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By J. C. Squire, E. W. Baker, G. A. Sullivan, G. W. Flathers

A mine collapse severs communication with trapped miners. Landlines are crushed and commercially available radios cannot penetrate hundreds of feet of dense, conductive earth without the use of regenerative repeaters that may also be crushed. This paper describes a proof-of-concept device that uses seismic P-waves, instead of radio waves, to allow communication of a code that represents prearranged messages, including the safe haven location identifier, number of people and air quality, from trapped miners to aboveground rescue units. The transmitter designed is about 0.03 m3 (1 ft3) in size and can broadcast for four hours from its 27-kg (60-lb) battery pack. The receiver consists of a geophone and a 2.5-kg (5.5- lb) signal conditioning unit attached to a laptop computer, which displays the communication signal in real time. Testing in a bituminous coal mine with an MSHA representative revealed the device was able to transmit through 271 m (890 ft) of overburden, at 0° and 12° from vertical, using 500 W of power.

Jan 1, 2009

By William Hodder, Lisa Smiley, Ehsan Alav

The Don River & Central Waterfront Coxwell Sanitary Bypass Tunnel (CBT) Project in Toronto will extend approximately 10.5 km and be lined using a precast concrete segmental tunnel liner with an internal diameter of 6,300 mm and external diameter of 6,900 mm. The CBT liner was grouted through ports drilled in the segments. The Westerly Storage Tunnel (WST) in Cleveland will extend approximately 2.93 km long and will be lined by using a similar precast concrete segmental tunnel liner with an internal diameter of 7,620 mm and external diameter of 8,230 mm. The WST liner was grouted using both grout ports built into the tail can of the TBM and through segments. Each tunnel was mined primarily in shale with varying levels of weathering and both tunnels had dry and wet sections. This paper will document the means and methods for grouting in each tunnel as well as the methods utilized to proof grout and the results found.

Jun 13, 2021

By Howard G. Coopersmith

A resource of low grade good quality diamonds has been discovered through the Diamond Company NL-Moonstone Diamond Corp. Joint Venture. A limited bulk sample diamond test of two large kimberlite pipes on the Kelsey Lake Property, Colorado, has been completed. These kimberlite pipes have petrological and mineralogical indications of the presence of diamond. Small diamonds were recovered from surface samples. Drilling and trenching revealed both pipes were complexes of diatreme facies kimberlite. One pipe contains crater facies kimberlite as well. This is the first reported occurrence of crater facies kimberlite in the Province. Approximately 1000 tonnes of kimberlite rock was excavated and processed through a scrubber -HMS -Sortex -Grease Plant. Significant diamonds were recovered. The diamonds were generally of good color and clarity, with many being in the gem and near gem categories. Grades are considered low however. Additionally, a small potential resource of alluvial diamonds is present.

