References of "Jaimes Contreras, Rafael Antonio"
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See detailEFFECT OF RAW MATERIAL PROPERTIES ON THE KINETICS OF IRON ORES GRANULATION
Jaimes Contreras, Rafael Antonio ULg; van Loo, Fréderic; Douce, Jean-François et al

Poster (2013, June 26)

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See detailEFFECT OF RAW MATERIAL PROPERTIES ON THE KINETICS OF IRON ORES GRANULATION
Jaimes Contreras, Rafael Antonio ULg; van Loo, Fréderic; Douce, Jean-François et al

Conference (2013, June 26)

The current study is focused on the iron ores granulation process in a laboratory-scale batch drum granulator using water as a binder, and on the investigation of the influence of raw material properties ... [more ▼]

The current study is focused on the iron ores granulation process in a laboratory-scale batch drum granulator using water as a binder, and on the investigation of the influence of raw material properties (morphology and wettability of the primary particles) on its kinetics. Nowadays processing of iron ores often requires a modification of particle size by means of granulation in order to improve further processability. A comparison of the granulation behaviour of three types of iron ores (magnetite, hematite and goethite) has been carried out. The wettability of the powders has been characterised by contact angle measurement. The results confirm the hydrophobic and hydrophilic characters of magnetite and goethite respectively. The granulation kinetics (evolution of particle size distribution as a function of time) of each type of iron ores was measured. [less ▲]

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See detailQuantitative Microtexture Analysis of Carbonate Rocks Using Bireflectance Imaging
Jaimes Contreras, Rafael Antonio ULg; Pilawski, Dimitri; Califice, Arnaud ULg et al

in Proceedings IAMG 2010 (2010)

Microtextural analysis of rocks has been addressed by several authors as an essential means to better understand the natural genesis of the material. But, it is also of paramount importance to those who ... [more ▼]

Microtextural analysis of rocks has been addressed by several authors as an essential means to better understand the natural genesis of the material. But, it is also of paramount importance to those who try to predict the geotechnical or industrial behaviour of a rock under many forms of solicitation (mechanical, thermal, etc.). Quantitative modal (phase) analysis using point counting has already been discussed in depth by authors such as Chayes more than fifty years ago. Nowadays, automated image analysis with millions of pixels is easily available and improves statistical accuracy provided the classification step is correctly performed. Spitefully the assignment of a pixel to a given mineral phase or to a given crystal is often poorly satisfactory and remains the bottleneck of a fully automated textural analysis. Methods using a manual rotation of a polarizer in transmitted light microscopy have been developed by Starkey and Samantaray (1993) and further automated and improved by Fueten (1997). These allow to better delineate individual crystals in a thin section due to contrast in birefringence. In this paper a similar technique using multiple orientations of a polarizer in reflected light microscopy has been used to contrast individual crystals in carbonated rocks. The maximum and minimum grey levels registered for each pixel allow for computing a bireflectance image whose variance is a good indicator of the misalignment of cristallographical orientations in the section. Moreover, the maximum of the reflectance gradient obtained for each orientation generates a good image of the grain boundaries and the presence of pores. This last one is quantitatively analysed using the intercept method to estimate the mean and variance of the grain size distribution. The paper presents a quantitative comparison of several different microtextures. [less ▲]

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