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By M. Mirnezami, J. A. Finch, M. S. Hashemi A.

This study examined the effects of pH and sulphate concentration on the surface charge and stability of alumina and pyrite dispersions. The relationship between these properties was investigated using measurements of electrophoretic mobility and settling velocity. The maximum aggregation for both minerals was observed near the iso-electric point (iep) where the force of repulsion is at a minimum. Aggregation decreased at pH values away from the iep, where an increased surface charge causes electrostatic repulsion between particles. Zeta potential data revealed that sulphate ions were adsorbed only on positively charged surfaces for both minerals. Adsorption of sulphates on the alumina surface increased aggregation by reducing the surface charge from >+25 mV to close to zero. These results indicate an electrostatic bonding of sulphate ions to alumina surface. Preliminary results on the interaction of pyrite and sulphate ions indicate a similar response.

Jan 1, 2004

By A. Ignatieff

"THE WORLD'S coal resources represent the largest component of non-renewable energy resources. Coal is now regaining Its position following a temporary decline, particularly in North America during a period of about a quarter of a century. This period provided the opportunity to improve both surface and underground mechanization, thereby increasing the productivity and improving conditions for humans in the mines. Similarly, in preparation, improved cleaning of coal from various impurities including sulphur was achieved, to meet the more demanding requirements for coking coal. Progress was also made in combustion, particularly related to the reduction of pollution. Canada participated in most of these developments, despite the country's strong commitment of the use of hydrocarbons during this period. _Bearing in mind the vastness of this land (3.85 million sq. miles) by comparison with countries like U.S.A., U.S.S.R., and China, Canada's coal resources estimated to date are not large and they are scattered. The original evaluation of 1913 estimated the ""reserves"" from seams over one foot in thickness and a limiting depth of 4,000 ft at 1.2 trillion metric tons. D:. ~.R. MacKay, in his evaluation for the 1946 Royal Commission on the coal industry, known as the Carroll Commission, reduced the ""reserves"" to 99 billion short tons. The increased knowledge now available would indicate that the 1913 estimated was too liberal and the 1946 estimate too conservative but both were closer to a resource than to a reserve designation. Some adjustments of Dr. MacKay's estimates were made in 1970 by B.A. Latour of the Geological Survey of Canada and L.P. Chrismas of Energy, Mines and Resources Canada (EMR). In the last decade the Alberta Energy Resources Conservation Board has developed its own methods of evaluating coal resources and reserves. A methodical approach of exploration and evaluation was carried out by Saskatchewan jointly with the federal government of the lignite resources of Southern Saskatchewan. A similar joint program is in progress in Nova Scotia. Meanwhile, the industry itself carried on an extensive exploration program on the outcrops of promising projects in the Inner Foothills belt of Alberta and British Columbia in preparation for surface mining on a very large scale, with some development of hydraulic mines. All these activities have been reflected in the increase of the country's resources and reserves, which now fortunately are separately defined. In 1979 EMR issued Report E.R. 79/9(1>; the data were developed in 1978 and provided to the World Energy Conference Organization<2>. In 1980 the World Coal Study (Wocol), an international group that included Canada carried out a study which updated the W.E.C. data, indicating some reduction of the 1978 figures; quantities were reported in million metric tons of coal equivalent (C.E.)*(Jl."

