The invention discloses a high-efficiency energy-saving
hydrochloric acid pickling waste liquor triple-effect negative-pressure
graphite evaporation crystallizer, belonging to the field of
pickling waste liquoir treatment. The
evaporation crystallizer disclosed by the invention comprises an
evaporation concentration unit, a feed unit, a gas condensation unit, a cooling
crystallization unit, a
solid-liquid separation unit, a
mother liquor circulating unit and a vacuum unit. The
hydrochloric acid pickling waste liquor is heated in a
vacuum state, so that volatile
chlorine hydride and water in the solution are evaporated together, and are condensed through the gas condensation unit to form reusable clean
hydrochloric acid; and the concentration of the nonvolatile
metal salt in the solution is continuously increased to form a
metal salt supersaturated solution, and the
metal salt supersaturated solution is cooled by the cooling
crystallization unit, so that part of
metal salts are precipitated in the crystalline-state hydrous
crystal, thereby achieving the goal of separating the solute and
solvent in the solution. The invention mainly aims to provide a high-efficiency energy-saving hydrochloric acid pickling waste liquor triple-effect negative-pressure
graphite evaporation crystallizer which has the advantages of favorable
antiseptic property, high
recovery ratio and low treatment cost.