Search Documents

By K Hortin

Kidd Creek mine in north western Ontario is developing phase 1 of the deep mine project for mining between 2100 m and 3100 m below surface. Heat problems were experienced during the 2003 summer in working places about 2300 m below surface. At the time the mine had a æcold stopeÆ for cooling the air supplied to the mine below 1500 m from surface. The æcold stopeÆ is where during winter, ice is created in both the open pit and its connecting airways to the mine and used to cool air in summer. The operation and limitations of the existing cold stope were evaluated and led to the requirement for additional mechanical cooling to be available for the summer of 2004. The first stage of a surface refrigeration plant providing 7.5 MWR of cooling was approved, the compressor set was ordered in early January 2004 and the plant commissioned six months later in early July 2004. Based on the current modifications to the mining plan, further plant expansions are required in 2006 and 2009 leading to a total of 19 MWR of mechanical refrigeration and 8.5 MWR equivalent from the extended cold stope. The refrigeration system is described with emphasis on the specific adaptations necessary to suit Canadian conditions. Additional investigations were; using the refrigeration compressors in winter for heating and, extending the performance of either cold stopes or alternative ice storage systems. The winter use of refrigeration involve removing heat from the mine exhaust air to provide a cooling load and to use the hot water in the condensing circuit to heat the intake air and reduce reliance on mine air heating with natural gas. This paper follows on from an earlier one presented at the Seventh International Mine Ventilation Congress where the background and planning of the mine ventilation and cooling requirements were described for extending the mine at depth to 3100 m.

Jan 1, 2005

By P. M. Lin

A subsidence monitoring program over a longwall panel was established (1) to explore the impacts of dynamic subsidence on the ground surface and structures and (2) to correlate the movements between the structures and their corresponding points on the ground. The program consisted of a transverse line survey and a series of survey points around the structures on the ground surface and their corresponding survey points on the exterior walls of the structures. The vertical displacement of each point can be expressed as: where Si is subsidence at i point; Sif is the final subsidence at i point; F is face location in terms of distance from the i point and SD is seam depth. The development of subsidence can be divided into five stages. Damage to the structures starts at the beginning of the second stage, The maximum damage developed in the middle of the third stage. The relationship of the vertical displacement between ground surface and structures can be expressed as: G = aH + b where G is ground displacement, H is structures displacement, and a and b are constants. The relationship is linear. However, the strain is non-linear and more complicated because of the interaction of the ground surface and structure.

