International, Inc. Tel: 973 6336878 Fax: 973 6330828 Email: email@example.com [Bestac International, Inc.] ©Copyright, All rights reserved.
Bestac International, Inc.
Tel: 973 6336878
Fax: 973 6330828
[Bestac International, Inc.]
©Copyright, All rights reserved.
Alumina is produced by processing bauxite ore. After crushing and grinding the ore to less than 1mm it is then subjected to high temperature and pressure after the addition of concentrated sodium hydroxide. The alumina dissolves in the highly caustic liquor and of the many impurities only silica is soluble.
After digestion the sand particles are removed with the slurry being settled in primary thickeners where the flocculant is added. This is a critical stage in achieving very clear overflow clarities. The underflow, or red mud, then passes to a counter current decantation process where further alumina from the liquor is recovered via a series of washer decanters. Again flocculant is used here to promote settling and acceptable overflow clarities.
The pregnant liquor from the primary thickeners is filtered, then cooled (taking up to 48 hours) and seeded with alumina hydrate to promote precipitation of alumina trihydrate. This is then filtered and washed finally calcined to produce alumina.
For the primary thickeners the recommended
For the washer decanters the recommended