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By SUMANT KUMAR SAMAL, BHAGIRATHA MISHRA, MANOJA KUMAR MOHANTY, SUBASH CHANDRA MISHRA

Steelmaking consumes the majority of chromium and manganese ferroalloys for purposes such as to impart various properties to steel. The quality of ore governs the process kinetics as well as the process economy of the ferroalloy industry. The present study demonstrates the thermal transformation behavior of chromite and manganese ores with varying compositions. Simultaneous thermal analysis (differential thermal analysis/thermogravimetry, DTA/TG) was conducted on these ore samples, where the transformation of mineral phases was correlated with the thermogram characteristics and quantified. Phase, microstructure and compositional analysis results of individual ores corroborated with thermal analysis are in good agreement. Chromite samples are ferruginous with goethite and gibbsite contents, whereas manganese ores vary in composition and also exhibit multiple and/or overlapping transformations.

By Susumu Uchiyama

This machine was manufactured for excavation of the Roppongi station of the Tokyo Metro Line 12. This machine can excavate both the platform and the rail track at the same time in locations where the traffic is congested and has following features: A multi-centered TBM of the size of 7.06(H) x 13.18(W) m The world first H&V TBM, with right and left machine parts articulated vertically and separately for position control A large erector for simultaneous erection of column and central segments of special shape to construct a highly reliable tunnel This paper reports the design concept, construction, and work record.

Jan 1, 1999

By Barbara C. Schickner

The long-awaited COSMAR study prepared under the auspices of the National Academy of Science reaches one emphatic conclusion that has been enthusiastically seconded by the mining industry: The 1977 federal surface mining act is "poorly suited" as a vehicle to regulate noncoal mining. Though the industry greeted the report with approval, the weight it will carry and the extent of its impact are yet to be felt. The COSMAR report makes no recommendations-that's a job left to the Administration's Council on Environmental Quality-and the prospect of legislation still hovers. For a closer look at the study, MINING ENGINEERING talked to COSMAR committee chairman James Boyd, a well-known presence in the mining arena for over 50 years. After highlighting some of the study's major points, Dr. Boyd comments on the report's impact and possible repercussions. Dr. Boyd, for those readers who haven't seen the COSMAR report, would you summarize some of its major findings? The committee analyzed the surface mining act to determine if it was applicable to noncoal mining and found that there were provisions of the act that either could not be met by existing technology or would be extremely difficult and not necessarily beneficial to adapt. We found that most noncoal mineral mines, despite their obvious diversity, can be considered in two major groups: 93% of all mines move 45% of all materials mined (mostly small units mining construction materials); and the few gigantic regional operations (2%)-copper, iron, phosphate, and uranium mines-that move 50% of the material. With few exceptions, neither of the two groups is amenable to the coal mining practices addressed by the act. The strip mine law was designed for coal mining, where land is regraded, revegetated, and returned to usefulness. In contrast, construction mineral quarries supply local needs for decades, remove most of the material from the immediate vicinity, and cannot be returned to their premining uses (though they have innumerable other valuable uses). The nation's huge mineral deposits require enormous capital investments, are vital to the nation's economy, and can take centuries to exploit. Any attempt to return these locations to premining use would be illogical. Pebble phosphate in Florida and red-bed copper in Oklahoma come near to meeting the conditions contemplated in the act. In addition to COSMAR's basic finding, the study also makes the following points: •Mining uses a relatively small part of the land resource, in contrast to

Jan 4, 1980

The La Colosa, Colombia porphyry gold deposit is currently in the pre-feasibility stage. This large deposit has many types of gold mineralization: native gold, electrum, and tellurides. These variations in the gold mineralization lead to variability in the gold recovery. The final process flowsheet may include gravity concentration with cyanide leaching. Metallurgical testwork is utilized to identify the zones of ore that may be problematic to recover. To help select the samples that represent the fluctuating variability zones, geometallurgical models are constructed using mineralogy and geology data. These zones are then wireframed and compared to the geological and structural models for spatial correlation. Samples for the variability testwork will be selected from these different zones to identify and analyse the effect the different gold mineralization types have on the recovery. By using geometallurgy to aid in the sample selection for metallurgical testwork, the variability in the ore body can be understood and constrained to aid in process optimization.

