Method for reducing alumina or magnesia by utilizing supersonic gas flow

摘要

An alumina- or magnesia-reducing process in which a greenhouse gas or substance harmful to the human body is not emitted, which can achieve improved energy efficiency in comparison with the Hall-Heroult or Pidgeon methods. The process includes: introducing an alumina or magnesia powder with a carrier gas to the upstream side of a throat provided on a reducing unit; pressure-transferring the powder and carrier gas to the throat by an operative gas introduced to the upstream side of the throat; irradiating the throat with a laser beam to convert the alumina or magnesia into a plasma state and dissociate the alumina or magnesia thermally; jetting the thermally dissociated product through a nozzle provided on the downstream side of the throat at a supersonic speed to form a frozen flow; and isolating aluminum or magnesium. Hydrogen may be added to the operative gas to accelerate the reduction of alumina or magnesia.

主权项

1. A method for reducing alumina or magnesia, the method comprising:
heating alumina powders or magnesia powders by heating means for putting it in a plasma state so as to thermally dissociate aluminum or magnesium from oxygen, and ejecting gas in the plasma state in a form of a supersonic jet steam from a nozzle so as to make it in frozen flow, to thereby isolate aluminum or magnesium.