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By R F. G Phelps

The former Gwynfynydd gold mine is located within the heart of the Snowdonia National Park, North Wales, United Kingdom. The black shale-hosted quartz reefs have intermittently produced more than 50 000 ounces of gold since 1863. Its most recent period of operation by Welsh Gold PLC was between 1992 and 1999 when it extracted 10 000 tonnes annually from a total resource base of 180 000 tonnes. A historical mining grade of 15 grammes/tonne was recovered from the Chidlaw Reef on which all production was based. Erratically distributed gold pockets hosted in the footwall zone of a 3 - 6 m wide quartz reef characterise the mineralisation. The gold exhibits a high-nugget effect and as a consequence the accurate determination of tonnage and grade was difficult. Production was undertaken by overhand shrinkage stoping. Due to its location within a National Park certain environmental constraints were placed on the operators. The principal requirement of planning permission was that processing should take place above ground and not involve chemicals. As a result, an underground mill based on physical separation methods was constructed in response to these environmental constraints. Much of the mine discharge is related to the flow of rainwater through the workings from surface openings on the reefs. Discharge from the underground milling facility was enhanced in various metals, particularly zinc, though was reduced to legally acceptable levels using liming tanks prior to discharge into the River Mawddach. The company was required to monitor and treat all water discharged from the mine before it reached the river. The mine closed in 1999, since which time a tip re-processing has continued as part of an environmental remediation and gold supply program.

Jan 1, 2002

By J W. Dong, Y M. Li, J L. Tian, Z H. Jiang

Electroslag remelting is widely used to produce various special steels, mainly because of its ability to provide high cleanliness and excellent homogeneity of ingot. Undoubtedly an optimal slag plays a key role in removing inclusions and enhancing the mechanical properties of a specific special steel. In order to improve the metallurgical performance of the slag in electroslag refining of die steel, a variety of slags have already been developed using traditional trial-and-error methods. Nonetheless, these slags may not be inherently optimal for the specific requirements of actual die steel refining processes. In this work, we have designed a CaF2-CaO-Al2O3-SiO2-MgO quinary slag system using genetic algorithms method aiming to remove the existing large size inclusions (D and Ds type) in high quality die steel. The comprehensive effects of five components (CaF2, CaO, Al2O3, SiO2 and MgO) were studied based on existing fundamental theory. The slag composition was screened considering the parameters such as melting point, electrical conductivity, calcium ion concentration, and appropriate viscosity etc. Furthermore, the candidate optimal slag was applied in the industrial production of die steel by electroslag remelting method. The detection results indicate that majority large inclusions (D and Ds type) have been successfully removed, showing significant advantage to traditional slags. This result has demonstrated the genetic method to be efficient and reliable. In addition, depending on the personalised demand of other steel and alloys, this method allows for the adjustment of the screening frameworks and processes to develop the candidate optimal slags. This method has not been reported previously in the field of electroslag composition design, and compared with the traditional trial-and-error method, the new method will save a lot of time and experimental costs.

Jun 19, 2024

By Brendan Demich, Linda L. Chasko, Brendan Macdonald, Timothy J. Orr, Jessie J. Mechling, Cassandra Hoebbel, Jason Navoyski, William Helfrich, Jessica Cohen, Paul E. Schmidt, Jennica L. Bellanca

The National Institute for Occupational Safety and Health (NIOSH) in partnership with the Mine Safety and Health Administration (MSHA) developed VR Mine Rescue Training (VR-MRT). It is a training platform that allows mine rescue team members to explore virtual emergency scenarios collaboratively. Team members use a head-mounted display to visualize and interact together with equipment, hazards, and dynamic ventilation. All player actions are recorded and displayed for debriefing. Researchers at NIOSH demonstrated the training platform at various mine rescue competitions, including the International Mine Rescue Competition, and collected feedback. Participants’ responses were overwhelmingly positive. This paper describes the development of the software platform and the results of the usability surveys and interviews.

