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Ahmed K.,Xstrata Process Support | Izadi I.,Isfahan University of Technology | Chen T.,University of Alberta | Joe D.,Imperial Oil | Burton T.,Imperial Oil
IEEE Transactions on Automation Science and Engineering | Year: 2013

Flooding of alarms is a very crucial problem in process industries. An alarm flood makes an operator ineffective of taking necessary actions, and often risking an emergency shutdown or a major upset. In this work, the flooding of alarms is discussed based on the standards presented in ISA 18.2. A new analysis method is proposed to investigate similar alarm floods from the historic alarm data and group them on the basis of the patterns of alarm occurrences. A case study on real industrial alarm data is also presented to demonstrate the utility of the proposed analysis. © 2004-2012 IEEE.


Lotter N.O.,Xstrata Process Support | Bradshaw D.J.,Julius Kruttschnitt Mineral Research Center
Minerals Engineering | Year: 2010

Mixtures of collectors have been widely used for many years in sulphide flotation, and a range of performance benefits have been reported for many different systems. The combinations of collector types have varied, as have the ratios that have been used. Synergistic effects have been obtained (greater than the sum of the parts) and in some cases the mechanisms of this improved behaviour have been identified. These benefits have been attributed to increased carrying capacity of the froth phase, faster kinetics, and more successful recovery of middling or coarse particles. It is the interaction between the various components of the mixed collector system, rather than the individual main effects, that dominate the performance benefits. The process benefits include increased paymetal recoveries and grades - as well as increased rates of recovery whilst using lower dosages of reagents. Various mechanisms have been reported and are discussed. These have been shown to affect different composition/liberation classes and sizes of mineral particles. In recent years, automated quantitative mineralogy and surface analysis technology such as ToF-SIMS have enabled the development of better information, to establish what aspect of the process has been affected. This has been successful mostly for use in a diagnostic capacity. Candidate selection for the mixed collector suite is presently based on experience and contextual knowledge. Predictive properties from these systems are a desirable future goal. Currently optimum combinations are preferably identified experimentally at laboratory scale prior to any plant trial. It is recommended that such laboratory work be performed using a factorial design with replicates and quality controls, such as may be delivered from High-Confidence Flotation Testing. The purpose of this paper is to summarise and review current theory and practice in the usage of mixtures of collectors in sulphide flotation - both in the application and in research in order to develop insights and guidelines to develop a methodology for use in a predictive capacity. A case study demonstrating this approach will be published at a later date. © 2010 Elsevier Ltd. All rights reserved.


Kwatara M.,86 Grey Wolf Bay | Tayabally J.,Xstrata Nickel | Peek E.,Xstrata Process Support | Schonewille R.,Xstrata Nickel
TMS Annual Meeting | Year: 2011

The potential recovery of nickel from a South-American saprolitic laterite ore using the segregation roasting technique was investigated. The ore was heated to temperatures that ranged between 900 and 1000°C in a rotary kiln. In all the tests, the laterite ore was first mixed with a predetermined amount of calcium chloride and either coal or coke. By varying the temperature, calcium chloride and reductant in the different tests, a preliminary set of optimal conditions was established for the specific laterite ore that was tested. A combination of chemical analysis and electron-probe-micro-analysis (EPMA) were used to determine and evaluate the effectiveness of segregation roasting on the recovery of nickel. The present paper describes the test procedure and the results that were obtained.


Lotter N.O.,Xstrata Process Support | Oliveira J.F.,Xstrata Process Support | Hannaford A.L.,Ivanplats | Amos S.R.,Ivanplats
Minerals Engineering | Year: 2013

Ivanplats Ltd. appointed Xstrata Process Support to perform the flowsheeting development work for their hypogene and supergene geomet units of the Kamoa Copper deposit, located west of Kolwezi in the Democratic Republic of the Congo. Through appropriate use of Gy's sampling and subsampling models, and systematic flowsheet development using modern Process Mineralogy, an optimised Milestone Flowsheet was developed, delivering a final concentrate grade of 32.8% Cu at 85.4% recovery with hypogene ore, and 45.1% Cu grade at a recovery of 83.4% for supergene ore. These results were obtained from representative samples of drill-core, quantitative mineralogy and high-confidence flotation testing. The significant value of this development is that a single flowsheet will treat both hypogene and supergene ores and produce treatable concentrates. Further work to advance the flowsheet performance beyond this milestone benchmark, and to perform variability testing for this resource, has been identified for investigation in the near future. © 2013 Elsevier Ltd. All rights reserved.


