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By D. G. Hulbert, D. J. Oosthuizen, D. de V. van der Spuy

Expert Online, as a software system, is aimed at providing plant operators in the minerals industry with effective training and on-the-job assistance. It incorporates a number of features to achieve this goal, of which the most important is its ability to explain the dynamics of the plant and control system in simple language, mimicking an informed plant expert who has online access to the inner workings of the plant and control system. This is made possible by a novel form of Artificial Intelligence, called the Interpreting Expert System. Previous implementations of the IES were only capable of explaining controller actions. Expert Online will extend this capability to also perform the more difficult task of explaining process behaviour. Expert Online will implement three main processes, namely the accumulation of data from the controllers and plant models, the interpretation, processing and filtering of that data and lastly communicating the relevant information to the user, both as written messages and in other audio-visual forms. Although Expert Online is aimed at the operator, other plant personnel, like supervisors and plant managers, will also benefit from it. This paper focuses on the structural and functional design of Expert Online for implementation on the latest version of Mintek’s open control platform, PlantStar, highlighting advances and additions since the previous implementations of the Interpreting Expert System and concluding with an example illustrating some of the principles.

Jan 1, 2003

INTRODUCTION This paper was originally presented at the Platinum Adding Value Conference, held at Sun City from the 4th to 6th October 2004. Narrow reef mining may not be applicable to the base metal operations in Zambia, however, it is considered that the methodology used is equally appropriate to the development of technology and mining methods in mining environments other than narrow reef mining. The purpose of this paper is to explore the integration of technology and stoping systems. For the last hundred years the South African narrow reef mining industry has battled to control working costs in a labour intensive industry. It is only through the application of appropriate technology that change will occur. Stoping systems, because it is the stoping method and methodology that is at the heart of the mining system. Introduce a different technology that results in a more efficient stoping system and the mining system will look after itself. The technology applied to stoping in narrow reef mining, over the last 100 years, can be categorised as follows: ? The introduction of pneumatic rockdrills early this century. The cumbersome rig mounted units being replaced by smaller, lighter, hand held units that were then made easier to use with the addition of an air leg. (The so called Swedish method of mining.) As late as the early 1970s some drilling was still being carried out without the assistance of an air leg. ? Scraper winches to replace gravity and shovels to move rock both in the face and the gullies were first introduced in the late 1920s. ? Hydraulic props installed close to the face and capable of applying force against the hangingwall as well as yielding in a controlled manner under dynamic load arrived in the 1960s. In many instances these have now been replaced by yielding elongates fitted with water hydraulic tensioning devices. ? Some people argue that the introduction of tungsten carbide inserts, to improve drilling, was equally important.

Jan 1, 2005

1. Book reviews Dislocations and properties of real materials, edited by M.H. Loretto. London, The Institute of Metals, 1985. 392 pp. Reviewer: F.R.N. Nabarro Au &Ag heap and dump leaching practice, edited by J.B. Hiskey. AIME, 1984. 162 pp. $20 (member), $15 (student member), $30 (non-member) plus $3.50 for postage and handling. (Order from SME Books, Caller no. D, Littleton, CO 80127, U.S.A.). Reviewer: R.A. Snodgrass The cost and availability of Colombian coal, by Eric D. Jamieson, with the assistance of Kathleen Jamieson. London, lEA Coal Research (14/15 Lower Grosvenor Place, London SWl W OEX). £50 (in member countries), £100 (in non-member countries). Reviewer: W.C. Mather Extraction Metallurgy '85. London, The Institution of Mining and Metallurgy, 1985. £42. Reviewer: R.A. Snodgrass 2. Recent publications Mining annual review 1985. London, Mining Journal, Jun. 1985. 600 pp. £26.50 (surface), £39.50 (air). High heat production (HHP) granites, hydrothermal circulation and ore genesis. London, The Institution of Mining and Metallurgy, 1985. 593 pp. £27 (members), £30 (non-members). Potential mineral resources of Egypt. 144 pp. US$10. Available from Bendix Field Engineering Corporation-MPGAP, Box 1237, Grand Junction, CO 81502, U.S.A. 3. Mintek reports Report M212 South African costs of equipment for the metallurgical industry (1984). Report M213 The response of as-rolled 3CR12 steel to heat treatment. Report M214 A computer programme for use in the development of multi-element X-ray-fluorescence methods of analysis. Report M221 Commodity profiles for selected metals. Report MIO7D Upgrading of alaskite rock to feldspathic sand. (First issued Jun. 1983; reissued Nov. 1985). IMM awards Given below are details of the trust funds to which applications are invited for grants, etc., payable in 1986. Application forms, which must be returned to the Secretary before 17th March, 1986, are available on request. Applicants should note that, in general, preference will be given to members of the Institution.