Feb 27, 2013

By S. Ouyang

The four most important parameters controlling the flow of as in coal are the gas content, permeability, diffusion coefficient and clear characteristics. Estimates of these and, more importantly, a good knowledge about the variations in their values over time are important for proper simulation of long-term gas production. This paper describes experimental techniques for the estimation of diffusion-coefficient and permeability values, along with their time dependency under simulated in situ conditions. It is shown that the permeability and diffusion-coefficient values are not constant, as they are usually assumed to be. There is a significant variation in their values, probably as a result of changes in the microstructures of coal associated with release and flow of gas. Finally, a technique to estimate clear parameter is presented.

Jan 1, 1997

By K. Adam

The sustainable management of solid wastes, including the wastes emanating from portable batteries, consists one of the main objectives of the current EU Environment Framework Programme. Overall reduction in the quantity and volume of disposed wastes, elimination of dangerous species within the waste streams and wastes recycling comprise specific targets of this policy. Within this framework a Greek funded research project entitled ?Development of an Integrated Alternative System for the Environmentally compatible Management of Used Batteries and Accumulators - DIASBAT?, was recently completed by a research team consisting of major Greek Battery producers and retailers, Research Organisations, Universities and Environmental Consultants. The aim of the project was the development of an Efficient Alternative Management System for spent portable Batteries and Accumulators, (B&A), in compliance with the prevailing EU and national environmental legislation, taking advantage of the state-of the art technology. The present article summarises the research carried out within the DIASBAT project in order to review and develop a set of sustainability indicators for the assessment of the effectiveness of Spent Portable Batteries Management Systems (SPBMS). Based on the European experience and practice, various indicators were initially examined regarding the performance evaluation of SPBMS. Specifically, the indicators used in European studies conducted to assess the environmental, social and economic impacts of the recently issued Batteries Directive 2006/66/EC, as well as the indicators used by European Collection and Recycling Organisations (CROs) to assess the performance of SBPMS across Europe were presented and analyzed. Additionally, the set of indicators used within DIASBAT to assess the effectiveness of alternative Spent Portable Batteries Collection Schemes developed within the project, are presented. The experimental collection networks of the DIASBAT project included schools, selected retail stores and a pilot network set up by the Greek Institute of Geology and Mineral Exploration (IGME). From the evaluation of the various indicators, it was deduced that in order to assess an Integrated Spent Portable Batteries Alternative Management System, a multi criteria analysis approach is required. Within the general principles of sustainable development, there is a need for different qualitative and quantitative indicators to be combined, taking into consideration critical parameters such as: annual portable batteries collection rates, compliance with the targets set up by the prevailing European and national legislation, economic performance of the System - and finally social criteria - environmental sensitization according to age, gender, economic prosperity, educational level etc.

Jan 1, 2007

By R. R. Klimpel

This paper is a summary of the author's industrial experiences on the selection and optimization of flotation reagent schemes for the recovery of gold species. The trends given are a composite of data and experiences gained on 24 different gold ores from around the globe. The primary emphasis is on the benefits of matching the associated gold mineralogy to a reagent scheme most appropriate for that mineralogy. Two general categories are discussed: the flotation of free or native gold species and the flotation of gold associated with a variety of sulfide minerals. Important plant operating factors influencing each of these two categories are presented with supporting examples. Carefully matching reagent chemistry and appropriate operating conditions to any given gold-bearing ore will not only lower the total reagent cost but, more importantly, can lead to measurable increases in gold recovery.

