Abstract: A simplified method and apparatus for handling black liquor (or other spent liquor from the pulp industry) includes utilization of a mixing tank directly with a black liquor storage tank. The mixing tank has a side wall defined by a part of the side wall of the black liquor storage tank, and the mixing tank may either be disposed within the volume of the storage tank, or immediately exterior of it. Fly ash from a recovery boiler and make-up chemical are introduced into the mixing tank along with black liquor from evaporators, and the mixed liquid from mixing tank overflows into the interior volume of the black liquor storage tank. From the storage tank the black liquor is sent to a recovery boiler where it is burned. Also, some black liquor from the recovery boiler is recirculated to the storage tank, and introduced into the storage tank remote from the mixing tank.