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By Stephen C. Tadolini

The U.S. Bureau of Mines has developed ultrasonic measurement instrumentation capable of measuring strains and elongations on tensioned and untensioned mine roof bolting systems. This report evaluates the pulsed-phase-lock-loop and pulse-echo systems. The pulse-echo systems measure time of flight of a signal through the bolt. The ultrasonic instrument converts the measurement into elongations or stress. The most recent Bureau instrument development converts travel-time measurements directly into elongation, load, stress, and torque by simple data manipulation from the keyboard. Bolt preparation and instrument calibration are described in detail.

Jan 1, 1990

By D. M. Walters

To achieve safe and healthy working conditions in shaft sinking operations, ventilation, and where necessary cooling, must be provided. These requirements are considered for sinking vertical, sub-vertical and decline shafts. Regulatory requirements, determining air volumes and amount of cooling required, the various ventilation methods used such as force, exhaust, twin columns, air reversal using four gate systems and the equipment required to achieve this, are discussed. Consideration is also given to the sinking of single and twin declines using diesel equipment, calculating the air volumes required to dilute pollutants and the various methods for achieving this. Also discussed is the importance of having early ventilation design input to the overall design of the mine. In many cases ventilation can be the prime determinant for the size and configuration of the shafts or declines that have to be sunk.

Jan 1, 2009

By Anthony Iannacchione

Designing coal pillars to provide resistance against overburden loads has long been an aim of rock mechanics engineers. The need for accurate pillar strength models has become more urgent as greater overburdens are encountered and pillar sizes grow larger. Current pillar design models differ widely in their predictions of the trend in pillar strength with increasing pillar width-to-height ratio. The goal of this paper is to evaluate current pillar strength theories, using a comprehensive data base of stress measurements from coal pillars. The stress measurements indicate that coal pillars maintain relatively high stresses near the ribline, and that the stress gradient within the yield zone can be approximated as a straight line. Several problems are identified for further research, including calibration procedures for different types of stress cells, strain softening behavior in the yield zone, and measurement of stresses in the cores of very wide pillars.

Jan 1, 1992

Previous published papers by Fraser (1), Hey (2), and Stillwell (3), have given respectively, details of:-1. The practice in the pilot plant operated at Zeehan for the treatment of ores from the Rosebery field.2. The design, based largely on the experience gained at Zeehan, of the concentrator built at Rosebery.3. The nature of the orebodies of the zinc-lead lode at Rosebery.Changes and developments, at the Rosebery concentrator, since operations commenced, are now described with particular reference to recent practice.Three concentrates are produced, viz.: a copper, a lead, and a zinc concentrate. The current flow-sheet is shown in Fig. 1. Typical concentrate assays are...THE OREThe ore treated is derived from the Rosebery and Hercules Mines and is, milled in the ratio of, approximately, two parts of the former to one of the latter. The ores from the two mines may be considered as being similar in general character, although the Rosebery ore contains more pyrite. It is from this mine that any increased tonnage is expected. The ore is a mass of fine-grained, intimately associated sulphides, with practically no coarse...

Jan 1, 1949

By J. F. Reddick

The South African coal mining industry is currently disposing of about 10 million tons of ultra-fine coal (<150 µm) per year. Once discarded, these sulphur-containing ultra-fines contribute to several environmental problems. As part of a project initiated by the Water Research Commission to investigate the use of Cleaner Production (CP) in the mining industry, a study was carried out to determine whether a CP approach could be used to identify opportunities to reduce this coal waste, and to determine which of these opportunities would be most feasible. In order to do this, a CP assessment was conducted at three case study collieries in the South African Witbank coalfield. Mass-balancing and sampling, followed by laboratory characterisation tests and site surveys, were used to determine the quantity, quality and sources of the ultra-fine coal at the three collieries. Literature reviews, brainstorming sessions and interviews then followed to generate the CP options. An environ-mental, economic and technical feasibility assessment was then prepared for each option, to determine the most viable interventions for implementation. A number of opportunities were identified through the assessment. By preventing coarser coal from being discarded with the ultra-fine coal, the quantity of coal disposed of could be decreased at all three collieries, and by up to 24% in one case. Increasing the crusher top size would reduce the amount of coal that is milled to less than 150 µm, so that less is wasted. The ultra-fines that have already been disposed of on slurry dams can be completely reclaimed and converted into a valuable product, which can be sold as power station feedstock. The newly processed ultra-fines could be beneficiated using flotation and exported together with the coarser coal. The results of the assessments thus suggested that workable CP opportunities to reduce ultra-fine coal wastage exist at the sites investigated, and that their feasibility is colliery-specific. The associated financial benefits of the proposed options suggested that CP is a realistic approach to addressing environmental problems. Keywords: Cleaner Production; coal mining; coal-washing; ultra-fines

