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By Christiaan Zeilstra, Jan van der Stel, Koen Meijer, Gerard Louwerse, Tim Peeters

The steel industry is producing about 5% of the world wide CO2 emission. Therefore the European steel industry has defined a research program to reduce the CO2 emission by 50% per ton: ULCOS. Since its start in 2004 ULCOS has identified four technologies for further development. Two of these technologies which produce liquid hot metal are discussed. The ULCOS blast furnace is based on recycling of decarbonated topgas and the capture and storage of CO2. The concept has been demonstrated during three campaigns at LKAB EBF in Luleå, Sweden. The smelting reduction process HIsarna is a combination of the cyclone-technology and Hismelt. The process has been demonstrated successfully in four campaigns at a pilot installation on the IJmuiden steelmaking site.

Jan 1, 2015

By Ainul Akhtar, Steve Cockcroft, Jixiang Xu, Daan Maijer, Lu Yao

"Nitrogen rich Ti-N inclusions are one of the more difficult inclusions to remove during liquid metal refining of titanium. If present in the final component, they can significantly decrease the mechanical performance of titanium and its alloys in applications involving cyclic loading. Understanding the kinetics of dissolution of Ti-N particles during consolidation/melting of titanium can help us better operate and design the melting processes to minimize their occurrence in Premium Quality Titanium production. A numerical model based on finite difference method has been developed to calculate the dissolution of a spherical Ti-N particles in molten titanium. Analytical solutions were used to verify the finite difference code for calculation of concentration profile and the dissolution of spherical solids. Taking into account the limitations in these approaches for the different cases examined, the invariant field approximation showed good agreement with the results from the numerical analysis. Evolution of the size of a spherical Ti-N particle during dissolution was predicted by the numerical model and the particle dissolves in 163 s.INTRODUCTION Properties like low density, high specific strength and excellent corrosion resistance make titanium attractive for a variety of applications. Key characteristics in the processing of titanium and its alloys include its high sensitivity to impurities, especially atmospheric oxygen and nitrogen and its high reactivity in the molten state. Nitrogen rich inclusions Ti-N, also known as Type ? or hard alpha defects, usually have substantially higher hardness and lower ductility than the surrounding material. Because they can act as fatigue initiation sites, Ti-N inclusions can significantly decrease the mechanical performance of titanium and its alloys in applications involving cyclic loading, even in minor amounts (tenth of a percent) (Lampman, 1990; Moiseyev, 2005; Lütjering & Williams, 2007). Ti-N encompasses as a broad range of nitrogen contents from a few wt% up to stoichiometric TiN. The liquidus temperature of Ti-N titanium increases substantially with increasing nitrogen content. Consequently, depending on the concentration of nitrogen, the melting point of Ti-N inclusions can be above bulk liquid metal temperatures during melt processing. Thus, removal of Ti-N defects hinges on dissolution and not melting."

Jan 1, 2017

By N. Manopulo, J. Maier, L. Tong, C. Becker, P. Hora

The contribution presents a new finite element approach in which the common updated Lagrangian formulation is replaced by a spatial flow formulation applying a special arbitrary Lagrangian-Eulerian for-mulation (ALE). The description separates spatially the process in a die inside zone and in a profile zone. For the description of the inside zone, where the filling process occurs, a special Euler time independent mesh is applied. By this formulation the mesh has to be generated only once, which simplifies the generation of spatially optimized meshes. For mapping of the material flow during the filling process the method uses a flow surface traction method as applied in casting simulations. A further strength of the new method is the computational efficiency which allows the modelling of extrusion process with the highest complexity with a response time of 12 hours, which is important for the industrial optimization process.

Jan 1, 2015

By A. Blackmore, A. Lamoureux, J. Woloshyn

This paper provides an overview of recent applications of Computational Fluid Dynamics (CFD) to combustion related fugitive emissions problems. The aim is to illustrate the capabilities and discuss the present limitations in this field. Examples include design of retrofitted NOx reduction technology in a kiln and in a boiler, and the prediction of pollutants such as SO2 and metallurgical dust emanating from a copper flash smelting furnace. It is demonstrated that CFD is an effective tool for reducing technical risk in design, for identifying the root-cause problems and testing solutions, and for concurrently assessing emissions reduction and process impact. In addition, the value of CFD for demonstrating due diligence for regulatory compliance is discussed.

