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By D M. Frantois-Bongarton

"A few situations are first reviewed where practical shortcuts lead to acceptable solutions where none seemed to be possible. These include: The solving of many complex sampling optimisation problems with the simple approach of the worst case policy (WCP). A simple approach to single-stage sampling problems will be mentioned at continuation. In the plants, minimising the impact of border effects in incorrect samplers, so that the resulting samples are approximately correct and acceptable in practice because the bias risk attached to them is controlled. Examples are given, as well as practical tools and a general methodology.Finally, some sources of undue conservatism are reviewed with general recommendations aiming at eliminating them.CITATION:Frantois-Bongarton, D M, 2012. Practical considerations and shortcuts in sampling, in Proceedings Sampling 2012, pp 171-174 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 21, 2012

By J Joy, A Bye, G V. Kizil

This paper presents an application of the newly developed risk-cost-benefit (RCB) framework to support risk management decisions for the selection of wall monitoring technologies at an open cut mine site. The RCB framework quantitatively assessed the risk of unstable slope-induced wall failure and its impact on both loss of life and coal recovery. The RCB framework was utilised in the selection of an optimum group of risk-controls to effectively manage the risk of wall failure to ensure safety and optimal production occurred. The RCB framework incorporates mathematical modules that integrated RCB calculations and risk-control effectiveness assessments to determine the risk reduction and financial impact of the examined safety initiatives.This paper provides an overview of the five-staged RCB framework, incorporating the RCB decision support tools, RCBGEN (Risk-Cost-Benefit Generator) and RCEMETHOD (Risk-Control Effectiveness Method), and demonstrates its application to slope stability risk management at the case study site. The RCB charts are designed to display a balance between risk, cost and benefit for easy interpretation by decision makers to support the objective selection of an optimum suite of risk-controls. The RCB analysis revealed that a combination of ævisual inspections, automatic extensometers and radarÆ for fast- and slow-wall failures with structure were sufficient to reduce the probability of loss of life (PLoL) to the æModerateÆ zone as defined by the Australian Geomechanics Society (AGS, 2007) for the case study site. The new framework presented in this paper provides a method to effectively determine the suitability of risk-controls and supports industry efforts to reduce risk to as low as reasonably practicable (ALARP).CITATION:Kizil, G V, Bye, A and Joy, J, 2012. Risk-cost-benefit analysis of early warning technologies impact for wall failure risk management in surface mines, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 55-64 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

The Bega granite at Whipstick, N.S.W., consists of a granite metasomatically altered to leucogranites and a spessartite-granite. The ore occurs in pipes controlled by jointing and shows evidence of post-depositional tectonic forces.The principal ore minerals are molybdenite and bismuthinite, with minor amounts of uraninite, pyrite, gold, bismuth, joseite A, joseite B, tetradymite, chalcopyrite, arsenopyrite, and skutterudite. The gangue minerals are microcline, albite, quartz, muscovite, and spessartite, with fluorite, chlorite, magnetite, and biotite as accessory minerals.The intrusion of granite was followed initially by ascending metasomatic fluids which penetrated along joints to be trapped in the domed roof of the intrusion to form the leucocratic granite. Iron-manganese-rich fluids metasomatically altered the granite to a spessartitegranite which is associated with the later deposited ore.Quartz veins and dykes of varying composition post date the ore deposition.

