Method of producing petroleum coke calcinate

Claim 1

An improved method of producing petroleum coke calcinate with a residual hydrocarbon content of not more than 0.1% by weight from wet green coke in a cylindrical rotary kiln with a one-way gas flow comprising the steps of (1) indirectly drying the wet coke in a revolving dryer with flue gas having a temperature of 400°-450° C. to a residual moisture content of about 0.5-7.0% by weight; (2) calcining and heating the dried green coke from step (1) in a revolving calciner; (3) indirectly cooling the product of step (2) in a revolving cooler at a temperature of 100°-200° C.; (4) removing simultaneously the dust-laden vapors from the indirect drying and calcining steps (1) and (2) and mixing the same with lean gas; (5) burning the vapor-gas mixture from step (4) in a boiler-steam generator with air to a flue gas at a temperature of 400°-450° C.; (6) conducting said flue gas to the indirect drying step (1) for heating purposes whereby the temperature of the flue gas decreases to about 280°-320° C.; (7) separating coke dust from the cooled flue gas from step (6) electrostatically to a residual dust content on a dry basis of less than 100 mg/nm 3 in said flue gas; (8) discharging the gas from step (7) to the atmosphere; and (9) feeding coke dust collected in process steps (1), (2) and (7) in dose quantities to the dried-green coke being calcined in order to maintain a uniform flow behavior of the coke during calcination.