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Extensive testing in the past ten years has shown that where a uniform natural gamma background is present in the strata bordering the seam, the thickness of the boundary coal left in place after mining can be determined by measuring the attenuation of that radiation (Nelson and Bessinger, 1989). Measurements made by the authors in underground mines in Pennsylvania, West Virginia, Ohio, Illinois, and Kentucky, and by others in Wyoming and New Mexico, have shown the presence of such a gamma background (Nelson, 1989). Natural gamma coal thickness sensors of several configurations have been tested in mines owned and operated by the Consolidation Coal Company in Pennsylvania and west Virginia (Nelson and Bessinger, 1988).

Jan 1, 1990

By Susan G. Bilhorn

A number of studies have been conducted in active and inactive mine environments using continuous monitoring and data acquisition systems to detect various parameters. In addition to the information obtained for research purposes, these monitoring systems can provide a means to remotely collect required information (such as radon daughter concentrations and air velocity) and control various conditions (such as fan operation and air door position) in numerous working sections of an active mine. Selection of detector locations and placement, which are critical to obtain the information and control desired while not inhibiting mine operations and influencing the detector readings, are covered in this paper.

Jan 1, 1984

By J. C. Reid

Pre-cambrian scheelite deposits in Northeastern Brazil are widespread in a high grade metamorphic terrain. Previously these deposits had been interpreted as contact-metasomatic. In this paper, a volcanigenic model is invoked based on the volcanic setting (proximal to distal) and the absence of associated felsic intrusives and spatially associated metasomatic skarns. The tungsten was introduced into sediments by volcanic- exhalative processes and subsequently remobilized and further concentrated by heat and metamorphis fluids associated with high-grade metamorphism and migmitization. An alternative syngenetic - diagenetic model is discussed which requires the transport of tungsten by heteropoly acids and deposition of the tungsten as a function of Eh and Ph conditions and different clastic depositional environments. While such stratabound tungsten deposits are considered rare in North America, the hypotheses developed in this paper may open new areas for exploration.

Jan 1, 1983

By J. R. Nawrot

Reclamation of potentially acid producing coal processing waste requires a 4-foot cover, and/or treatment to allow vegetation establishment. If not planned properly, soil covering alone does not prevent refuse acidification or formation of acid seeps. Adequate neutralization enhancement prior to soil covering can maintain an alkaline environment in the soil refuse interface and prevent acidification. Direct vegetation establishment using only limestone amendment (without soil cover) can successfully reclaim aged and weathered fine (Blurry) and coarse (gob) refuse if adequate neutralization treatment is provided for the oxidized surface zone. Acid seeps, representing an "after-the-fact" verification of an imbalance of acid-base equilibrium may also be corrected using upslope alkaline recharge techniques. Concentrated alkaline recharge pools have been constructed above previously soil covered acid gob at the Peabody Will Scarlet Mine to abate acid seeps. Preliminary monitoring results (1989-1992) from a concentrated alkaline recharge pool demonstration project in the Pit 4 area of the Will Scarlet Mine have documented a 50 to 80 percent reduction in acidity in the principal recharge pool groundwater zone. A 22% reduction in acidity has occurred in the primary seeps located downslope from the alkaline recharge pools. The initial improvements in water quality are seen as a positive indication that groundwater acidity will decrease further and amelioration of the acid seep will continue.

Jan 1, 1993

By T. Kawashima

The expanding volume of maritime coal transportation is intensifying the problems concerning large vessel service port construction, transshipment and environmental control. The major problem is the transshipment of coal. Customary methods for bulk transfer must be improved and/or new systems developed. Slurry unloading has a key role in the new systems. The present report reviews progress in slurry transportation research which has been done in Japan since the 1960s when large scale experiments for domestic transportation were done. Experiments on the effects of vibration on the slurry cargo and on reslurrying are discussed.