Jan 1, 2007

The following is a summary of some of the companies that were exhibiting their products and services at MINExpo INTERNATIONAL 2000. Atlas Copco develops, manufactures and markets rock drilling tools, tunneling and mining equipment, and surface and geotechnical drilling equipment. The company provides a line of drilling products, including production drilling rigs, rock reinforcement bolts and rock drills. Atlas Copco’s Boomer is a series of high-capacity drill rigs that provides economy, production capacity and reliability

Jan 1, 2000

By A. Wahab Khair, John G. Oldsen, John C. Stankus, Song Guo

During the last several years, implementation of trusses, in lieu of wood cribs, has been successful for supplemental tailgate support in the Pittsburgh seam. This paper reviews, the truss support system provided by the new high strength 0.6" tensioned cable truss, which is now also being used in cribless tailgates. Cable loading and roof deformation were monitored to evaluate roof and floor performance. The test results indicate that the cable truss system successfully controlled the roof and floor during the first and second panel extraction. This paper will describe the advantages of cable trusses and their load transfer mechanism as well as mine evaluation.

Feb 24, 1997

By L. H. Banning

This investigation was undertaken to obtain basic information necessary for the design and operation of a plant for recovering metallic values from nickeliferous laterite and serpentine of the Philippine Islands. It was divided into three parts: (1) Mineralogical studies and preliminary mineral dressing tests; (2) electric smelting of the ores, upgrading of ferronickel by blowing with oxygen, smelting laterite slag to produce crude iron, and the production of mild steel; and (3) nickel and cobalt recovery from upgraded ferronickel. Results of the investigation indicate that it should be feasible to recover nickel, iron, and possibly cobalt products from the laterite and ferro-nickel from the serpentine. Mineralogical studies were made on representative fractions of the laterite and serpentine tonnage samples and on five selected samples; mineral dressing tests were made only on laterite. The nickel occurs principally associated with hydrous iron oxides and chemically combined with serpentine; garnierite was the only discrete nickel mineral identified, and it was found in a highly decomposed serpentine. The bulk of the cobalt was found in wadlike manganese oxide material. Approximately twice as much chromite was found in the laterite as in the serpentine, By mineral dressing techniques, laterite was separated into two fractions: one fraction contained over 90 percent of the nickel and cobalt, and 83 percent of the iron; the other fraction contained 74 percent of the chromium. A cobalt concentrate (1.1 percent Co) was produced by a scrubbing and sizing procedure.

Jan 1, 1962

By W. R. Green, B. W. Barde

"Geological exploration involves the collection and analysis of a wide variety of information. A basic problem in interpretation is to determine the interrelationship s of the different data. A number of statistical methods can be applied to this problem, provided that subsets of data can be selected.We have recently developed a set of interactive computer programs which provide the cap ability to quickly examine a large set of data, and may be used by people with little previous computer experience. There are two main stages in using this system. First is selection of subsets of data , by applying various tests on the values of given items. This includes matching specific entries in descriptive fields, and minimum - maximum tests on numeric fields. The second stage is basic statistical analysis and data display , including histograms, 2-D scalier plots, probability (cumulative frequency) plots, and correlation matrices. All output can be viewed on a computer terminal, and important parameters changed to produce the most effective display for use in interpretation.This system has been applied to a number of different exploration problems. An example was the determination of the nature and extent of mineralization of a gold prospect in the Queen Charlotte Islands, from drill-hole data. With the aid of the computer programs , a mineralized zone was defined, and locations for further exploration identified."