Jan 1, 1989

By Christopher J. Bise

INTRODUCTION The level of analysis for the selection of extraction practices and equipment for surface mining differs significantly from that found in underground mining. In underground mines, manufacturers establish the operating ranges of the equipment, such as continuous miners, loaders, and boring machines, based upon required clearances. Even in conventional mining, the drilling and blasting operation is usually based upon experience. The selection of extraction methods and equipment for surface mining is more complex. Since the equipment is not as confined as in deep mining, and the topography tends to be highly variable over the limits of the mining property, primary extraction equipment must be sized according to reach and capacity. Further, due to the depositional characteristics of the over- burden, drilling and blasting patterns must be well- designed to provide proper fragmentation. The following sections provide a general outline for the selection of surface excavation practices and equipment. The topics covered include drilling and blasting and the selection of both primary extraction equipment (draglines and stripping shovels) and secondary extraction equipment (bulldozers, scrapers, and front-end loaders). EXCAVATION FUNDAMENTALS Before discussing surface excavation, a few concepts need to be defined. A bank cubic yard of material is equal to one cubic yard as it lies in its natural or undisturbed state. A loose cubic yard is that portion of a bank yard that after being disturbed has expanded to measure one cubic yard. Swell is the volume increase of a material when it is removed from the natural state. Finally, load factor is the percentage decrease in the density of a material from its natural state to a loose state. Table 1 summarizes these concepts for various materials. When the amount of overburden to be removed to meet a predetermined production rate is established, a suitable bucket size for the primary stripping equipment must be calculated. The following equation can be used: NBSIZE = TBC/[(OF) (BF)] (1) where NBSIZE is the actual bucket capacity after considering the swell percentage, the bucket fill factor, and the operating efficiency; TBC is the theoretical bucket capacity (TBC = COB/NTCPM); OF is the operating efficiency; BF is the bucket fill factor; COB is the cubic yards of overburden to be removed; NTCPM is the number of theoretical cycles per month [NTCPM = (SMH) (3600)/(CT)]; SMH is the scheduled monthly hours; and CT is the cycle time in seconds. FRAGMENTATION PROCEDURES Drilling Where the strength of overburden material is such that blasting is required prior to excavation, drilling is conducted before using explosives. Two methods of drilling are found in mining-percussion and rotary. Penetration of overburden by percussion drilling is carried out by successive impacts of the bit into the rock. Emphasis in this section will be placed on rotary drilling, because for surface mining it is the most versatile form of overburden penetration. Rotary drilling is conducted by rotating a rigid string of tubular rods to which a rock-cutting bit is attached. The drilling energy is supplied by rotation as well as thrust and the cutting action consists of abrasion, scraping, spalling, or chipping. The size range for rotary-drilled blastholes is from 4 in. to 15 in., with 9 in. and 12 in. being common sizes. There are two types of bits used for rotary drilling-drag and rolling cutter. Drag bits are applicable in soft to medium-soft shales or their equivalents. Since their effectiveness is dependent upon a successful scraping action, drilling thrust is lower for drag bits than for rolling cutter bits; the opposite is true for torque requirements. The bits are usually fitted with replace- able tungsten-carbide cutters. Rolling cutter bits, though available in a two-cone configuration, are usually of the three-cone style (Table 2). The rolling cones have either large steel teeth for drilling through soft formations or small tungsten-car- bide inserts for drilling through hard formations. Table 3 relates bit size and weight to the strength of the rock. The major advantage of rotary drilling is its rapid drilling rate. This is due to the fact that, unlike percussion drilling, rock penetration is uniform with depth. Blasting Effective bank preparation deals not only with the fragmentation of overburden but also with the mini-

Jan 1, 1986

By J. H. Zhang

An atomic force microscope has been used to measure the forces acting between two silica and two rutile surfaces in the presence and absence of cationic surfactants, CnTACl (n = 12~18). The forces measured in the absence of surfactant can be fitted to the DLVO theory. At short separations, however, the silica surfaces exhibited repulsive hydration forces, while the rutile surfaces did not. On the other hand, the forces measured in the presence of the cationic surfactants show long-range attractions that are larger than the van der Waals forces. The long range attractions are the strongest at of the point of charge neutralization (p.c.n.), which decreases with increasing surfactant chain length. The possible origin of the long-range attraction has been tested in view of the charged-patch model of Miklavic et al. (1994). However, the sizes of the patches back-calculated from the model were much larger than those the patches (or hemi-micelles) determined experimentally and reported in the literature. It is, therefore, suggested that the long-range attractions observed in the present work are due to the structural response of the water molecules in the vicinity of hydrophobic surfaces.

Jan 1, 2014

Surfaces forces have been measured between gold sphere and gold-coated glass plate in xanthate solutions using an atomic force microscope (AFM). The measurements conducted in potassium amyl xanthate (PAX) and potassium ethyl xanthate (KEX) solutions showed long-range hydrophobic forces, with the force curves showing no evidence for nanonubbles on the surface. The strongest hydrophobic force was measured at contact angle of 94° with a decay length of 23 nm. The hydrophobic force became weaker at higher concentrations and after a long immersion time, which may be attributed to the xanthate species adsorbed on top of the first mono layer. The hydrophobic force became stronger when the residual xanthate solution is displaced by pure water, indicating that hydrophobic force becomes the strongest in pure water.

Jan 1, 2009

Many investigators measured surface forces between hydrophobic macroscopic surfaces using atomic force microscope (AFM). Some investigators observed long-range attractions and attributed them to the presence of hydrophobic forces, while others suggested that they are artifacts of the nano-bubbles and cavities associated with the hydrophobic surfaces. Still others suggested that the long-range attractions are due to the electrostatic interactions between charged patches present on opposing surfaces and hence are unrelated to surface hydrophobicity. In the present work, we have measured long-range attractions between gold- (or silver-) coated surfaces hydrophobized in potassium ethyl xanthate (KEX) solutions at pH 9.2 under controlled potential conditions. The results of our AFM force measurements are consistent with those of the contact angle and voltammetry experiments, indicating that the long-range attractions are hydrophobic forces.

