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By A. Santha Ram

The Indian Mining sector is subjected to a number of trends including call for global transition towards the route to sustainable development. Several regulations were enacted by the Government departments, from time to time, in order to identify the problems faced by the mining industry, including small-scale mining operations and to suggest appropriate mitigation measures in the form of environmental standards and certifications. During this process, a pursuit of sustainable development is regarded as an important area responding to socio-economic conditions, priorities and thus guides eventually corporate policies and practices. Thus, there is a need to formulate strategies for sustainable development. Based on these strategies some environmental indicators were developed in order to track down the progress and to evaluate its success. A case study pertaining to a group of iron ore mines in North Goa and Chromite mines in Sukinda, Orissa was selected for this study. Base line environmental data has been generated in the respective study sites. A core set of environmental indicators monitoring environmental progress based on the P-S-R model pioneered by OECD is linked with indicators for assessing the integration of environmental concerns.

Jan 1, 2003

By Y. Wang, K. S. E. Forssberg, A. Johansson, X. Lu

This paper presents the desulphurisation of a fine graphite powder below 80 µm by high gradient magnetic separation. The removal of pyrite (FeS2) and pyrrhotite (Fe1-xS) from the fine graphite powder was carried out with a modified version of the Sala dry HGMS with vibration assistance. In addition, a comparative study with dry and wet HGMS systems has also been performed. In order to establish the performance of the desulphurisation, a test series of varying parameters such as magnetic induction, matrix type/configuration and vibration were performed. As an equipment/process for removing sulphurous impurities from the fine graphite powder, the dry HGMS is deemed useful and comparative with the wet HGMS.

Jan 1, 2002

By Scott Ellenbecker

The formation in Newmont Mining?s Phoenix Mine near Battle Mountain, NV contains high levels of abrasive quartzite as well as gold, copper and silver. Newmont started mining operations at Phoenix (formerly Battle Mountain Gold) three years ago and the planners knew they were working with a challenging geological formation. But as it turned out, it was more challenging than anticipated. Mine manager Mark Evatz said, ?Anything that touches Phoenix rock wears fast. The rock fights back here.? To contend with the hard conditions, Newmont uses Atlas Copco?s Pit Viper 271 (PV-271) blasthole drill. Because of the hardness of the rock, drilling at Phoenix requires hammer drilling and the mine uses Atlas Copco TD65 hammers with 171 mm (6.75 in.) bits. The mine?s PV-271?s are outfitted with a single 41 m3/min (1450 cfm), 2.4 MPa (350 psi), oil-flooded air compressor. Phoenix has six Atlas Copco PV-271 drill rigs plus an Atlas Copco DML and a DM45 midrange blasthole rig. The mine?s goal is to keep 3.6 Mt (4 million st) of muck in inventory to stay ahead of the shovels and support needed operational flexibility (ore control related). Drilling efficiency has been a continuous point of improvement since operations began at the mine. The single-pass depth capability of 16.5 m (55 ft) on the PV-271 helped with that. Originally, the plans called for 6-m (20-ft) bench heights, supported by 7-m (23-ft) drill depths, and time spent moving from hole to hole was eating up productivity. Drilling on that plan resulted in drilling an average of 14 m/h (47 ft/hour). When depths were changed to 13-m (44-ft) drill depth, supporting blasting of 12-m (40-ft) benches, they were able to use the single pass capacity of the PV-271. Performance increased to more than 18 m/h (60-ft/hour) an hour. Although the drill depth change largely supported the improvement, other aspects of continuous improvement associated with improved knowledge of the Pit Viper drills helped as well.

