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By J. Shahabpour

"Many porphyry copper deposits of the Kerman copper province in central Iran are associated with a consistent structurally con-trolled main drainage pattern, which is shown in this paper to be a useful regional prospecting tool in the search for new deposits. The main drainage trends also generally allow the distiction of high-grade (>0.2% Cu) from low-grade (<0.2% Cu) deposits. Topographic maps1:50 000 or geologic maps 1:100 000 have been found suitable for identification of promising drainages.IntroductionTrends of the main drainage systems transecting the high-grade porphyry copper deposits of the Kerman Region in Iran coincide with Quaternary age regional faults and fractures. Observation of such drainage trends can expedite regional evaluation prior to field examination. Thirty deposits located in the Kerman Region (Fig. 1) have been studied to identify common features that can be used for exploration purposes, especially for the first stage of regional exploration. A variety of field criteria are available for subsequent rapid field checking prior to trenching and more costly methods such as drilling, etc.Characteristic geomorphic features have been considered as aids in mineral exploration by many authors (e.g., Faniran, 1971; Piotrovski and Lubkashov, 1976; Verstappen, 1983). Clark et al. (1967) indicated the relationship between geomorphology and the supergene enrichment of copper in Atacama Desert, Chile, and correlated three periods of supergene enrichment with three periods of pediment disection. Seeland (1978) used fluvial drainage patterns for uranium and hydrocarbon exploration in the Wind River basin, Wyoming. Postolenko and Konopleva (1973) used the reconstruction of ancient valley systems for exploration of gold placers"

Jan 1, 1996

Professor N. S. Budavari holds a Dip!. Min. Eng. from the Technical University of Sopr on, Hungary, and a Ph.D. degree from the University of Newcastle-upon-Tyne, U.K. Mr J. J. Geldenhuys, Pr. Eng., is Divisional Manager Mining of Anglovaal Limited, being in charge of Prieska Copper Mines (Pty) Limited, Loraine Gold Mines, Limited, and Village Main Reef Gold Mining Company Limited.

Jan 1, 1983

By James M. Link

Underground coal mining is the most hazardous industrial occupation in the United States.. Haulage accidents in underground coal mines contribute substantially to the occupational hazards of this type of work. In an effort to improve mine safety, a completely hydraulic transport system has been designed to move coal from the mine face to the preparation plant. The capital investment for the hydraulic haulage system is great, and the size of the mine developed for this study is large. Mine production for the conventional haulage mine is 1. 1 million tons of clean coal per year, while the hydraulic haulage mine will produce over 1.6 million tons of clean coal per year. Safety statistics for a number of mines of this size are shown.

Jan 1, 1975

By John Murray, Daniel Ebin, Robert Gould

The Atlanta Plane Train project at Hartsfield-Jackson Atlanta International Airport employed the progressive design-build approach. This provided opportunities for collaboration between the design-builder, design engineer, and owner and the implementation of innovative design and construction approaches. The innovations have reduced risks, allowed for adjustments during design to accommodate new challenges, and provided open-book cost and schedule evaluations. The progressive design-build approach has also allowed for pricing of work to occur in phases—capturing the design/construction challenges as the project evolves and when they are more clearly defined. While this has allowed for pricing to be performed with better project understanding and therefore less contingency, the associated time frame for approvals has required careful consideration to avoid impacts to the schedule. This paper discusses the benefits and challenges of the progressive design-build approach.