Jan 1, 2012

By Clyde DeRossett

Surface fractures, sometimes of significant size, are observed in eastern Kentucky over high extraction areas. Field observations were correlated with mine maps and a regional subsidence prediction computer model. The opening of large fractures is attributed to the presence of a pre-mining joint system, which exists near outcrop in the eroded Appalachian plateau. Lithological composition of the overburden influences the process of fracture opening. No correlation was found between the areas of the predicted maximum horizontal extensions and the actual location of fractures. In this paper a mechanism of fracture formation as a result of the high extraction mining is presented, with recommendations for mine planning to minimize surface damage.

Jan 1, 1993

By I. Yildirim

Free energy of interaction between particles in water can be calculated if one knows the values of appropriate interfacial tensions, which in turn can be determined from the surface free energies of the particles involved. The latter can be determined using the Van Oss-Chaudhury-Good (OCG) equation. This method requires the measurement of contact angles of well-defined liquids on the surfaces of the particles of interest. In the present work, the contact angles were determined using heat of wetting, capillary rise, and thin-layer wicking methods. The results are compared, and the utility of the surface free energy data obtained from the contact angles are discussed.

Jan 1, 2002

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 C. M. K. Boldt

Between 1989 and 1991, the greatest number of accidents in surface coal and metal/nonmetal mines involved haulage trucks. In 1995, the most frequently cited factor contributing to the 100 fatalities in these mines was powered haulage. In 1996, over 50% of the 84 Fatalities in mining that year were in surface mining. Because some of the world's largest mobile equipment is used in surface mines, and this equipment is involved in so many accidents and fatalities, new technologies are needed to alert truck drivers and people in spaces around the truck to the possibilities of collisions.

Jan 1, 1999

Underground mining in the West Moreton coal field started in the 1870's. Subsidence related to coal mining activities is an ongoing problem facing planners and developers in the Ipswich area in South Eastern Queensland. The history of coal mining in the area over the last 110 years has left the legacy of periodic surface instability in several areas. In general, modern engineering analysis with current mining methods combine to create predicatable analysis of surface stability and movement. Where old workings using several variations of the bord and pillar system are affected by current activity, the predictibility of the surface movement is greatly reduced. Geological complexities further complicate the analysis. Mining and the related dewatering affects the stresses on pillars in old workings. This is caused by reducing buoyancy effects caused by changes in the water levels in old workings. Of particular relevance is the depth of workings and strength of the coal and overburden. The type of subsidence affecting the surface can range from localised pillar failure, to roof failure and potholing and the likelihood of the particular form of subsidence can be assessed from studying the workings in relation to the stratigraphy and structure of the coal measure Formations.

Jan 1, 1988

By Daniel P. Lathrop, Leslie C. Taylor, William L. Fourney

Except when the target is on the surface, e.g. a tank track, the most important loading mechanism from a buried charge on a target above it is the impact of soil propelled at the target by the expanding gas from the explosion. Detonation of a shallow buried explosive generally yields an unstable interface between the rising soil and the air which appears to be the result of Richtmyer-Meshkov instability. Irregular “fingers” of saturated sand extend into the air above a more generalized dome of soil. These fingers move at a much higher velocity than the material between them at smaller stand off distances. As a result, the local load on the target at positions on the target at the same distance from the charge may vary by 50% or more from shot to shot or even within a single shot. This variation requires a large design safety factor to assure the integrity of design of mine-resistant vehicles.

Jan 1, 2009

By L. W. McKeehan, W. C. Elmore

THE magnetic powder method, long used for roughly mapping magnetic fields, has recently been refined 1,2 for investigating the microscopic variations in the surface magnetization of ferromagnetic crystals. Bitter' first discovered regular powder patterns connected with the crystal structure of such specimens. Several other investigators3 have used Bitter's original technique, with slight modifications, to study the variation of the patterns with variations in the magnetizing field applied parallel to the surface, and their dependence upon the state of strain, of polish and of crystal cut. All of the explanations of these patterns on metallic ferromagnetics have been couched in general terms. In a preliminary report we have described an improvement in the powder technique which led us to the discovery of a new effect throwing considerable light on the magnetic secondary structure of alpha iron4 and of nickel' single crystals. We now report additional evidence confirming the existence and stability of a magnetic block secondary structure. SPECIMENS The following list describes the specimens used in the present investigation. DESIGNATION DESCRIPTION A1 Silicon ferrite furnished to us by Dr. W. E. Ruder, of the General Electric Co., for which he gave the following typical analysis: C, 0.05; P, 0.038; 5, 0.026; Mn, 0.15; Si, 3.24. Disk, 0.60 cm. diameter, about 0.05 cm. thick.