Jan 1, 2009

By E. M. Williams

The U.S. Bureau of Mines recently conducted a limited-scope study on the use of lineament analysis and electromagnetic geophysics to better identify the surface expressions of faults at the Cimmaron Mine near Raton, NM, an operating longwall mine in the York Canyon mine complex. Two normal faults were encountered by the mine, one during gate road development and drilling and another only through drilling. The potential ground control problems and offsets associated with these faults will severely impact long-range development plans, so it is essential to know the lateral extent of these faults within the coal reserves. The surface topography at the site is fairly rugged, yet outcrop exposure is poor. There is no obvious visible geologic evidence to indicate that the faults identified at depth extend to the surface. Both the geophysical and remote sensing techniques provided information on the presence and extent of important geologic structures which could not be gained just from drilling and surface outcrops. The geophysical surveys also were invaluable in confirming the presence of subsurface geologic structures in the vicinity of the lineaments assumed to be associated with the faulting.

Jan 1, 1995

By D. Brady

There are many examples, historical and recent, from the underground coal mining industry where during emergency response the response and ultimately the outcomes, could have been significantly improved if adequate systems had been in place for the collection and management of relevant information preceding the incident, the acquisition of information during the incident and the use of the information for risk mitigation and decision making purposes. The subject and process of knowledge management is possibly the most critical for would be rescuers of endangered coal mine workers, as it has been demonstrated at numerous coal mine incidents that a lack of or mismanagement of crucial information can be fatal for both the rescuer and/or the endangered coal mine worker. This paper will underline the scope and importance of robust knowledge management systems for emergency response within the underground coal mining industry and the process by which it is being achieved within the Queensland Mines Rescue Service and the NSW Mines Rescue Service.

Jan 1, 2012

By John A. Herbst

Mineral processors have evolved from "handbook-based" decision makers to "model-based" decision makers. With this evolution have come significant improvements through increasing productivity, decreasing capital and operating costs and increasing product quality. This paper traces the development of model-based decision-making technology over the last 40 years and documents the benefits resulting from systems optimization using these tools. Some speculation is ventured concerning the future of model-based decision-making tools and their use in the field of mineral processing.

Jan 1, 2000

By L. E. Beverage

In 2006, the Mine Improvement and New Emergency Response Act (?2006 MINER Act?), Pub. L. No. 109-236, 120 Stat. 493 (2006) was enacted in a bi-partisan move to strengthen the 1977 Mine Safety and Health Act. This action followed several underground coal mining accidents at the Sago and Aracoma Mines in West Virginia and the Darby Mine in Kentucky. The focus of that legislation was, in part, to force technological development and implementation. It involved the recomposition and training of rescue teams. Requirements for sealing worked out areas of mines were changed when MSHA invoked its Emergency Temporary Standard (?ETS?) authority for the first time in many years. Increased penalty amounts were established for certain types of violations for all types of mining, and minimums were set for unwarrantable failure violations issued under Section 104 (d)(1) and (d)(2); 30 U.S.C. Section 814 (d)(1),(2). The entire 30 C.F.R. Part 100 penalty criteria was revamped in a rulemaking, effective in April 2007. The visions were ambitious and noteworthy and those in industry and government have spent the last four years working through the aftermath of intended and unintended consequences of these changes. The penalty structure arrived at in 2007 has proven unwieldy and has contributed to the increase in contested caseload now before the Federal Mine Safety and Health Review Commission. In essence, litigation under the Mine Act ground to a virtual halt when the number of cases increased but the budget for Administrative Law Judges, who hear the cases, and the Solicitor?s office who represents MSHA, was not increased. Addressing the backlog effectively was one of the major challenges when Joe Main was confirmed as Assistant Secretary in early 2010.

Jan 1, 2011

By R. P. King

Knowledge of the behaviour of flotation machines had developed and increased considerably over the last few years. Although much work remains to be done on the study of the fundamental processes that influence the collection of hydrophobic particles at an air-water interface, there is enough information to permit the building of realistic models of the gross flotation behaviour of various ores. These models serve as an ideal base for the development of simulation techniques for the steady-state behaviour of entire flotation plants that consist of a large number of individual flotation machines. Simulation techniques have a very real role to play in assisting with the design of new plants and in improving the operation of exisiting plants. Recently, highly efficient data-logging systems have been introduced on flotation plants. These systems are based on the on-line measurement of volumetric flowrate, pulp densities, and metal contents, and they generate enormous quantities of information regarding the operation of the plant. Unfortunately, this information is largely wasted at the present time because efficient data-reduction techniques, although available10 are not in common use. Simulation techniques play a central role in such data reduction because they form the essential link between the fundamental kinetic flotation processes on the one hand and the plant data on the other.