Jan 1, 1968

By Alessandra Souza Martins

O aço inoxidável super duplex vem apresentando um desempenho satisfatório em ambientes de maior agressividade. Esse tipo de aço possui boas propriedades de resistência mecânica, resistência à corrosão e tenacidade ao impacto. Entretanto, mesmo apresentando desempenho satisfatório, esses aços podem apresentar problemas de corrosão quando sofrem algum tratamento térmico, devido à precipitação de uma fase deletéria chamada de alfa linha (?’), a qual precipita em temperaturas entre 300°C e 550°C e pode ocasionar uma diminuição da resistência à corrosão e tenacidade do material. Portanto, o objetivo deste trabalho é avaliar a resistência à corrosão dos aços inoxidáveis super duplex de grau 5A e 6A após sofrerem tratamento térmico a 475oC. A diferença entre os aços de grau 5A e 6A ocorre na presença de cobre e tungstênio na composição química do aço com grau 6A. A resistência à corrosão dos corpos de prova foi avaliada por meio das seguintes técnicas eletroquímicas: polarização anódica, espectroscopia de impedância eletroquímica e temperatura crítica de pite. A resistência mecânica dos corpos de prova foi avaliada por meio da técnica de dureza Brinell. Foi realizada também a caraterização microestrutural e a quantificação das fases do material. Os resultados mostraram um aumento da dureza do material, indicando um aumento da presença da fase ?’ com 10 horas de tratamento térmico apresentaram maior resistência à corrosão.

Aug 8, 2018

By Osvaldo A. Bascur

Connectivity between mining and metallurgical process operations and their business systems has become a reality. Expanded use of plant information on the desktop is a standard tool for revenue improvement, cost reduction, and adherence to production constraints. The industrial component desktop support access to information for continuous improvement and innovation by staff personnel and engineers. Collaboration between groups enables the implementation of an overall process effectiveness index based on losses due to equipment availability, production recovery and quality rate. In this sense, the paper point out three cases studies of large integrated power stations.

May 25, 1998

By I Lourel

In evaluating the installation of an in-pit crushing and conveying (IPCC) system for any mine, a number of options are available for each of the dig side, transport and dump side operations. Some of them are moreappropriate than others; given the pit arrangement, the material being handled and the rates at which it needs to be moved. This paper seeks to document the options that might be employed, and to rank them in terms of their applicability at any mine and their practicality overall, with a view to nominating those that would be most suitable for further study.

Jan 1, 2009

The purpose of this study is to formulate practical guidelines for active underground mining in close proximity to water bodies. This was accomplished through systematic completion of three phases of study: I) Collection and Documentation of Data; II) Application of Existing Guidelines to Case Histories of Previous Inundations; and III) Development of Recommended Guidelines for Underground Coal Mining Near Bodies of Water. Phase I of the study involved a worldwide data collection effort designed to obtain foreign and domestic guidelines for mining near water bodies, and accident records and case histories of accidental mine inundations. Within Phase II, existing guidelines were categorized and classified and then evaluated as to their effectiveness in precluding past inundations had they been in effect at the time of inrush. Advantages and disadvantages of existing guidelines were defined. Drawing on the broad data base established in previous study efforts, Phase III was directed at development of viable guidelines to promote the greatest possible coal extraction while precluding accidental mine inundation. Two levels of guidelines are presented; Level I Guidelines require little or no subsurface exploration on the part of the mine operator, while Level II Guidelines recommend various testing and investigative procedures to permit greatest possible mineral extraction. This report presents findings and conclusions of the study.

Jan 1, 1976

By Lester M. Adams

In 1980, the Bureau of Mines surveyed a group of mine seals in Randolph County, WV, to evaluate their effectiveness for reducing toxic pollutants in mine water discharges. The survey focused on 11 block wet mine seals, but mine seals of several other types were also examined. The seals were installed in 1966 and 1967 in abandoned drift portals by the Federal Water Quality Administration (FWQA), a predecessor of the Environmental Protection Agency (EPA), in cooperation with the Bureau of Mines and other Federal and State agencies, in a project known as Elkins Mine Drainage Pollution Control Demonstration Project. The seals were designed to prevent air from entering the mine portals while allowing mine water to flow out. It was believed that by preventing air from entering inactive or abandoned mines, the formation of toxic pollutants and acid mine drainage (AMD) could be reduced. Evaluation of the seals was based on water flow measurements, water analyses, and visual observations. The Bureau's 1980 data were compared with past data collected by the EPA. Several leaks and failures were observed in the clay seals, as evidenced by apparent blowouts and the absence of vegetation where the mine water surfaced. Analyses of the 1980 data indicated some improvement in the quality of water discharged from many of the wet air seals.

