Method and apparatus for treating an ore comprising mineral substrate
particles surrounded by hydrocarbon compounds, especially tar sand
grains, process tailings, and contaminated soils, to recover a
hydrocarbon portion and a cleaned substrate portion. In a preferably
continuous process, hydrocarbonaceous rock, sand, ore, tailings, or soil
containing bitumen, petroleum, and/or kerogen may be crushed or otherwise
comminuted as needed to provide a particle size of sand or smaller. The
ore is mixed with water to form a slurry, which may also contain alkali,
for example, sodium hydroxide or sodium bicarbonate. The slurry is heated
to about 80.degree. C. and is intensively sheared to condition the slurry
for separation, preferably by shear-fracture of the hydrocarbon layers
surrounding the particles in the grains. The conditioned slurry is
blended with a peroxide in aqueous solution, preferably hydrogen
peroxide, which enters the grains and is decomposed therein, creating
bubbles of free oxygen within the grains which disrupt the hydrocarbon
envelope. In decomposing, the peroxide increases the hydrophilicity of
the particle surfaces. Both free and bound hydrocarbons in the ore are
thereby released from the mineral substrate particles. The resulting
hydrocarbon globules are separated from the substrate particles by
flotation, accelerated by attached oxygen bubbles. Alkali and/or peroxide
may be added during the flotation process. Water and mineral tailings
from the process are substantially free of hydrocarbon contamination and
are environmentally suitable for landfill disposal.