Jan 1, 2015

By Feng Xue, Mi Xujun, Peng Lijun, Yin Xiangqian, Liu Dongmei, Xie Haofeng, Huang Guojie, Yang Zhen

The Age-hardening Cu-Cr alloys are extensively used in integrated circuit lead frame, railway contact wire, resistance welding electrode and continuous casting mold copper plate, owing to having an excellent combination of high electrical or thermal conductivity and high strength. High temperature performance is very important during the service process. Effect of Magnesium and Zirconium on softening behavior of Cr-Cr alloy are investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). During the softening process in the Cu-Cr alloy, the recrystallization process, grain growth and Cr precipitates coarsening are observed. The addition of Mg or Zr to the Cu-Cr alloy, the resistance to elevated temperature can be significantly improved, owing to being restrained the growth of the precipitates by segregating along precipitates surface. INTRODUCTION Age-hardening Cu-Cr system alloys can be widely uesed in many fileds such as electrodes for spot welding (Hatakeyama et al., 2008; Cheng, Shen & Yu, 2013; Zhou et al., 2016; Chbihi, Sauvage & Blavette, 2012), intergrated circuit lead frame (Hatakeyama et al., 2008; Cheng, Shen & Yu, 2013; Zhou et al., 2016; Liu et al., 2006; Pang et al., Xia et al., 2012; Wang et al., 2009; Huang et al., 2003; Cheng, Yu & Shen, 2014; Zhang et al., 2016; Li et al., 2007) and railway contact wire (Cheng, Shen & Yu, 2013; Zhou et al., 2016; Chbihi, Sauvage & Blavette, 2012; Liu et al., 2006; Pang et al., Xia et al., 2012; Wang et al., 2009; Huang et al., 2003), because it has high strength, good electrical and thermal conductivity. The precipitation behavior of binary or ternary Cu-Cr alloys had been investigated by many researchers (Chbihi, Sauvage & Blavette, 2012; Peng et al., 2017; Batra et al., 2002). In addition, to obtain additional mechanical properties without much deterioration in electrical conductivity, trace addition of alloying elements like Zr, Ag, rare metals (Y and Ce) and Mg are added into Cu-Cr alloy. The addition Mg to Cu-Cr alloy accelerated the process of precipitates nucleation and restrained the growth of the precipitates by segregating along precipitates surface during aging, which enhanced the stability of the deformation microstructure and improved the mechanical properties of the alloy (Zhao et al., 2018). Additional zirconium in Cu-Cr alloy enhances the strength by the decrease in inter-precipitate spacing of Cr precipitates and the formation of Cu5Zr phase (Chihiro, Ryoichi & Kazue, 2008). Owing to the decrease in inter-precipitation spacing of Cr precipitates and to the Ag-atom-drag effect on dislocation motion, the addition of Ag can increase in strength, stress relaxation resistance and without much deterioration in electrical conductivity (Chihiro, Ryoichi & Kazue, 2008). The enhance in strength and electrical conductivity of the Cu-Cr-Zr alloy by adding Ce and Y elements are attributed to removing oxygen and sulfur from as-cast alloy (Li et al., 2006). However, the effect of Mg or Zr element on microstructure and properties of Cu-Cr alloy during the softening process are not clear. Therefore, Microstructure evolution and properties of a Cu-Cr systems alloy were investigated in detail by OM and TEM. The Relationship between microstructure and properties of Cu-Cr systems alloy was also discussed.