Jan 1, 1985

By R. Esteban, D. Runnels, J. Torrealba-Vargas, G. Couture

"Data handling is an important step in the development of a simulator of a mineral processing circuit. The model requires representative data of the scenario to be modeled. The model development involves protocols that must be followed very closely to complete a successful project.Data handling of large and diverse datasets (metallurgical test results, geological data, mining models, historical data, etc.) is a key element of the model. The information needs to be processed, reconciled, interpreted, modeled and presented to support the design or the optimization of a mineral processing plant.Best practice recommends that teams from different disciplines (such as mining, metallurgy, geology and environmental) interact to define the most important variables that could influence the simulator. For example by adopting a geometallurgical approach in the earlier stages of the project, it is possible to consolidate the number of main ore rock types in a testwork program (saving money and time) by involving geologists and metallurgists in the sample selection and data interpretation.Planning the development of a model involves an understanding of the software capabilities but also the limitations and the magnitude of the data required to calibrate the model in case of changes in the project.A successful model requires a deep understanding of the circuit to be modeled and thus plant personnel should be considered as members of the team.This paper describes the use of the "state of the art" tools for data analysis, simulation and optimization; and shows three practical examples of the use those tools in the design of mineral processing plants."

Jan 1, 2015

By M. L. Smith

"In the Phosporia formation of SE Idaho, ore quality varies by depth, seam and distance along strike; phosphorus recovery is sensitive to these variations. Plant ore feed can be blended over time to minimize this fluctuation by using a combination of mine production and inventory stockpile scheduling. Mixed-integer and goal programming has been used to optimize short-term mine production, but the seasonal nature of mine haulage requires the use of stockpiles both at the mill and the mine. The contents of the stockpiles can also be optimized as part of the production scheduling problem, but introducing inventory control introduces a nonlinear term into the formulation. A solution using a piecewise linear formulation is modelled and solved using AMPL/Cplex, and solution strategies are discussed for similar large-scale problems. IntroductionIdaho’s minable deposits of phosphate rock are found in the Meade Peak member of the Phosphoria Formation; two separate zones of this formation are mined with a combined thickness of 30 ft to 60 ft. A generalized stratigraphic section of the Phosphoria section is shown in Figure 1, illustrating the degree of complexity encountered when scheduling mine production. Alteration of the formation results in higher grade ore zones near the surface and variable in P2O5 levels between seams and along strike. This variability is seen as well in other quality characteristics critical to the production of acid and elemental phosphorus. Further, plant recovery and nodule quality are sensitive to variations in ore feed; variability in SiO2, carbonates, moisture, organics (carbon), P2O5 and other constituents of the ore can strongly affect plant recovery. Because ore quality characteristics can vary as a function of the alteration zone (or seam) being mined as well as the depth and distance along the strike of the formation, scheduling of mine production can have a highly significant effect on recovery in the plant. As illustrated in Figure 1, there are nine seams containing 20% to 35% P2O5. Phosphoric acid and elemental phosphorus production requires an ore content of 30% and 25% P2O5, respectively. Variability between numerous beds that are mined and quality variation within a seam due to alteration greatly complicates production scheduling with the result that erratic mill feed characteristics greatly decrease recovery."

Jan 1, 1999

By A. G. Slade

"This paper deals with the direct application of rock mechanics in the underground mines at the Sudbury Operations of Falconbridge Nickel Mines Ltd. It covers mining methods, the use of photoelastic models, the fore-casting of rock strains and their elimination, closure methods and other common methods of ground control.INTRODUCTIONROCK MECHANICS IS A STUDY IN ROCK BEHAVIOUR and, although it is being termed a new science, it has been practiced since the industry began. Every person involved with rock excavations, from the mine superintendent to the stope driller, is actually practising rock mechanics. They probably call it by another name -experience, and applications of this knowledge are in evidence throughout the Falconbridge operations. Only in recent years have formal rock mechanics studies been employed to provide technical assistance to the mine operators in their primary objective of producing ore safely."