Jan 1, 1991

By J. R. Kadambi, C. Shingote, J. Furlan, R. Ke

"Hydrocyclone separators are widely used in various industrial applications in the oil and mining industries to sort, classify and separate solid particles or liquid droplets within liquid suspensions, which are considered to be multi-phase systems. Numerous valuable studies have been conducted in recent years to investigate the flow fields inside hydrocyclones. However, much of the information regarding the performance of cyclones in the literature has limitations, based in some part on the respective current-available theoretical models, and much of it cannot be considered as completely applicable to most real-world applications; many of the studies investigated the flow fields within extremely simplified hydraulic designs that are not representative of the complex geometries or large sizes which are typical in industry. Therefore, in this study, the two phase flow system inside the actual hydraulic geometry of a milling circuit hydrocyclone was explored with the aid of both computational and experimental techniques (Particle Image Velocimetry). In this study, the flow field with an air core has been investigated; in essence, the research was a two-phase problem, which caused some challenges on both the computational and experimental sides. Two turbulence models were used in the numerical calculations: the Reynolds Stress Model and Large Eddy Simulation. The computational studies are mainly focused on the prediction of the dimensions and shape of the air core. Different section planes of the hydrocyclone were selected as planes of interest and then were divided into several fields of view (FOV) for PIV measurements. Two dimensional experimental velocity vector maps were obtained in each of the fields of view. The computational results were validated globally using pressure and flow rate readings at the boundaries and locally by comparison to the PIV velocity vector maps and profiles. Keywords: Computational fluid dynamics (CFD); Hydrocyclone; Particle image velocimetry (PIV); Reynolds Stress Model (RSM); Large Eddy Simulation (LES). INTRODUCTION A hydrocyclone is a device used to separate a solid-liquid, liquid-liquid, solid-gas, or liquid-gas suspensions into at least two separate density or particle size components. Hence, the flow field of the hydrocyclone is generally considered a multi-phases flow system. Application of hydrocyclones have been used in numerous industries including oil, drilling, metal working, and mineral processing since 1891, when E. Bretney obtained the first patent for the predecessor design of all contemporary hydrocyclones. A modern hydrocyclone typically consists a cylindrical section at the top where the liquid is being fed tangentially, and a conical chamber attached to the bottom of the cylindrical section, as shown in Figure 1. The characteristics of the feed stream that is injected into the cylindrical chamber play a significant role in hydrocyclone operation. The inlet is tangential relative to the cylindrical chamber and hence causes a centripetal force in the flow field which is considered as the primary separation mechanism."

Jan 1, 2017

By M. C. Rockwell

There are approximately 1,800,000 t of discarded dolomitic-limestone tailings from the Gays River lead/zinc mining operation in Nova Scotia. Neutralization effectiveness similar to an agricultural grade limestone and low contents of residual metals make the tailings a suitable source' of soil conditioner material for the local market. However, the fine particle size, 98% passing 147µm, and a high moisture content make their handling and application difficult. Agglomeration of the tailings into relatively small hard pellets was investigated and difficul¬ties were overcome. Pellets with a range of pH values and various amounts of soil nutrients and moisture content less than 10% were obtained, from tailings containing 20% initial moisture, through the addition of less than 15% selected materials.

Jan 1, 1985

By Haydn H. Murray, Sam M. Pickering

The term kaolin is used here, in a commercial sense, for near- white clay deposits which are dominantly comprised of the mineral kaolinite, or for products refined from such deposits. The term "china clay" has been used in the past as a synonym for kaolin, a reference to its first being mined some 3000 years ago at a hill near Jauchau Fu, Jiangxi Province, China as a porcelain raw material. The name kaolin was derived from the Chinese Kauling, which means high ridge. For most modem industrial applications kaolin must be extensively refined and processed from the crude state to enhance whiteness, purity, and other important commercial characteristics. After such processing, kaolin ranks as one of the most valuable of industrial clays, and it is used to some extent in most manufactured consumer products. In 1991, the United States alone produced kaolin valued at $1,072,366,000. It is applied very widely as a pigment, filler, coater, extender, ceramic raw material, catalyst base, electrical insulator, and pharmaceutical. Some more prominent uses include paper filling and coating; paint, plastic, adhesive, and ink pigment; rubber reinforcing agent; ceramic raw material for porcelain, dinnerware, tile, and enamels; catalyst base for petroleum cracking and auto exhaust emission catalytic control devices; cosmetics base; and digestive coating remedy. Those properties of kaolin clay which make it suited to these applications are related to its physical, optical, mineralogical, and chemical nature.

Jan 1, 1994

By Walter C. Jr. Sherman

6.1-SOIL MECHANICS WALTER C. SHERMAN, JR. 6.1.1-DEFINITION Soil mechanics is concerned with the behavior of soils in relation to the design, construction and performance of engineering works. In this context, soils include all uncemented materials, such as, gravels, sands, silts and clays, either naturally or artificially deposited, and, under certain conditions, weakly cemented, badly broken or weathered rocks. Many types of mine wastes have physical properties similar to those of soils and thus are amenable to analysis by the principles of soil mechanics. The principles of soil mechanics are used to solve such problems as the stability of various types of structures with respect to failure of the supporting soils, determination of soil pressures and deformations in the design of foundations and retaining structures, analyses of seepage and under seepage, and stability with respect to sliding of excavated and natural slopes and embankments. 6.1.2--SOIL PROPERTIES Soils are classified on the basis of index properties, such as, particle-size distribution and plasticity characteristics. The Unified Soil Classification System1 used to classify soils for engineering purposes is shown in Table 6-1. Other physical properties important from an engineering standpoint include natural water content, density, permeability, shear strength and compressibility. Physical properties are evaluated on the basis of carefully conducted laboratory tests. Procedures for laboratory testing are presented by Lambe. 2 Soils, either of natural or artificial deposition, are complex three-phase materials consisting of solids, water and gas (usually air or water vapor). One of the most important principles in soil mechanics is based on the concept of effective stress in the soil-water system. A stress, a, applied to a saturated soil is taken partly by the soil particles (effective stress, a'), and partly by the water in the voids (neutral stress or pore water pressure, u,) so that a' = a - u,. Only the effective stress affects the mobilization of frictional resistance between soil particles. In partially saturated soils, the pore-water pressure is negative due to capillary effects. The effective stress relation remains valid for small negative pore pressures, but anomolies arise if the soil is significantly unsaturated. In this case, the pore pressure is commonly assumed as equal to the pore air pressure, u,, so that [ u' = u - u..] 6.1.3--SOIL EXPLORATIONS Soil explorations are carried out by borings or test pits. Hvorslev3 has reviewed procedures and boring requirements, such as, type, depth and spacing employed. In general, soil strata are logged and representative exploratory samples are recovered for classification purposes and for determining the subsurface soil profile, which is constructed utilizing also knowledge of the geology of a site. Undisturbed samples are recovered if the properties of the undisturbed soil are required, as generally is the case. The undisturbed soil sampler consists of a thin-wall tube

Jan 1, 1973

By C. F. Kaiser

The Broken Hill proprietary company Limited grate kiln pellet plant (1) located at Whyalla in South Australia commenced production on May 13, 1968. During commissioning, about 25,000 long tons of fluxed pellets were produced. Plant performance was satisfactory and acceptable under the plant guarantee. For production reasons, it was necessary to curtail the fluxed pellet run and revert to the production of acid pellets. In 1970, some 250,000 long tons of fluxed pellets were produced under varying operating conditions to determine the requirements for optimum quality pellets at acceptable production rates. In excess of 180,000 long tons of these fluxed pellets were exported to Japan. Problems experienced in production of the fluxed pellets are detailed, and the quality of the fluxed pellets compared to that of normal acid pellets produced at Whyalla. Brief Plant Details Run of mine ore treated was predominantly soft and friable and contained an average of 66 per cent Fe, 1.7 per cent Si02 and 1.8 per cent Al203. The main iron mineral in the ore was hematite with some martite also present. Plant feed was ground dry in ball mills 11 ft in diameter by 29 ft long to a Blaine surface area of 1600 sq.cm/g and the ground ore was wetted in a pug mill. Balling was carried out in balling drums 10 ft in diameter by 32 ft long. Induration equipment included an eighteen windbox grate 12 ft 2 in. wide by 164 ft 1 in. long, a rotary kiln 18 ft 6 in. diameter by 118 ft 8 in. long and an annular cooler 50 ft mean diameter by 7 it wide.

Jan 1, 1972

By Thornton L. Neathery

A small area in the Alabama Piedmont was studied to determine if metallic enrichment was associated with local magnetic anomalies. Cores from two holes in these magnetic anomalous areas have sulfide (pyrite, pyrrhotite, chalcopyrite) film on slicken-side and fracture surfaces. Two hundred and fifty soil samples were collected from the top of the "B" horizon on 1, 000 foot centers over the general trend of magnetic anomalies. Soil samples were leached with a 1:2. 7 mixture of HF and H2SO4 and the dilute filtrate analyzed for Cu, Pb, Zn, Ni, Co, Cr, Mo, and Cd, using atomic absorption methods. Concentration-value maps were prepared for each element. Small areas of anomalous concentrations were defined for Cu, Pb, Zn, Mo, and Ni. Some of these areas generally coincides with magnetic anomalies. Concentration values (ppm) range from: Cu 165.0 - 0. 5; Pb 265. 0 - 0.0; Zn 1386.0 - 43. 0; Ni 187.0 - 10.0; Co 207.0 - 6. 5; Cr 117.5 - 2.0; Mo 95.0 - 0.0; and Cd 32. 5 - 2.0. Studies of other magnetic anomalies appear warranted.

