MULTI-EFFECT COUNTER-FLOW EVAPORATING SYSTEM FOR CONCENTRATION OF ALUMINATE SOLUTION Russian patent published in 2004 - IPC

FIELD: production of alumina and other branches of hydrometallurgy. SUBSTANCE: the invention presents a multi-effect counter-flow evaporating system for concentration of aluminate solution, that may be used in production of alumina and in other branches of hydrometallurgy. The multi-effect counter-flow evaporating system for concentration of the aluminate solution contains equipped with heaters evaporating apparatuses having vertical tubes and the self-evaporators of the evaporated solution. At that the first evaporating apparatus located along the course of the heating steam is made in the form of the apparatus with natural circulation and a remote boiling zone, and the second evaporating apparatus is made in the form of the apparatus with a dropping film. All the evaporating apparatuses, except for the first one, are supplied with pumps. This evaporator system differs that all the rest evaporating apparatuses are made in the form of apparatuses with a dropping film and one of the pumps of each of these apparatuses with a dropping film is linked by pipelines with the lower solution (mud) chamber of that evaporating apparatus and with the previous reheater located on the heating steam course. Another pump of each of these apparatuses with a dropping film is linked by pipelines with its lower and upper solution (mud) chambers. The lower solution (mud) chamber of the first located along the heating steam course evaporating apparatus is supplied with a steam inlet and a connected to it jet pump located in the chamber under the tube plate. Besides, the steam inlet of the lower solution (mud) chamber of the first located along the heating steam course evaporating apparatus is linked through a pipeline with a source of steam, for example, with a heat-electric generating station,. The inlet of the steam delivery into the lower solution (mid) chamber of the first he first located along the heating steam course evaporating apparatus is linked with inter-tubes space of this apparatus. Each self-evaporator of an evaporated solution is supplied with a shell installed coaxially inside the self-evaporator above the inlet of delivery of the evaporated solution (mud). At that the upper butt of the shell is located below the outlet of the aluminate solution discharge from a self-evaporator. The multi-effect counter-flow evaporating system for concentration of the aluminate solution is highly efficient and allows to produce the aluminate solution of the given concentration and purified from soda and organic impurities and fit for return in the basic process of production of alumina. EFFECT: The multi-effect counter-flow evaporating system for concentration of the aluminate solution is highly efficient and allows to produce the aluminate solution of the given concentration and high quality of purification. 4 cl, 1 dwg