Jan 1, 1984

By Yehia M. Youssef, Nourhan Moukhtar, M. H. Abdel-Aziz, Ibrahim Hassan

Copper was recovered from copper sulfate solution in a batch-recycled galvanic reactor operated under forced convection with the generation of electrical energy during the cementation process. The divided galvanic cell consisted of parallel copper and zinc plates. The mass transfer rate and the amount of electrical energy generated were found to be directly proportional to the solution flow rate and the initial concentration of metallic ions and inversely proportional to the distance between electrodes. The experimental results were expressed in terms of a dimensionless correlation including all parameters. The wastewater treatment presented herein cell can be utilized to recover many soluble heavy metal ions from solution with high efficiency.

Oct 2, 2020

By J. Parreira

This paper presents a deterministic/stochastic model that was created to compare an autonomous haulage truck system to a manual one by calculating and estimating benchmarked Key Performance Indicators (KPIs) such as productivity, safety, breakdown frequencies, maintenance costs, labour costs, fuel consumption, tire wear, and haulage cycle times.

Aug 1, 2013

By S. R. S. Sastri

By using the data of E.A. Hersam and F.C. Bond's equation for energy consumption in comminution, a method was developed to analyze the performance of industrial jaw crushers. The study showed that industrial jaw crushers are generally operated below capacity. The study also showed that industrial jaw crushers generally have sufficient installed power to operate at, full capacity. The method presented can be used to estimate the capacities and power requirements of jaw crushers.

Jan 1, 1995

By M. N. Rubin

This report summarizes the work performed under USBM contract J0100018. The purpose of this work was to document the currently available noise control techniques that can be incorporated into new coal preparation plants during the design stage. This was accomplished by reviewing the related experience of the contractor and subcontractor (Bolt Beranek and Newman Inc.), conducting an extensive literature search, visiting operating coal preparation plants, and contacting various equipment manufacturers. The treatments addressed include equipment substitution, changes in plant layout, and retrofit treatments for existing equipment.

Jan 1, 1982

By Steven K. Ruggieri

This report describes the operation and maintenance of the Mobile Inert Gas Generator for use in the Remote Sealing System for fighting underground coal mine fires. Seals are emplaced in mine passageways between the fire zone and the rest of the mine isolating the fire zone from the mine. The seals consist of fly ash that has been pneumatically conveyed via inert gas through a borehole connecting the surface and the passageway, Inert gas is used as the fly ash seal transport medium (instead of fresh air) since the introduction of large volumes of fresh air in the vicinity of the fire zone would be undesirable. The inert gas generation equipment is mounted on two flatbed trailers, the "hot" trailer and the "cold" trailer. The hot trailer contains the combustion and cooling equipment. The cold trailer contains the moisture removal and compression equipment necessary to convey the fly ash. The system is self-sufficient and requires only fuel and fly ash deliveries. The Inert Gas Generator has been thoroughly performance tested and has been operated in the field for approximately 200 hr. The system was employed in the demonstration of the entire Remote Mine Sealing System at the Jenney Mine in the Fall of 1978. The system is currently available for fighting any future underground coal mine fires.

Jan 1, 1980

By F. O. Verret

Several grindability tests were developed over the years to design grinding circuits or optimize existing operations. Each test has its own strengths and weaknesses and it is imperative to select the proper test procedure(s) to meet project deliverables and minimize the risk of a project. Pilot plant testing of large bulk samples historically constituted the traditional approach for AG or SAG design, but was gradually replaced by small-scale tests. Nowadays, conducting grindability tests requiring only a few kilos of material on several samples is a more typical approach to grinding mill design. This paper summarises the requirements and deliverables of various bench-scale test procedures, their strengths and weaknesses, and cases where AG/SAG pilot testing should still be performed.