Jan 1, 1968

By F. Nava-Alonso, E. Pérez-García, A. Uribe-Salas, J. C. Fuentes-Aceituno, A. A. González-Ibarra, E. N. Castillo-Ventureño

"Precious metals cannot easily be recovered from tellurides by the standard cyanidation process. This work assesses the cyanidation of synthetic samples of precious metals tellurides and explores some alternatives for the leaching of these species (i.e. cyanidation in presence of lead nitrate and thiosulfate leaching). For this purpose, three chemical systems were studied: (1) cyanidation of silver telluride and the effect of lead (II) nitrate addition, (2) cyanidation at high alkalinity and high cyanide concentration of a gold-gold telluride sample containing tellurium and tellurium dioxide, and (3) thiosulfate leaching of silver telluride employing cupric sulfate as oxidant and EDTA as complexing agent for copper. Results showed that standard cyanidation dissolves 10.5% of silver from silver telluride in six hours, while with the addition of 100 mg/L lead increased the silver dissolution up to 100% in the same time. The standard cyanidation of the gold-gold telluride sample dissolves only metallic gold in six hours, while when cyanide concentration and pH were increased, gold and gold telluride were simultaneously dissolved. Finally, thiosulfate leaching dissolves 43.1% of silver from silver telluride in six hours.INTRODUCTION Precious metals tellurides are classified as refractory ores due to the difficulties associated with processing them by the standard cyanidation method. The increasing presence of gold/silver tellurides in some deposits around the world, specifically in Sonora, Mexico, requires new approaches to the cyanidation process, or the development of new leaching techniques. Treatments have been proposed for the recovery of gold and silver from their tellurides, including roasting, preoxidation, cyanidation with lead nitrate, and the use of leaching agents other than cyanide (Zhang, et al., 2010; Ellis and Deschenes, 2016). This work presents preliminary results of three options to recover precious metals from pure tellurides: the cyanidation of gold telluride at high cyanide concentration and high alkalinity, the addition of lead nitrate to the standard cyanidation process, and the use of sodium thiosulfate as leaching reagent."

Jan 1, 2017

By H. Saeedi Ali, A. J. Monhemius

"Anglo Asian Mining’s Gedabek mine is situated in the Lesser Caucasus mountains in Western Azerbaijan. The ore body is a complex copper-gold porphyry deposit, comprising intermixed oxidized, transition and sulphidic gold and copper-bearing ores. Gold in the sulphide ores is generally not refractory and is recoverable by cyanide leaching, but the secondary copper minerals, which are also cyanide soluble, lead to high cyanide consumptions. Ore processing at Gedabek is by agitation leaching for high grade ore (>1g Au/t) and heap leaching for lower grade ore. In order to cope with the high copper concentrations in the cyanide leach liquors, a unique combination of resin-in-pulp for selective gold extraction and SART processing for copper removal and cyanide recovery is used. In 2015, a flotation plant was added to treat the tailings from the agitation leach plant before the tails are sent to the tailings dam. This plant produces a copper sulphide flotation concentrate and also recovers some of the residual gold and silver in the tailings. Since February 2017, due to lower grades of gold and higher copper in the feed ore, the decision was taken to alter the flow sheet and to carry out flotation ahead of agitation leaching, to reduce the cyanide consumption during leaching by removing soluble copper minerals. The paper compares and contrasts the performance of the plant in the two configurations, namely, (i) leaching followed by flotation and (ii) flotation followed by leaching.INTRODUCTION In May 2009, Anglo Asian Mining started open pit mining for gold on its Gedabek property in the Lesser Caucasus Mountains in western Azerbaijan. Gedabek is situated on the highly mineralized Tethyan Belt that runs from the Himalayas to the Balkans. The ore body at Gedabek is a complex copper-gold porphyry deposit, comprising intermixed oxidized, transition and sulphidic gold-bearing ores. The sulphidic ores contain mainly pyrite and chalcopyrite, with some secondary copper sulphide minerals, such as bornite and chalcocite, and minor amounts of sphalerite, galena and tetrahedrite. Gold in the sulphide ores is generally not refractory and is recoverable by cyanide leaching, but the secondary copper minerals, which are also cyanide soluble, lead to high cyanide consumptions and passivation of free gold."

