Process for preparing pure solutions of alkali aluminates

Zp sob spo v v tom, e se nastavuje molov² pom r alkalick ho oxidu k oxidu hlinit mu p° sadou alkalick ho hydroxidu a/nebo oxidu hlinit ho na 1 a 5 a takto z skan roztoky se oxiduj oxida n m prost°edkem a zah° vaj se na 50 a 100 .degree.C. N sleduje prvn i t n mechanick²m odd lov n m za p° sady pomocn²ch prost°edk , nap°. celul zy nebo k°emeliny, pot se koncentruj na 10 a 25 % hmotn. oxidu hlinit ho a pak se tyto roztoky podrobuj druh mu i t n za p° sady pomocn²ch prost°edk a druh oxidaci.\ The proposed process is characterized by adjusting molar ratio of an alkali oxide to aluminium oxide by the addition of an alkali hydroxide and/or aluminium oxide to 1 to 5 and so obtained solutions are then subjected to oxidation with an oxidizing agent and heating to 50 to 100 degC. The previous stage id followed up with a first purification by mechanical separation under addition of auxiliary preparations such as cellulose or diatomaceous earth. Subsequently the solutions are concentrated to 10 to 25 percent by weight of aluminium oxide and then they are subjected to a second purification under addition of auxiliary preparations and subjecting them to the second oxidation.