Jan 1, 1982

By Donald G. Rogich

The concept of initiating a large action-oriented contract, directed toward inherently safe mining systems, was conceived by the U. S. Bureau of Mines in January 1970. At that time we were in the process of establishing research contracts and grants, about 100 of which were let in FY 71 to deal individually with fairly specific technological areas. These projects in the aggregate covered a wide spectrum of health and safety problems. What appeared to be necessary was the creation of a project or program that would provide a focal point for the demonstration of many of the results of this research and also in the action sense culminate with working hardware and systems that could be tested and demonstrated over a fairly long teen. The concept of working demonstrable systems, rather than just a conceptual study, was, felt to be necessary for two significant reasons. In the development of any new system, the translation from concept to working hardware is usually a costly and time consuming process which acts as a deterrent to implementation. Secondly, many decisions in the mining community to change equipment or systems ,are based on first hand observation of the new system, in operational practice, an attitude which is certainly understandable in view of the high capital costs of equipment. The decision was made to procure a single R&D contract which would be aimed at developing underground coal mining systems which

Jan 1, 1972

By Germán Toledo

The closure of TSF represents a critical milestone in the life cycle of mining operations, requiring the integration of technical, environmental, and social dimensions to ensure long-term safety and sustainability. The GISTM introduces the concept of “safe closure” as a demonstrable technical condition in which there are no ongoing material risks to people or the environment. This status must be validated by an independent technical reviewer and formally approved by the Accountable Executive. This article presents a risk-based methodology to support the achievement of safe closure, aligned with the principles and requirements of the GISTM. The proposed approach emphasizes the need to identify, assess, and manage closure and post-closure risks progressively throughout all phases of the TSF life cycle: from site selection and design, through construction and operation, to closure implementation and long-term monitoring. The methodology integrates key elements of effective risk management, including comprehensive knowledge bases, consideration of climate change, credible failure modes, continuous monitoring, stakeholder engagement, and governance. The ALARP principle is applied to demonstrate that residual risks have been reduced to tolerable levels. By incorporating closure planning from the earliest stages and adopting a risk-based view throughout the entire life cycle, this methodology aims to support mining organizations in achieving a verifiable and responsible closure of tailings facilities, in line with international best practices such as those of ANCOLD and ICOLD. The proposed framework offers a practical contribution to strengthening the credibility, effectiveness, and sustainability of tailings closure processes.

Feb 22, 2026

By Luis R. Bittencourt

Research efforts have been made to characterize a refractory Brazilian bauxite ore composed basically of gibbsite, kaolinite and quartz. Detailed polished-section microprobe analysis of the unbroken ore has been used to describe the liberation characteristics and the association between mineral phases. The linear grade distributions for selected particle size fractions were determined by means? of a particular implementation of King's Random Fracture Model that uses the exponential model for the distribution of linear intercepts through both dispersed (kaolinite) and continuous (gibbsite) phases. The corresponding volumetric grade distributions were then determined by means of a constrained optimization technique for the solution of the transformation equation. Batch flotation experiments were carried out to determine the kinetics for particles of different sizes and the results correlated with the liberation spectrum for each size class.

Jan 1, 1991

By M. P. Roy, P. K. Singh, A. K. Mishra, Ashish K. Vishwakarma, Vivek K. Himanshu

Ground vibration is one of the major hazards produced by rock-blasting operation. The accurate prediction of vibration is necessary for designing controlled blasting parameters. The existing vibration predictors consider maximum explosive charge weight per delay and distance as the parameters responsible for ground vibration. These predictors are based on the assumption that the geometrical parameters of the blast will be constant for a site. However, the mining sites with bigger production targets have varying geometrical parameters to suit the excavator utility. Accordingly, the other blast design parameters will also have an impact on ground vibration intensity. A principal component analysis is a dimension reduction technique. This technique along with multivariate logarithmic regression has been used in this paper to predict the ground vibration. The technique has classified the blast design parameters into four principal components. The regression with the scores from these principal components has been carried out. The evaluation of the model performance of predictors along with the existing empirical predictors has been carried out using R2 and RMSE values. The evaluation suggests that the predictor with logarithmic regression followed by principal component analysis gives better performance with respect to the existing empirical predictors.

Jul 30, 2022

By J. R. Carr

A crucial concern when implementing computer algorithms for geostatistical analyses on microcomputers is speed of execution. Kriging, in particular, typically relies on a Gauss elimination algorithm to solve for weights. Because such an algorithm is required for each estimate, the solution for weights can result in very slow program execution speed on a microcomputer. One approach to enhancing the efficiency of Gauss elimination is demonstrated herein. The upper triangle plus diagonal of the intersample covariance matrix is used in a modified banded Gauss elimination algorithm. Results show that such an algorithm yields approximately a two-fold reduction in execution time for kriging when the number of nearest neighbors used for estimation is large.