Jan 1, 2000

"A fire design innovation of the concrete lining of the Ohio River Bridges East End Crossing Tunnel has been developed. As a result from a fire suppression and tunnel ventilation system, the project design Heat Release Rate (HRR) was able to be constrained from 300 MW to about 50 MW. With this reduced HRR, concrete lining without passive fire protection may be acceptable, if the tunnel concrete lining will not result in explosive spalling during the designed fire event. Concrete explosive spalling test was proposed to verify this assumption. Since no standard concrete fire explosive spalling testing procedure exists, a project specific testing procedure was developed and fire tests conducted. From fire test results, it is concluded that the proposed tunnel concrete lining, in conjunction with the proposed fire suppressing and ventilation system, will not experience explosive spalling and does not require a passive fire protection system. INTRODUCTION The Ohio River Bridge East End Crossing Tunnel is part of a Public Private Partnership project, which connects transportation network between Louisville, Kentucky and southern Indiana. Located in Louisville, Kentucky, the twin-tube highway tunnel provides northbound and southbound lanes of the Kentucky approach to a new bridge across the Ohio River. Tunnel lengths are approximately 1,675-ft and 1,685 for the northbound tube and the southbound tube, respectively. Connected by two cross-passages, both tubes have a roadway width of 40-ft, for 3-lane traffic, and a vertical clearance of 26.5-ft.The Tunnel was constructed by drill and blast method with shotcrete and rock dowels as initial ground supports. The final tunnel lining consists of 16 inches cast-in-place concrete lining and 20 inches invert slab, with a waterproofing system around the tunnel perimeter. Two (2) tunnel side drains and one (1) invert drain were provided for each tube. This paper describes the rational in assessing fire design requirements of the tunnel final concrete lining, to answer the question whether a passive fire protection system is needed or not."

Jan 1, 2016

By Nobuharu Isago, Atsushi Kusaka, Kosuke Kawata

"Strong earthquakes occur frequently in Japan, and some rock tunnels have sustained severe damages on their permanent lining. Many road tunnels, which were constructed by conventional steel arch support and timber lagging method, exist in Japan and they need risk mitigation measures against earthquakes as per our empirical knowledge. Many reinforcing measures for deformed tunnels that may be effective against earthquakes are developed; however, behaviors during earthquakes are not fully understood.In this study, static loading tests and numerical analysis, which simulate a loading condition during earthquakes, were carried out to clarify the effect of the countermeasures. The Load-bearing capacity is estimated for the tunnel structures facilitated by the installment of an inverted arch; however, a joint between inverted arch and sidewall become structural weakness. Rock bolts and carbon fiber sheets have a potential able to mitigate the risks of collapse of the lining by the forces from an earthquake.INTRODUCTIONA number of rock tunnels with no apparent unfavorable ground conditions suffered severe damage, including the collapse of their permanent lining, in large seismic events such as the Chuetsu Earthquake in 2004 (e.g., Mashimo 2005). Since these tunnels were considered to exhibit the required structural strength to survive earthquakes, studies are being carried out to clarify the mechanical behavior of tunnels during earthquakes and their damage mechanism (e.g., Kusaka et al. 2009); however, the aseismic design methodology for mountain tunnels has not yet been established.In many cases of earthquake-damaged tunnels, some defects already existed, such as improper construction and deterioration of lining concrete. Although countermeasures are usually implemented against such problems, their earthquake-resistant effect was not fully understood.In this study, static loading tests and numerical analyses to reproduce these tests were carried out assuming that a rock tunnel was affected by the earthquake to clarify the mechanism of the lining damage and the effect of the countermeasures."

Jan 1, 2016

By J. W. Wilson, S. Nakajima, B. D. Singh

According to the Project Independence blueprint, a 270 percent increase in coal production is expected from western coal fields compared to an increase of 100 percent for the nation as a whole. Furthermore, 30 percent of the total United States coal reserves lie in the western states, which are classified as beyond the strippable limits and can be recovered only by underground methods. In view of the fact that the majority of the seams in the West are thicker than those presently mined in other parts of the country, it is important to consider the parameters that relate to mining thick seams and the factors that affect such mining systems. Apart from thick seams, a common feature of many western coal fields is the occurrence of multiple seams that lie in close proximity to one another. These multiple seam deposits present difficult mining problems that have not been encountered to any degree in other U.S. coal fields; for example, ground pressure changes in one mine level caused by mining in the other, sudden water or gas influx from the adjacent levels, the danger of spontaneous combustion in gobs and large and complex subsidence displacements on the surface. Perhaps equally important is the fact that the country can ill afford the present systems of underground mining that attain only 50 to 60 percent coal recovery. With the probability of increased thick seam mining, conservation shall be a focal point in future mine design systems. It is possible that in the future it will be forbidden to adopt the present day wasteful mining methods to ensure that coal can be conserved for future generations.

