1 Textural properties in density-separated coal fractions Fernando Rubiera a , José B. Parra a , Ana Arenillas a , Steve T. Hall b , Chandu L. Shah b and José J. Pis a a Instituto Nacional del Carbón, CSIC, Apartado 73, 33080, Oviedo, Spain b School of Chemical, Environmental and Mining Engineering, University of Nottingham, NG7 2RD, United Kingdom ABSTRACT The results presented in this work are part of a more extensive research program aimed at assessing the impact of coal porous structure on density-based process evaluation and modelling. The coal samples used were obtained from two different density-based cleaning processes, a Vorsyl dense medium separator for treating an anthracite (TW) with a size fraction of 0.5-8.0 mm and a spiral concentrator for treating a bituminous coal (DH) with a size of less than 2 mm. Textural characterisation of the samples was carried out by measuring true (helium) and apparent (mercury) densities and mercury porosimetry up to a maximum pressure of 200 MPa. Adsorption isotherms in CO 2 at 273 K were also determined for both coal series. In the case of the bituminous coal series a linear relationship between porosity and ash content was found. This may have important implications if coal porosity and/or textural parameters need to be incorporated into new density-based simulation models. Keywords: Coal; Density separation; Textural characterisation INTRODUCTION Practically all aspects of coal utilisation are influenced by porosity and pore structure; for instance, gasification, liquefaction, production of metallurgical coke and activated carbon 1 . Similarly coal beneficiation can also be affected by the porosity of coals. It has been reported by researchers that coal porosity may have a significant effect on dewatering 2 and froth flotation of coal 3 . The latter paper also showed that adding reagents to coal in a fixed proportion to the coal mass without any knowledge of the internal pore structure may give misleading results. Coal float-sink separation, on the other hand, is commonly performed down to about 0.5 mm particle size in order to