| 摘要 |
FIELD: chemistry.SUBSTANCE: bauxite is processed by Bayer method, in accordance with which: a) bauxite are is prepared, b) it is leached, with obtaining pulp, which contains solution enriched with dissolved alumina, and red mud, c) solution is separated from red mud, d) solution, enriched with aluminium oxide is brought into strongly nonequilibrium state of oversaturation usually by cooling and dilution, alumina trihydrate particles being introduced into it for decomposition, i.e. precipitation of alumina in form of alumina trihydrate, e) aluminium oxide depleted solution is subjected to concentration, usually by evaporation and, possibly, addition of sodium hydroxide to obtain concentrated solution, which is returned into production cycle to stage b) of bauxite leaching. Between stage c) and stage d) aluminium oxide enriched solution is subjected to control filtration for solution to contain less than 10 mg/l of insoluble particles at filtration output. In the course of control filtration stage filtering device, including zone, in which aluminium oxide enriched solution, after passing through filtering medium, is under pressure, constituting more than 2 bar, preferably more than 3 bar.EFFECT: invention makes it possible to increase process productivity.24 cl, 1 dwg |
