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By F. Khorram

Image processing is a technique that simulates the human vision system. This technique enables applying every statistical or intelligent operation to recognize differences. In this way this new technique is used in quality control systems in most industries. Studying sedimentary rocks is very important from the economic point of view. Some units of sedimentary sequences involve different mineral deposits, hydrocarbon and water resources. Therefore it is important to identify and classify different sedimentary rocks. Descriptive classification of sedimentary rocks is usually based on visual and textural features and chemical composition of a sample. In this paper different samples of a limestone mine in central part of Iran are classified. The samples were collected from different parts of the mine and crushed down in size from 2.58 cm to 3.58 cm. The rock samples were labeled based on percentage of chemical and lithological compositions. Each sample was assigned to one of the distinguished groups. The images of the samples were taken in appropriate environment and processed. A total of 74 features were extracted from the identified rock samples in all images. In order to feature dimensional decrease, principal component analysis method was used. Then Bayesian statistical algorithm was used as a useful tool for classification. Classification Correctness Rate (CCR), calculated for the test data sets are %88, %68, %61 and %72 for the first to fourth class respectively. Therefore it can be inferred that the extracted features of images are appropriate indicators for different samples identification. These precise results besides the advantages of image processing technique, which are increasing speed of operation and decreasing cost, appears to be a desirable success.

Jan 1, 2012

Mining is taking place at increasing depths of cover on the Southern Coalfield beneath predominantly massive sandstone strata. Within the next twenty years, there will be longwall mining at depths greater than 600 m. As the Sydney Metropolitan area continues to expand and as coal mining approaches these urban areas subsidence will continue to become an increasinglY important aspect of coal mining research. Investigations, commenced in the mid 1960's, allow prediction of subsidence in the Southern Coalheld with reasonable confidence. The work is showing that the characteristics of thc subsidence troughs over the deeper mining at Appin differ from the characteristics of mine subsidence at less cover.The longwall mining at Appin Colliery has resulted in a maximum measured subsidenee of 730 mm. The maximum strains were small because of the large radii of curvature of the subsidence profiles. There was no damage to any of the buildings in the township of Appin.

Jan 1, 1982

By Lee Sieng Kai

This paper presents the result of the analysis of strain-dependent concrete modulus from full-scale static axial compression load tests conducted on more than 200 instrumented cast-in-place barrettes and bored piles over the past 12 years, covering commonly adopted grades of concrete for heavy foundation construction in Malaysia and Singapore. The concrete modulus values, Ec, analysed were directly back-calculated from the material of the instrumented test piles by means of placing a layer of vibrating wire strain gauges near the pile head region. The best fit curve for back-calculated concrete secant modulus versus measured axial strain follows non-linear behaviour for both categories of test pile samples analysed. The result of the analysis seems to suggest that using average constant modulus value would generally lead to a significant error in load distribution computation, particularly at high stresses region.

Jan 1, 2006

By Raja V. Ramani

The potential usefulnuss of reclaimed surface-mined land has received much attention in recent times. This attention is partially due to the establishment of federal environmental reclamation standards but concern for achieving better land uses has also been shown by interested members of the mining industry. In an effort to develop a procedure for evaluating postmining land use potentials, specific mines in various regions of the U. S. were studied to determine the extent of current mined-land planning and to discover characteristics that are regional in nature. As part of this investigation, a 430-acre surface mine in Clear-field County, Pennsylvania has been studied. Established site planning principles have been applied to the case study site including formation of a data base, development of alternate land use plans, and evaluation of the economic, environmental, and social impacts of the land use alternatives. Key factors affecting site realization have been identified along with positive suggestions for applying land use planning processes to mined-land planning.

Jan 1, 1983

By K. Freytag

The extraction of lignite in open-cast mines has a severe impact on the landscape. Proper landscaping after the shut-down of the mines has always been the statutory responsibility of the mine operator. The large area of the land used for open-cast lignite mining requires special regional planning procedures well in advance of the permitting procedure stipulated in the mining law. The lignite plan determines, among other things, the objectives of land reclamation. These objectives will then be outlined in more detail in the mine operation plans and implemented accordingly. Apart from the actual mining laws and regulations, a large number of environmental laws also determine the process of land reclamation. The success achieved in the field of land reclamation in all mining regions during the recent decades has shown that the lignite mining industry creates new landscapes that do not leave any scars in the countryside and merge very well with it.

