Apparatus and method for removing oil from oil-coated particles

An apparatus for removing oil from particles coated with oil, said apparatus comprising:

• a housing (1) for receiving a slurry of coated particles, said housing containing a fluidizing unit (3) which has an axis, a liquid supply duct (5) with an outlet (4), and a discharge duct (6) extending through said liquid supply duct so that said liquid supply duct surrounds a portion of said discharge duct, the liquid supply duct having at its end an inlet (7), the outlet of the liquid supply duct and the inlet of the discharge duct being axially separated in the fluidizing unit by an amount selected in accordance with a desired slurry density for a discharge of the fluidizing unit, water being fed to the liquid supply duct under pressure from outside the housing having flow characteristics selected in accordance with a desired slurry density for a discharge of the fluidizing unit, the water swirling from the liquid supply duct outlet to create a vortex in the housing which disturbs the oil and particles to cause the oil to be stripped, at least partially, from the particles received in the housing, and causes the oil and particles entrained in the water to travel into the discharge duct as a discharge slurry of the desired density, the slurry being comprised of the solid particles, the oil stripped from the particles, and the water;
• and
• a first separator (8) coupled to said discharge duct of said fluidizing unit for receiving the discharge slurry, said first separator comprising a liquid/solid separation hydrocyclone having an overflow outlet;
• and
• a second separator (14) coupled to said overflow outlet of said first separator, said second separator comprising a liquid/liquid separation hydrocyclone,
• the separation efficiency of at least one of said hydrocyclones being slurry density dependent.

An apparatus for removing oil from particles coated with oil, said apparatus comprising:

• a housing (1) for receiving a slurry of coated particles, said housing containing a fluidizing unit (3) which has an axis, a liquid supply duct (5) with an outlet (4), and a discharge duct (6) extending through said liquid supply duct so that said liquid supply duct surrounds a portion of said discharge duct, the liquid supply duct having at its end an inlet (7), water being fed to the liquid supply duct under pressure from outside the housing, the outlet of the liquid supply duct and the inlet of the discharge duct being axially separated in the fluidizing unit by an amount selected in accordance with a desired slurry density for a discharge of the fluidizing unit, water being fed to the liquid supply duct under pressure from outside the housing having flow characteristics selected in accordance with a desired slurry density for a discharge of the fluidizing unit, the water swirling from the liquid supply duct outlet to create a vortex in the housing which disturbs the oil and particles to cause the oil to be stripped, at least partially, from the particles received in the housing, and causes the oil and particles entrained in the water to travel into the discharge duct as a discharge slurry, the slurry being comprised of the solid particles, the oil stripped from the particles, and the water, said housing having an overflow conduit (23);
• and
• a first separator (40) coupled to said discharge duct of said fluidizing unit for receiving the discharge slurry and separating the particles from the oil and water, the separation efficiency of said first separator being slurry density dependent;
• and
• a second, three phase, separator (26) receiving the oil and water from said first separator unit, the overflow conduit of said housing being connected to said second separator.

A separator for separating solid particles from a mixture containing solid particles and a fluid component, said separator comprising:

• a housing (1) having an upper part and a lower part, said housing having an inlet (2) for the mixture and a fluid outlet (23) associated with said upper part;
• the inlet for the mixture leading to a cyclonic separator (50, 62) such that the mixture supplied through the inlet is caused to swirl in the cyclonic separator, said cyclonic separator having an overflow (51, 64) for the discharge of fluids to said upper part of said housing, and an underflow (54, 65) for the discharge of solid particles and a portion of fluid to said lower part of said housing;
• and
• a fluidizing unit (3) positioned in said lower part of said housing, said fluidizing unit having a liquid supply duct (5) with an outlet (4) and arranged to be fed with liquid under pressure from outside the housing, and having a discharge duct (6) extending through said liquid supply duct so that said liquid supply duct surrounds a portion of said discharge duct, the liquid supply duct and having at its end an inlet (7) for receiving the solid particles and discharging them from the lower part of the housing.