Jan 1, 1972

By S. Lee, F. Campero

"Past heap leach design has evaluated hydrodynamic parameters based on a uniform particle size of heap material, but has ignored the equal importance of the instability of fine migration within heap stack in the beginning stages of the irrigation process. The proposed probabilistic model evaluates internal fine erosion and segregation potential of well-graded crushed ores by considering the entire particle size distribution shape and site compaction degree. Using this model, unsaturated flow model parameters were successfully evaluated based on synthesized soil-water characteristic curve (SWCC). Additionally, one-dimensional unsaturated transient flow modeling with Hydrus 1D® showed that the different recovery efficiencies of heap material under unsaturated flow patterns depending on the particle size distribution and compaction degree of heap material. Agglomeration preprocess employed by most heap leach sites can reduce the potential of fine erosion within heap material significantly, but internal stability of crushed ores and hydrodynamic-based analysis of heap material’s pore structure is equally important in the prescreening stage in order to improve efficiency of the heap leach and avoid a costly agglomeration process. INTRODUCTION Accurate estimation of heap leach recovery is a difficult task due to the variety of design parameters that need to be considered - such as geochemistry, hydro-dynamics, and geotechnical design aspects, most notably particle size distribution through the process of agglomeration. After agglomeration techniques were introduced to heap leach design, the influence of particle size distribution and compaction degree in enhanced heap leach recovery has been neglected. The main purpose of agglomeration is to prevent fine segregation and internal erosion during and after heap stacking for well graded crushed ores, which will eventually diminish heap reach recovery. Recent studies show that agglomerated heap materials that had been consolidated at 10 meters below heap surface can release the fines after contact time with lixiviant to the compacted heap material and produce poor drainage performance (Milczarek et al, 2013). It must be noted that engineers and practitioners should investigate feasibility of agglomeration benefit prior to heap leach design because the agglomeration process can incur up to 20 or 30% of project costs. Internal stability of stacked heap material is mainly governed by the particle size distribution of crushed ores. Depending on this stability, segregation and internal erosion of fines can be mitigated by the application of moderate compaction effort during heap construction. Investigation of segregation and internal erosion potential therefore takes precedence for well graded crushed ore since reaction time and contact area with lixivant are greater in finer ores."

Jan 1, 2016

By D. Lynn, D. Arthur

Infrastructures continue to age and drinking water supplies are becoming scarce in the San Fernando Valley of Los Angeles, California. Frontier-Kemper Constructors, Inc. (FKCI) was engaged by the Los Angeles Department of Water and Power (LADWP) to complete the River Supply Conduit Improvement Upper Reach—Unit 7 Project (RSC7). Two tunnel sections were bored using a 2.64 meter diameter Microtunnel Boring Machine (MTBM) and a 4.12 meter diameter Earth Pressure Balance Tunnel Boring Machine (EPBTBM) to excavate approximately 3,733 meters (3.7 km) of tunnels through highly abrasive late-Pleistocene-age Quaternary alluvial deposits (Old Alluvium) and Holocene age Young Alluvium deposits above the water table. This paper discusses the challenges encountered managing the TBM’s equipment degradation, use of soil conditioners, cutterhead wear, torque and advance rates while maintaining the necessary face-pressures and parameters to limit over excavation and ground settlement.