Jun 25, 2023

By Peter Sylvén, Darwin Morales

Despite being crucial for the smelting process, furnace tapping using oxygen lances has not been considered an operation that brings value. Therefore, these important tools have not seen a significant change in over 100 years. Problems related to the use of oxygen lances include: • Inaccurate tool: causing damages shortening the life of the taphole refractories. • Safety: extended exposure to the operator in an unsafe area of the furnace. • Cost: high oxygen consumption & high lance consumption. • Time consuming and frustrating to connect one lance to another. This paper will suggest a very good solution; new concept thermal lances. We will show how these provide an outstanding performance for a more efficient, faster and cost-effective furnace tapping operation. These new lances are very accurate tools that enable the operator to perform a more controlled operation; resulting in longer taphole life, fewer repairs and less down-time.

Jan 1, 2016

By T Stambolie

Mine planning processes are continuously evolving, increasing in complexity, and are required to be developed in shorter timeframes, often missing important steps in the process. Underground coal mines are also moving into more challenging environments, with the more favourable resources having been exhausted. In addition to traditional mine planning processes there is an increasing level of complexities associated with parallel systems including the preparation of Joint Ore Reserves Committee (JORC) compliant estimates (JORC, 2012 and Guidelines Review Committee, 2014) or seeking critical regulatory development consent to undertake mining. There is a clear link between geotechnical considerations and success of mining operations, and therefore it is essential that such considerations are elevated in both status and priority. It is obvious that geotechnical considerations are paramount in any mine, however it is imperative to accept that such considerations, and the collection of information relating to such, are undertaken from the onset of any mining project. CITATION:Stambolie, T, 2018. Elevating geotechnical considerations in the Australian underground coal industry and mine planning process, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 383–391 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By G M. Young

IT IS most appropriate that this first Memorial Lecture should be given in the Province of Quebec, near the site of the first metallurgical industry in Canada. At La Forge, about seven miles north of Three Rivers, iron was produced in 1783. We are told that the early settlers obtained most of their iron-ware -stoves, kettles, axes and ploughshares -from this smelter, with its foundry and forge. The Canadian copper industry also had its beginnings in Quebec when, nearly 100 years later, in the 1880's, several small copper smelters were erected in the Eastern Townships. Later, in 1899, Canada's first aluminum smelter was built at Shawinigan. From these small beginnings has grown a vast metals industry, the export value of its products being only exceeded by that of our forest products -newsprint, pulp-wood and lumber. As we are not a large country in terms of population, our domestic capacity to consume is often small in relation to our developed capacity to produce.

Jan 1, 1963

By Tom Barczak, Julian Restrepo, Zach Agioutantis

"The Alpha Foundation for the Improvement of Mine Safety and Health, Inc. (Foundation) was established as part of a Non-Prosecution Agreement (Agreement) entered in December 2011 by the United States Attorney's Office for the Southern District of West Virginia, the United States Department of Justice and Alpha Natural Resources, Inc. (""Alpha"") and Alpha Appalachia Holdings, Inc. This Agreement was related to the explosion at Upper Big Branch Mine, an underground coal mine owned by Performance Coal Company, a former affiliate of Massey Energy Company, which Alpha acquired in June 2011. Pursuant to that agreement, Alpha agreed to establish a trust to fund projects designed to improve mine health and safety by providing $48,000,000 into the trust. The mission and vision of the Foundation are as follows:Mission: To improve mine health and safety through funding research and development projects by qualified academic institutions and other not-for-profit organizations.Vision: To enable miners in the future to be free of work-related injury or disease by the implementation of the results of the projects funded by the Foundation and undertaken by the best researchers from any discipline that can contribute.The focus of the research effort is not limited to coal mine explosion prevention, and in fact encompasses the entire spectrum of health and safety, addressing issues in both underground and surface mining operations in all mining sectors. Four major focus areas are identified (see Figure 1): 1) Health and Safety Interventions; 2) Mine Escape, Rescue, and Training; 3) Safety and Health Management and Training; and 4) Injury and Disease Exposure and Risk Factors.The Foundation is seeking to expand the knowledge base of mining safety and health information that can lead to resolving complex mining problems. To that end, the projects funded by this effort are designed to provide a spectrum of knowledge potentially encompassing the following:• Surveillance data - Collect and analyze surveillance data that better documents the prevalence and trends of occupational safety and health across the mining industry."