Jan 1, 1974

By Eric Forssberg, Mats Hallin

INTRODUCTION Evaluation and optimization of mineral processes has been going on since the the first plant started hundreds of years ago. A huge mass of knowledge has been collected since then. The main problem with this type of empirical knowledge of complex processes is that it is very difficult to formulate and document. The methods used for collecting the knowledge is not consistent but-varies with "he person" that does it. In the late 60's and early 70's efforts were made to use computer based techniques to evaluate process performance and to formulate process models for mineral processes. Models were developed, such as the flotation model by R. P. King (1973) which is still used to simulate flotation circuit behaviour. During the 70's. a number of mass balancing packages were developed together with process simulation packages. The industrial sector also made great efforts to develop and utilize computer based systems for process control and evaluation. The expert system that BOLIDEN created in 1974 at the Kristineberg plant was a remarkable achievement considering the hardware (CDC 3600) and the software tools (FORTRAN) available at that time. The main obstacle to successfully implement optimizing computer control of mineral processes was and still is the limited knowledge about the dynamics of complex processes. There are, however. many activities going on in this area today and it seems that the technology is very near a break through. Process evaluation is the most important tool to improve and maintain the optimal performance of a process. Today dedicated computer based techniques are used for fast and reliable screening of the processes. The stages in process evaluation consist of three basic steps: - Data acquisition, manually or by data logging. - Data refining, mass balancing and parameter calculation. - Data evaluation. The refined data can then be used for model construction/calibration and subsequently for process simulation. This paper describes two studies where the techniques mentioned above are used to evaluate and simulate

Jan 1, 1991

By R. O. Burt

The paper examines the role of gravity concentration in both an historical contest and within the modern mineral processing industry. It discusses the principles of the process on both a theoretical and practical level. The importance of ore mineralogy and its effect on the choice of the wide range of equipment available is discussed. The paper concludes with a discussion on the relative merits of gravity concentration to other forms of processing and seeks to answer the classical question - "Quo Vadis?"

Jan 1, 1982

By B. C. Haydon

Manganese silver ores are well known to be refractory towards cyanidation. Various processes have been suggested for improving the amenability of these ores. A sulfurous acid pre-leach is one such process. This paper traces the development and implementation of the sulfurous acid pre-leach process for the retreatment of manganese silver tailings at Tonopah, Nevada. An account of the test work program is presented, followed by a description of the operating plant and specimen metallurgical performance. The paper also summarizes the history of the Tonopah tailings, their mineralogy and makes reference to previous application of the sulfurous acid pre-leach process.

Jan 1, 1984

By T. R. Ellis

The author attempted to concurrently apply the US Uniform Standards of Professional Appraisal Practice (USPAP) and the Australian VALMIN Code to a complex mineral property appraisal assignment and previously to some modest assignments. This led the author into many severe difficulties. These difficulties included the high standards needed in the work of others and information and statements required from the client under the VALMIN Code. The exercises highlighted many positive features of both sets of standards. However, the author concluded that, without modification, VALMIN is incompatible with USPAP and the US regulatory environ¬ment. The author found that VALMIN violates US legal decisions regarding real property appraisal due to its requirement to include many items of business value. The US Securities and Exchange Commission's prohibition on reporting quantitative resource estimates proved to be a severe problem under VALMIN. Some VALMIN requirements could not be met due to the extent and quality of documents specified. Implications and thoughts regarding the development of a set of US minerals appraisal standards are discussed. Management considerations for complex mineral-property appraisal assignments are also presented.