Coursol P.,Xstrata Process Support | Tripathi N.,Xstrata Process Support | Mackey P.,Xstrata Process Support | Leggett T.,Xstrata Copper Kidd Metallurgical Site Xstrata Copper | De Friedberg A.S.,Xstrata Copper Kidd Metallurgical Site Xstrata Copper
Canadian Metallurgical Quarterly | Year: 2010

The Kidd Creek smelter of Xstrata Copper, in operation since 1981, employs the Mitsubishi Process. This continuous smelting process utilizes the unique three furnace system consisting of the smelting furnace (S-Furnace), the slag cleaning furnace (CL-Furnace) and the converting furnace (C-Furnace). The present paper focusses on the slag and matte chemistry of the S-Furnace and the CL-Furnace. In particular, the slag chemistry in each of these furnaces was investigated using the Factsage™ software to better understand the impact of slag and matte compositions on the slag liquidus and the oxidic copper content of the slag. In order to perform the calculations to the required degree of accuracy, all degrees of freedom were fixed with respect to actual industrial parameters such as the slag, matte and gas phase compositions for each furnace. The investigation confirmed the impact of %CaO, %Al 2O3 and %MgO, each of which tend to increase the magnetite liquidus at high Fe/SiO2 ratios. The impact of the Fe/SiO 2 ratio in slag was further investigated since typically it is employed at the plant to control the slag liquidus, generally at a constant level of minor slag components (%Al2O3, %CaO and %MgO). To a lesser but still significant extent, the level of ZnO in the slag was also found to impact the slag liquidus. All process parameters were varied separately to identify the impact of process variability on copper losses and slag liquidus. The results are presented and discussed with respect to the current operation of the S-furnace and ideas for potential improvements are also identified. © Canadian Institute of Mining, Metallurgy and Petroleum.


Lotter N.O.,Xstrata Process Support | Kormos L.J.,Xstrata Process Support | Oliveira J.,Xstrata Process Support | Fragomeni D.,Xstrata Process Support | Whiteman E.,Xstrata Process Support
Minerals Engineering | Year: 2011

Process diagnosis, flowsheet design and optimisation are most effectively and efficiently achieved through the use of metallurgical testwork combined with modern quantitative mineralogical techniques. The integration of these two areas of study form the discipline known as process mineralogy. A brief history of the discipline is described along with the program now in place at Xstrata Process Support (XPS). Representative sampling protocols for orebodies, plant or test products, the use of geometallurgical unit classification, stratified sampling, high confidence metallurgical test programmes, concentrator sampling audits (Benchmark Surveys) and the use of quantitative mineralogy (QEMSCAN and EPMA) are key components of the strategy. Two case studies from Xstrata Nickel's Nickel Rim South Mine in Sudbury and its Raglan Concentrator in Quebec are described to show how mineralogical data can be integrated into metallurgical programs to assist mineral processing engineers to design and optimise flowsheets and how the use of quantitative mineralogy can be used to benchmark plant performance and enable predictions of performance ahead of plant changes. © 2010 Elsevier Ltd. All rights reserved.


Peek E.,Xstrata Process Support
TMS Annual Meeting | Year: 2011

The two dominant metallurgical problems in treating most base metal sulphide concentrates in both the chloride and sulphate system are iron removal and sulphur elimination, respectively [1-3]. In this paper the opportunities, limitations and fundamentals of the chloride metallurgy system are described against this background. Only the treatment of oxide and sulphide ores is considered. Both hydrometallurgical and pyrometallurgical unit process operations are highlighted, since most successful base metal processes are based on a combination of the two. Hence, an overview of the technical and also some economical aspects of chloride metallurgy are presented. This overview summarizes the successful applications of chloride metallurgy, but it will not give exhaustive process and plant descriptions. It predominantly focuses on the essential technical features of the metallurgical unit process operations, while providing numerous references separately.

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