Jan 1, 1977

By Gregory Beckstrom

"During a year of challenges in the mining industry, two groups collaborated Aug. 17- 20 for a joint conference on industrial minerals of the Upper Midwest. Hosted in Minneapolis, MN, the 4th Annual SME Twin Cities technical conference and the 51st Annual Forum on the Geology of Industrial Minerals (FGIM) drew attendees from throughout the United States and Canada.Highlights of the event included a one-day field trip on Aug. 17 to a crushed stone and gravel mining and processing operations near the Twin Cities, followed by a visit to a historic mine tunnel within the St. Peter sandstone formation. The latter was used as a speakeasy during America’s prohibition era. A two-day field trip on Aug. 19-20 made stops in central and northeastern Minnesota at a granite quarry and processing plant, a peat harvesting and packaging plant, an iron mine and taconite processing plant, and a silica sand storage and loading operation. In a nod to one of Minnesota’s celebrated luminaries, the group also stopped in Hibbing to visit the boyhood home of Robert Allen Zimmerman, better known to the rest of the world as Bob Dylan.A full-day technical program featuring talks on environmental impacts of silica sand mining, regulatory updates, mine land reclamation and methods for identifying construction material failures (alkali-silica reaction) was bookended by the two field trips.According to Minnesota state geologist Harvey Thorleifson, the keynote speaker of the technical program, “This joint SME and Forum on the Geology of Industrial Minerals conference is a reflection of the important role of the mining industry in society, of the important role that partnerships play, and of the prominence of industrial minerals on the Twin Cities region and iron ore on a national scale.” He added, “While this is a tough year for the mining industry in the region, we are confident in the strength of the profession and the industry in the medium term, as we anticipate a superb SME national conference in Minneapolis in 2018.”"

Jan 1, 2015

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 J. C. Yingling

[New stochastic process models are developed to calculate the probability of various fill levels in section feeders as a function of vehicle interarrival times, payloads and feeder-discharge rates. These models may be utilized to establish the minimum feeder-discharge rate necessary to prevent a feeder, with a particular surge storage capacity, from constraining the section's production rate. In addition, it is shown how the output from these models may also be utilized to calculate the probability of various flow rates at junctions in the conveyor haulage network, enabling one to size gathering belts. The model provides a basis for optimizing, (in economic terms) capacity specifications for feeders and conveyor belts in the materials-handling system by considering tradeoffs in the size of the two types of units.]

Jan 1, 1997

By Shimi Tzobery, Jay Davenport, Raymond Henn, Sam Bandimere

Over the past several decades, the use of cement-based grouts using ultra fine cement as a replacement for portland cement has begun to gain acceptance as an alternative to chemical solution grouts used in permeation grouting. The amount of information currently available on grouts made with ultrafine cement is limited. The authors used a previously developed field testing program to perform additional tests to evaluate the permeation performance of portland and ultrafine cement-based grouts. For the first time, the 2003 testing program included an attempt to determine the 28 day compressive strength of the sand permeated by the grout.

Jan 1, 2005

By Matthew Deutsch

A common casualty of modern openpit mine optimization is the assurance that the resulting design is actually achievable. Optimized mine plans that consider value and a bare minimum of precedence constraints do not, in general, translate into practical, operational mine designs that can be used in the field. Ultimate pits may come to a sharp point at the bottom. Schedules may require taking small parcels of material from many disparate areas of the pit in a single period, and grade control polygons may be ragged, narrow and not minable with realistic equipment. In this paper, these three fundamental openpit mine optimization problems are addressed by encoding them as maximum satisfiability problems. Maximum satisfiability provides a useful framework for problems that are nonlinear and may guarantee the optimality that metaheuristics cannot.

By C. I. Basilio

The adsorption of O-isopropyl-N-ethylthionocarbamate (IPETC) and O-isobutyl-N-ethoxycarbonylthionocarbamate (IBECTC) on chalcocite, chalcopyrite and pyrite has been studied using UV and in-situ FTIR~ATR spectroscopy. Thionocarbamates were found -to adsorb strongly on chalcocite at pH 4-10, but consider-ably less on chalcopyrite and pyrite. The FTIR spectra show that the surface species of thiono-carbamates are bonded to metal atoms on the mineral surfaces. However, at high concentrations, IBECTC also forms physically-adsorbed species. Adsorption of these thionocarbamates cannot remove or prevent the formation of sulfoxy oxidation products on pyrite, unlike the case with the xanthate-pyrite system. This finding may account for the observed flotation selectivity of these reagents against pyrite. The spectroscopic information is compared with flotation test results.