Jan 1, 2000

By Fitzhugh T. Lee

Results from the first part of a two-part investigation of the stability of highwalls in open-pit coal mines in the Paleocene Fort Union Formation of the western Powder River Basin of Wyoming and Montana indicate that these highwalls are subject to time-dependent deformation. Field investigations and laboratory physical properties tests of coal and overburden rocks suggest that several factors influence highwall stability. Some of these factors are rebound of overconsolidated rocks, desiccation, water, orientation and spacing of fractures, and strength and deformation properties. Factors of safety for a typical highwall in the study area (calculated by the finite element method) may be less than 1.0 when open fractures are present and the highwall has degraded. Although it is concluded that most open-pit highwalls in the Fort Union Formation within the study area have adequate short-term stability, these highwalls do deteriorate and become progressively less stable. Because of this, postmining failures are common and stability conditions could become critical if mining were delayed and then resumed after a period of several months. The second part of the investigation will utilize field measurements of rock-mass properties and instrumentation of actively mined highwalls to obtain data for comparison with the results of the initial investigation. Because the height of highwalls will increase as the more shallow coal is exhausted, these data will also be used to predict the behavior of slopes higher than those presently found in the western Powder River Basin.

Jan 1, 1977

By S. Peng, Yi Luo

Subsurface strata movements and deformations associated with underground longwall mining activities could cause certain influences to subsurface structures and water bodies. Methods have been developed for the prediction of final and dynamic subsurface movements and deformations induced by underground longwall mining operations in the eastern coal fields. Two new types of strata deformation, vertical and total strains, which could be useful in the field of subsidence research in assessing subsidence influences to the subsurface structures and water bodies, have been introduced. Using the subsurface subsidence prediction model, three types of subsidence influences to surface and subsurface hydrological systems have been identified. Attempts have been made to quantify the two types of subsidence influences that could cause water loss and could lower water levels in aquifers.

Jan 1, 2010

When longwall equipment is being specified, a nominal capacity is generally given on which to base the design of the various face and out-bye systems and components. This capacity generally comes from a nominal annual capacity requirement based on realistic utilization rates. From illustrative examples of simple system simulation, this paper sets out to show that a single nominal capacity is not sufficient to size the different systems. The manner in which the Longwall is operated and the overall system configuration and availability can have a significant impact on overall productivity.

Jan 1, 2008

By Mark Newton Lowry

In the garden of national problems recognized by the American public, imports of mineral products is a hardy perennial. Concern for the security of mineral supplies has preoccupied nations since the industrial revolution and the mechanization of warfare. Since 1973, Americans have also been sensitized to the potential economic costs of overseas mineral supply disruptions and the cartelization of foreign production. Though oil prices have plunged since 1981, the import dependency issue remains topical. Political turmoil in Southern Africa reminds us that mineral supply disruptions will occur in the future as they have in the past. Producers of iron and steel, copper, and refined petroleum products seek protection from imports on national security grounds. The Reagan administration is proposing sweeping changes in the management of the federal mineral stockpiles. s an enduring need to take stock of the mineral trade position of the United States. This article considers the changing role that the U.S. has played in the twentieth century in non-fuel minerals trade. We begin by enunciating some principles that are useful in analyzing this trade. The changing pattern of trade in the 1900-1969 period is then reviewed. There follows a more detailed analysis of mineral trade trends in the 1970-84 period. Some consideration is given in the final section to the significance of non-fuel mineral trade for the U.S. economy. THE ECONOMICS OF U.S. MINERAL TRADE The allocation of non-fuel mineral products in the United States has in this century been accomplished primarily through the market mechanism. Except where trade barriers have distorted price signals, this means that mineral supplies have been obtained from the least cost source, with little regard for their country of origin. Mineral prices facing U.S. firms are sensitive to shifts in the domestic supply and demand, but are also sensitive to economic conditions overseas. The balance of trade in each mineral product has depended on the amount that is profitably produced and consumed domestically at the world price. The nation has produced exactly as much as it has consumed only by chance. U.S. demand for non-fuel minerals is derived from the demand for manufactures, farm commodities, and other goods whose production requires mineral products as inputs. The demand for such goods can be quite volatile, and in most industries moves cyclically due to its sensitivity to the level of aggregate economic activity. The supply of mineral products depends on the cost of extracting and processing mineral raw materials. These costs do not vary greatly in the short run. Because of these attributes of mineral markets, U. S. trade in mineral products fluctuates considerably from year to year. Most of this volatility results from shifts in domestic and overseas demand and from changes in exchange rates and trade barriers. Longer run changes in the mineral trade pattern can also be discerned. These depend on secular trends in demand and in the cost of mineral extraction and processing at home and overseas. The United States was originally endowed with extensive reserves of an array of mineral-rich ores and fossil fuels. It is also a nation with an entrepreneurial climate and technological capability conducive to extracting and processing those reserves. Not surprisingly, it has at one time or another ranked among the world's leading producers of a great many mineral products. With a population that is large and an economy that is technologically advanced by world standards, the U.S. has also been a leading consumer of mineral products. Because of its voracious appetite, the bulk of mineral products produced domestically has traditionally been consumed domestically as well. Net exports have been sizable only in those industries in which the nation has enjoyed an extraordinary cost advantage. Depletion has gradually reduced the cost advantage that the U.S. mining industry once enjoyed. The economic conditions that encouraged early development of U.S. mineral resources have

