AbstractAnionic polyacrylamide was used to flocculate kaolin slurries. Both linear and branched polyacrylamide were polymerized. The polymer samples were fractionated and the molecular weights determined on the fractionated samples. The molecular weight range studied varied from 10,000 to 3,000,000. Each polyacrylamide sample was hydrolyzed to anionic levels ranging from 5 to 25 percent. The flocculating performance of the above polymers was measured on kaolin slurries using both settling tests with 3 kaolin and jar tests with 200 ppm kaolin. The effect of anionic polyacrylamide conformation on the flocculating rates was determined by varying the pH and hydrolysis level. The effect of the polymer configuration was studied by varying the molecular weight and using both linear and branched samples. In every case tested the linear polyacrylamide was a more effective flocculant than the branched polymer. The polyacrylamide effectiveness increased with increasing molecular weight for both the linear and branched samples tested. Increasing the mean end‐to‐end distance of the dissolved polymer molecular increased its flocculating effectiveness. This increased length could be accomplished by changing either the pH or the hydrolysis level. The results of the study were the same whether settling tests or jar tests were used as a performance crite
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