Jan 1, 2005

By Peter Moser, G. Reihholf

Holcim, one of the world's leading suppliers of cement, aggregates and concrete, has set up a few years ago a working group “Quarry” in order to optimize the performance of its central European quarry operations in terms of work safety, environmental standards and economic performance. One of the activities of this working group "Quarry" addresses the subject of blast fragmentation in the quarries. A benchmark study of the blast work in all quarries has shown substantial differences for the various operations in terms of drill& blast costs. Especially big differences were found with respect to the drilling patterns as a function of the borehole diameters and with respect to the utilization of the borehole volume for charging the explosives.

Jan 1, 2006

By D. Witchard, G. C. Penny

An important conclusion of the study is that altering the properties of the granulation water is a practical way of improving the sintering performance of blends that contain porous ores, and more work is under way to investigate other additives. Previous studies of iron ore blends containing pisolite ore showed that losses in sintering productivity were a result of deteriorating green-bed permeability. Pisolite ores are extremely porous and absorb a proportion of the water added during granulation. Although increased water addition could be used to counteract losses in productivity, the current study examined methods of inhibiting water absorption by pisolite ore as a means of improving productivity. Additives were used to alter the properties of the granulating water. With no increase in mix moisture contents pilot-scale sintering studies showed that sugar-based additives gave productivities that are higher than those obtained for a comparable ore blend containing haematite rather than the pisolitic ore. Several techniques of adding the sugar to the sinter mix were examined and found to increase productivity to varying degrees. Theoretical considerations, in some cases supported by experimental results, indicate that sugar-based additives not only inhibited water absorption by porous ore particles but also improved the permeability of the sintering bed. The study also suggested that, contrary to some commonly held views, the highly reactive nature of Yandi ore from Western Australia is beneficial for sintering. Porous ores enabled the formation of a strong sinter at fast flame-front speeds-both good strength and a short sintering time are requirements for high-productivity operation

Jun 18, 1905

By Manqiu Xu, Songtao Yang, Zongfu Dai, Robert Pelton, Carla Abarca

"Fine mineral particles are difficult to process by flotation because of their low collision efficiencies with air bubbles. Decreasing air bubble size and increasing mineral particle size through flocculation are the most common approaches to improve flotation efficiencies. Herein we demonstrate that nanoparticle flotation collectors can be engineered to selectively induce fine mineral particle aggregation and promote flotation.Flotation tests of clean fine pentlandite (Pn) and Clarabelle Mill (CBM) rock tails and pyrrhotite (Po) tails that contained significant amount of fine pentlandite have confirmed that the nanoparticles can serve as both collectors and selective flocculants for fine pentlandite. In the case of clean fine Pn, the nanoparticle collectors virtually can float almost all Pn fines. Scoping tests on CBM tails have shown significant improvement in nickel recovery. Addition of nanoparticles as a flotation aid can recover 20% of the nickel contained in the rock tails and 40% of the Pn contained in the Po tails compared to current mill operations giving 0% nickel recovery from rock tails and no Pn selectivity from Po tails. Ongoing work includes attempts to identify optimal strategies for employing nanoparticles in fines flotation.IntroductionFine particle flotation is an industry-wide challenge in mineral processing. Fine mineral particles are difficult to process by flotation because fine particles have low mass and thus low momentum, which results in their low collision efficiency with air bubbles (Dai, Fornasiero, & Ralston, 1999). In addition, fine particles have not only high specific surface area but also more active surface area, which causes high reagent consumption. For base metal sulphide minerals, particle size between 10 µm and 70 µm is a typical range where high flotation recoveries can be achieved with conventional flotation chemistry and acceptable cell residence times. For pentlandite, the flotation recoveries decrease sharply when the particle size is below 10 µm and hydraulic entrainment is the dominant mechanism, giving recoveries proportional to water recovery and no Pn enrichment. (Jameson, Nguyen, & Ata, 2007)"

Jan 1, 2015

By John J. Sammarco

Mining has one of the highest annual average fatality rates among major US industries. Health and safety dangers have been inherent to mining since the early days of picks and shovels. Even though miners’ health and safety has improved over the years, mining is still one of the most dangerous occupations. Mining was traditionally a low tech industry. It is now driven by competitive pressures to go high-tech by using programmable electronics (PE) for machine control, atmospheric monitoring and material processing. The industry’s experience with the functional safety of PE is limited compared with other industries. Thus, PE is an emerging technology for mining that can potentially create or worsen hazards.