Jan 1, 1986

By I. Gil, J. -C. Roegiers

Abstract Hydraulic fracturing is a technology that has been utilized for more than 50 years in the oil industry. It was originally used for stimulating hard, brittle formations which typically exhibit low permeabilities and roughly linear elastic behavior. Nonetheless, an increasingly important segment of the industry is currently stimulating very soft and poorly consolidated formations; where the assumptions of ideal elasticity and relatively small fluid leakoff fail to hold (e.g. Gulf of Mexico, West Africa, Alaska, East China). In these rocks, hydraulic fracturing stimulation has been used for several years to control and solve critical production problems such as sanding and formation damage (caused during completion and drilling operations). Although successful1, the application of this method has not been accompanied by robust fracturing modeling techniques. In addition, long term production increases were often not materialized. In other words, engineers have been able, via trial-and-error, to avoid major ‘operational’ problems but with no optimization of such treatments. Thus, most hydraulic fracturing projects carried out in poorly consolidated rocks render unexpected results. A recent worldwide survey on net pressures by the Delft Fracturing Consortium (Papanastasiou, 1997) indicated that net pressures encountered in the field are 50% to 100% higher than the net pressures predicted by conventional fracturing simulators. The difference is yet higher for the case of poorly consolidated formations (Pak, 1997). The theory for the construction of a fully coupled elastoplastic three-dimensional hydrofrac simulator, specifically conceived for unconsolidated rocks, is presented in this paper. This novel model calculates the dimensions and changes in shape of the fracture(s) being created during hydraulic fracturing operations. No assumptions are made regarding either shape or geometry of the crack(s). Three main failure criteria are used simultaneously in this model: tensile and shear stresses, and volumetric strain. Incremental forms of the governing equations of equilibrium and fluid flow are presented. The scheme chosen for solving this problem is the finite elements method, which allows both equations to be solved simultaneously at any instant in time. Résumé La fracturation hydraulique est une technologie qu’a été utilisé pour plus que 50 ans dans l'industrie pétrolière. Elle a été utilisée au début pour stimuler les formations dure et fragile que typiquement ont des perméabilités basses et un comportement élastique à peu près linéaire. Néanmoins, un segment plus important de l'industrie stimule actuellement des formations mal consolidées; où les suppositions d'élasticité idéale et de relativement petite fuite de fluide ne se tiennent pas raison (par exemple le Golfe de Mexique, l'Afrique d'ouest, Alaska, la Chine de l'est). Dans ces roches, la stimulation avec fracturation hydraulique a été utilisée pour plusieurs années pour contrôler et résoudre les problèmes critiques de production comme les dommages de formation et d’ensablement (causé pendant les opérations de l'accomplissement et forage). Bien que prospère, l'application de cette méthode n'a pas été accompagnée de techniques robustes pour le modelage de fractures. En outre, les augmentations à long terme de production n'ont pas été souvent concrétisées. En d'autre termes, les ingénieurs ont pu, via le procès et l’erreur, éviter les majeur problèmes ‘opérationnel’ mais avec aucune optimisation de tels traitements. Ainsi, la plupart des projets de fracturation hydraulique ont été exécuté dans des roches mal consolidées et ont rendu résultat totalement inattendu. Une récente étude mondiale sur les pressions nettes par le Consortium Delft pour Fracturer (Papanastasiou, 1997) a indiqué que les pressions nettes qu’ont été rencontré dans le champ sont environ 50% à 100% plus hautes que les pressions nettes prédites par les simulateurs fracturant conventionnels. La différence est pourtant plus importante pour le cas de formations mal consolidées (Pak, 1997). La théorie de construction d'un simulateur elastoplastic d’hydrofrac à trois dimensions entièrement couplé, en particulier conçu pour les roches non consolidés, est présentée dans ce papier. Ce nouveau modèle calcule les dimensions et les changements dans la forme de(s) fracture(s) étant créé pendant les opérations de fracturation hydraulique. Aucune supposition n’a été faites en ce que concernant la forme ou la géométrie

