The paper presents the experimental research findings for the spraying characteristics of promising composite fuels. Slurries were produced from typical coal processing waste (filter cake), a liquid bio-additive (rapeseed oil), biomass (sawdust) and a liquid noncombustible binder (water). The most important spraying characteristic is the distribution of fuel components in a jet. Optical recording techniques (Laser Induced Fluorescence, Interferometric Particle Imaging and Shadow Photography) were used to study it. A fluorophore (Rhodamine B) was used in the experiments. A group of light filters was also employed for wavelengths 580–680 nm. The research made it possible to identify zones, containing individual components and/or their mixtures, in a sprayed fuel jet. The average concentrations of coal processing waste in individual droplets and in an overall aerosol flow were recorded. The proportion of droplets containing wood biomass in a spray flow was determined. A method was proposed to reliably determine the structure of fuel jets with different component compositions. The method involves combining three optical techniques. The experimental data obtained make it possible to predict the conditions for efficient ignition and combustion of slurry fuel components in combustion chambers, taking into account their separation and atomization when they are sprayed by nozzles.