Washing soluble salts out of metallurgical slags - esp. to remove chloride(s) from light alloy slags

摘要

The slag is crushed, and is fed into a drum for leaching with water to form a brine (a) which is sepd. together with nonmetallic particles (b) contg. alumina, from the metallic fraction (c) due to the difference in density. Part (a1) of the brine (a) contg. particles (b) is fed to a vacuum crystallisation plant, whereas the remainder (a2) of the brine is fed into a second leaching drum. Brine (a) is pref. fed through a centrifuge for partial removal of solids (b), and then through a filter press. The pref. plant includes a decantation tank from which part (a2) of the brine can be obtd. and fed to the second drum or into a third washing drum used to treat sediment from the decanation tank. Used in the recovery of NaCl and KCl via the brine; and also the recovery of solids viz. Al2O3, MgO and SiO2 which can be used in the building industry.