METHOD OF EVAPORATING ALUMINATE SOLUTIONS AND PLANTS FOR METHOD EMBODIMENT Russian patent published in 2002 - IPC

FIELD: production of alumina, more specifically, process of evaporation of aluminate solutions in counterflow plants. SUBSTANCE: method includes heating of solution, successive boiling-down and self-evaporation. A part of solution is supplied from the second evaporator body in steam flow to the first evaporator body with maintenance of Na₂O_caust concentration within 250-290 g/l in solution of the first evaporator body and remaining part of solution of the second evaporator body and solution of the first evaporator body are withdrawn for self-evaporation. Method provides for use of counterflow evaporation plant with self-evaporator of the first body. Th second body of the evaporation plant is connected by means of pipelines of boiled-down solution with regulators to the first body and solution of self-evaporator of the second body. In said pant, as compared with the prototype, the first and second stages of boiling-down are combined in one plant with use of cheaper and economical evaporation apparatus with natural circulation fro crystallization of soda in large particles without prolonged shutdowns of plant for washing and reduction of productivity due to washing with boiled-down solution without variation of boiling-down conditions. EFFECT: higher efficiency. 3 cl, 2 dwg