Jan 1, 1999

By William C. Cooley

This report includes a review of all relevant data on underground hydraulic coal mining technology collected during Phases I and II of the contract. Data collection and analysis procedures are discussed. Information is included on past and existing underground hydraulic coal nines in the USSR (27 mines), Poland (1 mina), Germany (1 mine), Japan (1 mine), Canada (1 mine), China (1 nine), as well as underground tests conducted in the United Kingdom (2 mines), and in the United States (5 mines). Data is also included on Czechoslovakia and New Zealand. In all operational hydraulic mines, coal is transported underground in flumes. In most cases, bituminous coal is broken by monitors with nozzle diameters larger than 16 mm (0.63 in.) and jet pressures of 50 to 125 atm (710 to 1780 psi). Technical design and performance data are included on all key types of equipment and components which have been developed for, used in, or which could be potentially be used in hydraulic coal mining systems. Data sheets are presented on 180 types of equipment, divided into 24 major categories. Where available, sketches, drawings, photographs, and price estimates are included. Data are included on pitching coal seams in the United States which potentially can be mined by hydraulic methods. Preliminary conclusions are presented, subject to revision as a result of economic feasibility studies to be completed during Phase III. An outline is presented of the final report, which will include economic studies and recommendations for research and development.

Jan 1, 1975

By Brian Maroney

In this paper an overview of the California Department of Transportation's (CALTRANS) bridge design criteria is presented. Special emphasis is focused upon seismic design and retrofit criteria. Topics include earthquake load definitions, foundation and structure type selection, structural earthquake analysis, and structure behavioral requirements.

Jan 1, 1993

By E. G. King

The literature contains little thermodynamic information regarding inter-oxidic compounds of the ferroalloy elements and, as a result, thermodynamic considerations of extractive and utilization processes involving these elements have been hampered. As part of a Bureau of Mines program to improve this situation, this paper reports the heats of formation of three calcium vanadates and two magnesium vanadates. There were no previous similar data for any of these compounds. The experimental method was hydrochloric acid solution calorimetry, using calorimetric reaction schemes involving the vanadates and their component oxides. The results were expressed as heats of formation from the component oxides and from the elements. Corresponding free energy of formation values were calculated. The data show that the calcium and magnesium vanadates are stable with respect to all possible decompositions in which vanadium remains pentavalent. This conclusion is similar to the one drawn by Koehler6 for three sodium vanadates.

Jan 1, 1962

By E. L. Singleton

This Bureau of Mines investigation was initiated to study and establish some of the chemical and physical characteristics of the condensed Mno-Si02 system. To prevent oxidation of the manganous ion, I atmosphere of purified helium was used in the furnaces. Solidus-liquidus curves and invariant points were established from melting-point determinations and were supplemented from data obtained by the static-quenching method. Experimental findings and data are for the intermediate compounds of tephroite and rhodonite with their respective eutectics represented at 25.5 and 37.2 weight-percent silica. Tephroite melts congruently at 1,347° C., and rhodonite melts incongruently at 1,286° 8.. A metastable transformation was determined to exist at the 1,347° C. isotherm, the congruent melting point of tephroite. A composite X-ray-diffraction pattern was formulated for synthetic rhodonite. This investigation contributes fundamental data leading toward a better understanding of the more complex slag systems.

