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In formulating its strategic plan in 1998 the New Zealand Minerals Industry identified two related critical issues facing it. These are, broadly speaking, the issues of access to minerals; and the perception the public has towards the industry and its behaviour towards the environment. This presentation will report on the Industry's response to the public perception issue. The Industry has, through the NZMIA Council, and its Communication and Website Committees, developed and implemented strategies covering: communication through the print media, and through its website www.minerals.co.nz, a long-term educational outreach programme with schools, focussing on the significance of minerals, their contribution to community wellbeing and the negligible long-term environmental effects of the Industry's activities.

Jan 1, 2000

To develop a conceptual design for an automated longwall mining system, one should know what has been done, what is being done today and what is being planned for tomorrow. The bibliography referenced and discussed in this report provides a good source for that knowledge. To scientifically determine where attention should be focused to up-grade a system, the system must be quantized as far as possible. The Mechanization Profile of Appendix A-I is discussed in this report and has been used to analyze and determine the degree of mechanization currently in use and/or described in the literature for all three major elements of the long-wall system, namely, Winning, Roof Support and Haulage. The charted profiles make it self-evident where attention and design effort is needed to remove human operators from the face of the mine.

Jan 1, 1975

By B E. Hall, D B. Kahler

"'Optimisation' has become a catchcry among many mining companies looking to tell the market how mining businesses will be improved and shareholder value increased. Consequently, the term 'optimisation' has been adopted by many service providers as they look to assist mining companies in achieving their objectives. But the explosion of services and products being offered with the label 'optimisation' has created some confusion. Mining companies ask for help in 'optimising' and service providers offer their assistance because they have a product that has the word 'optimisation' in its title. This is of course an over-simplification, but not by much! The authors' discussions in recent years with both mining companies and service providers have uncovered a number of very different definitions of optimisation.This paper provides a framework for identifying the scope and approach of different mining optimisation products and services, particularly the distinction between optimisation of components of the operation and the business as a whole. The different types of business optimisation are discussed, highlighting the failings of the mining industry's typical approach of strategy selection (as opposed to strategy optimisation). Mining business optimisation is discussed as a wicked problem, with the implication of this on how strategy optimisation models should be used and what the objectives of a business optimisation study should be.Case studies are also included to illustrate how fully flexible strategy optimisation models have been applied to assist decision-makers understand the impacts of changes in one part of the operation on the whole mining and treatment process, from geological models to the sale of product to customers.CITATION:Kahler, D B and Hall, B E, 2016. Strategic decision-making in mining – business optimisation using flexible evaluation models, in Proceedings Project Evaluation 2016, pp 215–225 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By J. G. Pippenger

Rio Tinto Coal Australia (RTCA) developed the Meandu Mine in Queensland, Australia in 1983 to supply thermal coal to the adjacent and newly constructed Tarong Power Station (TPS). In designing the mine, RTCA selected Meandu?s best economic reserves for a 27-year life based on station owner Tarong Energy Corp.?s (TECs) estimated life for TPS. That 27-year plan changed dramatically in the early 2000s when TEC approved life extensions to TPS?s four existing units plus construction of a fifth unit. After reviewing Meandu?s remaining reserves, RTCA decided the nearby Kunioon reserve offered the more economic option for maintaining deliveries beyond 2010. Those plans changed again in 2007 when TEC chose to purchase the Meandu Mine and nearby reserves. TEC then selected Thiess Pty Ltd. (Thiess) to continue operating Meandu until the new mine at Kunioon could be developed. After assuming operation of the mine in 2008, Thiess began a review of Meandu?s remaining reserves and found considerable coal available with economic potential. Working jointly with TEC, Thiess performed several analyses on Meandu and subsequently the Kunioon coal reserves. The results changed TEC?s decision from expediting Kunioon?s construction to instead continuing Meandu?s operation for up to 15 additional years.

