analysis conducted in 1995 identified the need for improved system availability and efficiency. The WIPP, located near Carlsbad, New Mexico, is a U.S. Department of Energy (DOE) Carlsbad Area Office facility designed to permanently dispose of U.S. defense-generated transuranic waste in a deep bedded salt deposit. Engineers at the WIPP performed a feasibility analysis for either modifying, supplementing, or replacing its two main mine fans. Since the centrifugal fans were installed in 1988, multiple operational and performance concerns have been identified. A comprehensive engineering study was conducted (K. McDaniel, et al., 1997) to: identify and quantify operational concerns, evaluate possible alternatives, and recommend an optimum solution. The study indicated that adding a third single-duty centrifugal fan similar to the two existing fans, and equipping that fan with Inlet Van Controls (IVCs) was the best choice. This alternative provided the most desirable combination of operational readiness, and improving system performance. The fan installation project accommodates several operational and scheduling constraints. WIPP is scheduled to receive waste in May 1998. This milestone is proceeded by an operational readiness review. Fan installation could not be allowed to compromise the WIPP&apos;s ability to declare facility readiness and had to minimize operational disruptions during the system tie-in. All engineering for the project is completed and physical modifications started in July 1997. The project will be completed in early 1998.

Jan 1, 1998