Jun 13, 2021

By R. R. Oder

Reported are weight, particle size, gross chemistry and magnetism measurements for lithic, mineral and fused soil components separated from five lunar soils using dry, open-gradient, magnetic separation. Pure diamagnetic anorthite, a feedstock for the electrochemical separation of oxygen and metals, has been separated from anorthistic highland soils. In addition, paramagnetic ilmenite has been separated from high-titanium, basaltic mare soils. Ilmenite, a feedstock for oxygen preparation by hydrogen reduction, may also serve as a source of He3 for use in fusion power generation. Agglutinates (vesicular, glassy components containing metallic iron) have been separated from all of the soils. Iron and refractories can be used for space construction. Metallic iron is easily detected in lunar soils by magnetic susceptibility measurements. Based on the exploratory laboratory results, conceptualizations of innovative magnets for processing lunar soils are presented.

Jan 1, 1993

By E. Kaya

Investigations of fine grinding of bituminous coal in a laboratory-scale pulverizer are described. The results indicate essentially "normal" breakage behavior at relatively coarse sizes (greater than about 20 µm) but show clear evidence for re-agglomeration in the fine size range (less than about 10 µm). A simplified population balance model for simultaneous growth and breakage has been formulated. Breakage rates and breakage distributions are assumed to follow the patterns typically observed in simple grinding systems. It is recognized, however, that solid particles and agglomerates may exhibit different breakage behavior. Agglomeration rates are assumed to be determined by contact probability, i.e. by the relative numbers of interacting particles. Based on comparisons of model simulations and experimental data, it appears that agglomerate re-breakage rates and fragment size distributions are quite different from those for solid particles. The result is that product size passes through a minimum and then increases with time as agglomeration begins to dominate.

Jan 1, 1996

By William W. Wellborn

Abrasives are substances both natural and synthetic that are used to grind, polish, abrade, scour, clean, or otherwise remove solid material usually by rubbing action (as in a grinding wheel), but also by impact (pressure blasting). Facts about the discovery, early use, adaptation, and development of abrasives prior to the 20th century are few. From the sparse, earliest information that is available, it would appear that the science of abrasives began when, to fashion his tools, man began to select certain kinds of rocks in preference to others because of their peculiar properties. There is evidence that stones were sawed by some sort of grinding machine as early as 4000 BC in Egypt. The real expansion of abrasives use coincided with the beginning of metallurgy in the Middle East around 2000 BC. The earliest confirmed use of abrasives for grinding metal comes from a steel dagger found along with a sharpening stone which was dated at about 1500 BC. Natural and manufactured abrasive substances play an important role in fashioning and finishing numerous products with a wide variety of end-use applications. The mining and preparation of crude, natural abrasives for their markets and the manufacture of synthetic and other abrasive materials contribute significantly to the US economy (Table 1). In addition, just as sawing to specific dimensions enhanced the value of the Egyptian stone, the use of abrasives in fabrication of modem products, and the addition of abrasives to others, add value. GENERAL CONSIDERATIONS The most important physical properties of materials that qualify as abrasives are hardness, toughness (or rigidity), grain shape and size, character of fracture (or cleavage), and purity (or uniformity). To fabricate bonded abrasive products such as grinding wheels, additional considerations include stability under high heat and bonding characteristics of grain surfaces. The economic factors of cost and availability are always important. No one singular property is paramount for any use. For some applications extreme hardness and toughness are needed, as in diamonds for drill bits. For other uses, factors of greatest importance are hardness and ability to break down slowly and, in the process, develop fresh cutting edges when grains become worn. In garnet sandpaper, for example, highly cleavable, friable, or extremely tough grains are not desirable. For other uses, extreme hardness may be objectionable. Abrasives for dentifrices and for glass-cleaning soaps are cases in point. For the most efficient uses in more critical applications, different types of abrasives are rarely completely interchangeable. While crushed quartz and garnet are both used in sandpaper, the two abrasives are not at all interchangeable in their applications. In the final analysis, the choice of a high-grade abrasive depends upon the quality and quantity of work performed by the abrasive per unit of cost. Initial cost of an artificial abrasive may be much greater than that of a natural abrasive, but the artificial mineral may do so much better work and do it so much faster that the ultimate cost is less. It is for this reason that artificial abrasives have largely replaced natural abrasives.