Jan 1, 1990

By Paul Eimon

The 1981 Fall field trip of the Denver Region Exploration Geologists' Society focuses on Creede. That is appropriate - because significant mining history has been made and is being made in this off-the-beaten track, high-country mining district. Creede is one of the few Colorado bonanza towns which was big in the 19th Century, had its ups and downs, and produced almost continuously since its discovery. Creede is important to geologists for its: precious and base metal production, current exploration activity, and research into near-surface hydrothermal systems. United States Geological Survey research and field geologists zeroed in on Creede some 25 years ago and their steady, consistent work is now being spotlighted and appreciated.

Jan 1, 1981

By N. Myung, G. Hwang, H. Kim, Y. Han, S. Choi

"According to research presently being conducted on selective lithium recovery in seawater, inorganic adsorbents with high selectivity and capacity for capturing lithium ions from liquid lithium resources are called lithium ion-sieves (LISs). Their low toxicity, low cost and high chemical stability make LISs suitable for lithium recovery from seawater. In the present study, the ultrathin LMO nanofibers with controlled diameter were successfully fabricated by an electrospinning technique with a hypothesis that greater aspect ratio (i.e., smaller diameter) would lead to the enhanced recovery of lithium ion from seawater. Design of Experiment (DOE) and dimensionless analysis were performed to systematically optimize the diameter and morphology of nanofibers. Several complementary techniques including FE-SEM and XRD were used to evaluate the physical/physicochemical properties of the nanofibers. Lastly, the lithium ion recovery was tested for the nanofibers with different physical properties using lithium ion solution. INTRODUCTION Demand for lithium resources is increasing in many industries across the world.1-2 However, the conventional resources for lithium is very limited, and it even gets worse to secure the resources due to low grade and/or complexity of feed materials. Much effort has been, therefore, devoted to obtaining lithium from aqueous lithium resources. Several methods such as solar evaporation3-4, co-precipitation5, and solvent extraction6 have been proposed for recovering lithium from an aqueous lithium source, but there are limitations on its use; It takes a very long time or conditions such as temperature, pH and Mg/Li ratio are severe. Lithium ion-sieve (LIS) materials are considered as a good lithium adsorbent because of their unique chemical structure that can selectively separate lithium ion from brine and seawater.7- 10 Furthermore, their low toxicity, low cost, and high chemical stability make LIS suitable for lithium recovery from aqueous lithium resources. Spinel hydrous manganese oxide (HMn2O4) derived from spinel lithium manganese oxide (LiMn2O4) after topotactically extracting lithium from the spinel structure by acid treatment is most widely investigated LIS.10, LIS materials have been actively studied in various forms for easy handling and high efficiency (i.e. membrane11,12, foam13-14, granular15,16). Among them, the 1-D nanostructure LIS with high specific surface area is excellent in efficiency.9 In this study, we present the part of our recently submitted work17. Specifically, we fabricated systemically lithium manganese oxide nanofibers with different diameter as a lithium ion adsorbent using electrospinning technique through design of experiment (DOE). Enhanced lithium ion adsorption properties of the HMn2O4 nanofibers with different diameter were investigated in lithium liquid resources."

Jan 1, 2018

By E. F. Schnitzer

During 1996 and 1997, Oregon experienced flooding on a scale not seen in many years. Some gravel pits located near rivers experienced erosion and, in several cases, breaches between the gravel pit and the river. Initial evaluation of several sites that experienced breaches indicates that impacts to the river system are complex and vary significantly from site to site. The impacts to the adjacent river system may be viewed as both positive and negative. Several floodplain-mining sites in Oregon located in areas of historic river flow have reverted to active riverbed. In many cases, state and federal fisheries biologists and university researchers see the resulting increase in channel complexity and habitat as favorable. The Oregon Department of Geology and Mineral Industries -Mined Land Reclamation Program (DOGAMI-MLR) is performing additional studies of the impacts to the off-channel areas that resulted from the 1996 floods. More data is needed to make sound floodplain decisions regarding mining.

Jan 1, 1999

By D. G. Chedgy

This article presents a novel design, called the Climax High Capacity Processor (HCP), for pre-combustion cleaning of coal. This design is particularly suitable for the plant capacities of 400 -660 TPH. The HCP is different from the conventional designs with an equivalent throughput in three major aspects: 1) the use of one large capacity HM cyclone to separate coarse and intermediate raw coal in a single circuit; 2) the elimination of the conventional secondary magnetics recovery system by use of the high efficiency Climax magnetic separators; 3) the use of "single line" piping with a minimum requirement of ancillary devices. In comparison with conventional designs with similar capacity, the HCP plant costs much less in capital investment, operation and maintenance.