Jan 1, 1962

By S. C. Chelgani

The Thor lake deposit is a world class resource of rare earth (REE) metals and minerals in Canada. Development work to optimize a REE mineral recovery process flow sheet is underway, however, given the ore mineralogy; the developed reagent scheme is relatively complex. As part of a research project, micro flotation tests were conducted on a feed sample in order to examine factors affecting stream partitioning. SEM-EDX was performed to evaluate variability in grain composition between streams (concentrate and tails) and TOF-SIMS surface analysis was used to determine statistically significant differences in surface species particularly related to potential activation (or depression) of the examined mineral phases. SEM-EDX analysis reveal that the concentrate has a significantly higher proportion of REE bearing grains (carbonates and phosphates) relative to the tail (almost none were identified). Spectral fingerprinting by TOF-SIMS has allowed for the identification of all reagent species investigated. Reagent signal intensity discrimination on test stream mineral surfaces was observed by the TOF-SIMS analysis using reagents at plant concentration levels. TOF-SIMS analysis confirmed that REE bearing grains reporting to the concentrate are doing so in response to collector attachment whereas grains reporting to the tail are doing so in response to a lack of collector and/or in combination with the presence of the depressant. The surface analysis of gangue phases reveal a similar reagent discrimination; the signal intensity of collector species was significantly higher on the concentrate samples relative to the tails while depressant species were significantly enriched on the surface of the gangue phases in the tail samples. A detailed evaluation of the surface species representing the various reagents used in flotation scheme revealed a distinct competitive relationship between two of the reagents. The surface analysis identified that when used in concurrently, there appears to be a negative feedback resulting in a significant reduction in loading for several of the collectors on grains reporting to the concentrate. An evaluation of the effect of reagents on REE mineral in pilot plant is currently under way. Key words: Rare earth minerals, Flotation, Surface chemistry, TOF-SIMS, SEM-EDX

Feb 27, 2013

By R C. Cox

The Brukunga pyrite mine was operated from 1955 to 1972 to supply feedstock for sulfuric acid production in the South Australian fertilizer industry. Iron sulfide ore, mined by Nairne Pyrite Ltd, was finely crushed and concentrated onsite with the concentrates being sent by road and rail to Port Adelaide for roasting. Waste rock was dumped at two locations on the western side of Dawesley Creek and the tailings pumped to a valley-fill storage facility on the eastern side. Production of 1.5 Mt concentrate resulted in 3.5 Mt tailings and 8 Mt waste rock. The site has been administered by the South Australian Government since August 1977 and a lime treatment plant has been operated on the site since September 1980. Environmental issues arising from these operations included: diversion of Dawesley Creek to accommodate the waste rock dumps; dumping of low-grade sulfidic ore in waste rock dumps at the angle of repose immediately adjacent to Dawesley Creek; exposed fresh sulfide mineralisation in the quarry floor; tailings storage facility dam wall constructed by upstream up-lift using tailings and waste rock; an acid water pond sited on the tailings; and pollution of natural drainage. As a result, the minesite rapidly became a source of acid drainage and potential contaminants (sulfate, Al, Fe, Mn, Cd, Zn, and Ni). Various Government bodies have been responsible for considerable effort and expenditure in reducing the flow of acid seepage and contaminants into Dawesley Creek. Presently an estimated 60 per cent of seepage from the waste rock dumps, tailings storage facility and quarry is collected and neutralised prior to discharge into the creek. Tailings have been covered with waste rock, biosolids, neutralisation sludge and soil and planted with grasses, shrubs and trees to reduce rainfall infiltration. Monitoring of water flows, water quality and riparian ecosystems is on-going. Consultants have been engaged to develop cost-effective remediation techniques and a five-member Brukunga Mine Site Remediation Board was appointed to oversee remediation of the site and liaise with the community. Construction has commenced on the diversion of Dawesley Creek, and plans are being developed for the relocation of waste rock back to the quarry benches and upgrading of the neutralisation plant. The paper examines operations, environmental monitoring, remediation, research and community involvement with respect to current best practice.

Jan 1, 2003

By A Unlutepe

The Bosphorus Rail Tunnel Project, located in Istanbul, Turkey, aims to provide a Euro-Asian rail link, via an immersed tube tunnel crossing the Bosphorus Strait, along which will run all commuter, freight and intercity passenger trains of Turkish State Railways (TCDD), as well as the future extension to the European rail network. The total length of upgrading and new railway construction will be approximately 76 km. The main structures include the immersed tube tunnel; mechanised shield tunnels; new Austrian tunnelling method (NATM) tunnels; cut-and-cover, at-grade and retained-cut/fill structures; and some service structures. This paper discusses Phase 1 implementation of the project, one of the major transportation infrastructure projects in the world today, whose varied structures present stimulating engineering and construction challenges.

