The objective of this study is to relate the flotation of coarse composite particles with their mineral composition. For this purpose, composites of quartz particles in lead borate matrix were fabricated in different size fractions. The quartz in the composite particles was selectively hydrophobised. The composite particles were floated and backscattered scanning electron microscopy was used to measure the number of particles in each flotation product, their size and liberation class. Results showed that the flotation of these composite particles decreased with increasing particle size, and decreasing the quartz (the hydrophobic phase) liberation class. Furthermore, it was also found that diesel oil addition improves the adhesion of composite particles with bubbles, and consequently enhances their flotation recovery. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.