Jan 1, 1984

By R. G. Kidel, S. C. Doming

The project has shown that it is feasible for a junior company to reopen a narrow vein-style gold mine and successfully take it into production. An intimate understanding of the mineralisation and a flexible approach to mining are crucial, as are stringent cost control and efforts to keep overheads low. The project has confirmed the geological complexity of the Main Lodes, which consist of highly sheared quartz-sulphide infill in strongly sericitised granodiorite. The existence of discrete high-grade zones within the Hangingwall Lodes has also been confirmed. Broad low-grade zones continue to be recognised and require the local application of bulk longhole mining methods. The initial mine plan called for predominantly longhole stoping, but adverse ground conditions have meant that a switch to air-leg mining has produced higher run-of-mine grades. The excess capacity at the processing plant can best be used by batch processing, with its reduced maintenance requirements

Jun 21, 1905

By P. M. Daling

This report, sponsored by the U.S. Bureau of mines, presents the results of an examination of available safety assessment methods and their applicability to the mining industry. Standard safety analysis procedures were evaluated for relevance to the mining industry and mire operators&apos; needs. The major safety concerns and needs of mine operators were identified through telephone contacts and a visit to a mine site. Safety assessment methods recommended for use by the mining Industry were also investigated for potential adaptability to a user-interactive computer system. Several methods were determined to be Immediately transferrable to the mining industry; these techniques are described in a user&apos;s handbook produced as part of this project. The handbook gives detailed instructions on appropriate application and utilization of these methods. Other techniques will require further development before they can be effectively transferred to the mining Industry. These methods, their advantages, disadvantages and resource requirements are described in the final project report. Recommended system safety analysis techniques facilitate an evaluation of total mine system safety and a determination of safety-related interactions among systems within a mine. The application of these methods to the mining industry could result In reductions in both the frequency and the consequences of mine accidents.

Jan 1, 1983

?Longhole blast hole drilling? techniques are not new to the mining industry. Appropriate mechanization and improvement of the techniques and application has evolved from the industry requirements. Today safety and economics play a larger role in the excavation of ore passes, ventilation passes, and relatively small inclined excavations in the conventional gold and platinum industry. The application of dropraise drilling from the top or from the bottom is discussed investigating the current techniques available, DTH application, advantages and disadvantages, limiting factors, typical layouts and proposals, the drop raising technique and future applications. Similarly, the application of longhole blast hole drilling in tabular and massive orebodies is discussed with emphasis on the DTH application, advantages and disadvantages, limiting factors, typical layouts, the long hole stoping techniques and future applications.

Jan 1, 2003

By William E. Young

There are many large rhodonite-bearing veins containing manganese in the Eureka-Animas Forks area of the San Juan Mountains in Colorado. The Sunnyside vein is the largest known vein in the area. As observed on the surface, the vein is mineralized over 8,000 feet and attains a maximum width of 200 feet. The average width of the vein and its branches and ramifications is 58 feet in the area that was mapped in detail. The weighted-average analysis of surface and underground samples from the northeastern extension of the Sunnyside vein is 8 percent manganese. Most other known veins in the area have a similar manganese content. The Hidden Treasure vein lies southeast of the Sunnyside-No Name-Mastadon vein. The weighted average of the analyses of surface and underground samples from this vein is 13 percent manganese. Exposures of the Scotia-Silver Chord vein are visible over a strike length of 4,000 feet on Treasure Mountain. Diamond-drill holes show that the vein contains 10 percent or more manganese to a depth of 400 feet. The vein has an average width of 28 feet. The Independence vein is exposed on the surface for a distance of 600 feet and has an average width of 6 feet. Three cut samples taken across the vein had an average content of 20.7 percent manganese. Sampling of the outcrops of eight veins in the Placer Gulch area also indicates manganese. Numerous other veins cropping out in the surrounding area are similar to the outcrop of the Sunnyside vein system mineralogically and are worth investigating.