Jan 1, 1935

By Maria I. De Rosa

Table 19 and figure 7 show the number of fires and fire injuries for surface metal/nonmetal mines by state during 1990-2001. Table 19 also shows the injury risk rates, employees' working hours, and lost workdays. A total of 79 fires occurred in 16 states during 1990-2001 for these mines. Forty-five of the fires caused 44 injuries and 2 fatalities (including 9 fires and 7 injuries involving contractors). The yearly average was 6.6 fires and 3.7 injuries. Sixty-five fires with 31 injuries and 2 fatalities occurred at metal mines, and 14 fires with 13 injuries occurred at nonmetal mines. The Ewhr value was 546 x 106 hr (In = 0.016), and the LWD value was 13,134. Nevada and Arizona had the most fires (19 fires, 10 injuries, and 1 fatality; and 19 fires and 11 injuries, respectively). They were followed by Minnesota (11 fires, 4 injuries, and 1 fatality) and Alaska (6 fires and 4 injuries). Of these states, Alaska had the highest injury risk rate value (In = 0.079). Table 20, partly illustrated in figure 8, shows the number of fires, fire injuries, fire fatalities, risk rates, employees' working hours, and lost workdays by time period. The number of fires increased during the second period, then decreased during most of the remaining periods. The number of fire injuries decreased during most of the periods (a small increase is seen during the last period), accompanied by a decline in employees' working hours during most of the periods (a small increase is seen during the third and fourth periods). The In values follow patterns similar to those shown by the number of fire injuries. Tables 21-26 show the number of fires by ignition source, method of detection and suppression, equipment involved, location, and burning material by time period. Figure 9 shows the major variables related to fires for 1990-2001. Table 27 shows the number of fire injuries per number of fires causing injuries and total fires by year, ignition source, equipment involved, and location.

Jan 1, 2004

By William A. Hustrulid

The subject of surface mine development is large. This section covers the fundamental concepts involved in both the open pit mining of thick or steeply dipping deposits as well as the strip mining of thin, shallow, and relatively flat-lying seams or beds. Design involves the marrying of geometries, ore and waste characteristics, equipment, and economics so that the desired result is achieved. Generally, there are many possible combinations from which to choose. For example, extraction over a short time period requires one strategy while quite another is applied for longer times. Variations in supply and demand require some flexibility of operation. Customer requirements impose certain constraints regarding the set of possible designs. Over recent years, planning and operating considerations for surface mining imposed by environmental requirements have increased markedly. There have, at the same time, been enormous advances made in the design aids available to the mine planner. Computer simulation of the various options, whether it be for mine design or equipment selection, provides detailed information for decision making in real time. A significant challenge to the engineer/planner is how to best use the aids avail-able. Because of the widespread use of commercially available and in-house computer software by industry, this section does not deal with the details of planning (for basic coverage of mine development, see Section 7). Rather, some of the basic concepts are stressed. The principles involved in equipment sizing and selection are discussed. A highly important but sometimes over-looked aspect of planning, haul road design, is also covered. For surface mining operations of the future, in-pit crushing and conveying will become even more important. Some of the considerations for application evaluation are included. The section concludes with some future concepts for surface mining.