Jan 1, 2017

By Alessandro Navarra, Amir Arash Rafiei, Kristian Waters

Mathematical programming (MP) is fundamental to systems engineering and operations management, but has not been widely adopted by mineral processors. The current paper presents an interdisciplinary approach, using MP to incorporate basic notions of mass balancing into an optimization framework. The optimization is typically related to economic profitability. Two- and three-product formulas are extended to give formal descriptions of alternate modes of operation, and a global representation of the concentrator. At this global level, the framework may assist plant managers to make tactical decisions based on incoming feed data. The MP framework is demonstrated through sample calculations describing a lead-zinc concentrator.

Jan 1, 2015

By J. J. Taute, O. S. Tinkler, G. Zárate, K. C. Sole, J. Steeples

Global practice in copper solvent extraction is reviewed, based on individual plant operating data for 2018. The survey respondents account for almost 40% of global copper cathode production by solvent extraction and electrowinning. Regional trends in operating conditions, as related to the prevailing ore mineralogy, leaching processes, and life of mine are evaluated. The adoption and expansion of this technology in the African Copperbelt and Asia are assessed, together with the associated challenges of specific orebody characteristics. Trends in feed and electrolyte compositions and flow rates, and extractant and diluent selection, together with their impact on copper recovery are reviewed. The evolution of equipment design and associated ancillary processes are discussed, and new projects identified. INTRODUCTION Continuing from similar surveys carried out in 1997, 1999, 2003, 2007, and 2013 (Robinson, Davenport, & Jenkins, 1997; Jenkins, Davenport, Kennedy, & Robinson, 1999; Robinson, Sandoval, & Cook, 2003; Robinson, Moats, Davenport, Karcas, Demetrio, & Domic, 2007; Sole, Zarate, Steeples, Tinkler, & Robinson, 2013), global operating practice in copper solvent extraction (SX) in 2018 is reviewed. Contributing operations include established sites in the USA (8), Chile (9), Peru (2), Spain (1), Mexico (2), and Australia (2), as well as newer operations in Africa (7) and Asia (3). This survey represents 2018 copper cathode production of 1.91 Mt, or about 43% of world production by solvent extraction combined with electrowinning (SX–EW). Trends in operating conditions and performance, as well as equipment design and process technology choices are analysed. The significant expansion in production in the African Copper Belt is also discussed. There are currently about 130 operations worldwide producing some 4.6 Mt copper by SX–EW; of these, about half produced more than 10 000 t/a. Figure 1 shows global copper production by country. As it has for several decades, Chile remains dominant, with 36% of global production of cathode copper. Since 2005, the Democratic Republic of Congo (DRC) has increased production year on year, and now represents 23% of the global total (International Copper Study Group, 2017; Statistica, 2018). Copper production in Asia has grown significantly in the past decade, particularly since the ramp-up of Wanbao in Myanmar. There used to be numerous small copper SX plants in China (Schlesinger, King, Sole, & Davenport, 2011), although most of these have now shut down and Chinese production is lower than it was five years ago. The most important trend, however, is the rise of Chinese-owned mining companies, particularly in Central Africa, but also around the world more generally.

Jan 1, 2019

By J. Dennett, M. Faris, M. Antonio, M. Collins, N. Tuffrey, R. Ellenwood, V. Reddy