Jan 1, 1986

global mining boom and in-creased demand for iron ore has lead to a resurgence in the mining industry in Minnesota. At the combined 81st Annual Minnesota Section of SME Meeting and 69th Annual University of Minnesota Mining Symposium, April 15-16 in Duluth, MN, this resurgence was the hot topic as new mining projects were featured in the keynote session. The meeting attracted more than 400 mining industry professionals, including engineers, executives, mining managers and suppliers from around the world. This year?s theme was ?New Ventures in Mining.? The meeting included concurrent technical papers sessions, a keynote session that featured three distinguished speakers and a panel discussion that provided updates on new mining developments in the state. The Minnesota Section of SME technical papers were presented in concurrent sessions, one on mining and one on mineral processing. The mining session included papers on drilling, ore blending, slope stabilization, dust control and operations management. The mineral processing session included papers on plant-control technology, ball mills, pellet strength and fans. Also offered was an SME short course titled ?Simulation based pellet induration optimization.? The Minnesota Section of SME held its annual business meeting during the conference. The 69th Annual University of Minnesota Mining Symposium technical sessions were held on April 15 and also consisted of concurrent sessions on mining and mineral processing. Mining session topics included logistics management, real-time performance measurement, uses for taconite aggregate and environmental issues. The mineral processing session included papers on ore liberation characteristics, zeta potential studies, induration modeling, fuel optimization and conveyor belts. The combined conference included a tradeshow with more than 80 booth spaces featuring vendors offering products and services to Minnesota?s booming mining industry. More than 900 people, including conference registrants and special invited guests of the vendors, at-tended the tradeshow opening reception. This was the largest trade show in many years ? an indication of the vitality of the mining industry in Minnesota.