Jan 1, 2011

By David Crouthamel, Raymond Henn

"The need to fill the void space or annulus created between an excavated tunnel or shaft and the final lining system has long been a requirement in underground construction. Most of those types of voids are created as a result of employing the two pass tunneling lining method. Filling of this void is called backfilling. For many years the materials used as backfill were primarily reinforced and non-reinforced concrete, sanded grout, neat cement grout, or blown-in sand/pea gravel. However, in the past 20 years the use of cellular grouts/cellular concrete as the backfill material has greatly increased. Most cellular grout is made of a mixture of water, Portland cement (with or without the addition of fly ash), a foaming agent and admixtures such as a water-reducer or superplasticizer.It is the authors’ preference to use the term cellular grout as opposed to cellular concrete since by ACI Concrete Terminology an ACI Standard (ACI CT 13), concrete contains aggregates. Normally cellular grout does not contain sand (finite aggregate), but almost never contain course aggregates.The authors believe there are several reasons for this increased use of cellular grout as backfill, such as:• The increase utilization of the various trenchless tunneling methods. Tunnels constructed using trenchless method tend to be smaller in size, excavated diameter or cross sectional area. Making man-entry for placing backfill from inside the secondary liner, utilizing pre-installed grout posts, more difficult if not impossible. It is these workspace restrictions that are the drivers as to when to utilize grout ports installed during the pipe/liner fabrication versus grout delivery pipes installed within the void/annulus space.• The ability of cellular backfills to be pumped and flow longer distances.• The unit weight of cellular grouts can be controlled by mix design and generally can range from 560 Kg/m3 (35 lbs/CF) to 1040 Kg/m3 (65 lbs/CF)."

Jan 12, 2017

By Paul W. Mayne

Axial pile performance can be rationally evaluated within an elastic continuum framework using field results from seismic piezocone tests (SCPTu). Adopting a versatile Randolph-type elastic pile model, the approach can be applied to either traditional top down loading using an anchored reaction beam or the newer Osterberg cell that simultaneously pushes the base and shaft in opposite directions. The axial load distribution within the shaft is also evaluated. For site-specific data at a given site, the SCPTu is an optimal means for collection of subsurface information because it combines penetrometer readings and downhole geophysics in one sounding. The results obtained are at opposite ends of the stress-strain-strength curves, specifically the peak strength for capacity interpretations and the small-strain stiffness (Emax) for evaluating the initial deformations. Axial pile capacity can be analyzed using both direct and indirect CPT methods. As such, the approach allows for a complete representation of the axial load-displacement-capacity curve for pile response. Case studies are presented for deep foundations situated in stiff clays at two national geotechnical test sites located in Houston and College Station, Texas, using top down loading, as well as a third case study of a drilled shaft in clay till loaded by O-cell in Alberta.

Jan 1, 2009

By Brian Y. Lattimer, Kray D. Luxbacher, Jonathan L. Hodges, Manuel J. Barros-Daza

The abstract discusses the importance of predicting fire response time (the time before conditions become untenable for firefighters) in underground coal mines. It introduces a data-driven approach using artificial neural networks (ANNs) to predict response time and fire size based on measurable parameters like CO concentration, mine geometry, air velocity, and time since fire detection. The approach was tested using simulations from fire models (FDS and FSSIM), showing promising results for real-time predictions during mine fires.

Mar 6, 2022

By J. A. Caceres

Mining planning and mineral processing are almost two unconnected areas. The mining area builds its economical models considering the plant like a constant parameter: a constant throughput, an average recovery and a unitary cost. On the other hand, the mineral processing area assumes a mine plan with grades, ore type, work index, estimating the performances in an independent way. Previous researches have evaluated the advantage for increasing throughput by increasing the liberation size, thus sacrificing recovery. These valuables approaches have left behind the work index factor, critical variable for Recovery-Throughput capacity estimation. This study describes a method combining mineral processing and mining planning. This method incorporates the grinding and flotation performances into the mining economic models optimizing simultaneously the Throughput- Wi(Work index)- Recovery relations with mining sequence, cut-off strategies, and reserve schedules. This method has been used at Andina Mine Chile, showing 18% net present value increasing with minimum investment associated.

May 1, 2003

By Brendan Donnelly, Jung-Hoon Sul, Lasitha Piyathilaka, Sanghyun Jeong, Benjamin Probyn

The chains of armored face conveyor (AFCs) are constantly in contact with water and wet coal, which results in a significant proportion of unplanned downtime experienced on longwall equipment due to corrosion. While reverse osmosis (RO) is one of the most prevalent water treatment methods for reducing salinity and dissolved solids in coal mining, its impact on the corrosion of the AFC chains has not been well studied. This work studies the direct effects of RO water on the corrosion of AFC chains. Immersion tests followed by surface micromorphology analysis and corrosion indices indicate that the RO water increased the corrosion rate of the AFC chains due to the reduced tendency of preventive films on the chains.