"In January 2012, AngloGold Ashanti Córrego do Sítio Mineração, with assistance from Sherritt International Corporation, commissioned a new autoclave for pressure oxidation of refractory gold concentrate at the Córrego do Sítio operation in Brazil. Start-up of the plant occurred in a few weeks and enhanced gold recovery was realized almost immediately, with 94% gold extraction achieved in carbon in leach (CIL), compared to less than 70% without pressure oxidation. This paper describes start-up and commissioning of the plant and provides an overview of plant performance over the last five years.INTRODUCTION In 2008, AngloGold Ashanti purchased the former São Bento property from Eldorado Gold, which, along with AngloGold Ashanti’s existing Córrego do Sítio mine, was renamed AngloGold Ashanti Córrego do Sítio Mineração (AGA Mineração). Later that year, the Sherritt Technologies division of Sherritt International Corporation (Sherritt) was contacted to begin batch and continuous pilot plant tests to determine the amenability of the AGA Mineração refractory gold concentrates to the pressure oxidation process. Based on the results of the batch and pilot plant tests, AGA Mineração requested basic and detailed engineering studies to be conducted by Sherritt, eventually leading to commissioning of the plant in January 2012. AGA Mineração’s plant is located in southeastern Brazil in the state of Minas Gerais, near the city of Belo Horizonte. AGA Mineração`s Phase 1 mine plan covers three sites in the Laranjeiras, Carvoaria Velha and Cachorro Bravo ore bodies, and is designed to process 60,000 tonnes of refractory gold concentrate per year to produce 140,000 ounces of gold per year with an 11 year life of mine (AngloGold Annual Financial Statements, 2010). Recovery of gold at AGA Mineração is based on Sherritt`s pressure oxidation technology for refractory gold concentrates (Berezowsky et al., 1991; Collins et al., 2011a; Collins et al., 2011b). This process had previously been applied to the recovery of gold at the São Bento site (Carvalho et al., 1988; de Silva et al., 1989), in a plant that was operational between 1986 and 2007 (Silva et al., 2004)."

Jan 1, 2017

By Dougla McDonald, Richard Poulin

"Most mine managers in Canada today will agree that one of the keys to mining efficiency and productivity is their human resources. A5 a result, many mines develop some sort of incentive designed to tap their employees&apos; capabilities to the fullest extent. Historically, the most common plans used have been ""piece-rate"" plans, where individual or small groups of miners are paid a financial bonus based on some measure of their productivity. Recently, however, incentive plans that take a more team-based approach have been developed in some Canadian mines. One such plan will be defined in this paper, and its popularity in the industry today discussed.Gainsharing PlansThere are two primary components to a gainsharing plan. The first is a cash incentive, which is paid to all employees and based on factors that are highly correlated with employee productivity, and key to the profitability of the mine. For example, the typical gainsharing cash incentive is based on the cost/unit of metal produced. Management (in consultation with employees in some cases) will establish the budgeted cost per tonne, and any savings in this amount is shared between the company and the employees. The second is a management philosophy and associated communication network, which is designed to foster an environment that encourages information exchanges, communication, participation, and trust between employees and management. The typical gainsharing communication network consists of two tiers of committees. The first, operational committees, include all employees working in the same department or departments which frequently interact. The employees meet monthly with management personnel to discuss problems encountered and brainstorm for solutions. In most cases, these committees will nominate a person in the group to structure the meeting to maximize its efficiency. The second, the screening committee, is a single group consisting of representatives from the various operational groups, whose primary job is to ensure that the plan is effective, and the objectives and results generated by the plan remain consistent with the mine objectives. In short, gainsharing plans tell employees that their bonus depends upon performance and then gives them the opportunity and incentive to affect that performance. The opportunity is provided by a communication network and positive management practices, and the incentive comes in the form of ""intrinsic"" rewards of participation and the ""extrinsic"" rewards of the bonus payments. Figure I will clarify the relationship between the intrinsic and extrinsic rewards."

Jan 1, 1995

By R. A. Kipp

THE dry concentration of ores and minerals is a subject on which there is very little engineering literature available. With the advent of flotation, practically all milling research was turned to this development as it held the answer to large-scale economic operations. However, there are many concentration problems that can be more adequately and economically handled by the dry methods that have been developed, and, consequently, I believe it is very advisable for mining men to become fully 'conversant with just what can be done in the dry state. Therefore, today, I should like to give a brief summary of the processes that are available and, in a general way, how they can be a p-p lied. I shall confine my remarks mainly to two dry processes: THE Am FLOTA'l'ION TABLE AND THE ELECTROSTATIC SEPARATOR Dry Magnetic Separators should probably also be included, but I am