Dec 1, 2022

By A S. Derrington

In some parts of Australia, mine air cooling may not be needed until a depth of 1300 m below surface is reached. In other locations, it may be essential at a depth of only 300 m below surface. The reasons for these differences are multifaceted. This paper discusses the main factors and describes a simple method to assess whether or not mine air cooling will be required. The method uses a graphical relationship that considers depth below surface, geothermal gradient, surface climatic conditions and directness of the mine intake routes. This relationship has been developed, tested and refined over a period of more than ten years using data collected from most of Australia’s deeper metalliferous mines. The method provides a ‘first-pass’ indication of whether more detailed cooling studies may be needed. Perhaps more importantly, the method’s underpinning by benchmarking against other mines improves confidence in the assessment results. Like any empirical method, the context must be understood and this aspect is also discussedCITATION:Derrington, A S, 2014. Will your mine require cooling?, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 181–186 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

South Africa?s now a member of this body, tailored on the World Bank, and headquartered in Abidjan-Cote d&apos;Ivoire. As a funding agency for capital projects within 59 member countries of the ADB it is to be expected that there are guidelines to the requirements for funding application and for project management and control.

Jan 1, 1996

By Robert Bégin

Reconnue pour son expertise en formation minière, la Commission scolaire de l?Or-et-des-Bois, dans le cadre du projet MRN-ACDI en Bolivie, a reçu en 1999 le mandat d?implanter un programme de formation en santé et sécurité du travail dans les mines artisanales boliviennes. À la suite d?une mission préliminaire en Bolivie et de la venue à Val-d?Or d?une délégation bolivienne, il a été convenu de l?adaptabilité du modèle québécois du programme de «formation modulaire du travailleur minier» au contexte bolivien. Là-bas, les méthodes de travail sont essentiellement artisanales et la pauvreté extrême des mineurs les pousse à prendre des risques quotidiens. Les modules de formation priorisés sont : «Introduction à la santé et à la sécurité du travail», «Principes d?écaillage» et «Matériel de sautage et explosifs». Les universités Tomas Frias de Potosí et Siglo Veinte de Llallagua sont responsables de l?élaboration et de l?implantation du programme dans deux coopératives minières de leurs secteurs. Dans une phase ultérieure, le programme sera étendu à plus large échelle. Enfin, des missions de suivi et d?encadrement sont effectuées périodiquement par les représentants de la Commission scolaire de l?Or-et-des-Bois. La formation en santé et sécurité dans le milieu de travail constitue un nouveau défi pour les universités boliviennes et une source d?espoir pour les mineurs des coopératives minières.

May 1, 2001

By P. Schloth, H. van Swygenhoven, N. Chobaut, J-M. Drezet

"In the current trend toward thicker aluminium plates, a major concern is the stress build-up during quenching which causes distortions during machining. Indeed, cooling rates are not high enough, especially at the core of such thick plates, to prevent any precipitation and quench induced precipitates lower the hardening potential. Multi-scale modelling is required when predicting macro-scale stresses after quenching for thick heat treatable aluminium components. The reason is the instantaneous strong coupling between phase precipitation at the nano-scale and material hardening due to precipitation or softening owing to solute depletion at the microscale. For thick parts, quenching intensities decrease when going from the skin to the core of the component, thus introducing a gradient of nanostructure and consequently a gradient of mechanical properties. In addition, large thermally induced deformations lead to high macroscale residual stresses although part of them is relaxed by plastic deformation. These stresses have been measured in water quenched thick plates of 7040 and 7449 aluminium alloys using neutron diffraction and layer removal techniques and the results when compared with a thermomechanical finite element model of quenching highlight the influence of precipitation.IntroductionIn the processing route of heat-treatable aluminium alloys (AA), a critical step is quenching from the solutionizing temperature. High cooling rates are desired, as they avoid formation of coarse precipitates, which reduce mechanical properties. Fast quenching, however, cannot be achieved in the centre of thick components, where the quenching rate can be more than one order of magnitude lower than at the surface. The existence of a thermal gradient between core and surface leads to a differential thermal deformation which is accommodated by elastic and plastic deformation to comply with the compatibility of deformation. Whenever the material yields, especially at high temperature when the yield strength is low, residual stress remains after quenching due to the irreversibility of plastic deformation. After quenching, the plates are in a state of residual stress that causes unacceptable distortions during machining and may reduce service life drastically. Since stress relaxation is negligible during ageing treatments [1 ], agehardened aluminium parts are usually stress relieved prior to ageing. This is typically achieved by applying plastic deformation: stretching from 1.5 to 3 % in the rolling direction (L) can reduce the internal stresses by a factor of approximately 10 [2, 3]. However, complex geometries or thicker components like thick sheets require other approaches. Reducing the quenching rate by using boiling water for instance leads to lower residual stresses [1, 4]."