May 1, 2024

By Juan J. Monsalve, AMAN SONI, Nino Ripepi, Richard Bishop

The design and strength of pillars are important parameters when implementing the room-and-pillar mining method in a limestone mine. The process becomes complex with the presence of karst voids, which are frequent phenomena in carbonate rock formations. This research continues a previous study aimed at studying the effect of karst voids on the strength of a particular limestone pillar. Using calculated pillar strength and estimated redistributed stresses, it was assessed that the pillar can counter more stress than currently imparted on it. Numerical modeling studies combining in situ stress determination and excavation sequencing were used to estimate the existing stresses on the pillar. Different possibilities of modification to existing pillar design were simulated using distinct element method (DEM) modeling to determine a better design.

Jun 1, 2023

By R. S. Dean

T HE theory of hardening by heat treatment was, as usual, the most actively discussed phase of metal working theory and in spite of the fact that it is now ten years since the dispersion theory was proposed by Messrs. Merica, Waltenberg, and Scott, it still retains a dominating influence. It is being increasingly recognized. however, that in its simplest form, that is, the purely mechanical effect of very fine crystallites distributed through a groundmass, it is distinctly in- adequate. To explain the observed facts we are obliged to assume some well-defined intermediate stage between supercooled solid solution and conglomerate, however fine be the particles of the latter. This intermediate has been inferred by Gaylor and Preston to be "the rejection of the atoms of the dissolved metal from the lattice of the solid solution accompanied by the possible formation of molecules."' Perhaps this may well be designated as the formation of supersaturated solid solution. Some very definite evidence of such an inter- mediate stage has been found in the hardening of steel where it appears that the very hard martensite may be considered as a supersaturated solution of carbon in a iron. The X-ray spectrometry of drastically quenched steel shows a tetragonal lattice whose parameter changes by tempering at 100" until it coincides with the cubic lattice of iron.? The same gradual change of the tetragonal to the cubic lattice has been observed by Sekito when esamining layers on increasing depth below the surface of a quenched carbon steel.

Jan 1, 1930

By A. C. Fieldner

Much activity is called for in the present period of hightened national effort, and wise direction of such a program must always be conditioned by positive knowledge gained in years of slow and painstaking study and development. Research and technologic investigations on coal by the Bureau of Mines have been described in a series of annual

Jan 1, 1941

By Z. T. Bieniawski, José Miguel Galera, Benjamín Celada

TBM case histories from over 400 tunnel sections are analyzed presenting a comprehensive application of the Rock Mass Excavability (RME) index (Bieniawski et al.2006). The paper introduces two new adjustment factors, called the Factor of Tunnel Length and the Factor of Crew Effectiveness, which were established to represent more realistically the interaction of the rock mass characteristics, the TBM parameters and the performance of the crew operating the machine. A new correlation is provided for predicting the average rate of advance of double-shield TBMs working specifically in the double-shield mode.

Jan 1, 2007

By Jaeheon Lee, Junmo Ahn, Jae-Yeon Kim, Yoo-Jin Kim, Jiajia Wu, Eun-Woo Kim, Jai-Won Byeon, Jun-Jae Lee

The surge in demand for battery materials, coupled with environmental challenges linked to battery disposal, underscores the need to recycle spent lithium-ion batteries (LIBs). Green recycling approaches, in particular, have garnered attention for battery recycling. In this study, a hydrometallurgical method using a synergetic organic lixiviant combining methanesulfonic acid (MSA) and citric acid (CA) as an alternative to inorganic mineral acids was introduced as a green approach to recycle cathode materials of LIBs. The conditions for leaching and recovery processes were optimized. Cathode materials were regenerated using the recovered materials. Moreover, the leaching performance and economic feasibility of this leaching system were compared with those of various other organic acids.

