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Mr. Chairman, distinguished guests, ladies and gentlemen. Thank you for asking me to your conference, with its most fundamental and appropriate topic of 'Investment in Mining'. I must confess at the outset that I am one of those Australians who has rarely visited your fair land of New Zealand. This is in fact only my third visit, with all three related to Institute Conferences, and all much too brief. In so many ways your country provides a counterpoise to ours, despite the obvious disparities in size and population. And I am not only referring to the Bledisloe Cup! We would certainly each be much more lonely without the other, in this strange long-lost corner of the globe û if globes can have corners. Such an important factor in common in our shared heritages has been the mineral industry we have won from our alluvials and our rocks û especially for gold. So much of the major mineral developments which have supplied the world's appetite for metals and fuels in the past two hundred years has come from the countries settled in that period by people from Europe, especially those from the British Isles. So much of the technology for mineral and metal extraction has come from the skills of those people in New Zealand and Australia. And so much of the further development of metal processing and manufacturing of productive equipment has come from those people and from their cousins throughout the world. It is, I believe, a fair question to ask why we have failed to build on those early and considerable successes, and why we have in so many ways apparently been so content to allow others to add value to our raw materials, and to take our technological developments on to levels far beyond those that our domestic markets could sustain.

Jan 1, 1988

By R. E. Mclvor

This is an update of an original dissertation on this topic by Lavallee, McIvor and Stolovitch (1992). A step-by-step, technical procedure used to measure and improve the performance of plant grinding circuits was adapted into a training program. ?Systematic Design of Instruction? was applied to: ? Determine if training was a suitable way to deliver this new technology; ? Define the technical content of the program; ? Select program specifications based on learner and context characteristics; ? Design, create and test prototypes of the training modules; and, ? Establish a process for plant implementation. The training program covers numerous skills that are extremely valuable for plant personnel, not only in the grinding area, but also for many other parts of the plant. This paper describes how new skills are brought into the workplace through designed instruction can be an effective alternative to hiring during severe skilled labor shortages.

Jan 1, 2008

By Sheridan A. Glen

As the Federal government along with individual states continue to grapple with the job of refining a comprehensive energy policy, coal continually stands out as an energy source which heralds a combination of old and new capabilities like an energy planners prophecy, but which is plagued with serious environmental constraints. To determine what level of coal utilization is ultimately possible for states East of the Mississippi, whose high sulfur content coal presents the most paramount of challenges, one must consider product availability, via existing transportation modes, the developing industrial markets and the ability of coal to meet the challenge of becoming an environmentally acceptable fuel. Gasification is emerging as a form of utilization, which during the next twenty years stands a good chance of being able to meet the challenge of making coal an environmentally clean, easily transport-able and usable fuel. It can be argued that, of all the potential ways of utilizing high sulfur coal, coal gasification is perhaps the most expensive, the most financially risky and carries environmental liabilities of its own. Synthetic gas and oil markets will undeniably be a function of price and demand, which, for the purposes of this paper, I'm assuming will begin to merge in the late 1980's and into the 1990's. This is also presuming that public utility commissions will allow favorable price structure ruling so that gasified coal products can be rolled into their respective rate base, much the same as synthetic natural gas from petroleum by-products are currently being priced. The comparative economic markets of coal to gas pro-duct have plenty of time to mature. There is an approximate twelve-year lead time needed to bring coal gasification plants on line which will be able to compete in the market place for natural gas and oil customers.