Jan 1, 2003

By A. K. Das, S. Pathak, C. Bhanu, P. K. Tripathy

Ferroalloys are integral part of steel melting process. The purpose of using ferroalloys is three fold e.g. killing of steel, modifying the slag composition and steel alloying. Amount of ferroalloys used for alloying is subject to requirements of steel properties e.g. yield strength, ductility, formability etc. Variety of ferroalloys (some-times pure metal) is used by steel industries depending upon their techno-economic feasibility. Size, chemistry and modes of addition of ferroalloys are suitably engineered to bring in operational consistency and cost benefits. Of late, Tata Steel has tried out a few ferroalloys for the first time with interesting results to meet the specific requirements of high strength interstitial free (IF) and micro-alloyed steels. Some of these ferroalloys have been put into regular use with complete or partial replacement of ferroalloys used earlier. Size of one of the ferroalloys has also been modified without any other adverse effects. This paper summarizes requirements of ferroalloys for the steel industry with special emphasis on recent trials.

Jan 1, 2007

By Christian Heili

In 1991 the Government of the Republic of Zambia passed legislation providing for the privatisation of Zambia Consolidated Copper Mines Limited (ZCCM). The newly formed Mining Companies, established after nearly a decade of difficult and protracted negotiations on such matters as, cash at close; retained percentage interest by ZCCM; equity investment; future investment commitment and tax concessions, were faced with great internal challenges and a harsh external environment. There was a convergence of a number of negative forces that had and will continue to have an impact on the mining environment in Zambia. The most crucial of these being, the competitive pressures of the global economy, fluctuating copper price and the prevailing HIV/AIDS pandemic. In the short period after privatisation, the Industry has seen the collapse of Binani Industries (Luanshya Mine), the withdrawal of Anglo America Corporation from Konkola Copper Mines Plc and the disposal of Chambishi Cobalt and Acid Plants by Anglovaal Mining Ltd. The objective of this paper is to provide a theoretical and practically researched foundation, which may be used to assist Zambian Mining Companies in making informed decisions on the issue of Strategic Outsourcing and the degree to which this may support the successful and sustainable growth of the Zambian Copper Mining Industry. If judiciously implemented, Strategic Outsourcing has the potential to generate a practical business valuation and process to assist Mine Management in the achievement of their business goals and consequently the return on investment to their Shareholders.

Jan 1, 2005

By S. G. Gendler

One of the ways of trauma and occupational diseases level reduction is noted to be the improvement of the labour protection measures planning. As an indicator for prospective trends determination in the labour protection planning improvement sphere economic risk has been proposed to be used. The trauma and occupational diseases analysis based on the correlative and regressive methods has been carried out for the “Vorgashorskaya” mine of Pechora coal basin. Trauma and occupational diseases occurrences frequency and economic losses value have been estimated. Trauma and occupational diseases economic risk distribution analysis has been presented in respect to the different subdivisions and occupational groups of “Vorgashorskaya” mine.

Jan 1, 2003

By Li. S., C. Sili

Abstract. Study on nonlinear damage localization process of rocks under water chemical corrosion is a more interesting topic in rock mechanics research world widely. It is very important in estimating long term stability of rock engineering, design of nuclear waste repository and its performance estimation, geothermal and petroleum development. This paper reports that new development of study on the topic, including methodology, results of meso-mechanical test, real-time CT scan test and acoustic emission test, temporal fractal behaviors, neural dynamic modeling and chemical-induced damage law, etc. This paper also discusses the research directions of the topic in the near future. Zusammenfassung. Untersuchung zum durch die chemische Corrosion induzierten Schaedigungsprozess ist einer der Trends im Gebiet der Felsmechanik. Sie ist zugleich ein sehr wichtiges Forschungsprojekt u.a. fuer geotechnische Langzeitstabilitaetsanalyse, Langzeitsicherheit eines Endlagers, Erdwaerme- und Erdoelfoerderung. Dieser Aufsatz stellt die neusten Entwicklungen in den folgenden Teilgebieten zusammen: Untersuchungsmethoden, Laborversuchsergebnisse der Mikromechanik, der Computer-Tomographie und der akustischen Emission, zeitabhaengige Fraktaleigenschaften, Modelle fuer die Nervendynamik sowie Modelle fuer chemie-induzierte Schaedigungen. Zum Schluss werden kuenftige Forschungsschwerpunkte bzw. –richtungen diskutiert. Résumé L’étude du processus de la localisation de l’endommagement du à l’érosion chimique est un thème d’actualité pour la mécanique des roches. Elle est également un sujet de recherche d’importance dans l’évaluation de la stabilité à long terme des ouvrages rocheux, l’analyse du system de stockage des déchets nucléaires et l’évaluation de son comportement, l’exploitation de l’énergie thermique et pétrolifère, etc. Cet article présente le développement actuel dans ce domaine, incluant la méthodologie d’étude sur le processus de la localisation de l’endommagement dû à l’érosion chimique, l’analyse des essais mécaniques avec l’observation microscopique, du balayage en temps réel (CT), et de l’émission acoustique. On aborde ainsi modèle des caractéristiques fractural du temps, le modèle de la mécanique dynamique neural, ainsi que la loi de comportement d’endommagement dû à l’effet chimique. Enfin, les perspectives relatives à ces études sont présentées et discutées.