Jan 1, 1966

THE flotation plant at Mount Lyell was erected, primarily, for the treatment of ore from the Lyell Comstock mine. These workings are situated over a mile in a direct line north of the North Mount Lyell mine, and are connected with the Reduction Work at Queenstown by a 2-ft. gauge steel tramway via the Queen River valley a distance of 7 miles. The property was purchased from the Mount Lyell Comstock Copper Co. After the disastrous fire in the North Mount Lyell mine in October, 1912, steps were immediately taken to make Lyell Comstock ore available for treatment, in order to relieve distress caused by any prolonged stoppage of work, and subsequently 13,032 tons of ore, averaging 3.38 %copper, 0.28 oz. silver, and 0.034 oz. gold; were smelted. When operations were resumed at the North Mount Lyell mine, it was evident that there was no economic advantage in smelting Lyell Comstock ore as compared with the higher value North Mount Lyell ore, which was also a better flux for the Mount Lyell pyrites, and that the future of the Lyell Comstock ore depended upon cheap mining and successful concentration of the ore. Therefore, extensive trenching and diamond-drilling was carried out, and a sufficiently large quantity of ore proved available for cheap extraction by open-cut methods. At the same time bulk tests by flotation were carried out at the Minerals Separation testing plant in Melbourne on different classes of ore from the Mount Lyell Comstock mine proper, followed by laboratory tests at Queenstown on all classes of ore available. All these tests demonstrated that the ore was amenable to the process, provided that it was ground finely enough. Plant erection was delayed by the general dislocation of business at the outbreak of war, but finally it became...

Jan 1, 1920

By Sahoo K. C

Traditionally, the blast furnace (BF) has maintained a dominant position as the primary source of iron units. Notwithstanding the efficient nature of the process in respect of its material and energy consumption, the conventional blast furnace route is faced with limitations such as stringent quality metallurgical coke, high capital investment, etc. While BF will continue to retain its predominant position as the foremost ironmaking technology, the alternate processes may also have a role to play. Direct Reduced Iron (DRI) or sponge iron industry is all set to take a firm root in India as one important solution to the problems of shortage of metallurgical coal and ferrous scrap and high investment costs faced by the country&apos;s steel industry. The commercial proven DR processes coupled with electric arc furnace (EAF) steelmaking have also offered a viable alternative to the blast furnace - basic oxygen furnace (BF - BOF) route for the installation of integrated plants under specific local conditions. The performance and efficiency of DRI processes mainly depend upon the chemical and physical behaviour of the raw materials especially the iron bearing materials. Iron oxide pellet and sized lump ore constitute the oxide feed stock, while pellets form an ideal feed stock for direct reduction, use of lump ore is economically advantageous because of its lower price. National Mineral Development Corporation Limited (NMDC), being one of the major producer of iron ore in the country since last four decades, has established technology and developed process flowsheets for production of suitable calibrated lump ore for DRI production, besides supplying the natural lump ore for conventional blast furnace requirements. In addition to the above, extensive pilot plant tests have been carried out at the R&D Centre of NMDC for preparation of iron ore concentrates suitable both for direct reduction and blast furnace grade pellet feed using the iron ore fines from its own mines and as well as from the other iron ore mines in the country. For utilisation of the huge quantity of slimes generated in its ore processing plants, NMDC has planned to set up the first commercial plant adopting the smelt reduction process (ROMELT Process) for production of pig iron from Bailadila slimes. The paper mainly deals with various beneficiation techniques adopted for production of DRBF grade pellet feed from iron ore fines. Also presented in the paper, the extensive work carried out at R&D Centre on preparation and evaluation of calibrated lump ore (Natural Pellets), based on which, suitable modifications are incorporated in the ore processing plants of NMDC for production and supply of the same to sponge iron industries.

Jan 1, 1999

By A. G. Starliper

The Bureau of Mines made laboratory investigations to determine the feasibility of utilizing fine tungsten wires to reinforce a number of nonferrous metals and alloys and a superalloy, S-8l6. The composites of tungsten filament and metals were chosen to attain elevated temperature strength and corrosion resistance. Oriented clean or precoated tungsten wires were incorporated with the other metals by extrusion, swaging, and infiltration casting. Although widely varying characteristics were found in the composites, none were considered satisfactory for high-temperature use, chiefly because of reactions between the matrix metal-tungsten surface. Diffusion, solution, and chemical reactions between matrix and tungsten wires were sufficiently slow for some combinations, such as 15 v/o 8-816, to exhibit increased high-temperature strength for a limited time. A few metals failed to wet or bond to the tungsten surfaces, while a few responded after precoating with a third metal.