Jan 1, 1977

By B. Arjang

ABSTRACT: Ground stresses are one of the significant factors in the context of rockbursts and underground instability at some hard rock mines in Canada. Overcoring strain relief measurements using triaxiaI strain eel is were performed at depths between 60 to 1890 m at several mine sites to provide stress data for stability analysis and optimum mine design. Pre-mining ground stress determinations from 64 stress tensor analyses resulted in the following average stress gradients: Maximum horizontal stress. -Hmax - 8.18 - 0.0122 MPa/m depth Minimum horizontal stress. _-,,min - 3.64 - 0.0276 MPa/m depth Average horizontal stress. -11, 5.91 - 0.03-19 MPs m depth Vertical stress. '-, - 0.0266 - 0.008 MPa/m depth The maximum and minimum horizontal compressive stresses. with an average ratio of 1.75 ,0..45. prevail in east--west and northerly directions. respectively. Horizontal compressive stresses in excess of vertical overburden load were determined. indicating large variations in ratios to a depth of about 1000 m with decreasing trend towards depth. From present data. a particular regional zoning for the magnitude and direction of horizontal stress fields cannot be outlined. A common feature at mines with near vertical orebodies is that the maximum horizontal compressive stress acts perpendicular to strike while the minimum horizontal compressive stress is aligned on-strike. The vertical stress components approach the gravitational overburden load.

Jan 1, 1989

By H. Hearnden

Whereas in the past, ladles were simply a means of transferring molten products from furnace tapholes to points of discharge be they casting pans or waste dumps, the ladle is now becoming a more integral and versatile piece of equipment in the pyrometallurgical plant. The drive behind this development is the need for continuous improvement in performance where better, faster and cheaper means remaining competitive in the global market. This paper will explore the technologies available for the rendering of a costly and otherwise cumbersome piece of pyrometallurgical equipment more efficient and versatile in adding value to the final product. Essentially it all revolves around heat and more importantly the loss of it when tapping. The common practice is to move the molten product to its point of discharge quickly with the minimum of interruption to prevent skulling and hence the cost associated with clearing it. The advances in Oxy-fuel burners, AC or DC ladle furnaces, converters, gas purging and high velocity, bath injection systems has increased the versatility of processes and enhanced the potential for adding value to intermediate products through down stream practices such as granulation and atomisation.

Jan 1, 2004

By M. Hopf, E. Rossouw

Keywords: Pyrometallurgy, furnace, copper coolers, freeze lining, monitoring, Saveway The use of water-cooled copper components as sidewall elements of submerged arc furnaces and other pyrometallurgical applications has become increasingly common. The high cooling efficiency of copper has made it possible to increase the service life of furnace refractories when compared to conventional refractory linings. However even the self-healing effect of ?freezing? worn areas of the lining does not necessarily protect the copper coolers against wear or corrosion completely. In order to avoid furnace explosions, various methods have been used to monitor the wear of coolers. Unfortunately, these have not been able to consistently identify localized wear. Thos Begbie (South African) and SAVEWAY (German) jointly developed technology to embed a line sensor into the copper cooler during the casting process. This system allows an exhaustive monitoring of the copper cooler. A SAVELINE sensor is placed inside the copper-cooling panel between the water-cooling passage and the hot face of the panel. The sensor follows the meandering shape of the cooling water channels. In the first instance, the sensor provides analogue information as the thickness of the copper reduces. Secondly, this wear signal will be confirmed by a signal of interruption if the sensor is washed away. Because of the structure of the sensor, a self-diagnosis is possible and indications can be confirmed (double proofed). Subsequent to the manufacture of some test pieces, coolers for a large submerged arc furnace were manufactured. The sensorized coolers have been installed at the intermittent surface (slag line) where the largest amount of corrosion has been encountered. The system has been operating since December 2005 in what is considered one of the largest submerged arc furnaces in South Africa.

Jan 1, 2006

By David Mast, Amanda Foote, Mina Shinouda

The Michigan DOT’s I‑75 Modernization Project, Segment 3, is a 30-year, $1.2 Billion design-build-finance-maintain project in Southeast Michigan. The scope includes building a nearly 4-mile long, 14.5-foot ID stormwater storage tunnel. The tunnel and pump station are being built concurrent with new roads and bridges, requiring multiple levels of design and construction coordination. Underground risks include the poten‑ tial for encountering granular soils, groundwater, and explosive gases. The new tunnel will be mined by a new open-face TBM and lined with a one-pass steel-fiber-reinforced precast concrete segmental lining. Shaft construction began in early 2020 and tunnel mining in July 2020.

