Coal passivation process
First Claim
1. A process for passivating particulate pyrophoric low rank coals, in a fluidized treating vessel, wherein the material is simultaneously dried and coated with a hydrocarbon liquid, thereby rendering the material substantially resistant to reabsorption of moisture and adaptable for storage and shipment at ambient temperatures, comprising the steps of:
- a. feeding the material to the treating vessel;
b. drying the material with a hot inert gas, maintained at a temperature sufficient to vaporize the moisture without devolatilizing the particulate material, said inert gas being introduced below the material in the treating zone and maintained at sufficient velocity to form a fluidized bed;
c. introducing a heavy liquid hydrocarbon into the treating vessel;
d. substantially uniformly coating the material with between about 0.5 to 2.5 weight percent of a heavy hydrocarbon liquid;
e. removing an effluent gas stream consisting essentially of water and hydrocarbons from the vessel;
f. withdrawing the hydrocarbon coated particulate material from the treating vessel.
1 Assignment
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Accused Products
Abstract
Low rank coals such as subbituminous or lignites containing more than about 10 weight percent moisture are dried and passivated against reabsorption of moisture in a fluidized bed by heating the particulate coal with a warm inert gas passing upwardly through the bed and simultaneously coating the warm particulate coal with a heavy liquid hydrocarbon material. Such coating aids in the removal of the moisture and prevents the reabsorption of moisture by the coal and thereby prevents consequential heating and possibly spontaneous ignition of the coal during its subsequent transportation or storage.
64 Citations
11 Claims
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1. A process for passivating particulate pyrophoric low rank coals, in a fluidized treating vessel, wherein the material is simultaneously dried and coated with a hydrocarbon liquid, thereby rendering the material substantially resistant to reabsorption of moisture and adaptable for storage and shipment at ambient temperatures, comprising the steps of:
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a. feeding the material to the treating vessel; b. drying the material with a hot inert gas, maintained at a temperature sufficient to vaporize the moisture without devolatilizing the particulate material, said inert gas being introduced below the material in the treating zone and maintained at sufficient velocity to form a fluidized bed; c. introducing a heavy liquid hydrocarbon into the treating vessel; d. substantially uniformly coating the material with between about 0.5 to 2.5 weight percent of a heavy hydrocarbon liquid; e. removing an effluent gas stream consisting essentially of water and hydrocarbons from the vessel; f. withdrawing the hydrocarbon coated particulate material from the treating vessel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification