Patent ID: 8177867

Claim:
A slurry of coal particles in water suitable for use as an efficient-burning fuel, the slurry comprising: a colloidal fraction of coal particles dispersed in water, the coal particles comprising about 50 weight percent to about 80 weight percent of the slurry, and the water comprising about 20 weight percent to about 50 weight percent of the slurry, wherein the colloidal fraction of coal particles comprises a first plurality of coal particles having a particle size of about 100 nm to about 1 micron with an average particle size of about 200 nm to about 300 nm, and a second plurality of particles having a particle size greater than one micron to about 10 microns; and wherein the first plurality of coal particles of the colloidal fraction comprises about 20% to about 80% of the coal particles in the slurry.