Jun 13, 2021

By K. E. Soroka

More than 500 fires are now burning in abandoned coal waste banks and coal deposits in the United States. Once established, such fires can burn for decades, and extinguishing them by conventional methods such as surface sealing to exclude air, excavation to remove fuel, or flushing to cool the fire zone is usually difficult and always expensive. Burnout Control, a technique developed by the Bureau of Mines for the control of abandoned coal fires, involves the accelerated combustion of coal in place with total management of the heat and fumes produced. A burning waste bank or mine is placed under negative pressure relative to the atmosphere, and heat and combustion products are drawn from the combustion zone through an exhaust ventilation system. Heat produced appears as sensible heat in the exhaust, at temperatures as high as 1,0000 C (1,832° F), and could be recovered for the production of steam, hot water, process heat, or electricity. The Bureau's first held field demonstration of Burnout Control was at Calamity Hollow in Allegheny County, PA (near Pittsburgh). Calamity Hollow was the site of an underground mine in the 1900's and was surface mined in the 1940's. In the winter of 1961-62, a fire of undetermined origin was discovered in the exposed coal. In 1963, the Bureau constructed a trench barrier around the fire and a surface seal over the affected area. The fire was isolated but not completely extinguished. In 1979, when the Bureau began work on the Calamity Hollow Mine Fire Project to demonstrate controlled burnout, the fire was still smoldering on the hot side of the trench barrier. The project, which was begun in December 1979 and ended in July 1982, consisted of the design, construction, operation, and subsequent dismantling of a Burnout Control ventilation system. This report is the fifth in a five-part series that describes the Calamity Hollow Mine Fire Project. The first report, part 1, describes the design and construction of the field installation. Part 2 will present the results of a continuous 4-month burnout operation. (Because part 2 involves the analysis of a substantial body of data, it will not be published until after publication of parts 1, 3, 4, and 5.) Part 3 describes the instrumentation used to control and monitor the progress of the burnout operation. Parts 4 and 5 deal with the closeout phase of the field demonstration. Part 4 describes the procedure used to quench the fire, and this part (part 5) describes the final excavation and backfilling of the heated zones. The reports in this series document the Calamity Hollow controlled burnout demonstration which showed that (1) controlled in situ combustion is a feasible method for controlling underground fires in abandoned mines, (2) the resultant thermal exhaust output is sufficient for energy utilization, and (3) water injection-fume exhaustion is a potentially effective method for cooling large underground fire zones. Further investigations of both Burnout Control and the water-injection-fume exhaustion quenching procedure are planned.

Jan 1, 1986

By C. B. DUTTON, W. F. RITTMAN, E. W. Dean, M. S. HOWARD

NOMENCLATURE USED IN THIS REPORT. In this report the ending ene has been used throughout, except in the bibliography and in quotations from the writings of previous investigators, for all aromatic hydrocarbons, as, for instance, benzene, toluene, xylene. The ending ol, though largely used in technical description, is not correctly applicable to these hydrocarbons, and should be used to designate the impure mixtures of commerce, as distinguished from pure chemical compounds. PRESENT STATUS OF PETROLEUM-REFINING INDUSTRY. Although petroleum is widely distributed, being found in many parts of the world, and although information as to its occurrence and general characteristics seems to have existed from vcry early times, our knowledge of the chemical nature of this substance has been acquired largely within the past 40 years. Within this period a voluminous literature has accumulated, which records work as painstaking as has ever been undertaken in the whole field of chemistry, such as that of C. M. Warren, F. H. Storer, S. P. Sadtler, S. F. Peckham, and C. F. Mabery. Despite this fact, the commercial method of treating crude petroleum for the purpose of procuring marketable products is, in the main, essentially empirical. Much knowledge has been acquired as to methods of separating from crude petroleum such products as are desirable commercially, but little has been done to attain the maximum recovery of such products.