Jan 1, 2013

By D. D. Southworth

In 1987, the Bureau of Mines initiated a mineral assessment of the 5.7 million-acre Valdez Creek Mining District (VCMD). Following a literature search and interviews with persons knowledgeable about deposits within the district, limited on-site field visits were made to various deposits. Present within the district are the industrial minerals limestone, argillite, granite, basalt, perlite, zeolite, and sand and gravel. At least six limestone deposits of potentially economic size and grade are known to exist within the district. Adjacent to the Parks Highway and marginal to the district, a limestone deposit is currently being mined as a source of agricultural lime. A perlite occurrence near Yacko Creek was evaluated but proved not to be of industrial grade. The sand-and-gravel resources of the district are vast, but high silt content renders many of the glacial deposits unsuitable for use in construction applications.

Jan 1, 2011

By H. J. R. Way

Dr H. J. R. Way: In his reply to my queries Mr Bath still adheres to his statement that it may be possible to replace the estimated R200 million reduction in gold revenue in 1980 by exports of ferro-chromium, and apparently based his conclusion on a growth rate in demand for corrosion resistant steels of 10 per cent per annum in the next few years. As I pointed out at the previous discussion at Middelburg this would entail a production of about one million tons of ferro-chromium in 1980. Exact statistics of South African ferro-chromium production are not available, a fact which is very much to be regretted. But statistics of exports of ferro-chromium are available from "Foreign Trade Statistics" of the Customs and Excise. These show that South Africa exported 99,580 short tons in 1967. The quantity of ferro-chromium consumed in South Africa in 1967 was fairly small and we can therefore assume that the production was 99,580 tons. For this amount to grow to 1,000,000 tons in 1980 would require a growth rate of 19.4 per cent per annum. At 10 per cent this would grow to 344,000 tons and at 7 per cent 240,000 tons. The following growth rates in the form of average trends are pertinent: STEEL - Per annum World steel ingot production - 1957-67 – 6.8 per cent Free-world ingot production - 1957-67 – 6.0 per cent Consumptions of crude steel by four major Free-world Consumers - 1957-67 - 5.6 per cent CHROMITE World production - 1952-67 - 2.5 per cent South African total sales - 1948-67 – 5.4 per cent South African exports - 1948-67 – 3.9 per cent United States consumption, very irregular, but - 1962-67 – 6.5 per cent FERRO-CHROMIUM - Per annum United States consumption - 1952-67 - 6.5 per cent South African exports - 1957-62 - 25.2 per cent South African exports - 1962-66 - 41.9 per cent South African exports - 1966-68 - 21.2 per cent These figures show that exports of ferro-chromium have been growing at a very high rate varying from 21.2 per cent to 41.9 per cent since 1957, but in view of the market situation it seems somewhat doubtful if that high rate can be maintained up to 1980. Of our 1966 exports U.S.A. took 63 per cent which was 53 per cent of their total imports. Their average consumption is trending at a growth rate of 6.5 per cent per annum from 1952-67, but the growth from 1964-66 was 5- 2 per cent and 1966-67, -12 per cent!

Mar 1, 1968

By J. M. West

Increased leisure time and increased interest in the out-of-doors is leading more and more families to experiment with placer mining of gold, and some- times even to going on into small-scale production. This Bureau of Mines report supplies basic information un areas of occurrence, equipment needed, prospecting, sampling, mining, and regulations concerning the possession and sale of gold. Selected references are given for further study.