Jan 1, 2008

By Steven J. Page, Andrew B. Cecala, John A. Organiscak

In This Chapter [Drill dust control: wet and dry Enclosed cabs on drills and mobile equipment Haul road dust control] Overburden drilling generates most of the respirable dust that affects workers at surface mines. Both wet and dry methods are available to reduce this drill dust. Overburden removal by mobile excavation equipment such as bulldozers, front-end loaders, and haulage trucks can be dusty, particularly under dry and windy conditions. Tightly enclosed cabs with dust filtration systems can substantially lower the dust exposure of both drill and mobile equipment operators. Haul road dust control can be achieved by water application or chemical application. DRILL DUST CONTROL [Drill dust is controlled with wet or dry systems. Wet systems can be more efficient, but may freeze in the winter. Dry systems require careful maintenance of the drill deck shroud. An improved deck shroud is shown.] Wet Suppression. Wet drilling systems pump water into the bailing air from a water tank mounted on the drill. The water droplets in the bailing air trap dust particles as they travel up the annular space of the drilled hole, thus controlling dust as the air bails the cuttings from the hole [Page 1991]. In wet drilling systems, typical water flow rates are 0.1 to 2.0 gpm depending on the size and type of drill and the moisture level of the overburden. The drill operator controls the flow using a control valve located in the cab. Some drills are equipped with a flow meter to give the opera-tor a visual sign of the flow rate. Raising the water flow will improve dust capture, but too much water causes operational problems. Because of this, the drill operator must exercise care in find-ing the best water flow rate.

Jan 6, 2003

By Halter L. Gould

Since the turn of the century there has been a marked increase in population, industrial and economic growth, and in energy requirements in the United States. During this time our energy needs have been met largely by natural gas and petroleum, but as our reserves of these materials are depleted, we are going to depend more and more on our large reserves of coal. The mining of coal for electrical power production has increased at a rapid rate during the past decade. Over half the coal produced in the United States in 1971 came from mines utilizing surface mining operations (Paone, et al, 1974). Surface mining is expected to increase as the rising cost of oil places more demand on coal for energy. About 57 percent of the coal reserves in the United States lie in the area west of the 100th meridian. About one-quarter of this can be mined by current surface methods. This would involve the disturbance of approximately 1.5 million acres (600,000 hectares). By the year 2000, projections indicate disturbance of about 200,000 acres, or 300 square miles, in the West. Mined areas receiving more than 250 mm of annual precipitation can usually be revegetated without irrigation if the spoils are properly shaped, the surface layer consists of suitable plant growth media, and proven techniques in rehabilitating disturbed rangeland are applied. Areas receiving less than 250 mm of annual rainfall or with high evapotranspiration rates pose a more difficult problem. Revegetation of these areas can probably be accomplished only with major inputs of water and good management (National Academy of Science, 1974).

Jan 1, 1978

By O. W. Shimer, D. C. Helms, C. E. Brown

The early history and progress of anthracite stripping, from the first known operation at Summit Hill in 1821 through 1917, was covered in 1917 in a paper by J. B. Warriner,1 then chief engineer, now president of the Lehigh Navigation Coal Co., and stripping methods between 1917 and 1931 were the subject of a paper in 1931 by H. H. Otto,2 of the Hudson Coal Company. The present paper is confined to methods used today on pitching beds in the western middle and southern anthracite fields. The anthracite industry, not unlike other large industries, had been affected for more than a decade by the adverse economic conditions of the country. High development and operating costs and the competition of other fuels caused some collieries to be closed temporarily, while others were permanently abandoned. In order to obtain a larger tonnage at a lower development cost, a larger stripping program was put into effect by many companies. In 1932, stripping operations accounted for 3½ million tons, or 7 per cent of the total anthracite production of the year, and in the next 10 years this increased until more than double that amount, or over 14 per cent of the total production, was from stripping operations. These figures represent the total production of the entire anthracite region; unfortunately, the figures have not been separated from the different fields. There are some operations in the southern and middle western fields where the tonnage obtained from stripping amounts to more than 30 per cent of the total colliery production. Stripping operations on pitching beds present difficult problems. Owing to the various geological formations, a different situation is encountered in nearly every stripping pit; and because of the proximity of an overlying bed, it is very often necessary to load the entire overburden into trucks and haul it out of the pit to the dump area, although back filling and casting is done whenever possible. Beds in the areas described in this paper pitch from 20" to 90° and some are on the invert in many sharp folds and faults. Planning The more successful strippings have had adequate engineering analysis. Some work is being done without much preliminary planning, but many strippings would have failed completely if close supervision by the engineering department had not been maintained. Locations of stripping areas are determined as follows: I. By constructing cross sections over the areas and drilling sufficient diamond-drill or well drill holes to study the strata and to determine the location, thickness and pitch of the beds.