Jan 1, 1916

THE following short paper on the Blair Athol coal-field will no doubt have a twofold interest to members from the fact that its main seam, known as the "Big Seam" of a maximum thickness of 91 ft without a band, is unique, being probably the thickestseam of high-grade clean coal yet known, and also because of the interesting problem it presents the colliery engineer-viz., which system of mining is the best to secure the highest economical extraction.Location - Blair Athol is a mining township in Central Queensland, situated at an altitude of about 1100 ft. above sea-level at the end of a branch railway line 74, miles from Emerald, on the Main Central Western line, and 240 miles by rail from Rockhampton.Geology - The coal-measures appear to lie in a shallow basin of about four or five square miles in area, surrounded on all sides by slates and schists, which are overlaid oh three sides by alluvial deposits of up to 150 ft. in thickness, and on the fourth by a thick basalt bed, as yet unproved, some miles beyond which the auriferous slates outcrop. These alluvial deposits have been largely worked in years past and gave high gold returns, the chief diggings being Clermont and Macdonald's Flats in the south, the Springs and Black Ridge in the north-east, and Yankee Creek and others on the west. The surface of the coal-fields may be described as unbroken, but undulating, with gentle southerly dip, the watercourses opening out into wide flats. The absence of creeks or deep gullies accounts for no outcrops being visible on the surface, and the coal-measures...

Jan 1, 1918

By Lumley G, Rowlands D

The overburden slusher (OS) is proposed as a stripping tool that is expected to find application in overburden stripping operations including open cut coal and oil shale mines. OS is expected to combat the effects of increasing depth on the productivity of conventional dragline stripping.Although previously developed stripping techniques have included the use of drag scrapers the OS is sufficiently different as to constitute a new stripping method.A study undertaken at the University of Queensland during 1985 is believed to be the first major study on the use of the OS and preliminary economic results are very encouraging. It appears that the OS has the capacity to remove overburden at a cheaper unit cost than the equivalent powered dragline stripping machine at any comparable depth of overburden. The OS is not adversely affected by increasing stripping depth to the same extent as a dragline. In addition, the action of the OS machine allows for the lowering of spoil face angles, thereby reducing spoil slope stability problems encountered in deep open cut strip mines.

Jan 1, 1986

By Kathryn L. Neale, Derek L. Mulligan, Robin E. Goad, Norman A. Duke, A. Hamid Mumin, W. John Camier