Jan 1, 2019

By Li Qihou, Li Yuhu, Liu Zhihong, Liu Zhiyong, Yang Xiaofeng

Scorodite samples were synthesized, in adding or without crystal seed respectively by using Atmospheric Scorodite Process (ASP), Hydrothermal Scorodite Process (HSP), and Improved Atmospheric Scorodite Process (IASP) individually; and their crystal structure, crystallinity, morphology, particle size, specific surface area, Fe/As mole ratio, as well as the leaching stability were characterized, aimed to reveal the relationships among the synthesis methods, the compositional and structural properties, and the leaching stabilities of scorodite. The results show that synthesis methods have significant effects on the compositional and structural properties of scorodite. Scorodite samples of high crystallinity, small specific surface area, and low Fe/As mole ratio, possess high leaching stability. The order in the leaching stability of scorodite samples synthesized in this study is as follow: ASP<HSP<IASP. Scorodite particles in the sample synthesized by IASP without crystal seed are in large sizes and of pyramidal morphology enclosed mainly by crystal planes of {111}; and the sample possesses the crystallinity of 84.5%, the particle size (D50) of 28.2 m, the BET specific surface area of 3.72 m2/g, and the Fe/As mole ratio of 1.05; after leaching this sample by using acetate buffer solution of pH 4.95 for 10 days, the total arsenic concentration in the leaching solution is merely 1.14 mg/L.

Jan 1, 2015

By Lauri Pesonen

"Although electrical energy use at copper smelters is typically about 15-20% of operational costs, it is something which is not very often analyzed and discussed at a detail level in technical papers and presentations. This paper aims to list different equipment configurations per smelter area and estimate their electrical energy consumptions versus unit of material processed. In addition chosen smelting technology and oxygen enrichment rates affect the overall electricity consumption and therefore some overall guidance is provided for efficiency gains.INTRODUCTION In principle, processing plants, such as copper smelters, require electrical and chemical energy together with some degree of human input to process input materials into desirable output form like metallic copper. From the standpoint of metallurgical plant designers, the thermodynamics of smelting, when it comes to releasing and conserving thermal energy, is sufficiently understood and frequently discussed in the literature in detail, but judging from the quantity of publications, the way how we exactly utilize electrical energy is not. This article is meant to illustrate how electrical energy consumption is distributed among different process units and equipment types at copper smelters using various smelting technologies. In general, typically about 15-20% of operational costs are related to electricity and at locations with high electricity prices the potential savings can be quite significant for the overall profitability of the plant operations. In today’s tight profit margin environment any potential savings are more than welcome. The purpose here is not to promote any certain copper smelting technology, but to open a discussion on how and where we use electrical energy, and how the overall energy use could be lowered with the implementation of newest electric power saving designs and solutions. Using the principles outlined in this article, it should be fairly easy and straightforward to replicate the calculations and even improve them wherever it is seen necessary for the greater benefit for us all in this industry"

Jan 1, 2017

By Alessandro Navarra, Kristian Waters

Mineral concentrators are designed from preliminary geological data, and are therefore subject to geological uncertainty. This uncertainty has a demonstrable impact on the mining lifecycle, and has motivated stochastic strategic mine planning algorithms. The current paper describes how these algorithms may be extended to consider mineral processing operations in conjunction with open-pit mining operations. In particular, the paper describes an effective way to incorporate variable concentrator feed grade into these algorithms, which is the first step toward more elaborate representations of mineral concentrators. The resulting framework will be able to connect geological data to alternate configurations of the downstream resources, hence comparing the benefit of each configuration, and the corresponding capital investments. Sample computations are presented, comparing the NPV and utilization for several different mineral processing capacities.

Jan 1, 2015

By Hiroyuki Sano, Hiroshi Chida, Katsuya Toda, Takafumi Sasaki

Saganoseki Smelter & Refinery is one of the largest copper producers in Japan to produce 450,000 tons of new copper annually. Saganoseki used to operate six PS converters with "4 Hot-2 Blow" scheme, but managed to change its operation to "3 Hot-2 Blow" scheme with four PS converters, while maintaining the same production capacity. To achieve the operational change, the following improvements have been carried out; 1) Extending service life from 220 to 350 batches, 2) Shortening cycle time by increasing the blowing rate and the matte grade, 3) Reducing environmental impact by applying sophisticated fugitive gas collection system and 4) Saving energy by waste heat boiler’s modifications. The operational change has been successfully executed, and results in drastic productivity increase and cost reduction. Currently, Saganoseki is maintaining the efficient and consistent operation with 4 PS converters. This paper describes the above-mentioned improvements for increasing productivity and the recent operational conditions of the PS converters.