Jan 1, 1968

By C M. Wawryk, S L. Garwin, J D. Foden

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Batu Hijau porphyry Cu-Au deposit in south-western Sumbawa, Indonesia is an ideal natural laboratory to study the fractionation of iron isotopes in magmatic rocks that range in composition from basaltic andesite to tonalite. Intrusive rocks are associated with a porphyry system that contains well-preserved early hypogene copper mineralisation. We analysed pre-, syn- and post-mineralisation igneous intrusive rocks. We also separated magnetite, chalcopyrite and bornite from hypogene porphyry-style quartz veins, and measured the Fe-isotope ratios of samples by solution multi-collector ICP-MS. Iron isotopic composition of samples from the magmatic suite show an increasing d57Fe with increasing SiO2, supporting geochemical and textural evidence that the Batu Hijau Tonalites underwent closed system fractionation. Equilibrium and co-existing mineral textures allow the calculation of the following preliminary empirical mineral-mineral fractionation factors at 500°C for certain mineral pairs.Iron isotopes have the potential to provide geothermometric data to complement fluid inclusion data, especially where heating stages have operational limitations and where fluid boiling results in a wide variety of inclusion types that may make analysis difficult.CITATION:Wawryk, C M, Foden, J D and Garwin, S L, 2015. Iron isotope fractionation in magmatic-hydrothermal minerals – a porphyry copper case study from the Batu Hijau deposit, Sumbawa, Indonesia, in Proceedings PACRIM 2015 Congress, pp 389–396 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By M. du Toit

Cromanite?is a new high-strength austenitic stainless steel developed by Columbus Stainless. It contains approximately 19 percent chromium, 10 per cent manganese and 0,5 per cent nitrogen. Cromanite can be welded successfully, but due to the high nitrogen content of the base metal, certain precautions have to be taken to ensure sound welds with the desired combination of properties. Although no matching filler metals are currently available, Cromanite can be welded using a range of commercially available stainless steel welding consumables. Welds produced using E309L, E307, E307Si and E312 filler wires are resistant to hot cracking and the formation of nitrogen-induced porosity, but the hardness, strength, ductility and toughness of the welds are generally inferior to those of the base metal. In applications where full use is made of Cromanite?s high strength, welds with matching strength levels would be required. In wear applications, where Cromanite is used primarily for its work-hardening properties and corrosion resistance, lower strength welds would probably be acceptable. Welds produced using E307 filler metal demonstrate the best combination of properties for use in wear applications. The welds display high rates of work-hardening that would result in increases in hardness and strength when subjected to abrasive or high impact environments.

Jan 1, 1999

By Met M. E

In choosing the subject for my address to you this evening I was actuated by the knowledge that in the past Australian metallurgical problems have been solved by the introduction of extremely interesting processes. Frequently such processes originated in this country, or at least were first adopted here on a large scale.Chronologically there comes to mind the application of chlorination to the Mount Morgan ores from 1888 onwards.Then the application of pyritic smelting to the Mount Lyell ore body in 1896, followed closely by the successful flotation of zinc blendÇ! at Broken Hill, about 1900, and the treatment of the refractory Kalgoorlie gold ores by roasting and cyaniding. With the development of the differential flotation process at Broken Hill came the production of a slime lead concentrate carrying zinc which necessitated the use of a high zinc slag in the lead smelting process. Although previously considered impossible, the necessarytechnique was successfully evolved at Port Pirie resulting in the accumulation of large tonnages of zinc-bearing slag as potential sources of that metal. The past twenty years have witnessed:-(a) The establishment of a flourishing iron and steel industry, with its attendant coking and by-product plant at two centres in New South Wales, namely, Newcastle and Port Kembla.(b) The establishment of an electrolytic zinc process at Risdon in Tasmania.*Presidential Address, Melbourne, 20th August, 1936.

Jan 1, 1936

By M. J. Scoble, L. M. Daneshmend, C. Hendricks

Paper presented at a meeting on: Artificial intelligence in the minerals sector, held in Nottingham, UK, 20 April 1993. An attempt is made to relate emerging technologies to education and training requirements by examining the nature of the Canadian mining industry's human resources. Particular attention is given to the trends evident in mine automation and their likely impact on instructional needs. The characteristics of "computer-aided instruction" systems are reviewed and related to the implementation and support of mine-wide monitoring and communication networks, which are seen as fundamental to the eventual automation of underground hardrock mines

Apr 1, 1994