Effects of Physico-chemical Parameters on Dewatering: A Case Study.
Adv in Filtration & Sep Tech Sep; 4:167-180
The U.S. Bureau of Mines Tuscaloosa Research Center is investigating solid-liquid separation with the goal of improving the dewatering of mineral slurries. This study investigated the effects of physical and chemical parameters such as mixing and polymer type on dewatering of mineral slurries. Small-scale laboratory tests, using an in-line mixer, were conducted to investigate the effect of variation in reynolds number on the dewaterability of a bentonite slurry. These tests showed that lower polymer dosages were required with polyethylene oxide (peo) than with photofloc 1027 and that the peo-treated slurries can withstand more shear than those treated with photofloc 1027. Similar studies using tank mixers showed that only peo produced strong flocs and that higher peo dosages were required with this mixer than with the in-line mixer. Based on the positive laboratory results, large-scale studies were conducted at various placer gold mines in Alaska. These studies confirmed that mixing is a major factor in flocculation. Results also showed that in three out of four field tests, in-line mixing produced better solid-liquid separation than conventional tank mixing and that peo produced water with low turbidity.
Adv. in Filtration & Sep. Tech. V. 4, Fine Particle Filt. & Sep. Am. Filt. Soc., PP. 167-180