Jan 1, 2015

By R. Duinker

"This paper, an update to the 2003 paper titled "Knowledge, Technology and Profit" (Twigge-Molecey, 2003) analyzes 45 "problem projects" from the mining and metals industry over the last eleven years representing $133 billion in CAPEX. The projects have been designated as "problem projects" as they did not meet their owner’s initial expectations for project performance as defined in the paper. This paper explores some of the challenges that were present, through interviews with the knowledgeable individuals that were familiar with the projects and investigations using publically available information. The aim of the exercise was to identify the key challenges faced by the projects, and the contributing factors that led to the project failures so that the lessons can be applied to future projects.The project challenges have been categorized into four themes, technical, organizational, environmental & social and missing "homework" prior to board approval. Of noteworthy interest is that environmental permitting aspects have risen to become a significant and notable contributor to problem projects in 11 years from 2003 to 2014. It is further observed that many projects have been challenged by increasing size and complexity and with execution in more remote locations since the previous paper.It is a reality that every project will face challenges. Some projects are simply more challenging than others, and success or failure of the project is often determined by whether the project team is fully prepared to respond to the challenges. This in turn is largely dependent on whether the project "homework" was adequately completed and considered for all aspects of the project."

Jan 1, 2015

By J-F. Béland, N. Parson

Aluminum extrusions are widely used for automotive crash management systems due to their superior specific energy absorption capabilities, as compared to steel. The Al-Mg-Si alloy series can be readily extruded into complex multi-hollow profiles, as required in crash systems, and can be used to target a range of desired strength levels. This paper focuses on the development of an axial crush test protocol and evaluation of the crush performance of common 6XXX series alloys for a variety of tempers. The observed crush behaviour is then compared to tensile test results.

Jan 1, 2015

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 K. Miao, W. Mu, M. Sharma, A. Haas, N. Dogan

"The ever increasing demand for cleaner steels with low inclusion content has highlighted the limits of our current knowledge for controlling and predicting inclusion agglomeration and removal during liquid steel processing. Key knowledge gaps in this area result from the complex nature of the problems associated with measuring and visualizing the phenomena studied. Confocal scanning laser microscope (CSLM) allows for continuous in situ observation of micron-size samples in real time, at high resolution, under conditions relevant to the steelmaking process. This paper summarizes some of recent CSLM applications in our laboratory to illustrate the methods of analyzing transient behavior. The reaction between inclusions and slag is given as an example. The dissolution rate of calcium aluminate inclusions in CaO-SiO2-Al2O3 slags has been studied at elevated temperatures: 1500, 1550 and 1600°C as well as thermodynamic/kinetic analysis. It is found that total dissolution time decreased with increasing temperature. The rate limiting steps are discussed. It is shown that the diffusion through a product layer is responsible for dissolution at 1500°C. At higher temperature, dissolution is most likely controlled by both boundary layer diffusion and chemical reaction at the slag-inclusion interface. In this paper, the evidence for and against the theory will be critically examined and repercussions of the theory to steel refining processes will be discussed.INTRODUCTION Inclusion formation during liquid steel refining is an unavoidable consequence of current ladle steelmaking processes. The nature and quantity of the inclusions formed in steel is critical in steelmaking, as it affects both productivity through clogging, and downstream physical properties of the steel. It is therefore crucial to better understand and control the formation, agglomeration and dissolution behaviour of inclusions in a slag in order to improve the removability of inclusions from liquid steel. Most research (Sandhage & Yurek, 1988; Sandhage & Yurek, 1990a; Sandhuge & Yurek, 1990b; Sandhuge, 1991) relevant to the kinetics of inclusion removal has been obtained by using a technique where simulated inclusion material (ceramic rods) is dipped in slag and the dissolution rate is measured. While much has been learned using this approach, the difference in scale from bulk materials to inclusions is likely to have a significant bearing on the dissolution kinetics of inclusions in a slag and will certainly result in a very different influence of capillary effects. Further, the data obtained using an indirect (dip test) procedure relies on a comparison of the initial and final conditions of a sample rather than in-situ observation which can be achieved in a confocal microscope in real time."

