| abstract |
1,206,711. Flocculated clays or sewage. DOW CHEMICAL CO. 4 Jan., 1968, No. 659/68. Headings C1A and C1C. [Also in Division C3] Aqueous suspensions of inorganic or organic solids are flocculated by addition of an acrylic acid polymer prepared by polymerization in an aqueous solution of pH 1 to 4 containing an inorganic salt in a proportion to precipitate the polymer. A slurry of montmorillonite clay is settled by addition thereto of an aqueous solution of polyacrylic acid or a copolymer of acrylic acid with acrylamide. Raw sewage is flocculated by addition of a mixture of an aqueous suspension of acrylic acid-acrylamide copolymer and an aqueous acidic solution of a polymer obtained by condensation of a polyalkyleneamine and ethylenedichloride, the said mixture being rendered alkaline with NaOH. |