Jan 1, 1961

By C. Schmidt, M. Kohnk, C. Siemers, J. Kiese

The application of conventional titanium alloys is limited to 550°C due to their poor oxidation resistance. In addition, severe grain growth is observed in single-phase titanium alloys in long-term runs at elevated temperature leading to a degradation of their mechanical properties. In exhaust applications in automotive or aerospace engineering, products are often manufactured by cold-deformation like deep-drawing or rolling which is normally difficult in oxidation-resistant titanium alloys due to the presence of titanium-silicides. Therefore, in the current study, titanium alloys based on CP Titanium Grade 1S (soft grade) were developed showing (1) improved oxidation resistance due to a concerted addition of silicon, iron and niobium, (2) microstructure stability by the precipitation of hafnium-silicides mainly on the grain boundaries and (3) good cold-deformation properties. The industrial production route was developed so that the new class of Ti-Si-Fe-Nb-Hf-alloys is now ready for application in exhaust systems of planes or cars at minimum 800°C.

Jan 1, 2015

By Bob Butler

Brunswick Mine has been involved in a comprehensive research program investigating site specific aspects of thiosalt management to eliminate its adverse environmental effects. Minimum annual reagent cost estimates for thiosalt treatment using hydrogen peroxide and sodium hypochlorite are $400K and $1.5 million respectively. Also, minimum costs for the use of bicarbonate to buffer the pH depression associated with thiosalt oxidation in the receiving environment is in the order of $400K annually. A design of experiment (DOE) research program identified that natural UV radiation, temperature, DO and water chemistry are key factors influencing the natural oxidation rate of thiosalts within Brunswick?s water management system. A DOE surface response model was used to describe the thiosalt oxidation kinetics, which were then used to develop a predictive oxidation model for thiosalt and pH control of the mill?s reclaim water system.

Nov 1, 2002

By G. R. Waters

"The technology behind industrial applications such as Hydrometallurgy continues to evolve, as do the corresponding regulations and specifications that ensure the safety of workers and the environment. Valves make up key aspects of this technology, and often represent the single point of failure for entire operations. More often than not, the valves being used in Hydrometallurgy applications are known as Severe Service Valves (SSVs) due to their ability to withstand the extreme conditions. Most experts agree that SSVs are identified by applications, and that these applications are challenging to the valve’s ability to provide a minimum acceptable level of performance over a minimum acceptable duration. The Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry has designated Ross Waters, President of CGIS, as Lead to the Task Force put in place to determine the minimum requirements a valve needs to be able to perform to when faced with extreme conditions, whether from pressure, temperature, toxicity, solids, or usage. This paper serves to determine what the minimum requirements are for SSVs in Hydrometallurgy applications. It will draw on five decades of industry experience from one of Canada’s leading valve experts.INTRODUCTION Severe Service Valves Severe Service Valves (SSVs) mean different things to different people. Until today, defining SSVs had little if any global agreement or recognition. That is about to change as the Manufacturers Standardization Society (MSS) has accepted an application to produce a Standard Practice so defining them. This paper provides information about the selection of SSVs in all industries but focusses on metallurgical processes and applications and offers examples to illustrate the successful and unsuccessful use of these valves. All of this with the purpose of raising the awareness of the industry on all sides, from the suppliers and manufacturers, specifiers and to the users and owners of them. It also supplies tools to understand where and why to separate SSVs from general purpose or commodity valves (GPVs). SSVs are often identified by applications, and these applications are challenging to the valve’s ability to survive. Within these applications the elements that make the service severe are being analyzed, quantified and qualified. From this, we expect to offer objective and repeatable definitions and guidance to improve the experience of SSVs, reduce unnecessary costs, provide longer service life and process runs, improve safety and reduce environmental issues."