Jan 1, 2017

By V. Prasad, A. Afacan, K. Popli, S. Dubljevic

Froth flotation is one of the most common and widely used separation processes in the mineral processing industry; however, its complexity means that complete understanding of the process has not yet been achieved. A dynamic fundamental model is needed to enhance the understanding of the process and to improve process control. It is challenging to capture all the phenomena involved; hence, we propose a multiscale modeling approach with a framework ranging from macroscopic (equipment scale) to microscopic (attachment, detachment) models along with distribution models for ore particle sizes. Real-time froth properties are obtained using a vision-based sensing system. These measurements can be used for developing a soft sensor for grade using statistical methods such as PCR (principal component regression) and PLS (partial least squares) regression. The fundamental model is updated in real-time using extended Kalman filtering. Attachment dynamics are studied for different particle size distributions. The modeling and soft sensing is tested on batch flotation cell for the pure mineral galena with different particle size distributions using Xanthate and MIBC as collector and frother, respectively. The model, online measurements and soft sensor are useful in developing monitoring methods for froth flotation.

Jan 1, 2015

By J. J. Jonas, G. R. Stewart, A. M. Elwazri

Two important parameters for dynamic recrystallization can be derived from the changes in the strain hardening rate: the critical strain for initiation of dynamic recrystallization and the point of maximum softening. In this work, these values are determined from the flow stress-strain data obtained in continuous compression testing in the range 900-1100°C. The resulting strains are used to calculate a kinetic model of dynamic recrystallization for two materials: 304 austenitic stainless steel and a hypereutectoid plain carbon steel. The mechanical parameters used to define the proposed model are confirmed with quantitative metallographic analysis of the recrystallized microstructure.

Jan 1, 2004

By J. Sliwinski, H. Kikutani, J. Atwood, D. Larimer, J. Pyecha

"The Pogo mine start-up milling targets of 2005 are vastly different than the targets of today. Improvements have been driven by unintentional design oversight, continual circuit optimization or optimization due to changing mineralogy. The more significant process improvements to date have occurred in the gravity, flotation and leach/CIP unit operations. Details of the significant improvements are presented along with the impacts to the process.INTRODUCTION Deposit Overview Pogo mine is located along the Goodpaster River, southeast of Fairbanks, Alaska. This deposit sits in the center of the Tintina Gold Province (Figure 1), a region of similar Intrusion Related Gold deposits in Interior Alaska, the Yukon and British Columbia Canada (McCoy et al., 1997). The Pogo deposit is hosted in a rock sequence of amphibolite-grade gneisses intruded by mid-Cretaceous granitic plutons and dikes, which in turn, were cut by and host the auriferous quartz veins of the Pogo deposit.The Pogo deposit is comprised of three distinct zones of auriferous quartz veins spatially adjacent to each other. These are the Liese Zone, North Zone, and the East Deep Zone. The Liese Zone consists of three stacked, massive quartz veins, designated the L1, L2, and L3. Vein thickness averages 3.0 m, with variations from 0.3–18 m thick. The North Zone mineralization is comprised of four veins with more consistent thickness, between 1 and 1.5 m. The East Deep deposit lies northeast of the Liese Zone ore body. It is separated by a post mineralization, quartz diorite pluton. The East Deep Zone is comprised of two stacked massive quartz veins with similar orientation as the Liese Zone."