Jan 1, 2016

By William J. Campbell

One of the principal objectives of the Bureau of Mines program for developing super refractory materials is to obtain fundamental data on the physical properties of refractory oxides. This particular investigation obtained accurate thermal expansion coefficients for alpha alumina and evaluated, critically, those coefficients with other published values. High-temperature X-ray diffractometer measurements, by the Bureau, showed that alpha alumina expands anisotropically with expansion parallel to the c axis approximately 10 percent greater than parallel to the a axis. Thermal expansion characteristics of four different alumina samples were determined up to 1,200° C.; the results are presented in both tabular and graphical form. The combined random and systematic errors in the measurements are considered less than 3 percent above 500° C, and approximately 2 percent at 1,000° C. No differences in expansion were observed between the samples or between the heating or cooling cycles.

Jan 1, 1961

By C Jenkins, J Jasper, Y Suryaputradinata, S Lozyk, M J. Hartmann

The primary objective of mining companies is to function as a profitable business by delivering products that fit customer requirements in a safe and sustainable manner. Optimum resource utilisation is a critical focus area to achieve this objective, and the long-term sustainable business performance of a mining company is determined by the extent to which this is achieved. Technology improvements and/or new technology development could improve resource utilisation. However, adding new projects to a Brownfield operation carries risk. Overall project schedules, tie-in schedules and safety risks normally receive adequate attention, but the introduction and integration of new technology to a Brownfield site also carries the significant risk of failure to achieve design performance (quality or throughput). This risk must be addressed via rigorous design phase risk assessments and piloting. Post commissioning, the effective metallurgical integration of any new technology/circuit/process plant into an existing process plant calls for critical assessment, through circuit performance testing, and optimisation to ensure alignment with design criteria. In addition, this approach provides clear focus areas for further optimisation of the new plant and additional opportunity for overall plant optimisation. Roy Hill recently navigated this process successfully, and this paper provides feedback on the journey that led to improved resource utilisation.

Nov 8, 2021

By Paul Summers, Kevin Richardson, Willem (Billy) Villet, Paul J. Sabatini, Edward C. Clukey

"Between 2008 and 2009, more than 6,000, 23-m long deep mixing method (DMM) elements were constructed to support 124 concrete mats comprising the foundations for the process trains for an LNG facility. The Owner requested first-of-its-kind analyses and assessments to confirm the quality and reliability of the DMM foundation. This paper provides information on these assessments and the procedures used to ultimately conclude that a fit-for-purpose foundation system was constructed.During early phases of construction, several DMM test cores revealed nodules of unmixed clay in upper core samples. A comprehensive review of available DMM core information was undertaken. It was concluded that the amount of coring being conducted as part of the contractor’s QA/QC program should be increased to achieve a foundation system with the required level of reliability.Three-dimensional finite element analyses were completed considering various distributions of defects in the DMM elements and the effects of potential downdrag on DMM elements. Calculated mat settlements and mat stresses were compared to cases without defects in the DMM elements. Various distributions of loaded and unloaded mat areas and number and position (both in the subsurface and laterally) of defects were considered. Four (of the 124) mats were identified as potentially “at-risk”. The settlement performance of these mats is currently being monitored and, to date, performance has been acceptable.IntroductionThe foundation support system for the process train at a major LNG facility comprises more than 6,000, 23-m long DMM elements. The general subsurface stratigraphy at the project site comprises (from the ground surface): (i) up to 8 m of fill sand initially placed underwater building to a stable construction platform; (ii) up to 12 m of soft organic clay (Unit II clay); and (iii) clayey sand and sand layers becoming progressively denser with depth (Unit III sands). Each DMM element comprised two secant 1.5-m diameter DMM columns. DMM elements were typically arranged as cells enclosing one, two, or three DMM elements."