Feb 1, 2024

By L. Linzer, J. Oelofse, T. Rangasamy

Extraction of isolated blocks of ground with elevated levels of stress and/or seismicity is a common occurrence in South African gold mines. Isolated blocks of ground that are divorced from the main orebody and are bound by complex, dip and strike parallel, non-persistent geological structures dominate the Klerksdorp gold fields. No quantifiable methods exist to assess the risk associated with mining these and other classes of remnants. A case history, from a gold mine that planned to extract three remnant blocks hosted in a large complex fault system, is used to illustrate the decision making process based on a combination of underground observations, numerical and seismic techniques. Simple risk estimation matrices were developed and used to estimate remnant-mining risk and finally to quantify the decision on which of the three remnant blocks could be extracted at the lowest possible geo-mechanical risk. Il est courant dans les mines aurifères sud-africaines d’extraire des blocs de terrain isolés qui possèdent des niveaux élevés de contraintes et/ou sismicité. Les régions aurifères de Klerksdorp sont dominées par des blocs de terrain isolés qui sont séparés du gisement principal et qui sont retenus par des structures géologiques non continues, à parallèle de pendage et direction, et complexes. Il n’existe pas de méthodes quantifiables pour évaluer le risque associé à l’extraction de ce genre et autres genres de résidus. Une observation de cas, celle d’une mine d’or qui avait l’intention d’extraire trois blocs de résidus qui se trouvaient dans un grand système complexe de faille, est utilisée pour illustrer le processus décisionnel basé sur une combinaison d’observations souterraines, et de techniques numériques et sismiques. Des matrices simples d’estimation de risque furent développées et utilisées pour estimer le risque lié à l’extraction des résidus et finalement pour quantifier la décision sur lequel des trois blocs de résidus pouvait être exploité au moindre risque géo-mécanique. Die Extraktion isolierter Gesteinsblöcke mit erhöhtem Spannugsniveau oder Seismizität ist in südafrikanischen Goldminen üblich. Isolierte Gesteinsblöcke, die von der Haupterzader getrennt und durch komplexe, parallele abfallende und horizontale nicht persistent geologische Strukturen gebunden sind, beherrschen das Klerksdorp Goldfeld. Es gibt keine quantifizierbare Methoden die das Risiko welches mit dem Abbau dieser und anderer Klassen verbunden ist beschreiben. Eine Fallstudie einer Goldmine, welche die Extraktion von drei in einem großem komplexen Verwerfungssystem eingelagerten Einschlußblöcken plante, wird verwendet um den Entscheidungsprozeß zu illustrieren, der auf einer Kombination von Untertag Beobachtungen und numerischen und seismischen Techniken basiert. Einfache Gefahreinschätzungsmatrizen wurden entwickelt und angewendet um das Abbaurestrisiko abzuschätzen und letztendlich die Entscheidung zu quantifizieren, welcher der drei Einschlußblöcke unter dem niedrigst möglichen geo-mechanischen Risiko extrahiert werden konnte .

Jan 1, 2003

By J. H. East, D. Harrington

"INTRODUCTION Shaft mines, coal and noncoal alike, have a common hoisting problem that remains largely unsolved - how to obtain a mechanical device that will suspend a cage or skip in a mine shaft if the hoisting rope should break or become detached from the cage or skip and that will function effectively under all conditions of service. Safety catches, or safety dogs, as they are commonly named, are installed on nearly all mine cages and many skips operating in American mines, but often, if the hoisting rope breaks, the cage or skip falls to the bottom of the shaft in spite of safety devices, causing much property damage and often fatalities.Available information relative to safety catches for mine cages and skips, desirable characteristics of safety catches and methods of testing safety catches to determine whether they are functioning correctly has been assembled in this publication for the convenience of those responsible for the safe operation of mine cages end skips and, more particularly, to focus attention on the need for a device that actually will stop and suspend a falling cage or skip under all conditions of use and do it without killing or maiming the occupants."

Feb 1, 1948

By Alfred Weiss

These volumes report on the study initiated by the U. S. Bureau of Mines to develop and apply a methodology to quantitatively assess the probability and potential benefits of technological innovation over the next twenty-five years. The potential was recognized for new technology to solve copper industry problems in the United States. Objectives of the study were to: (1) Develop a methodology to obtain the opinions of mineral experts about future events -their likelihood of occurrence, and, conditional on occurrence, when and to what extent they are likely to occur; (2) Identify, select, and describe potential technological innovations which would have significant impact on copper production; (3) Implement the methodology and obtain the opinions of the mineral experts regarding selected copper technologies; and (4) Analyze the expected future benefits of successful technological innovations :n the copper industry. Although individual technologies are continuously examined throughout the copper 'community', this study is the first known comprehensive forecast of future copper technology. This study is also believed to be unique 1n that it represents the consensus opinion of over sixty expert copper technologists on the expected use of innovative technology in the industry over the next 25 years. The report is contained in three volumes.