Jan 1, 1997

By P. H. S. W. Kulatilake

The presence of discontinuities strongly affects the mechanical and hydraulic behavior of rock masses. Joint geometry networks play a vital role in civil, mining, and petroleum engineering projects associated with jointed rock. The need for a realistic representation of joint geometry in rock masses has been recognized. The first part of the paper shows how to build three-dimensional stochastic joint network schemes and also shows how to perform validation studies for these schemes using joint data from the Stripa mine, Sweden. Due to the existence of complex joint patterns, mechanical behavior of jointed rock masses usually exhibit scale effects and an-isotropic properties. A correct understanding of the mechanical properties (strength and deformability) of jointed rock masses is important for designing and performance estimation of structures build in and on rock masses. Beyond a certain volume, the mass proper-ties of the rock may remain essentially constant with respect to the effect of joints. This minimum volume may be used as the element size to represent the equivalent properties of a statistically homogeneous rock mass volume which contains a significant number of joints. This volume may be termed as a "Representative Elementary Volume" (REV) and may be of great importance for engineering purposes. Investigations are underway at both the 2D and 3D levels to look into the possibility of establishing relationships between REV mechanical properties and joint geometry parameters. Recently developed joint geometry modeling schemes are linked with existing distinct element codes (both 2D and 3D) to create a stochastic/deterministic stress analysis approach in achieving the goal. Results obtained so far in this direction are presented in the second part of the paper.

Jan 1, 1992

By N. J. Ferguson

An upsurge in demand for Australian coal has seen a much needed programme for a new generation of coal ports. This paper discusses design concepts in planning a large modern terminal, with the 25 Nt/a Port Kembla and the 50 Mt/a Newcastle facilities as practical examples. The need is emphasised for a studied Master Plan, in-built materials handling flexibility and staged development. Trends in bulk ship design and loading methods are noted. Features of these Australian designs include methods of dealing with poor ground conditions, functional civil engineering for environmental protection and optimal marine structure designs.

Jan 1, 1982

By P. H. Qi

Activated carbon loaded with gold from different halide solutions has been characterized by thermal analysis techniques. The mechanism of gold uptake by carbon varies from predominately adsorption for gold iodide to predominately reduction for gold chloride. TGA and DT A measurements confirm the existence of adsorbed gold-halide species within the micropore structure of carbon. These results suggest that the ration of reduced; adsorbed gold increases for gold halides in the order Au-I > Au-Br > Au-Cl. In the case of Au-I, TA results for the loaded carbon were compared with pure compounds of 12, AuI and AuI3.

Jan 1, 1996

By Yves C. Lizotte

Although blasting remains the most inexpensive method of fragmentation in hardrock mining, the significance of the costs of blast-induced rockmass damage in terms of mining efficiency and safety is becoming increasingly recognized. There is no straightforward and systematic method of adequately measuring blast damage in on-going mining operations. This paper considers various techniques available to measure blast damage, making particular reference to recent underground hardrock mine studies. It concludes by proposing a damage audit procedure for integration into routine mine production control.

Jan 1, 1996

By W. H. Jang

Although surface chemistry fundamentals of semi-soluble minerals have been studied by many researchers, detailed understanding of these systems is still incomplete. In-situ FT-IR/IRS techniques have recently been used to successfully describe the adsorption of carboxylates at semi-soluble mineral surfaces. However, the wetting characteristics of these adsorbed films require further consideration. In this regard, the hydrophobicity and stability of transferred Langmuir-Blodgett (LB) monolayers of fatty acids at fluorite and calcite surfaces has been studied by contact angle measurements with polar and apolar liquids. Generally, it was found that the transferred LB monolayers of fatty acids at a calcite surface are unstable whereas such monolayers transferred at a fluorite surface are stable, as revealed from advancing and receding contact angle measurements. These results are believed to be due to the incomplete reaction of fatty acid monolayer at the calcite surface. In addition it was found that a closely packed well-ordered stearate monolayer with good hydrophobicity, equivalent to that of a transferred LB monolayer, can be formed at fluorite surfaces by spontaneous adsorption and self-assembly from aqueous solutions.

Jan 1, 1995

By K. H. Nimerick

A unique freeze conditioning agent (FCA) which functions by forming structurally weak ice rather than suppressing the freezing point of water has been successful in alleviating frozen coal problems. Frozen coal treated with FCA has been quickly unloaded at temperatures below -17.SoC (O°F). Other areas where FCA has found utility has been de-icing conveyor belts, idler, idler arms and other moving parts that have been impeded by ice.

Jan 1, 1977