Jan 1, 2008

By D. C. Fleck

Electrorefining yttrium from selected low-melting yttrium--base alloys is investigated, and various halide systems are studied as potential electrolytes for use in preparing low-oxygen yttrium by electrorefining unalloyed yttrium. Yttrium cathode products having significantly less metallic impurities than the anode materials were prepared from alloys containing nickel, iron, and manganese by electrorefining in LiCl-YC13 electrolytes at 900° to 1,000° C. Yttrium-copper and yttrium-magnesium alloys are not suitable as anode feed materials, An evaluation of chloride, fluoride, bromide, and mixed chloride-fluoride electrolytes showed that cathode products containing much less oxygen than the anode material can be obtained in the fluoride and mixed chloride-fluoride systems. Initial cathode current density has no apparent effect on the purity of the products obtained in both phases of the investigation.

Jan 1, 1973

By A. M. Clegg

In general, overall experience has shown that the approach to the appointment of a project manager is given much attention, but little specific attention is given first to the risk associated with the project conceptual design and its overall executability within either the new legislative framework or the sustainability of the outcome. The risk in project executability and sustainability within the ?new age? legislative framework of the Mining Charter, etc, is itself however, of far greater importance. The degree of importance being defined by the intended projects impact on the business going forward. This is particularly the case where the intention of the implementation is effectively to turn around or even enhance a loss-making strategic investment like a mine or process plant operation in an ?old-order rights? or Brownfield?s operation. This paper attempts to highlight the importance of a ?pre-project project? (PPP) to mitigate the risk in the ?new age?, with specific reference to operational due diligence (ODD) and project conceptual design.

Jan 1, 2005

By F. P. Haver

Primary lead is produced in the United States by the pyrometallurgical smelting of lead sulfide (galena, PbS) concentrates, which poses sulfur dioxide and lead air pollution control problems. The Federal Bureau of Mines has investigated an alternative hydrometallurgy procedure that does not generate gaseous sulfur oxides and diminishes the potential for the escape of lead into the atmosphere. The procedure involves leaching galena flotation concentrates with ferric chloride (FeC13) solution to obtain lead chloride (PbC12) and elemental sulfur as expressed by the following chemical reaction: PbS + 2FeC13 ? PbC12 + 2FeCl2 + S°. At 100° C, over 99 pct of the PbS in the concentrate is converted to PbCl2 in less than 15 min. The leach solution, composed of brine (NaCl) containing slightly more than the theoretical required amount of FeC13, dissolves the PbC12 as it is formed, leaving a residue of elemental sulfur plus gangue. High-purity PbC12 (>99.9 pct) crystallizes from the leach filtrate on cooling and is electrolyzed in a low-temperature, fused-salt cell to obtain corroding-grade metal (>99.94 pct Pb). Spent leach solution (FeC12) is regenerated for further use by reaction with the chlorine obtained in the electrolysis of lead chloride. Other values, such as Ag, Cu, Zn, and S°, are recovered by additional treatment of either the leach solution or leach residue.

Jan 1, 1976

By Peter de Bakker

The objective of this contract was to develop a simple, reliable, economical, remote-control roof bolting module for installation of mechanical and resin bolts. It was to be capable of placing longer than seam height bolts, up to 10 ft lengths, from a seam height of 36 to 72 in., while keeping the operator under supported roof. The resulting machine, called REM-Bolter, is a low profile unit that utilizes Foster-Miller Flexible Shaft Roof Drill, a Bendix Roof Bolt Inserter and a newly designed. Roof Bolt Lifter/Torquer. Every effort was made to strike a compromise between complete automation and complete manual control. In a controlled laboratory environment the REM-Bolter remotely installed 1000 bolts. Subsequently the machine was tested in an operating coal mine where 500 holes were drilled (and an equal number of bolts were installed) remotely, over a 4 month period. The results of all tests Live shown that the operator of a machine of this kind can quickly, and repeatedly, install rootbolts remotely from his operator compartment some 8 ft away from the drilling/bolting action. The report includes recommendations for improvements to the present REM-Bolter design that would translate the present test bed into a second generation test bed and a potential first generation production unit.

Jan 1, 1983