Jan 1, 1983

By G. Bartolacci, G. Couture, Levasseur. B., A. Lockhart, D. Nathan

"Pulp and froth zone characterization in a flotation circuit to improve transport of valuable minerals remains a challenge. Even though some significant breakthroughs have been made in the development of collectors in terms of selectivity, the control of gangue drainage is still the main bottleneck to achieve the production of a clean concentrate.Over the last decade, COREM’s team has been working on technologies to improve the selectivity of flotation circuits by tuning their hydrodynamic conditions using online instruments such as the bubble viewer, Jg sensor and gas hold-up. As part of its research program, COREM also developed the half-life column that establishes the relationship between the collection zone (bubble-particle attachment) and the cleaning zone (foam) of a flotation machine. In recent years, COREM has continued the development of the prototypes to make them more robust and improve the accuracy of their measurements.Recently, these hydrodynamic instruments were installed in an industrial process at Raglan Mine in order to diagnose and control the impact of hydrodynamic parameters versus the recovery and the quality of the Ni concentrate produced. Sampling campaigns of hydrodynamic parameters demonstrated that froth height could be optimized in order to increase recovery and quality of the concentrate at the same time. The specific effect of the froth height impacts both the pulp and the froth zones. Along with the impact on the drainage of the concentrate, it was observed that froth height also contributes to enhance the collection of particles in the pulp leading to an increase in metallic units.IntroductionOnce the particles of the minerals of interest are attached to the air bubbles injected in the pulp, the flotation process is driven by air dispersion parameters and froth properties. The pulp is usually responsible for the collision between air bubbles and hydrophobic particles of interest while the froth zone aims to upgrade the selectivity of the particles floated through drainage of the unwanted hydrophilic particles. Over the last four decades, flotation hydrodynamics has been extensively studied. Superficial gas velocity (Jg), gas hold-up (eg), Sauter mean bubble diameter measurements (d32) and bubble surface area flux (Sb) are among the most assessed parameters in flotation plants worldwide either to quantify the gas dispersion parameters or to optimize them (Fournier et al., 2015). McGill University has developed several sensors able to measure these parameters at industrial scale (Tavera et al., 1996; Finch et al., 1999; Chen et al. 2001)."

Jan 1, 2017

By Rita D. Sylvester

"This compilation lists and summarizes publications by Bureau authors published in the regular Bureau of Mines series, in scientific, technical, or trade journals, or in other media; those available from the Bureau of Mines are indicated. Patents issued to Bureau personnel are also listed, and instructions are given on how to apply for permission to use them. One of the outstanding features of this Special Publication is an exhausive subject and author index. IntroductionThe Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and present their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries, The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminar's; in reference books; and in other non-Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue describes reports and articles published during the period January 1, 1970, to December 31, 1974. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960;2 the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960;3 and the 5-year lists of Bureau publications and articles from January I, 1960, to December 31, 1964,4 and from January I, 1965, to December 31, 1969.5 It includes all the material in the four annual lists of Bureau publications and articles from January 1, 1970, to December 31, 1973."

Jan 1, 1975

By P Tzeferis

An exploratory laboratory work was carried out on microbial leaching of poor non-sulphide nickel ores, not amenable to conventional mineral processing operations. The results have shown that domestic low-grade lateritic ores of limonitic or haematitic type are amenable to bioleaching by fungal strains of Aspergillus sp and Penicillium sp. Maximum nickel and cobalt recoveries achieved were 60 per cent and 50 per cent respectively. Losses of soluble nickel in the fungal biomass were found in the range 3 - 11 per cent. Chemical analysis of the leach liquors showed the presence of significant amounts of citric, oxalic and other organic acids, indicating the role which certain metabolic products of fungal activity may play in the process. Possibilities for future investigations are discussed.

Jan 1, 1997