Jan 1, 1971

By A. Navarra, A. Quelopana

The mine production scheduling problem (MPSP) has been studied since the 1960s, and remains an active area of computational research. In extending the concepts of the MPSP, the automated mine may now be regarded as a hierarchical intelligent agent in which the bottom layer consists of distributed robotic equipment, while strategic functionality occupies the higher layers. Here we present a disambiguation of artificial intelligence, machine learning, computational optimization, and automation within the mining context. Specifically, the Q-learning algorithm has been adapted to generate the initial solutions for a high-performing strategic mine planning algorithm, originally developed by Lamghari, Dimitrakopoulos and Ferland, based on the variable neighbourhood descent (VND) metaheuristic. The hierarchical intelligent agent is presented as an integrative conceptual platform, defining the interaction between our new Q-learning adaptation and Lamghari’s VND, and potentially other hierarchically controlled components of an artificially intelligent mine, having various degrees of automation. Sample computations involving Q-learning and VND are presented.

Dec 1, 2021

By Marcos Paulo Kohler Caldas

Após a edição da RoHS Directive 2002/95/EC, diretiva que entrou em vigor em 1º de julho 2006 proibindo a utilização de seis substâncias perigosas: chumbo, mercúrio, cádmio, cromo hexavalente, bifenilos polibromados e éteres difenil-polibromados, fabricantes de equipamentos eletroeletrônicos passaram a utilizar soldas livres de chumbo (lead free) para montagem de suas placas de circuito impresso. A SAC 305 é um tipo de solda muito utilizada pelas empresas fabricantes de placas de circuito impresso. O presente trabalho visa caracterizar este tipo de solda verificando sua composição e identificar se a mesma se encontra livre de elementos perigosos ao ambiente. Avaliou-se a extração de metais como Ag e Sn através de digestão ácida em água-régia e rota HNO3 a temperatura ambiente. A composição do licor lixiviado foi caracterizada por espectrometria de emissão óptica com acoplamento de plasma induzido (ICP-OES). Os resultados indicam que a solda SAC 305 atende a RoHS, possui 2,7% Ag, 96,4% Sn e 0,9% de outros metais e a melhor rota para extração de Ag foi a HNO3 e para Sn foi a água-régia.

Aug 7, 2018

J. Lainson Wills, Ottawa, Can. (Communication to the Secretary) : The localities of the Quebec and Ontario apatite deposits, and the nature of their occurrence haye been often described in the Transactions and in other publications that are readily available, and I do not, therefore, intend to discuss the many details advanced in Mr. Small&apos;s paper beyond the following two points:

Jan 1, 1893

By R. L. Grayson, S. B. Bealko, L. L. Chasko, D. W. Alexander

In response to recent mining disasters and new mine rescue team legislation, NIOSH researchers conducted meetings across the United States with mine emergency response experts to investigate current needs and issues. Some of the issues include emergency response preparedness, mine rescue contests, real-life training capabilities and training facilities. Many new teams are being formed that must be trained for mine rescue team competitions as well as be ready to respond to a variety of mine emergencies, including a fire or explosion, a massive roof collapse, mine inundations or vertical shaft rescue situations. Therefore, it is important that these teams are adequately prepared and trained. This paper presents a summary of domestic and international coal mine rescue training facilities and identifies those that provide unique, real-life and/or state-of-the-art training. Research findings from this report will be used in further NIOSH investigations to improve coal mine rescue training.