Jan 1, 2017

By T. Plikas, T. Porretta, M. Al-Dojayli, B. Pretorius, J. Woloshyn, H. Ghorbani

"Water-cooled ducts represent an integral part of high temperature off-gas systems in metallurgical processes. Typically, off-gas enters these ducts at significantly elevated temperatures; therefore, water cooling may be required to maintain the duct skin temperature within allowable design limits. These off-gases are typically of high mineral content that could lead to dust buildup, and there is a possibility of slag buildup / molten metal splashing. Therefore, dust cleaning provisions may be necessary in order to remove or minimize accretion on the duct wall, which could otherwise impact the water cooling and the system process efficiency. These ducts may have complex geometry and experience a wide range of loading, including gravity loads, water and gas pressures, cyclic thermal loading and dynamic impact forces. Consequently, the thermo-mechanical assessment of such water-cooled ducts is critical and requires consideration phenomena such as high temperature gradients, potential nucleate boiling, thermal ratcheting and fatigue failures. Such assessment is not comprehensively covered by design-by-rule design codes and guidelines due to its complexity. This paper presents a successful implementation example of design-by-analysis methodology to improve the design and extend the life of a water-cooled furnace transition duct using Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA).INTRODUCTION Water-cooling represents an important part of high temperature off-gas systems in metallurgical processes. Typical temperatures of the off-gas in the furnace uptake are in excess of 1400°C, and thus there is a need to maintain the water-cooled duct and jacket skin temperatures within their material allowable design limits. Water-cooled channels have been used effectively in arc furnace roof design (Sosonkin et al., 1972; Smolyarenko and Khainson, 1988) and other furnaces as well as in furnace fuming jackets (Scholey et al., 1994). The design of these systems was based on one-dimensional analysis to ensure sufficient cooling is available under extreme furnace conditions (Smolyarenko and Khainson, 1988; Scholey et al., 1994). With advancement in furnace and fuming system designs, water-cooled duct designs have become more complicated in geometry. Numerical techniques, such as three-dimensional fluid flow and heat transfer modeling, are therefore needed to more accurately calculate water velocity, temperature and convective heat transfer coefficients in the water-cooled channels (Haywood et al., 2002; Henning et al., 2010). This is of particular importance around geometric corners where stagnant water flow may lead to local nucleate boiling at the critical heat flux, causing hot spots (Bergman et al., 2011). High wall skin temperatures increase the risk of failures due to thermal stresses as well as increasing corrosion rates (Gelfi et al., 2012), leading to costly equipment downtime and potential safety risks."

Jan 1, 2017

"ALTHOUGH Canadian metallurgists have long been active in research, the scope of the work was somewhat limited until the be-ginning -of World War II. The rapid industrial development of Canada during the past ten years has been accompanied by .a similar upsurge in research. However, the wide geographical distribution of the research centres has made it difficult for the individual research workers to meet together and to exchange ideas or even to learn what projects .are being investigated or the nature and extent of the facilities available for work of this kind.The purpose of the present symposium is to assemble data relating to projects under investigation and the facilities employed at the various metallurgical research laboratories in Canada, thus providing some measure of correlation so that workers in different locations may learn what kind of work •is being .done at other points throughout the country.In reporting the symposium it has not been possible to reproduce the papers in full, but excerpts have been selected that give the essentia1 data."

Jan 1, 1952

By Zhou Yanwen, Fudong Wang, Shing Liu

Mixed CrB2 and MoS2 powder (Cr:Mo=1:1 atomic %), without any further process, were used as the targets to be sputtered and deposited onto stainless steel and silicon substrates by pulsed DC power supply. The structures and properties of the CrBMoS films were then analyzed by using SEM, XRD, micro-hardness tester. The SEM morphology of the films showed dense, defect free structure, and the preferred orientations of the films were CrB2 (111) and MoS2 (200) according to XRD spectra. The thicknesses of the films were measured and the relationship between the deposition rates and pulsed factors was determined. The films, with the micro-hardness as high as 19GPa and friction coefficient as low as 0.02, could be considered to be the hard solid lubricant films.

Jan 1, 2015

By Patrick Chabot

Ce document présente une méthode hybride de long trou favorisant une méthode de minage initiale par chambre-magasin et complétée par une méthode de minage long trou. Cette méthode a été adaptée suite à plusieurs facteurs tels qu?une géologie complexe, une rareté de mineur d?expérience et un haut taux de roulement de main d?oeuvre spécialisée. Cette méthode a permis d&apos;excellents résultats par rapport à la dilution. De plus, la récupération de pilier à haute teneur par forage long trou sera expliquée. Cette méthode permet aussi de récupérer le minerai qui est resté accroché dans les chantiers chambre-magasins. Introduction : La mine Géant Dormant est une mine filonienne d?or située à environ 80km au nord de la ville d?Amos au Québec. Elle est en opération depuis 1988 et à la fin de 2007, elle a produit près de 885 000 onces d?or à partir d?environ 2 400 000 tonnes de minerai pour une teneur moyenne d?environ 11,5g /t Au. Cette mine est la propriété d?IAMGOLD Corporation depuis l?acquisition de Cambior par cette dernière au mois de novembre 2006. Elle emploie 151 employés permanents et environ 41 entrepreneurs.

Feb 1, 2008