Abstract: Disclosed is a combustible heavy hydrocarbon-in-water emulsion comprising: a. a nitrogen base neutralized phosphate-ester emulsifier in about 0.2 to about 1.0 wt. % amount; b. a water-soluble emulsion stabilizer comprising a high molecular weight water-soluble thickener in about 0.02 to about 0.2 wt. % amount; c. water in about 25 to 50 wt. % amount; and d. a high-softening point hydrocarbon material in an amount to make 100 wt. % emulsion wherein said hydrocarbon material is present in said emulsion in the form of substantially spherical particles having a median diameter in the range of 1 to 30 microns. Also disclosed and claimed is a combustible slurry fuel made from said emulsion which contains carbonaceous solids, particularly petroleum coke. The process for making the emulsion and slurry fuel is also disclosed and claimed.