Study Starch On Flocculation Behavior And Mechanism Of Hematite Fines

The influence of cassava starch, corn starch, soluble starch and dextrin on theflocculation of hematite fines were studied in different conditions by the sedimentationexperiments, surface tension, surface potential and infrared spectrometry in this paper.The surface tension of solution and variation of the surface electrical property ofhematite fines had been studied in absence and presence of reagents, the adsorptionproperty of hematite fines had been studied by the infrared spectrometry, themechanism of starch flocculation hematite fines were simply described.The sedimentation experiments results indicated that: the flocculation order of fourstarch on hematite fines is as follows: cassava starch, corn starch, soluble starch, dextrin.Four kinds of starch flocculation hematite fines, the optimal condition as follows:cassava starch preparation concentration was2%, preparation pH of7, slurry pH of12;corn starch preparation concentration was0.3%, preparation pH of12, slurry pH of12;soluble starch preparation concentration was0.1%, preparation pH of7, slurry pH of7;dextrin preparation concentration was1%, preparation pH of7, slurry pH of7.Elevating the temperature of the slurry is better for flocculation hematite fines.The transform of pH and addition of flocculants have a little effect on the surfacetension of solution, and it’s no harmful to the flotation operation. The absolute value ofdynamic potential results show that: Four kinds of starch have a similar effect of Zetapotential on the surface of hematite fines. With the increase of the pH value, hematitefines Zeta potential absolute value increases. In addition, adding flocculants will makethe point of zero charge of hematite acidic migration. Infrared spectrometry showed thatstarch chemical adsorption happened in the surface of hematite.The mechanism of four kinds of starch flocculation hematite fines is: the starchadsorption on the hematite surface, on the low alkaline conditions, starch relies on thefunction of bridge to flocculation hematite; On the high alkaline conditions, starchdepend on the function of bridge and hydrogen bonding interaction to flocculation hematite.