Influence of particle shape on size distribution measurements by 3D and 2D image analyses and laser diffraction

in Powder Technology (2013), 237

This paper highlights the fact that particle size distribution (PSD) is not unique for the same product, and is dependent on the chosen measurement technique, especially for asymmetric shapes. Laser ... [more ▼]

This paper highlights the fact that particle size distribution (PSD) is not unique for the same product, and is dependent on the chosen measurement technique, especially for asymmetric shapes. Laser diffraction and 2D image analysis are commonly used PSD measurement techniques. However, the resultsmay not be representative of the true physical dimensions of the particles. The influence of particle shape on PSD results obtained from 2D/3D image analysis and laser diffraction was investigated. Two metallic powders presenting extreme shape properties (round and elongated particles) were analyzed, as well as a blend of the two pure products. 2D image analysis and laser diffraction results were compared to 3D image analysis (measuring the true particle size). This paper compares the PSD results obtained from the three methods. Some commonly used size parameters in image analysis software did not give meaningful results in regard of the true physical dimensions of the particles. The existence of the two populations (products with extremely different shape and size characteristics) could not be identified with such size parameters, and laser diffraction also performed poorly. The PSD obtained from more precise size parameters (image analysis) better corresponded to the true dimensions of the particles. This study highlights the strengths and weaknesses of particle size analysis techniques when studying products presenting diverse particle shapes, and points out that caution is required in the choice of the size parameters, and in the interpretation of PSD results. [less ▲]

Online monitoring of the interaction of balls and slurry with the Sensomag ®

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 ▲]

Automated Mineral Mapping in Optical Ore Microscopy : accuracy and limitations

Conference (2012, September 03)

Particle size, shape and structure characterisation

Scientific conference (2012, May 15)

Ressources dans le rouge pour les technologies vertes ?

Conference given outside the academic context (2012)

3D Imaging of individual particles : a review

in Image Analysis and Stereology (2012), 31(2), 65-77

In recent years, impressive progress has been made in digital imaging and in particular in three dimensional visualisation and analysis of objects. This paper reviews the most recent literature on three ... [more ▼]

In recent years, impressive progress has been made in digital imaging and in particular in three dimensional visualisation and analysis of objects. This paper reviews the most recent literature on three dimensional imaging with a special attention to particulate systems analysis. After an introduction recalling some important concepts in spatial sampling and digital imaging, the paper reviews a series of techniques with a clear distinction between the surfometric and volumetric principles. The literature review is as broad as possible covering materials science as well as biology while keeping an eye on emerging technologies in optics and physics. The paper should be of interest to any scientist trying to picture particles in 3D with the best possible resolution for accurate size and shape estimation. Though techniques are adequate for nanoscopic and microscopic particles, no special size limit has been considered while compiling the review. [less ▲]

Shape simulation of granular particles in concrete and applications in DEM

in Brandt, A.M.; Olek, J.; Glinicki, L.A. (Eds.) et al Proceedings of the International Symposium Brittle Matrix Composites 10 (2012)

Particle packing density and limestone fillers for more sustainable cement

in Key Engineering Materials [=KEM] (2012), 517

Cement blending with mineral admixtures, especially with byproduct or waste product powder, can effectively reduce consumption of cement and promote the ecology. Recently, an innovative concept was ... [more ▼]

Cement blending with mineral admixtures, especially with byproduct or waste product powder, can effectively reduce consumption of cement and promote the ecology. Recently, an innovative concept was proposed to replace of “coarse” cement grains by the inert fillers for sustainable cement in the low w/c concrete cement. As a basic mechanism, particle packing plays an important role in such replacement or blending. In the first part of study, the paper discusses the particle packing aspect of cement grains, limestone filler (LF) and LF blended cement. The new developed wet packing method and a dry packing method are proposed for the evaluation purpose. The paper presents results of packing tests with the influences of PSD, cement type, vibration, mixing, blending proportions, etc. The advantages and limitations of two packing methods are also discussed in this paper. [less ▲]

Ressources dans le rouge pour les technologies vertes ?

Scientific conference (2011, November 16)

De nombreuses technologies qualifiées de vertes s’imposent dans notre quotidien et d’autres s’annoncent dans un futur très proche. Véhicules électriques, éoliennes, panneaux photovoltaïques, écrans plats ... [more ▼]

De nombreuses technologies qualifiées de vertes s’imposent dans notre quotidien et d’autres s’annoncent dans un futur très proche. Véhicules électriques, éoliennes, panneaux photovoltaïques, écrans plats, éclairages LED, … Ces technologies sont peu énergivores au premier abord, mais elles sont très gourmandes en éléments rares comme le Gallium, le Néodyme, le Lithium, le Germanium, etc. L’Union Européenne, par son appel « Raw Materials Initiative », a pris conscience de son extrême dépendance vis-à-vis de pays tiers en matière d’approvisionnement en métaux stratégiques. Ces mêmes pays, parmi lesquels la Chine ou la Bolivie, cherchent quant à eux à limiter leurs exportations de matières premières brutes, espérant devenir demain des fournisseurs de composants électroniques à haute valeur ajoutée (cathodes au Li, aimants permanents, diodes, …). Dans ce contexte, on peut s’interroger sur le devenir et la pérennité de la technologie européenne. Cet exposé aura pour objectif de clarifier les enjeux et les flux de ressources au travers de quelques exemples choisis. [less ▲]

Characterization of fine aggregates in concrete by different experimental approaches

in Proceedings 13 Int. Congress for Stereology (2011, October)

Being its major component, aggregate can occupy up to three-quarter of the volume of concrete. The structure of aggregate formed in hardened state impacts largely on mechanical and durability properties ... [more ▼]

Being its major component, aggregate can occupy up to three-quarter of the volume of concrete. The structure of aggregate formed in hardened state impacts largely on mechanical and durability properties of concrete. On another hand, physical characteristics of aggregate are primarily assumed to be relevant to granular behavior of aggregate. Therefore, characterization of aggregate is of high relevance to concrete studies. In this study, different types of fine aggregate used in concrete, namely river sand and crushed limestone, are selected for morphological characterization. Traditional sieve analysis and laser diffraction method are employed for separation and size analysis of specimens. Different types of fine aggregate samples with comparable size ranges are then analyzed by two advanced dry (static) and wet (dynamic) image analysers. These new analysers are especially suitable for characterization of fine particles, which is difficult by traditional image analysis equipments. Size and shape characteristics of different fine aggregates will be revealed by different experimental methods. The results on different parameters for shape characterization will be compared and discussed [less ▲]