Jan 1, 2003

By B. S. Spottiswoode

Lack of visibility makes it difficult for continuous miner (CM) operators to judge the desired sump depth. The resulting inaccuracies have proven to lead to significant production losses. This problem of measuring the depth of sump has been addressed in the past and a few measurement techniques have evolved. Despite various attempts, a suitable commercial depth of sump sensor does not yet exist. A system using the Doppler effect has been patented, developed and successfully tested. The method is non-intrusive and involves a beam of microwaves being projected obliquely at the roof. The received signal is analysed with respect to the transmitted signal, yielding the desired measure of displacement. Surface tests have revealed an accuracy of a few centimetres. Underground simulation tests on a load haulage dump (LHD) machine have verified the repeatability under the harsh conditions of interest. The system is presently being installed on a CM where it is to undergo a long-term performance evaluation. This paper presents the theory behind such a system, the hardware developed, the signal processing requirements and an analysis of the test results.

Sep 1, 2001

By Frank Johnson

Between 2000 and 2006, platinum production from the South African mines expanded from 206 to 307 tonnes (DME, 2007). Most of this additional metal has come from traditional ?narrow? reef stoping, generally taken to mean stoping in working places with a mining height of less than 1,5 metres. It is well known that narrow-reef stoping presents safety, technological and ergonometric challenges (Pickering, 2007). In planning for the expansion, which is still continuing, the platinum mining industry realized that it could not simply continue with traditional methods of narrow-reef mining. Particular issues identified were: ? High labour-intensivity: caused by use of hand-held rock drilling machines, labour-intensive support installation and stope cleaning; ? Dependence on rock-drillers: this occupation is no longer an attractive one and there is a reducing flow of new recruits; ? Safety: most of the work is performed close to the new faces, where there is the greatest exposure to the hazards of falling rock.

Jan 1, 2008

By G. Wu, S. Liu

In view of the singleness of traditional methods about international petroleum (Brant) price forecast, ten main factors that affect international petroleum price are fully analysed. Based on time series method and multivariate linear regression method, the simulation model with the theory and idea of system simulation is firstly established. And this forecasting system realizes visual operation under the environment of MATLAB/SIMULINK. So this article tries a new way for further exploring petroleum price’s running law and guiding its forecasting practice. Keywords: Petroleum price forecast, system simulation, residual error, physical flows information flows

Jan 1, 2003

By K. Sugawara, Y. Hirakawa, A. Sato

The rock mass properties such as deformability and permeability are highly dependent on the existence of cracks. The Ratio of Crack Opening Dependency (RCOD) was proposed as a new index to evaluate the deformability of infinite jointed rock mass. The RCOD is defined as the ratio of total amount of crack opening and the total deformation of jointed rock mass. The theoretical relation between the RCOD and the effective compliance of jointed rock mass is discussed and confirmed through two-dimensional numerical analysis by the SC-DDM, together with the applicability to the rock engineering. Les propriétés de masse rocheuse telles que la déformabilité et la perméabilité sont très dépendantes de l'existence de fissures. Le rapport de dépendance d'ouverture des fissures a été proposé comme un nouvel index d'évaluation de la déformabilité de masse rocheuse à assemblage infini. Le rapport de dépendance d'ouverture des fissures est défini comme étant le pourcentage de quantité totale d'ouverture des fissures et de déformation totale de la masse rocheuse assemblée. Le rapport théorique entre le rapport de dépendance d'ouverture des fissures et la compliance efficace de masse rocheuse assemblée sont traités et confirmés au travers d'une analyse numérique à deux dimensions par SC-DDM en même temps que l'applicabilité à l'ingénierie des roches. Die Felsmasseneigenschaften wie Verformbarkeit und Durchlässigkeit sind hochgradig abhängig von dem Vorhandensein von Rissen. Das Verhältnis der Riss-Öffnungsabhängigkeit (RCOD) wurde als neuer Index der Verformbargkeit von infinit zerklüfteter Felsmasse vorgeschlagen. Der RCOD wird als Verhältnis der Gesamtmenge der Rissöffnungen und der Gesamtverformung der zerklüfteten Felsmasse definiert. Die theoretische Beziehung zwischen RCOD und der effektiven Verformbarkeit von zerklüfteter Felsmasse wird diskutiert und durch zweidimensionale numerische Analyse mit SC-DDM bestätigt, zusammen mit der Anwendbarkeit auf Bergbautechnik.