Jan 1, 1994

By Dennis N. Poffenroth

One concern of the Mine Safety and Health Administration is the structural integrity of steel wire ropes used on mine personnel hoists and elevators. Failure of such ropes has resulted in loss of life and property. Although thorough and regular visual examinations are performed, hoist ropes may still fail from undetected internal wear, corrosion, and broken wires. To complement visual examinations, nondestructive rope inspection techniques have been developed to determine deterioration and removal criteria. The techniques use electromagnetic and permanent-magnet test instruments designed by a Canadian firm. This paper describes the operating principles, field and laboratory testing of these nondestructive testing instruments, and discusses the feasibility of using this type of testing as a supplement to visual examination and destructive tests.

Jan 1, 1982

By T. Gollaher

The use of paste thickeners for mineral tailings has gained increasing acceptance by the mining industry throughout the world and in the U.S. during the last five years. Advantages of water recovery and environmental sustainability are the driving forces for paste as an alternative to conventional thickening and the slurry pond. This paper presents a summary of the differences between paste and conventional tailings thickeners, along with recent examples of full-scale paste thickener installations.

Jan 1, 2010

By Peter Zhang, Daniel Su, Bo Kim, Zoheir Khademian

Building on the research results and knowledge obtained from the ongoing National Institute for Occupational Safety and Health (NIOSH) Gas Well Stability Research, researchers from the NIOSH provided detailed analyses on potential longwall mining and gas well casing interactions at an unconventional shale gas well pad in a West Virginia longwall mine. Following the recommendations from recent research findings, the 5-1/2-inch production casings in all five wells were left uncemented from 4,200 feet below the surface to the surface. Prior to the first longwall panel excavation, NIOSH researchers conducted sophisticated three-dimensional numerical modeling to predict longwall-induced deformations and gas well casing stresses, which were compared with post-first panel and post-second panel mining 40-arm caliper surveys. The pre-mining predictions and comparisons with post-mining 40-arm caliper surveys were presented to all parties involved, including the coal and gas operators, Mine Safety and Health Administration (MSHA), Pennsylvania Department of Environmental Protection (PADEP), and West Virginia Department of Mines (WVDOM), prior to the re-entry operation on December 13, 2022. To date, the re-entry operation is a resounding success.

Jul 1, 2023

By Melvin A. Jennings

Even though the title of this paper is quite long, the ideas presented herein are very simple. In fact, it occurs to me to be somewhat humble about coming before such a distinguished group with such a simple presentation. However, the application of these ideas has proven useful in at least two copper flotation plants. The purpose in presenting this paper is to inspire some interest in the great stores of data chat the Mining Industry often accumulates without making any attempt at analysis. Unfortunately, many milling engineers rely rather heavily on percent recovery as a strict measure of a concentrator's relative performance. The fallacy of this reasoning is not difficult to see since, by definition, percent recovery is a function of feed assay, tails; and concentrate grade. If copper tailing is constant, and it very nearly is for a strictly sulfide copper ore, percent recovery must fluctuate almost directly to the feed assay. The point that I wish to make here is that it is very seldom justified to compare the percent recovery figure from one period of time to another without considering the difference in feed assay. The problem of comparing results is even further complicated when the ores are of mixed oxide and sulfide mineralogy.

