POLYACRYLIC ACID AS HIGH-MOLECULAR FLOCCULANT SLURRY IN ALUMINA PRODUCTION, AND PROCESS FOR PREPARING SAID ACID Russian patent published in 1994 - IPC

FIELD: polyacrylic acid as a high-molecular polymeric flocculant precipitates the slurry in alumina production, and a process for preparing said acid. SUBSTANCE: polyacrylic acid has an intrinsic viscosity of and a molecular weight of (14-24.4)- (14-24,4)·10⁶. The acid is prepared by polymerization of acrylic acid in water at 20-40 C in the presence of a Co³⁺-glycine redox system at a Co³⁺ concentration of (0.1-1.5): (0,1-1,5)·10^-3 g·eq/l g eq/l and a glycine concentration of (0.2-15.0)(0,2-15,0)·10^-3 mole/l mole/g at their molar ratio of 1:1-20, respectively, and at an acrylic acid concentration of 20-30 wt % and pH of 1.7-1.85. EFFECT: improved properties of the polyacrylic acid and greater efficiency of the process. 3 cl, 2 tbl