Jan 1, 2003

By H. Wagner

During the last few years a large number of pillars in different mines were investigated. Pillar conditions were evaluated using subjective, empirical, geophysical and numerical methods. A critical comparison of the different methods showed some interesting coherence. This paper concentrates on experiences using the p-wave velocities as an indicator of pillar conditions. Während den letzten Jahren wurde eine große Anzahl von Bergfesten in verschiedenen Bergwerken auf ihren Zustand hin untersucht. Hierzu wurden subjektive, empirische, geophysikalische sowie numerische Methoden angewandt. Dieser Vortrag beschäftigt sich mit den Erfahrungen beim Einsatz der p-Wellengeschwindigkeit zur Beschreibung des Festenzustandes. Le condition géotechnique d’une grand nombre des piliers des mines souterraines différentes sont examinées ces dernières années. On a appliqué des méthodes subjectives, empiriques, géophysiques et numériques. Ce rapport occupe aux expériences avec l’application de la vélocité des ondes de compression pour tracer le condition des piliers.

Jan 1, 2003

By T. C. Alex, K. M. Godiwalla, R. K. Jana

Manganese nodule, available in ocean beds, is a potential resource of the future for copper, nickel and cobalt. Recovering only these metals, containing less than 3% by weight, will result in the generation of large amount of residue. In addition to the material losses, several environmental and ecological problems arise out of this. The present study has been aimed at reducing the environmental and ecological problems associated with massive generation of this residue together with utilization of the resources. Presence of ~ 20% manganese and ~16% silicon in the residue has prompted us to check its suitability as a raw material for silicomanganese production. Lower manganese content and lower Mn/Fe ratio of the residue than that required for silicomanganese production has been corrected in this study by suitable blending. The efficacy of blending and its thermodynamic aspects using FACTSAGE software are discussed. The studies conducted indicate viability of bulk utilisation of the residue through silicomanganese production and thereby reducing the burden on environment to a great extent.

Jan 1, 2007

By A. F. Spinks, S. P. Nicholls

"The Lower Orebody at Chingola Division of Nchanga Consolidated Copper Mines, Limited, is a stratified orebody that is mined by a continuous caving system. The accurate determination of the developed and semi-developed ore reserves has always been difficult. The new system proposed in 1971 is designed to update and, as new informa¬tion becomes available, to account for the depletion of, the reserves.There are three main inputs to the system. These are borehole data, survey data and extractions data. The borehole data are input to a geological borehole master file system, which holds every recorded detail of a borehole in an easily extractable form. These data can be extracted for ore reserve calculations or for contour mapping of orebodies and rock types. The grades for use in the ore reserve calculations are extracted from the relevant boreholes.The survey data are information on the position of the blocks and drifts, taken from plans, and information on the scraper drift and trough drive positions taken from sections. The information is extracted from the plans and sections using a D Mac pencil follower. The ore reserve is calculated from the survey data and the borehole data.Data on extractions are taken from scraper operators' logs, tramming records, skips hoisted records and accepted mill tonnages and grades. Using these data, the mill tonnages are reconciled back to the drifts, to deplete the current ore reserves.As new workings are brought into operation and further evaluation holes are drilled, the relevant data are input and the new developed ore reserve is calculated."

