| 摘要 |
1354349 Clarifying black liquor; flocculating ALLIED COLLOIDS MFG CO Ltd 29 Sept 1972 [12 Oct 1971] 47487/71 Headings C1A and C1C [Also in Division C3] Suspension of solids in liquid media (e.g. aqueous suspensions) are flocculated by utilizing as the flocculating agent, a copolymer containing within the molecular chain: (1) N-methylolacrylamide units and (2) N-aminomethylacrylamide units of formula in which R 1 and R 2 are the same or different C 1-4 alkyl or C 2-4 hydroxyalkyl groups or together form a heterocycle with the nitrogen atom, the mole ratio of (1) to (2) being 3 : 1 to 1 : 2À3, and optionally (3) up to 16 mole per cent of acrylamide units and/or up to 55 mole per cent of acrylic acid or acrylic acid salt units. Units (2) may be quaternized. The polymers are particularly suitable for the flocculation of " black liquor " which is obtained during the extraction of titanium from ilmenite. In Examples 5 and 6, samples of " black liquor " prepared in the laboratory from ilmenite are treated with copolymers containing N-methylol acrylamide and dimethylaminomethyl acrylamide units with or without acrylamide and/or sodium acrylate units. |