Jan 1, 2017

By The Hollinger Mill Staff

MR. E. L. Longmore (l), in presenting this paper at the Annual General Meeting, suggested that it was neither desirable nor necessary to read any but the briefest portion of the paper. He wished to emphasize that the scale of the milling operations at the Hollinger not only provided several units in continuous operation to ensure that the test work was being carried on under normal conditions, but also provided a large and competent staff to supervise such an extensive experiment and to criticize intelligently the recorded results. He wished to acknowledge the enthusiastic co-operation of the group of assistants whose excellent work was responsible for the confidence with which the conclusions could be presented. The following data were given as a supplement to the published paper. Following conclusion of the test work described in the paper, the size of the balls fed to the mill was changed from 3-in. diameter to 2Yz-in. Within a short time, a gradual rise in the tonnage rate took place and, as no other condition had been changed, the increased tonnage was credited to the changed character of the ball load. At present, the average daily tonnage for the mill with low discharge is 1,507 tons, an increase of 77 tons over the 1,430 tons ground when feeding a 3-in. ball. A similar increase in tonnage should be credited to the high-discharge test, if the 2;Y2-in. ball had been used at that time. This would raise the 1,117 tons ground at that time to a new figure of 1,177 tons. From a study made to determine those factors influencing the rate of pulp flow through the low-discharge mill, it became evident that the ball screen used on the high-discharge mill must have been restricting the flow through the mill, although this was not recognized at the time. Accord-ingly, it was decided to repeat the high-discharge run. Additional length was added to the 21-in. ring grizzly originally used, and the length of the reverse spiral was increased. The end of the grizzly was left open so that, if necessary, excess pulp might flow out. A coarse mesh 3 ft. by 3 ft. flat screen was provided to catch stray balls.

Jan 1, 1937

By J. C. HEILMAN

THE Tri-State district, named from its situation in three States, lies in the northeast corner of Oklahoma, the southeast corner of Kansas and the adjacent part of Missouri east of the common corner of the above States. Production in the past eighty years has come from scattered mines within an area of some 35 miles east and west, by 25 miles north and south, although the actual area of the mined ground is but a small fraction of this territory. The land is leased from the individual land-owners, and the size of the tracts varies from 4.0 to 200 acres, the smaller sized tracts predominating. The leases usually call for a royalty of 7% to 15 per cent of the gross receipts of the concentrates, continuous operation during the life of the lease and specifically set out that no ores can be brought in from a foreign lease for custom milling nor can any ore be removed from the lease for milling. The ownership of the tailings remains with the land-owner.

Jan 1, 1931

By Lawrence Bragg

WE associate metals with hardness, toughness, and strength. But a curious paradox lies at the root of the valuable mechanical proper-ties of the metallic state: in order to be strong, a metal must be weak. This paradox, and the equally surprising fact that, in a sense, metals are not true solids at all, are among the topics here discussed by Sir Lawrence Bragg. (1) WHAT METALS MEAN TO US We employ various materials to build or fabricate the many objects we use in everyday life, choosing those whose properties are most suitable for the purpose which the object has to serve. Certain of these materials have been used from the earliest times, such as stone, wood, leather, and animal or vegetable fibres, each with its own peculiar valuable properties. Stone resists crushing and is very durable and permanent, as indeed it must be, since it has so long resisted change as a part of-the earth's crust. It is there-fore ideal for walls and buildings, and very early in his history man discovered how to make artificial stones by burning clay, with the advantage that they could be given any desired shape, and made into bricks or given elaborate forms as pottery. Wood is strong and tough and light, it resists tension as well as compression, and is nor brittle like stone. It forms beams and furniture and parts of tools or weapons. Leather is tough but at the same time iris flexible; it is ideal as straps or sheers. Vegetable fibres such as linen or cotton, and animal fibres such as wool and silk, owe their value to their flexibility and strength in resisting extension. They can be spun into yarn or rope, and woven into cloth. The technological age in which we are now living is replacing the natural products used by early man by a series of artificial products, but it is remarkable to see how in nearly every case we are copying Nature's materials. The wide use of concrete represents a developed art of making artificial stone. Artificial fibres such as rayon or ?nylon replace cotton, wool, and flax. Plastics are coming very much to the fore; they correspond to early man's use of horn, another substance with peculiar properties of roughness in all directions without the 'grain' of wood. For the most part we are following in the footsteps of our remote ancestors, though we can make for ourselves what they had to cull from wood and field. There are exceptions; for instance, we have discovered comparatively recently the number of uses to which natural rubber can be put, and are now making it artificially. This is a really new discovery; our ancestors had nothing with such remarkable powers of elastic stretching without breaking, and resistance to being abraded.

