PURPOSE: To enhance the recovery ratio of coal and to reduce necessary crushing power, by applying electrostatic separation treatment to slack coals, with low concentration of ash content, which were respectively subjected to corona discharge treatment to separate high grade slack coals low in ash content and mixing both of them.
CONSTITUTION: High grade slack coal low in ash content separated and recovered by tertiary electrostatic separation treatment is met with and supplied to a duct 6 through a duct 8 while a separated low grade powder (ash coal after the recovery of almost all of coal components and having no commodity value) high in ash content is fed out through a waste feed-out line 14. The mixture of high grade slack coals respectively separated and recovered by first and third electrostatic separation treatments is transported to a bag filter 11 by a pneumatic transport means through the duct 6 to be collected and recovered by the bag filter 11 as purified slack coal which is, in turn, fed out from a feed-out line 13.
TAKAHASHI TAKEO
ONISHI AKIRA
AMANO SHUJI
SHICHIRI MASATAKA