"Abstract - The NICO and Sue-Dianne deposits are being explored and delineated by Fortune Minerals Limited in the Mazenod Lake District of the Northwest Territories, using an Olympic Dam model. The deposits were discovered in the south part of the Great Bear magmatic zone (GBMZ) within the Proterozoic, Bear Structural Province of the Canadian Shield. They are the only known significant Canadian examples of Proterozoic iron oxide-hosted polymetallic deposits. Worldwide, this class includes such deposits as Olympic Dam and Ernest Henry in Australia, Kiruna-Aitik in Sweden, and Salobo in Brazil. Their considerable size, up to 2 billion tonnes, and polymetallic ore assemblages make them highly attractive targets for exploration. Common characteristics of this class include their Early to Middle Proterozoic cratonic settings with extensional rifting evolving from collisional tectonics. Deposits typically occur along major structural lineaments within the aureoles of a distinctive suite of anorogenic potassium-rich "A-type" granite intrusions. Although hosted by diverse lithologies, deposits of this class are characterized by a number of other diagnostic regional- and deposit-scale features, which may be recognized in reconnaissance- and propertyscale geological and geophysical surveys.The southern GBMZ in Canada has several characteristics (age, tectonic setting, geology and geophysical attributes) similar to those of the Olympic Dam deposit and its other significant global analogues. Airborne and ground geophysical surveys carried out in the GBMZ identified coincident potassium, uranium, magnetic, resistivity, chargeability, and gravity anomalies centered over the NICO deposit. The nearby Sue-Dianne deposit is characterized by coincident uranium, potassium, magnetic, resistivity and chargeability anomalies. Both deposits occur within a regional, northweststriking, arcuate trend of volcanic and sedimentary rocks characterized by significant positive Bouguer-gravity and magnetic responses and are believed to represent a major basement discontinuity. The NICO anomalies are at the intersection of this regional trend with a major transverse fault through Lou Lake. Regional and local geophysical data indicate the presence of significant concentrations of iron oxide within a broad area of intense potassium metasomatism. Geological mapping identified cobalt, gold, bismuth, and copper mineralization in biotite-magnetite-amphibole-sulfiderich ironstone and schist. This mineralization is localized within altered wackes of the Snare Group, which are unconformably overlain by potassium feldspar- (±hematite ±magnetite) altered rhyolite of the Faber Group. The Sue-Dianne deposit is a hematite-magnetite-Fe-silicate-cemented diatreme complex enriched in copper, silver, gold, and uranium within a broad zone of potassium, iron, quartz, and epidote metasomatism. The diatreme is located at the intersection of two major faults at the north end of the basement discontinuity and is hosted in rhyodacite ignimbrite marginal to the Faber Lake rapakivi-granite pluton. At both deposits, diatreme- and maar-facies iron oxide-cemented breccia straddle the regional metasedimentary-volcanic unconformity, suggesting that mineralization formed in a near-surface environment synchronous with the onset of volcanism."

Jan 1, 2000

DOME MINES, Limited, is a gold producer situated in the Porcupine area of Ontario, 500 miles north of Toronto. During the year 1960, '71 4,600 tons of ore were milled, yielding gold bullion valued at $6,025,370. Prior to conversion to natural gas, an average of 3,200 tons of coal was consumed annually, one third of which was obtained from Canadian sources with the remainder coming from the United States. Due to the distances involved, the freight charges increased the pithead cost by as much as ISO per cent. Steam is generated at a central boiler plant and used for timber treatment, plant heating and process steam. Until August, 1960, steam was supplied during the winter months by two water tube coal-fired boilers, each rated at 200 boiler horsepower at 100 per cent output. Steam requirement was as high as 150 per cent of boiler rating in the colder periods. The summer load was

Jan 1, 1962

By Robert Linton

AT its meeting on May 21, the Board of Directors approved the recommendations submitted by President Lovejoy and named a nominating committee for the year that is especially well distributed as to major technical interest and as to geography. As may be seen from the list published herewith, two come from the East, two from the Midwest, and three from the far West. Mr. Linton, the chairman, has been a valued member of the Institute for 36 years. A memorandum drawn up by Paul D. Merica, representing the A.I.M.E., and W. R. Barclay, representing The Institute of Metals of Great Britain, setting forth a reciprocal plan for special memberships in each Institute for members of the other, was discussed. Both societies already have formally approved the plan in principle and Dr. Merica was clothed with full authority to agree on a few small details that have not been settled, and conclude the arrangement in behalf of the Institute.

Jan 1, 1936

By J. R. P. Aguirre

Minerales Monclova, S.A. de C.V. (MIMOSA) is owned by Grupo Acerero Del Norte (GAN). This company has 4 underground coal mines and 1 open pit to feed it?s steelmaking facilities located in the city of Monclova in the North of México in the state of Coahuila. The current underground mines are Mine 3, 5, 6 and 7 and the future projects are Mines 8 and 9. In the last years Mines 2 and 4 have been closed because they finished their coal resources. The remaining mines have bigger production and developments requirements in order to accomplish the goals of the company. The mines have been working in deeper and gassier areas. These conditions have required improvements in the ventilation design and methane control systems for all the mines. In some cases the ventilation of some of the MIMOSA?S mines has been increased 80%, and besides this, an intensive methane drainage program has been applied using horizontal in-seam boreholes and gob wells. The short-term ventilation plan includes the construction of 3 new vertical shafts with 5 and 6 meters diameter for Mines 5, 6 and 7 and the purchasing of bigger new main and backup fans for each one of these mines. One of these vertical shafts and the purchasing of the first 2 fans is already in process. This paper will explain the evolution and results of the ventilation and methane drainage systems in MIMOSA and the ventilation planning for the future years.