Jan 1, 1943

By F. W. Lee

The paramount importance of water to life of all forms on the earth is too well known to require elaboration in this brief paper. It has repeatedly been termed the most valuable of all our mineral resources. Its importance is justifiably recognized in the extensive areas covering the earth which receive sufficient rainfall to sustain a relatively luxuriant vegetation; but in those areas where rainfall is insufficient to support anything but a relatively meager plant growth, the location of a water supply and its development become of even more vital interest to those attempting to obtain a living from the soil. Geological investigations concerning the water supply of the United States have been most extensive, important work having been accomplished by Federal, State, and local governments and by private enterprise. A casual examination of the titles of the 739 Water-Supply Papers published by the United States Geological Survey3/ alone testifies 'to the vital nature of our water resources and the extensive work that has been done on them.

Jan 1, 1936

The mining industry has generally been slow to apply ion exchange processes to hydrometallurgical applications even if ion exchange offers an ideal solution for a particular problem. Two notable exceptions are in gold and uranium recovery. The largest application of ion exchange in the metals processing industry has been the use of resin-in-pulp (RIP) for gold recovery as an alternative to activated carbon. Iron is a ubiquitous impurity in hydrometallurgical solutions. In many cases, bulk removal of iron from the process solutions is accomplished by precipitation. However, precipitation for iron control is often accompanied by losses of base metals by co-precipitation. Increasingly, the option of ion exchange for removal of smaller amounts of iron from process solutions has been favoured. A number of applications have been developed and proven at the commercial scale for the removal/control of iron from a range of metal processing solutions. This paper provides an overview of the application of ion exchange for iron removal from a range of metal processing operations, including Cu, Ni and Co solutions. A number of case studies are provided which review operational and resin regeneration strategies and the impact upon the commercial operation of metal processing with improved iron control.

Jan 1, 2006

By Richard J. Bielicki

This Bureau of Mines study estimates the number of major pieces of coal- mining equipment that will be required to produce 950 million tons of marketable coal in 1980 and 1.2 billion tons in 1985. The coal tonnages were projected in the intermediate coal supply scenario of Project Independence Blueprint (PIB). The equipment projections were determined by consideration of historical trends and by evaluation of information from equipment manufacturers and mining companies. The ability of the manufacturers to meet the projected equipment demands was also determined. It was concluded that equipment supply offers no presently discernible constraint to mining 1.2 billion tons of coal in 1985. A shortfall in projected production for the intervening years, however, is probable owing to anticipated shortages of draglines.

Jan 1, 1976

By Moore, Richard B

PROBABLY no other metal excites as much interest, among both scientific men and the general public, as radium. This is due partly to the high cost of radium salts and partly to the peculiar properties of the element. Since radium-bearing ores were discovered in the United States, the interest of American scientific men has been stimulated and, at the present time, more radium is extracted and refined in this country than in all the rest of the world together. HISTORY The property of radioactivity was discovered, partly by accident, by Henri Becquerel, the French physicist, in 1896. He was experimenting with certain fluorescent substances in order to find, if possible, a connection between fluorescence and the recently discovered Y-rays. Among other chemicals which possess the property of fluorescence, he was using

Jan 8, 1918

By G B. Smith, D Hillier, T Gibbons, D B. Donato, M D. Adams, S Davies, R S. Schulz

