A new method based on cone-beam X-ray microtomography is described for direct determination of the three-dimensional liberation spectrum of multiphase particles 100 microns in size or less. Such a technique may provide the basis for more detailed and accurate liberation analysis in the 21st century. Previous research had demonstrated the ability to use traditional medical X-ray CT scanners to determine the liberation spectrum of coarse coal particles of 1 cm in size (washability analysis). Rather than stacking a series of two-dimensional slices for volumetric imaging as is commonly done in traditional medical computed tomography, a three-dimensional reconstruction image array is prepared directly from the two-dimensional projections for cone beam geometry. The advantage of high spatial resolution (approximately 15 mu m) with a microfocus X-ray generator combined with the benefit of direct processing of three-dimensional data, provide an excellent opportunity to overcome many of the limitations of current polished section techniques being used for the liberation analysis of multiphase particles.