Jan 1, 2009

By Alan D. Curtis

A standard planning block model for Phelps Dodge North America Operations has been developed to improve mine planning efficiency and performance in a skill starved environment. The model saves time on software management and training, consolidates data and standard information/output, enhances evaluation and strategic process, and improves communication between sites.

May 1, 2007

By Tao Zeng, Jianchao Li, Chang Jie, Jieyu Zhang, Jifang Xu, Kuochih Chou

"The densities of the selected quaternary Ca0-5%Mg0-Alz03-Si02 slag with low silica were measured by the Archimedean method in a wide temperature range from l 723K to 1823K. Slag compositions were chosen based on five different levels of Si02 content between 0.00 pct and 11.40 pct. The MgO content was equaled to 5.00 pct. The mass ratio of CaO/Alz03 was varied from 0.67 to 2.14. The effects of temperature, Ca0/Alz03 ratio and optical basicity were studied. It is shown that density decrease approximately linearly with an increase in temperature. With the same Si02 content, the density decreases with increasing of CaO/Alz03 ratio and optical basicity. Based on the experimental data as the boundary of the homogenous phase region predicated by F ACTSAGE software, the mass triangle model is used to calculate the density of selected limited homogenous phase region. The results showed that the mass triangle model is working well.IntroductionIt is of great importance to measure density of slag melt not only to the theory research for melt, which that is directly amenable to the structure correlations of molten slags, but also to the industrial application. Many metallurgy phenomena such as inclusion formation in molten melt and its removing, slag foaming, slag-metal reaction are closely related to the density of slag. Density is also required to estimate other fundamental properties, like surface tension, viscosity, and thermal conductivity from thermal diffusivity so that a relatively complete picture in regard to the behavior of high-temperature molten oxides could be made."

Jan 1, 2013

By V. Bondarenko

The forecasting of floating earth inrush into the working is to a great extent connected with the investigation of the rock mass stressed-deformed state around the working. The aim of such investigations is to estimate the carrier ability of the protective layer (which is stabilized by the physico-chemical mode of fixing) and to determine it's thickness, which is to be sufficient to present the floating earth inrush into the working. We consider the protective layer to have exhausted it's carrier ability if the rocks of this layer reached the overlimit phase of deformation and it's greater part (section), which adjoins the working. is destroyed up to the limit of the remaining strength. So, the aim of investigations is to determine the size of the rocks inelastic deformation zone in the roof of the working. It is necessary to take into account the presence of water saturated seam in the roof and the overlimit characteristics of the rocks, their ability to lower the carrier capacity up to the level of the remaining strength.

Jan 1, 1996

By Harvey P. Knudsen

This paper describes the results of a comparative study of the geostatistical ore reserve estimation method over three conventional methods; the polygon method, the inverse of the distance squared (IDS) method, and ELIP which is similar to IDS. Each method was evaluated on its ability to accurately predict individual block grades for one bench of the Pima Nine, located near Tucson, Arizona. Results at the Pima Mine indicate that the geostatistical method is no better nor worse in predicting block grades and total tonnage than the ELIP or IDS methods in contrast, the polygon method is clearly inferior. All of the methods would have given better results if geology had been included in the block model. At already producing mines ELlP or IDS may be good choices since they involve substantially less cost in computer time. For prospective or new properties, the geostatistical model is more attractive, due to its ability to construct confidence limits on the estimates.

Jan 1, 1976

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