Jan 1, 1946

By Frank H. Macpherson

Few people realize the tremendously important part that Saline and Pulaski Counties in central Arkansas have played in the winning of the war The present favorable war situation might have been very different if we had not had the bauxite produced during the past two years from these two small areas, a total Of about 15 square miles. As a general statement, it can be said that the Arkansas bauxite deposits are, individually, relatively small, irregular in thickness, somewhat scattered and, therefore, compared with coal or iron-ore or open-pit copper deposits, relatively ill adapted to a rapid and drastic expansion in output. A few years ago it would have seemed an impossibility for these two counties to produce over six million long dry tons of bauxite in one year. However, with the cooperation of the operators, that is what happened in 1943, when the state of Arkansas achieved the seemingly impossible with a production of 6,020,684 1 long tons (dried equivalent) of bauxite ore during the calendar year, compared with an average annual production of 323,7252 tons in the period 1931 to 1941. It became apparent early in the year '94' that the united States soon might be drawn into the war, and, therefore, that an immediate study of the domestic metal situation was necessary. Aluminum is by far the most important metal used in the manufacture of aircraft and many other implements of war and it was evident that there would have to be a tremendous increase in the domestic production of bauxite, which is practically the only present source of this metal. AS more than 95 per cent of the known bauxite reserves of the United states was in Arkansas, careful preliminary studies were made in that state by representatives of the united States Bureau of Mines, the United States Geological survey and the War Production Board in the summer of 1941 Reserves in other states also were studied. The result of these studies was a recommendation by the War Production Board that mining in the bauxite.producing areas of Arkansas be geared for maximum production, in order to supply sufficient ore for this country's war requirements and, if necessary, to supply the war needs of Canada as well. The annual goal of eight million long tons (dry weight) set for Arkansas by the war Production Board was exceeded in 1943, when in August the output reached a rate equivalent to more than 8,300,000 long tons, dry basis. Because of the comparatively small tonnage of bauxite reserves, Congress appropriated funds for an extensive drilling program to be carried out by the Bureau of Mines in cooperation with the Geological Survey. Drilling began in May 1942 but owing to delay in delivery of drills, and trucks upon which the drills were mounted the program did not get into peak operation until early in 1943. By the end of July 1944, the Bureau of Mines records indicated an addition to the Arkansas reserves of 10,000,000 long tons (wet basis) in place,

Jan 1, 1946

By J. S. Gardner, J. J. Zaluski

I. INTRODUCTION West Virginia has a long history of coal production.1 The state at one time led the nation in total coal production, while at the same time coal from West Virginia constituted one quarter of total U.S. coal production.2 In more recent years, however, West Virginia’s level of coal production has been reduced in comparison to that of other states due to the high relative cost of producing coal in the state.3 Another blow to the producers of coal in West Virginia is the action known as Bragg v. Robertson.4 In 1998 various individual plaintiffs, as well as a conservation group known as the West Virginia Highlands Conservancy, filed a civil action under a provision of the Surface Mining Control and Reclamation Act of 1977, Pub. L. No. 95-87, §522, 91 Stat. 445 (codified at 30 U.S.C. §§1201-1328) ("SMCRA" or the "Act") that allows declaratory and injunctive relief against state and federal officials for non-compliance with the Act.5 The plaintiffs generally claimed that the Director of the West Virginia Department of Environmental Protection ("WVDEP") had exhibited a pattern of violating mandatory non-discretionary duties under SMCRA and the West Virginia state regulatory program.6 These non-discretionary duties involved many areas of regulation, including water quality standards, disturbance of wetlands, hydrologic reclamation plans, Approximate Original Contour ("AOC") requirements and AOC variances, post-mining land uses, contemporaneous reclamation, and as explained later, the "buffer zone rule."7 In addition to these claims against WVDEP, the plaintiffs also alleged that certain individual members of the Army Corps of Engineers (the "Corps") had failed to carry out statutory duties under the Clean Water Act (the "CWA") and the National Environmental Policy Act ("NEPA").8 Generally, the complaint stated that the Corps did not have statutory authority under the CWA to regulate valley fills created for the purpose of the disposal of waste material, i.e., the overburden associated with mountain top mining.9 Alternatively, the plaintiffs claimed that even if the Corps could regulate valley fills, the Corps violated NEPA by issuing nationwide permits without required analysis. Finally, the plaintiffs asserted that the issuance of a nationwide permit for surface mining valley fills is unlawful.10

Jan 1, 2001