Jan 1, 2008

By W. Jacobi, K. Eisfeld

The primary objective of dosimetric modelling for the inhalation of radon daughters is the evaluation of the dose distribution and of the mean dose to sensitive cells or target tissues in the respiratory tract which are assumed to be responsible for the initiation of lung cancer. The results of such dosimetric models are influencing the practice of radiation protection in a twofold manner: Firstly, they enable us to identify appropriate operational quantities for air monitoring and for the surveillance of individual exposures to radon daughters. Secondly, they can be used to derive secondary and operational limits for these radionuclides from the basic dose limits. The dose to target tissues in the lung from inhaled radon daughters depends on various physical and biological parameters: The unattached fraction of daughter atoms, the AMAD of the carrier aerosol for attached atoms, the geometry of the respiratory airways, the breathing conditions, the parameters for the retention and translocation of daughter atoms in the different lung regions, and the location of the target cells or target tissues, respectively. Therefore, dosimetric modelling for radon daughters has to include a sensitivity analysis showing the influence of these parameters. To meet these objectives we have recently described in a comprehensive report an improved dosimetric model for the inhalation of 222Rn, 22ORn and their short lived daughters (Jacobi and Eisfeld, 1980). In the following this model is shortly described and the main results are summarized. DOSIMETRIC MODEL [Model Structure]. For the geometry of the bronchial airways the model A of Weibel (1963) was used. Each bronchial generation i (i =0.1 .... 16) was considered as a separate compartment i, for which the following transfer pathways for radon daughter atoms were taken into account (see fig. 1): (1) the uptake by deposition (deposition probability wi); (2) the translocation by ciliary clearance (rate constant [A]i); (3) the transfer to blood by diffusion through the bronchial epithelium (rate constant [A]b). To distinguish between attached (Index a) and free (index f) daughter atoms each bronchial generation was divided in two subcompartments (i.a and if) with a transfer rate constant [a]s (ia- if) characterizing the desorption or dissolution rate of attached atoms in the mucus fluid. Thus for daughter atoms primarily deposited in attached form the transfer to blood is a twostep process with the rate constants [a]s and [A]b which were assumed to be independent of the generation number i. [Deposition]. The deposition probabilities wi in each bronchial generation were calculated on the basis of the laminar diffusion model of Gormley et al. (1949); however the deposition in the upper airways was corrected for turbulent air flow, taking into account the results of our deposition experiments (Martin et al., 1972). Figure 2 shows the resulting deposition probabilities per unit surface area of the bronchial generations for nose breathing at a rate of 20 1/min. The values for attached daughter atoms refer to an AMAD of 0.2 - 0.3 µm ([O]g =3) for the carrier aerosol; the deposition values for free atoms were derived with a diffusion coefficient of 0.05 cm2/s, assuming a prefiltration of 50% in the naseopharyngeal region.

Jan 1, 1981

By H. Ankara

Determining the identicalness levels of the same model trucks working in open pit mine transportation system by means of statistical analysis methods is very significant in terms of availability analysis. In this study, the identicalness levels of two trucks picked randomly from the 170-short-tonne truck fleet working in open pit coal mine over one-year period were examined through a non-parametric test, Mann-Whitney U test for two samples. Time to failures (TTFs) and Time to Repairs (TTRs) of the trucks were analyzed with this test technique and then whether they were identical or not was determined. In order to determine whether the trucks identified to be identical at the end of this test displayed the same mining performances within the same open pit transportation system, the availability analysis of the identical trucks was carried out. As a result of the availability analysis, it was observed that the trucks had availability values that were very close to each other. It was also determined that Mann-Whitney U test could be employed together with availability analysis. Finally, it was observed that Mann-Whitney U test for two samples could yield rapid results in the performance analysis of complex systems like open pit mines.

Jan 1, 2010

By Charles H. Dowding

INTRODUCTION "On many projects, the tendency is to drop interest and support of the geological service as soon as it seems safe. That . . . is a short-sighted policy . . . It would be of further service perhaps to learn whether predictions were reasonably true to life." --C.P. Berkey, 1938 (3) This paper quantitatively compares predicted and encountered shear zone size and location and rock type for tunnels in the Colorado Mineral Belt. The Colarado Mineral Belt is composed of igneous formations with associated metamorphic rocks and faulting. As such, it represents the most complex of provinces for at-grade predictions (27). Shear zone and rock type data are assumed to be statistically homogeneous because of the common geology of the seven tunnels. It is often felt by geologists and engineers that the amount of information from which a geological model is created is so low that any statistical inferences are unstable. In other words, the addition of new data may drastically alter the means and variances suggested by the model. Therefore, predictions are rarely couched in quantitative statistical terms but modified with "probably," "most likely" or "possibly." Comparison of predicted and encountered data from past geological models will permit the "probably's" to be quantified and distilled from the art of geological prediction. To date, two other studies of the validity of predictions have been made (26 and 16). Together, these two studies indicate that

Jan 1, 1976