Jan 1, 2010

"Twin Creeks is a gold mining complex that is part of Newmont’s Nevada operations. The mining complex is composed of two openpits, Mega and Vista, external ore sources and a set of existing stockpiles, all of which provide ore for an autoclave, an oxide mill and a heap leach. Mega pit provides sulfide ore for the autoclave, whereas Vista pit provides oxide ore for the oxide mill and the heap leach. Both pits operate the same mining equipment and their extraction sequence must, therefore, be optimized simultaneously. Stringent blending requirements are associated with the operation of the autoclave for the sulfide ore. Strategic blending optimization on a large scale has brought significant value to the operation by increasing synergies. This paper presents the implementation of a stochastic optimization framework for the long-term production planning at Twin Creeks that simultaneously optimizes mining, stockpiling, blending and processing decision variables. The uncertainty and variability associated with the different sources of material are incorporated in the optimization model by means of stochastic simulations. The stochastic solution generated shows substantial benefits by increasing forecasted recoverable gold, leading to increased cash flows, while reducing the risk of not achieving forecasts by increasing the probabilities of meeting production and blending targets.IntroductionMine operations consist of multiple components such as mineral deposits, stockpiles, external sources, mills and autoclaves. These components represent a mineral value chain, also known in the literature as a mining complex (Montiel and Dimitrakopoulos 2015; Goodfellow and Dimitrakopoulos 2016). The material extracted from the mines flows through the different components and is transformed into sellable products. This flow of material in a mineral value chain involves complex, nonlinear transformations that render the use of industry-standard optimizers difficult. Furthermore, the optimization of a mining complex can be formulated as a mixed-integer, nonlinear optimization program with millions of integer variables representing mining, blending, stockpiling and processing decisions, prohibiting the use of conventional nonlinear optimization approaches. Previous methods that consider the joint optimization of multiple components of the mineral value chain are available (Hoerger, Seymour and Hoffman, 1999; Chanda, 2005; Stone et al., 2005; Wooller, 2005; Whittle, 2007, 2010; Bodon et al., 2010). Although these methods add value by increasing the synergy between the different components of the mining complex, they rely on simplifying assumptions that constrain their efficacy, while ignoring a most critical aspect. The latter aspect includes the geological uncertainty and actual variability of the materials in the mineral deposits mined and are supplied to the related mineral value chain, similarly to conventional life-of-mine planning methods used for individual mines (Dimitrakopoulos, Farrelly and Godoy, 2002; Godoy and Dimitrakopoulos, 2011; Spleit and Dimitrakopoulos, 2017). Additional simplifying assumptions may include: the consideration of a limited number of components, the combination of different methods, the aggregation of variables, fixed production schedules the definition of policies prior to optimization, such as cutoff- grade definition or destination of mining blocks, the linearization of nonlinear transformation functions and/or the disregard for the uncertainty of several critical parameters (Whittle, 2007). The simultaneous optimization of multiple components of a mining complex was introduced by Newmont. Hoerger, Seymour and Hoffman (1999) implemented a mixed-integer programming formulation to optimize Newmont’s Nevada operations. The model is based on the work of Urbaez and Dagdelen (1999) and simultaneously optimizes the extraction of materials from multiple deposits and the delivery of ore to multiple plants, as well as as"

Dec 1, 2018

By Lloyd A. Morley

A guide to the development and use of an APL computer program for the analysis of load-flow problems is presented. The program is designed to provide an interactive method of load-flow study to improve underground coal mine electrical system design and safety. The theoretical basis for load-flow analysis is discussed, along with per-unit calculations which facilitate computation. Specific input/output, execution and network modification procedures are presented for using the APL program. In addition, typical results are given for examples taken from power system analysis literature.

Jan 1, 1977

By B. Q. By

TiO2 is an ideal material for catalytic technology due to its unique properties. In this paper, Sm3+ doped TiO2 photo-catalyst was developed to improve the efficiency of TiO2 and to use the natural light as irradiation source, which was made from Titanium Tetrabutoxide and Samarium Oxide with the Sol-Gel process. The Sm3+-TiO2 photocatalyst was used to degrade reactive orange 4 (RO4) in Azo Dyes. The effects of solution pH, Sm3+ concentration and catalytic time on the degradation rate of RO4 were studied. The characteristics of the catalyst were analyzed with XRD and TEM. The experimental results show that the catalyst has high activity in the degradation of RO4. The Azo bonds of RO4 are active and easily broken by oxidation. The catalytic activity of the Sm3+ doped catalyst greatly depends on the pH of solution. The catalyst has high photo-catalytic activity at both neutral and alkaline conditions. The degradation mechanism of the Sm3+ doped TiO2 photo-catalyst was also discussed.