Responsible management of cyanide solutions and tailings on gold processing plants worldwide is an important aspect to these operations and is regulated via guidelines provided by the International Cyanide Management Code, an industry initiative designed to minimise cyanide risk to operators and the environment. Here we demonstrate the unprecedented causal relationships surrounding the saline (>14 000 mg/L total dissolved solids - TDS) and hypersaline (>50 000 mg/L TDS) cyanide solutions in gold plant tailings in the Central Goldfields of Western Australia, resulting in zero wildlife mortalities on three sites over the study period of almost one year. Wildlife interaction and ingestion is significantly lower than that experienced at other gold mine sites, with more rapid degradation of weak-acid dissociable (WAD) cyanide within the tailings storage facility (TSF). A rigorous chemical sampling using a novel æminimal accessÆ robotic sampler device and wildlife observation exercise was carried out at two hypersaline mine sites: Barrick Kanowna Belle (BKB) and Gold Fields St Ives (GSI) and one saline site, Barrick Granny Smith (BGS). The data was compared with available reported chemical sampling and wildlife observation data from a previously operational fresh water site (<2000 mg/L TDS) that had experienced wildlife mortalities, Case Study D (CSD). The comprehensive body of work, along with cyanide degradation test work carried out in the laboratory, was analysed via hypothesis development and testing, causation analysis and dynamic chemical modelling. The non-mortality effect on these sites appears to hold over a further four years of routine wildlife and cyanide monitoring by site personnel. This study has helped these three mine sites achieve and maintain full Compliance Cyanide Code status over a significant period while removing the need for operating the detoxification plants they would otherwise have required.CITATION:Adams, M D, Donato, D B, Schulz, R S, Smith, G B, Gibbons, T, Davies, S and Hillier, D, 2013. Hypersaline-induced reduction in cyanide ecotoxicity at gold operations, thereby obviating detoxification plants, in Proceedings World Gold 2013, pp 489-502 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By P. R. Brenchley

Main ore pass systems should last the life of a mine, and too often expensive and hazardous remedial measures are required to repair a damaged ore pass in an attempt to extend its life. In order to maximize the life expectancy of all ore passes at Moab Khotsong, ?wearing blocks? and ?softer support? systems, combined with basic rock engineering principles, have been implemented. Failure of an ore pass can have severe financial implications, both indirectly because the ore pass cannot deliver the broken rock either from level to level or directly in the shaft ore pass system to the required level for tramming to take place, and directly due to the cost of the repair work that is required. Several factors need to betaken into consideration so that production interruptions are eliminated or minimized. Investigations of damaged ore passes at Moab Khotsong and surrounding mines revealed some interesting mechanisms of damage, and some innovative methods of reducing or eliminating the damage have been implemented at Moab Khotsong. The system design was based on 30 years, experience in main shaft rock passes. The design was to counteract scaling, hang-ups and dust problems associated with main rock passes, and the objective was to increase the life of rockpasses. These problems, including the initial design aspects to try and eliminate the repair measures, are discussed in detail.

Jan 1, 2006

By B. Kraus

Many of us who have interacted with senior executives from leading oil and gas companies over the last few years on the subject of HSE performance have observed a marked shift in their engagement on this aspect of their business performance. There seems to be a shared impression that HSE performance will have markedly increased impact on their businesses going forward. On the back of this very real concern, many are taking material actions to secure a step change in their safety and environmental performance: hiring respected mainstream operational personnel to lead their HSE function; investing in capacity/skills development for HSE professionals to increase their effectiveness in addressing the needs of the business; taking a hard look at the efficacy of established management and audit programs (too much paper, not enough results?); investing in information management systems so they can have access to real time reliable performance indicators; and, critically, initiatives to reduce accident statistics (especially focused on fatalities and contractors? activities) and deliver meaningful reductions in their environmental footprints. Underpinning all of these actions is a clear sense that substantial, very well-intentioned activity and investment in HSE aspects of the business has not been hitting the mark and yielding too little return in terms of performance improvement. The very serious recent events on the US Gulf Coast and at a refinery in the US Pacific Northwest have added fuel to this fire. The need for approaches which will secure a step-change in performance on the front line in the global oil and gas industry has never been greater.

Jan 1, 2011