Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/21/2008
Publication Date: 5/16/2009
Citation: Shogren, R.L. 2009. Flocculation of Kaolin by Waxy Maize Starch Phosphates. Meeting Abstract. 76(2009):639-644.
Technical Abstract: Waxy maize starch phosphates were tested as flocculants in order to determine if they have the potential to replace petroleum-based polymer flocculants currently used commercially. Phosphorylation was carried out by dry heating of starches and sodium orthophosphates at 140 degrees C for 4 hours. Native and phosphorylated waxy maize starches were ineffective as flocculants for kaolin in deionized water. However in the presence of small amounts of Ca++ (1-4 mM), starch phosphates were effective flocculants of kaolin at concentrations as low at 3-4 ppm. The optimal degree of substitution (DS) for flocculation was 0.024 but the effect of DS was rather small over the range DS 0.007-0.08. Although a common synthetic polymer flocculant (polyacrylamide-co-acrylic acid) was effective at 1 ppm, the lower cost of starches should make them economically competitive.