References of "Leroy, Sophie"
     in
Bookmark and Share    
Full Text
See detailMineralogy of fine particles in slurry from multispectral imaging
Leroy, Sophie ULg; Dislaire, Godefroid ULg; Barnabé, Pierre ULg et al

Conference (2014, September 02)

Quantitative mineralogy of fine particles in slurry from multispectral imaging Sophie Leroy, Godefroid Dislaire, Pierre Barnabé and Eric Pirard Mineral processing especially in its final stages relies ... [more ▼]

Quantitative mineralogy of fine particles in slurry from multispectral imaging Sophie Leroy, Godefroid Dislaire, Pierre Barnabé and Eric Pirard Mineral processing especially in its final stages relies heavily on the differential behavior of particles in pulps. In order to monitor hydrocyclones and flotation cells in almost real time, it is important to develop at line particle characterization providing information on particle distribution but also mineralogy. A sampling device has been elaborated based on a flow cell with variable wall spacing linked to a high pressure peristaltic pump. This setup allows for dispersion and dilution of the mineral slurry into the cell. Depending on the ore or gangue minerals to be controlled, particles can be imaged either in diffuse reflectance or in transmittance mode. A simple multispectral imaging module has been designed to acquire images at eight different wavelengths. The design is based on a series of dichroic filters thereby avoiding any moving part and enabling a very fast acquisition of multispectral images. Imaging artifacts due, among others, to specular reflectance from the glass window are minimized. Multispectral classification is used to outline particles appearing in the field of view and to qualify their main mineral component. In particular, areas reflecting a meaningful and discriminative spectrum are identified and compared to a multispectral database. The database is continuously enriched through testing of pure mineral particles under similar pulp conditions (dilution, grain size,…). Results of final classification are compared to the modal analysis obtained from polished blocks and conventional reflected light microscopy. The technology developed in this work sets the basis for at line monitoring of ore slurries with reasonably simple mineralogy. Extension of the spectral range is being considered for future developments. [less ▲]

Detailed reference viewed: 10 (2 ULg)
Full Text
Peer Reviewed
See detailDetermination of Particle Size, Surface Area, and Shape of Supplementary Cementitious Materials by Using Different Techniques
Arvaniti, Eleni; Juenger, Maria; Bernal, Susan et al

in Materials and Structures (2014)

The particle size distribution, surface area and shape are fundamental characteristics of supplementary cementitious materials (SCMs). Accurate measurement of these properties is required in computational ... [more ▼]

The particle size distribution, surface area and shape are fundamental characteristics of supplementary cementitious materials (SCMs). Accurate measurement of these properties is required in computational efforts to model the hydration process, and the characterization of these parameters is also an important practical issue during the production and use of blended cements. Since there are no standard procedures specifically for the determination of physical properties of SCMs, the techniques that are currently used for characterizing Portland cement are applied to SCMs. Based on the fact that most of the techniques have been developed to measure cements, limitations occur when these methods are used for other materials than cement, particularly when these have lower fineness and different particle shape and mineralogical composition. Here, samples of fly ash, granulated blast furnace slag and silica fume were tested. Different results obtained using several methods for the determination of specific surface area are presented. Recommendations for testing SCMs using air permeability, sieving, laser diffraction, BET, image analysis and MIP are provided, which represent an output from the work of the RILEM Technical Committee on Hydration and Microstructure of Concrete with Supplementary Cementitious Materials (TC-238-SCM). [less ▲]

Detailed reference viewed: 10 (3 ULg)
Full Text
Peer Reviewed
See detailPhysical Characterization Methods for Supplementary Cementitious Materials.
Arvaniti, Eleni; Juenger, Maria; Bernal, Susan et al

in Materials and Structures (2014)

The main supplementary cementitious materials (SCMs) that are used today are industrial by-products. In most cases the quality of these materials cannot be controlled during their production, resulting in ... [more ▼]

The main supplementary cementitious materials (SCMs) that are used today are industrial by-products. In most cases the quality of these materials cannot be controlled during their production, resulting in materials with varied characteristics. The adequate physical characterization of SCMs is important to better predict their performance and optimize their use in concretes production. There are standardized methods used to determine the particle characteristics for Portland cements that are usually adopted to characterize SCMs; however, these methods may not be as accurate when applied to SCMs. This paper is an overview of the techniques that are currently used for the determination of the density, particle size distribution, surface area and shape of SCMs. The main principles of each method are presented. The limitations that occur for the SCMs measurements are also discussed. This paper is an output from the work of the RILEM Technical Committee on Hydration and Microstructure of Concrete with Supplementary Cementitious Materials (TC-238-SCM). [less ▲]

Detailed reference viewed: 6 (1 ULg)
Full Text
See detailOnline monitoring of the interaction of balls and slurry with the Sensomag ®
Köttgen, Axel; Leroy, Sophie ULg; Bastin, David ULg et al

Poster (2012, December 10)

Presentation of Optimag Project results. Optimag aims to optimize the ball milling operations through the use of an embarked sensor, called the Sensomag, and developed by Magotteaux to monitor in real ... [more ▼]

Presentation of Optimag Project results. Optimag aims to optimize the ball milling operations through the use of an embarked sensor, called the Sensomag, and developed by Magotteaux to monitor in real time the position of the slurry and the grinding balls. [less ▲]

Detailed reference viewed: 37 (6 ULg)
Full Text
Peer Reviewed
See detailImaging technologies to understand grinding at particle scale in a UG-2 platinum ore processing plant
Leroy, Sophie ULg; Pirard, Eric ULg

in XXVI INTERNATIONAL MINERAL PROCESSING CONGRESS (IMPC) 2012 PROCEEDINGS / NEW DELHI, INDIA / 24 - 28 SEPTEMBER 2012 (2012, September)

Detailed reference viewed: 64 (23 ULg)
Full Text
See detailBall milling control: the reconciliation of macroscopic SensoMag® data with microscopic optical information.
Leroy, Sophie ULg; Köttgen, Axel ULg; de Haas, Bernard et al

Poster (2012, February 08)

Detailed reference viewed: 68 (10 ULg)
Full Text
Peer Reviewed
See detailOptical analysis of particle size and chromite liberation from pulp samples of a UG2 ore regrinding circuit
Leroy, Sophie ULg; Dislaire, Godefroid; Bastin, David ULg et al

in Minerals Engineering (2011), 24

Since the early seventies high chromite and low base metal sulphide (BMS) contents of the UG2 reef imposes technological challenges to mineral processors and extractive metallurgists. Forty years later ... [more ▼]

Since the early seventies high chromite and low base metal sulphide (BMS) contents of the UG2 reef imposes technological challenges to mineral processors and extractive metallurgists. Forty years later, particle size distribution and size by size mineralogy are considered as key factors to the continuous improvement of the UG-2 ore metallurgy. With the successful development of ultra fine grinding technologies, a compromise has to be found between fine grinding to achieve platinum group minerals liberation and to avoid the overgrinding of gangue minerals, especially chromite gangue which is detrimental in smelting process. Indeed, fine chromite grains, despite of being naturally hydrophobic mineral, can be recovered in flotation concentrate by entrainment. In addition, overgrinding also increase liberation of naturally floatable gangue (talc) which contaminate the concentrate and need to be controlled during flotation. In this paper, innovative techniques of single particle image analysis from both dry and wet samples have been tentatively used to assess the chromite particle size distribution and the chromite grade of samples taken from a secondary milling circuit. Preliminary results demonstrate excellent potential for online particle imaging making use of both the particle geometry (size, shape) and the optical properties (translucency). [less ▲]

Detailed reference viewed: 173 (32 ULg)