Jan 1, 2017

By C. Edwards

ABSTRACT: Milling operations in northern Saskatchewan’s Athabasca Basin have produced uranium continuously since 1975. During that period, the Athabasca Basin has been one of the world’s premier uranium camps, yielding more than 660 million lb (299,370,964 kg) of U3O8. In this paper, the author describes former and current milling operations and discusses why and how the milling process has changed and developed over the past 35 years. The author’s considerations for the future of uranium extraction in the Athabasca Basin conclude the paper.

Jan 1, 2012

By G. J. Arseneau

ABSTRACT Mineral resource statements are reported as tonnage (volume × density) and grades. Effort is expended to accurately estimate the volume and grade, but accurately determining bulk density is often overlooked. Oversimplification of density modelling can result in potentially serious errors in tonnage estimates and over- or underestimation of metal content. A reliable bulk density model requires an adequate database and a good understanding of density variability, along with grade and geology. In this paper, the author summarizes density measuring techniques, draws on examples of simple and complex grade-variable density domains, and discusses improved approaches for minimizing density estimation errors.

Jan 1, 2014

By N Berkowitz

Slurry pipelining, as now under-stood and practised, can only command marginal interest in Canada, as long-distance railway freight charges in this country are generally lower than slurry pipeline tariffs. Several alternatives to conventional slurry transmission are, however, now emerging, and two such alternatives are briefly discussed with reference to coal pipelining. In one, coal is transported as a suspension in oil; the other contemplates the movement of paste "slugs." Preliminary economic estimates indicate that the resulant process simplification and adoption of common carrier principles could lead to cost reductions that might make Western coal competitive with imported fuel in the power generating stations of eastern Canada. R ECENT appraisals of slurry pipelining techniques, some-what incongruously &apos;based upon the performance of successful installations (1,2), are making it increasingly apparent that current solids pipelining methods can only command marginal interest as methods of bulk commodity transportation (3). Although some uncertainties remain in matters of detail, it is now generally conceded that long-distance slurry pipelining cannot compete against rationalized railway transportation unless movement of

Jan 1, 1963

By Douglas E. Wolfe, Jogender Singh, Robert Miller, Dong-Ming Zhu, Jeff Eldridge

This paper discusses microstructural changes produced by two novel approaches using electron beam physical vapor deposition (EB-PVD) in which periodic strain fields/microporosity was incorporated within the large columnar grains of Zr02- 8wt.%Y2O3 (8YSZ). The traditional columnar microstructure of partially stabilized zirconia has been slightly modified to produce a lower thermal conductive thermal barrier coating (TBC) by periodically interrupting the condensing vapor resulting in microstructural modifications with diffuse or sharp interfaces and morphological changes on the sub-micron scale without changing the composition of the TBC. These microstructural modifications resulted in a 20-30% reduction in the thermal conductivity, 28-56% increase in hemispherical reflectance, improved oxidation cyclic life (over 100%), and better strain tolerance as compared to standard ZrO2-8wt.%Y2O3 deposited on platinum-nickel-aluminide and CoNiCrA1Y bond-coated MAR-M-247 test samples. The TBC with tailored microstructures were examined by various techniques including scanning electron microscopy (SEM), x-ray diffraction (XRD), steady-state laser heat flux technique, and hemispherical reflectance.

Jan 1, 2004

By Ben C. McLellan, Philip J. Bangerter, Andrew Murphy, Glen D. Corder, Damien Giurco

Sustainability now forms a critical part of metallurgical plant design. In addition to compliance with requirements and corporate principles, design engineers must also consider how community and societal responses to the metallurgical industry affect the way they design and build plants. Three broad areas to consider are: the design engineer’s contribution to sustainability through the design process and the relationship to the social license to operate (SLO)—the unwritten license communities give companies to safely and responsibly operate the plant and equitably share benefits; the realization of sustainability goals through methodologies emerging in the design activities; and the integration of design frameworks into a contemporary project design context and its investment objectives. This chapter explores sustainability in metallurgical plant design in the context of SLO, design tools and frameworks, and community and societal influences.

Jan 1, 2015