Jan 1, 2014

By I. V. Lunkin, E. B. Muhamedzhanov, A. B. Begalinov, B. R. Rakishev

Almost all the ore deposits of ferrous, non-ferrous and rare metals of Kazakstan, are exploiting by the open-cast method, are the complex-structural, multi-component ones. Their rational working requires precise organization of extracting works. In this connection it is necessary to set up the best intercommunications between drilling-blasting, excavating-loading and transport works. This requires the stable functioning of the quarry for dispatch of ore raw material of required quality with minimum of corresponding expenses. For this purpose, proceeding from the quarry’s ore output and the assumed parameters of the exploitation system, the first problem about rational arrangement of excavating-loading equipment in extracting faces is solved. By solving the problem the model with dynamic, adapting properties had been used. It was solved numerically by the method of statistical tests. By setting up the necessary link between type-sizes of excavating-loading and transport equipment, the minimum prime cost of loading and transportation of 1 ton of mining mass from the face to the receiving station was adopted as the criterion of optimality. Depending on the type of excavating-loading equipment, the efficiency function may be different. By using wheel loaders, their displacement between the faces is possible, therefore, the efficiency function of the problem may include expenses for their displacement. By using excavators like power shovel, the problem’s restrictions must exclude its displacement between the faces. The efficiency function consists of minimum expenses for loading, proceeding from set of volumes of extraction from the faces, satisfying required quality. The volumes of extraction from the faces, satisfying required quality of ore in output stream, are determined by the method of statistical tests. Sample range is given, proceeding from the restrictions for maximum productivity of the excavating-loading equipment. Volumes of extraction, not satisfying required quality, are cut off. The efficiency function meaning is then determined and minimized. Keywords: Excavating-loading equipment, its placing in extracting faces, optimal load-carrying capacity, specific expenses for loading and transportation of mining mass.

Jan 1, 2003

By Ernst-Ulrich Reuther, Alexander Donmen

Mine ventilation in the German coal mining industry is concerned mainly with problems of thermal environment arising from greater depths and with increasing emission of methane gas. The development of computer techniques over the past ten years for solving these and ancillary problems is reviewed. The emphasis from a planning and control point of view falls mainly on ventilation network calculations, temperature predictions and advance estimates of methane emission.

Jan 1, 2014

By H. W. J. P. Neomagus, J. R. Bunt, D. L. Botha, N. T. Leokaoke

Coal briquetting traditionally makes use of high-dosage, nonpolymeric binders (such as coal tar pitch or molasses) or polyvinyl alcohol (PVA) at low dosages for the binding of fine and ultrafine coal. Due to constraints associated with the manufacturing and cost of PVA-bound briquettes, a novel polyacrylic binder was developed that could possibly be added in low dosages at room temperature. A set of formulations of two polyacrylic components (components A and B) was developed, from which an optimal binder mixture was determined. This formulation comprises 40wt.% component A and 10wt.% component B with a 0.04wt.% cross-linking additive, and the balance water. The uniaxial briquette compressive strength was used to obtain the optimal binder mixture. The binder mixture was added to the coal powder in dosages from 0.1 to 1.2wt.%. Mechanical tests and thermogravimetric analysis in an oxidized environment at a maximum temperature of 930°C were conducted. Binder-bound briquettes were compared to binderless briquettes and PVA-bound briquettes. Briquettes made from the polyacrylic formulation had uniaxial compressive strengths double that of the binderless briquette yield strength, as well as the minimum recommended compressive strength of 0.375 MPa. The organic binders did not affect the combustion of the briquettes, since the results compared well with the binderless briquettes. The polyacrylic formulation is considered to be a possible substitute for PVA in terms of mechanical and thermal properties and raw material cost.

Mar 1, 2021

The captions to Figs. 1 and 2 of the paper by B. J. Parry entitled 'High-strength cold-rolled steels' should read as follows:

Jan 1, 1984

By E. van Steen, G. M. Leteba

Optimizing the catalytic performance of multimetallic nanoparticle (NP) catalysts demands a concrete understanding of their design, while preferentially deploying wet chemical synthesis procedures to precisely control surface structural properties. Here we report the influence of reductants such as hydrogen-rich tetrabutylammonium borohydride (TBAB) and carbon monoxide-rich molybdenum carbonyl (Mo(CO)6) on the shape and morphological evolution of Pt-based binary (PtNi and PtCo) and ternary (PtNiAu and PtCoAu) nanostructures derived from a homogeneous solution of aminebased surface active agents (surfactants) in a high boiling point solvent. We successfully synthesized nanostructures exhibiting well-defined and composition-controlled surfaces deploying a one-pot synthetic approach. The development of the surface properties was, however, observed to be alloyspecific. The resultant highly monodisperse alloy NP with narrow size distributions and facet-oriented surfaces are expected to display enhanced functionality as catalysts for utilization in specific chemical reactions.

Jun 1, 2021