METHOD OF PREPARING COAGULANT Russian patent published in 2001 - IPC

FIELD: chemical technology, more particularly preparation of main aluminium chlorides which are widely used for purifying natural water and sewage. SUBSTANCE: method comprises treating aluminium chloride with aluminium hydroxide or aluminium oxide. Aluminium chloride solution is liquid isobutylbenzene production waste containing 1.5-2.25 g-mole/cu.dm, and aluminium hydroxide is aluminium containing higher fatty alcohol production waste in the form of aluminium hydroxide suspension with moisture content of 80-30%, and aluminium oxide is aluminium-containing higher alcohol production waste in the form of finely dispersed γ-Al₂O₃ powder which is product of combustion of slime at 960 C and containing 84- 90% of γ-Al₂O₃. Coagulant is prepared in aluminium oxychloride 2/3 grade form as 2.25-3.75 molar solution or 5/6 grade as 4.5-6.75 molar solution. Treatment of isobutylbenzene production waste with higher fatty alcohol production waste in the form of aluminium hydroxide suspension or finely dispersed γ-Al₂O₃ powder is carried out to prepare mono-and dimolar solutions of aluminium grade 2/3 and grade 5/6 solutions, respectively at the following stoichiometric ratios of components: AlCl₃:Al(OH)₃= (0,666-1,333):(1,222-2,666} and and AlCl₃:Al₂O₃= (0,333-0,666):(0,833-1,666). Treatment is carried out at room temperature. EFFECT: more efficient preparation method. 4 cl, 2 tbl