Jan 1, 1978

By G. C. Van Bever, J. J. Zaluski

Introduction The Surface Mining Control and Reclamation Act (Public Law 9587) (hereinafter the "Act" or "SMCRA") passed by Congress in August 1977 represents a comprehensive federal scheme for controlling surface coal mining and the surface effects of underground mining through permitting requirements, performance guidelines and reclamation planning. While the provisions of the Act have been the subject of numerous legal challenges and court battles over the years, it is difficult to identify a more controversial program within the Act than the provisions for designating lands as unsuitable for surface coal mining operations. The lands unsuitable designation process provides for the acceptance and review of petitions submitted by citizens or organizations seeking to have specified land areas designated unsuitable for all or certain types of surface coal mining activities. In filing these petitions, the interested parties or petitioners are required to make allegations about potential adverse impacts on people or the environment and submit evidence supporting their allegations. In 30 U.S.C. § 1272, Congress provided that "[a]ny person having an interest which is or may be adversely affected shall have the right to petition ... to have an area designated as unsuitable for surface coal mining operations." Under the Act, an area can be designated as unsuitable where the mining operation will (1) be incompatible with existing state or local land use plans, (2) affect fragile or historic lands, (3) affect renewable resource lands where mining operations could result in substantial loss or reduction of long-range productivity, or (4) affect natural hazard lands where such operations could substantially endanger life and property. In enacting SMCRA, Congress mandated that each state establish a process to determine which, if any, lands within the state are unsuitable for all or certain types of surface mining operations. In response to this federal legislation, the Kentucky General Assembly adopted a state regulatory program for surface mining that included provisions direct¬ing the Secretary of the Natural Resources and Environmental Protection Cabinet to establish a program for designating lands as unsuitable for surface mining as required by the Act. In recent litigation in Kentucky, several environmental groups filed a lands unsuitable petition, later joined by the University of Kentucky, challenging a proposal by Arch Mineral Corporation to surface mine over 3 million tons of recoverable coal. The petition sought to designate over 10,000 acres of land adjacent to Arch's proposed operations as unsuitable for surface mining operations, basically alleging that the mining would disturb an outdoor laboratory. The filing of the petition activated Kentucky's regulatory scheme for reviewing lands unsuitable petitions that can result in an absolute prohibition against surface mining on the petitioned land for historical, environmental and other related reasons. The designation process involves vague petition requirements creating a situation that Arch argued is devoid of constitutional due process and subject to abuse by the petitioner on many fronts. Arch maintained that the lands unsuitable regulations do not grant adequate protection to Arch's legitimate property rights under the due process clauses of the United States and Kentucky Constitutions and are thus void and unenforceable. The entire process resulting in a decision on the petition took just under 12 months in the Arch case, and although Arch was ultimately successful in preserving its right to mine, Arch's surface mining permit was held up for this period of time. This delay led to the cessation of mining operations by Arch and the idling of over 250 workers. This paper will review the lands unsuitable designation process and the significant implications the process has for existing surface mining operations, currently proposed operations and even those long-range operations not yet contemplated. Special emphasis will be given to Kentucky's lands unsuitable program. Finally, the recent litigation involving Arch Mineral Corporation and its effort to surface mine 81.5 acres of Arch controlled property will be utilized to illustrate this very unusual regulatory scheme. Regulatory background Chapter 30, Subchapter F of the Code of Federal Regulations (C.F.R.) promulgated to implement the provisions of SMCRA, requires that each state establish procedures under the state's surface mining program for designating non-federal and non-Indian state lands as unsuitable for all or certain types of surface coal mining operations. 30 C.F.R. § 764.1. The C.F.R. establishes minimum standards for state lands unsuitable programs and sets out requirements for filing a Lands Unsuitable Petition (hereinafter "LUP"), processing LUPs, decision-making guidelines and hearing requirements. Kentucky has adopted regulations providing for the implementation of the lands unsuitable process as part of the state's regulatory program under SMCRA. The following discussion summarizes the principle components of the Kentucky lands unsuitable program.

Jan 1, 1993

By D. W. Park

Underground room-and-pillar mining operations in the Warrior Coal Field in Alabama frequently suffer instability due to soft floor and thinly-laminated immediate roof. The investigation covered by this paper concerns a mine that was experiencing ground-control problems with weak floor conditions. Four hundred ft above the presently producing seam, another seam has been mined out. Several roof falls occurred locally, and as much as two ft of floor heaves have been experienced. The paper presents the results of comprehensive analysis conducted on floor heave, roof sagging, and the influence of the mined-out seam using instrumentation and numerical analysis.

Jan 1, 1991