Jan 1, 1988

By Paul F. Gnirk, Ralph A. Wagner, Joe L. Ratigan

This thermomechanical analysis used the finite element method to investigate the behavior of crushed salt backfill in a waste disposal room situated in a salt dome repository. The first of two objectives was to determine the transient temperature rise and degree of thermomechanical consolidation that occur in the backfill as a function of drillhole depths. The second objective involved the evaluation of closure due to salt creep of unlined emplacement drillholes and the determination of pressure on steel sleeve liners in the drillholes should liners become necessary for canister retrieval. The retrievability period was considered to extend for 25 years after waste emplacement. The canisters were assumed to contain ten-year old high level waste with a thermal output of 4.3 kW at the time of emplacement.

Jan 1, 1981

By Mark J. Zdunczyk

"The term “aggregate” has a number of definitions depending primarily on the use of the material. Aggregate in some context is sand, gravel, crushed stone, slag or other material of mineral composition used in bituminous and portland cement concrete, mortar, plaster, railroad ballast, filter beds and a variety of other uses where aggregates can be utilized.Of the natural aggregates, crushed stone is widely used for most construction purposes. Crushed stone can be mined from a variety of rock types such as limestone, dolomite (dolostone), granites, and granitic type rocks, basalt, gabbro (trap rock), sandstones, schist, marble, gneiss, quartzite, rhyolite, as well as other rock types. The U.S. Geological Survey (USGS) breaks down the rocks by type sold as follows: limestone, dolomite, marble, calcareous marl, shell, granite, trap rock (basalt, diorite) sandstone/quartzite, slate, volcanic cinder and scoria and miscellaneous stone.In 2015, the USGS estimates that 1.32 Gt (1.45 billion st) of crushed stone were produced in the United States. The volume of crushed stone produced, and the numerous mines that produce it make the crushed stone industry the largest mining industry in the United States. The five leading states for production of crushed stone in 2015 were Texas, Pennsylvania, Missouri, Florida and Ohio. The size of the first two states certainly helps in output because of the large market area. The remaining states benefit from being able to barge along rivers to outside markets in adjoining states. Georgia producers rail large amounts of granitic aggregate to Florida and adjacent states devoid of crushed stone aggregate, especially skid resistant aggregate (aggregate used on the top course of asphalt roads)."

Jul 1, 2016

By B. Briggs

Over the past 15 years, the tunneling industry has pushed towards a higher degree of mechanization in nearly every phase of construction. The overall objective of the mechanization was to increase production and the level of safety in tunnel operations. However, the overall complexity of some systems have been a hindrance to a seamless transition to the newer technologies as increased maintenance requirements and re-training of skilled workers has altered the benefit curve for some innovations.

Jan 1, 2010

By John W. Crawford

The majority of the regulations in Part 75 for underground coal mines have been in effect since March of 1970, almost nine years now. Although there have been some additions each year in specific areas where the need became apparent or the statute required some action, the bulk was promulgated on March 28, 1970 for the purpose of clarifying the statutory provisions of the Federal Coal Mine Health and Safety Act of 1969. Many of those regulations were derived from the Federal Mine Safety Code, or from experience gained by the Bureau of Mines in the enforcement of Public Law 552. Upon passage of the Federal Mine Safety and Health Act of 1977, these same regulations remained in effect and the statutory requirements of the Act placed a responsibility upon the Secretary of Labor to promulgate additional regulations in specific areas not previously covered. The Federal inspectorate has received formal training at the National Mine Health and Safety Academy in the proper application of the regulations, as well as routine retraining and special training courses subsequent to the promulgation of new regulations. With some exceptions, the vast majority of these regulations are nothing more than good mining practice. Basically, the regulatory problems are two-fold. There are a few specific regulations that, under certain circumstances, compliance is nearly, if not actually, impossible. There is non-uniform application of enforcement of regulations by the inspectorate based on opinions developed from personal experience of inspectors or lack of experience. The record is replete with examples of overzealous inspectors applying regulations that either do not exist or have been stretched far beyond the intent of the regulations.

Jan 1, 1979