Jan 1, 2014

By A. E. Wraith, R. Harris, J. Qiu, R. Parra

Small pilot scale experiments have shown that it is possible to almost fully eliminate the minor elements (ME), namely As, Sb, Bi and Pb contained in smelter dusts by vacuum calcination of mixtures of the dust with sulphidizing agents such as dirty copper concentrate or elemental sulphur at 900 °C and 80 +/- 30 Pa for 90 minutes. The products of this calcination are a residue comprising a purified mixture of copper containing compounds along with the gangue constituents and a high sulphur condensate comprising a mixture of the minor element compounds. In particular, the Cu:ME ratios of the concentrate and dust were increased from 250 and 50, from 28 and 12 and from 36 and 8 to roughly 3000, 3000 and 100 for the calcine, for Bi, As and Sb, respectively. It has also been calculated that (i) the copper content of the vacuum calcine may be recovered by feeding it into a Peirce-Smith converter during its slag blow, and (ii) the resulting recycling could increase the minor element treatment capacity of a smelter by 100 % while also reducing the blister As content by a factor of three. The experimental results are briefly discussed and a treated dust recycling option is examined. Example operating conditions are presented and available commercial technology for the vacuum calcination of the mixtures is reviewed.

Jan 1, 2007

By D. L. Koch, J. W. Tester, L. K. Sinclair

"In this study, hydraulic conductivity (K) geostatistics were used to predict residence time distribution of well-to-well flow. Flow profiles, fracture density measurements, and pumping tests were available from the highly fractured Florence Copper in situ leaching site. The flow profiles were used to establish the statistical distribution and spatial autocorrelation of K. Two tests were used for validation. The first test confirmed that fracture density and K are autocorrelated over similar length scales. In the second test, Monte Carlo flow simulations successfully recreated the results of pumping tests. Flow sim¬ulations were used to stochastically model well-to-well residence time distribution. RÉSUMÉ Dans cette étude, nous utilisons la géostatistique de la conductivité hydraulique (K) pour prévoir la distribution des temps de séjour (DTS) de l’écoulement entre les puits. Des profils de l’écoulement, des mesures de la densité des fractures et des essais de pompage existaient pour le site fortement fracturé de lixiviation in situ de Florence Copper. Les profils de l’écoulement ont permis d’établir la distribution statistique et l’autocorrélation spatiale de K. Deux essais ont servi à la validation ; le premier a confirmé que la densité des fractures et K sont autocorrélés sur des échelles de longueur similaires ; quant au second, des simulations d’écoulements de type Monte Carlo sont parvenues à reproduire les résultats des essais de pompage. Les simulations d’écoulement ont servi à établir un modèle stochastique de la DTS de l’écoulement entre les puits.INTRODUCTION In situ leaching is the circulation of a dilute acid or base solution in the subsurface, via a series of injection and recovery wells, to dissolve a target metal. In situ leach modelling requires forecasting the residence time distribution (RTD) of flow between wells. In fractured formations such as copper porphyry deposits, order-of-magnitude variations in hydraulic conductivity (K) can result in highly channeled flow, resulting in a heavy tailed RTD (Becker & Shapiro, 2003; Kang, Le Borgne, Dentz, Bour, & Juanes, 2015). Channeling through preferential pathways has impacted copper recovery at several past in situ leaching field tests (Cathles, Glenn, Lenzi, Nigrini, Deans, & Huff, 1978; Ahlness & Pojar, 1983; Schmidt, Earley, & Friedel, 1994; Sinclair & Thompson, 2015). The aim of this work is to combine multiple types of hydrogeological measurements to stochastically forecast the well-to-well RTD in fractured rock for the purposes of copper in situ leach modelling."

Jan 1, 2018