The characteristics of the collisions of droplets with the surfaces of particles and substrates of promising oil−water slurry components (oil, water and coal) were experimentally studied. Particles of coals of different ranks with significantly varying surface wettability were used. The following regimes of droplet−particle collisions were identified: agglomeration, stretching separation and stretching separation with child droplets. The main characteristics of resulting child droplets were calculated. Droplet−particle interaction regime maps in the B = f(We) coordinates were constructed. Equations to describe the boundaries of transitions between the droplet−particle interaction regimes (B = nWe) were obtained. The calculated approximation coefficients make it possible to predict threshold shifts in transition boundaries between the collision regimes for different fuel mixture components. Differences in the characteristics of secondary atomization of droplets interacting with particles were established. Guidelines were provided on applying the research findings to the development of technologies of composite liquid fuel droplet generation in combustion chambers with the separate injection of liquid and solid components, as well as technologies of secondary atomization of fuel droplets producing fine aerosol.