Jan 1, 2012

By S Bluhm, L van den Berg

In planning mine ventilation systems, heat issues are normally associated with deep-level mines where auto-compression and virgin rock temperatures play a major role. However, a number of mines suffer from high ambient temperatures and humidity, very steep virgin rock temperature gradients and an influx of hot groundwater. Mines in Australia and, particularly, South-East Asia have to deal with these environmental conditions, both in the operational and planning phases. These operations normally have to take heat into consideration during the planning stages at much shallower depths. In high rainfall regions, the water table is saturated and groundwater flow rates are particularly high, which add significant water heat load potential to the mine ventilation system.This paper considers the ventilation challenges associated with hot groundwater conditions in mechanised mines. The paper is based on specific project experience gained from a number of projects in the United States, Australia and South-East Asia and draws on data from mines that experience hot groundwater conditions. For one site, actual decline temperature survey measurements, modelling techniques, management strategies and design considerations are presented.CITATION:Van den Berg, L and Bluhm, S, 2015. Ventilation planning considerations when dealing with hot groundwater, in Proceedings The Australian Mine Ventilation Conference, pp 211–218 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By P. W. J. van Rensburg

The Institute was privileged to receive an invitation from the Armaments Corporation of South Africa (Armscor) for members to visit one of their plants. As these are factories, the number of visitors who could be accommodated was limited. As the opportunity seldom arises to learn something of this very large industry, there was great interest among members and many were disappointed in not being able to go. Underwater mining The 16th Annual Underwater Mining Institute will be held at Halifax, Nova Scotia, Canada, from 20th to 23rd October, 1985.

Jan 1, 1985

By Albert L. Toenges

This paper is the fourth of a series5/ that describes some methods and practices of mining coal mechanically where operations are conducted on more than one shift. Many inquiries have been received regarding methods of extracting pillars with mechanized equipment, and this paper deals primarily with this phase of mechanical mining. Some of the questions that have been asked are:

Jan 1, 1942

By CASSANDRA L. HOEBBEL, Emily J. Haas, MARGARET E. RYAN

In recent years, there has been increasing interest in the role that individual factors play in health and safety (H&S) outcomes in the mining industry. Two surveys, one measuring self-reported routine safety performance and one measuring individual perceived competence in the non-routine knowledge, skills, and abilities (KSAs) critical to emergency response, were administered to two samples of mineworkers in separate research studies over a 2-year period (N=2,020 and 696, respectively). Eight demographic items were common to both surveys and their associations with each performance outcome were tested in response to a series of exploratory research questions.

Jan 9, 2022

By William R. Yernberg

The Mineral Processing Plant Design, Practice and Control Conference was held from Oct. 20through 24, 2002, at the Fairmont Hotel, Vancouver, British Columbia, Canada. The conference was attended by nearly 400 of the world’s top mineral-processing specialists, including plant-design engineers, mineral-processing consultants, academics, suppliers and equipment manufacturers. The meeting was sponsored by SME and cosponsored by the Canadian Mineral Processing Division of the Canadian Institute of Mining, Metallurgy and Petroleum (CIM). The conference covered all aspects of mineral-processing design, construction and operation. The meeting included more than 130 technical presentations. Topics included sampling programs, feasibility studies, design criteria, process technologies, construction, start-up operations and shutdowns. To stimulate interaction and discussion throughout the five-day conference, the sessions were presented consecutively. Attendees had the opportunity to attend every session.

Jan 1, 2003

By AIME AIME

THE week, of April 5 will long be remembered by those that attended the Birmingham meetings of the Open-Hearth and Blast Furnace committees of the A.I.M.E. Iron and Steel Division. Birmingham iron and steel own received the 450 delegates with open arms; described and discussed their southern metallurgical practices and problems and compared experiences with their northern brother metallurgists in two days of technical sessions on Wednes-

Jan 1, 1937