淀粉对微细粒赤铁矿絮凝行为及机理研究

发布时间：2018-12-14 03:29

【摘要】：本文通过沉降试验对木薯淀粉、玉米淀粉、可溶性淀粉以及糊精这四种絮凝剂在不同条件下对微细粒赤铁矿絮凝行为的影响进行了详细的研究。通过表面张力、Zeta电位和红外光谱的测定研究了药剂作用前后溶液表面张力及赤铁矿表面Zeta电位的变化规律及絮凝剂在赤铁矿表面的吸附特性，并对淀粉絮凝微细粒赤铁矿的机理进行了简单的阐述。沉降试验表明，四种淀粉对赤铁矿絮凝效果的强弱依次为：木薯淀粉、玉米淀粉、可溶性淀粉和糊精。四种淀粉絮凝赤铁矿时，最佳条件为：木薯淀粉配制浓度为2%、配制pH值为7、矿浆pH值为12；玉米淀粉配制浓度为0.3%、配制pH值为12、矿浆pH值为12；可溶性淀粉配制浓度为0.1%、配制pH值为7、矿浆pH值为7；糊精配制浓度为1%、配制pH值为7、矿浆pH值为7。提高矿浆温度有利于赤铁矿的絮凝。表面张力测定结果表明：pH值的改变、絮凝剂的加入及二者共同作用时均不会对溶液的表面张力产生明显影响。Zeta电位测试表明：四种淀粉对赤铁矿表面Zeta电位影响相似，pH值的增加及淀粉的加入均会使赤铁矿表面的Zeta电位绝对值增加，使赤铁矿零电点向酸性发生偏移。红外光谱测定表明：淀粉在赤铁矿表面发生了化学吸附。四种淀粉对赤铁矿的絮凝机理为：淀粉在赤铁矿表面发生吸附，在低碱性下，主要依靠淀粉分子链的桥架作用对赤铁矿进行絮凝；高碱条件下，主要依靠淀粉分子链的桥架作用及氢键共同作用对赤铁矿进行絮凝。
[Abstract]:In this paper, the effects of cassava starch, corn starch, soluble starch and dextrin on the flocculation behavior of fine hematite under different conditions were studied in detail. The changes of surface tension and Zeta potential of hematite surface and the adsorption characteristics of flocculant on hematite surface were studied by measuring surface tension, Zeta potential and infrared spectrum. The mechanism of starch flocculation of fine hematite is briefly described. The sedimentation test showed that the flocculation effect of four starch on hematite was cassava starch, corn starch, soluble starch and dextrin. The optimum conditions for flocculating hematite with starch are as follows: the concentration of cassava starch is 2, the value of pH is 7, the value of pH of pulp is 12, the concentration of corn starch is 0.33, the value of preparation of starch is 12, the value of pulp is 12. The concentration of soluble starch is 0.1, pH value is 7, pH value of pulp is 7, dextrin concentration is 1, pH value is 7 and pH value of pulp is 7. Raising slurry temperature is beneficial to hematite flocculation. The results of surface tension measurement showed that the change of pH value, the addition of flocculant and the interaction between them had no obvious effect on the surface tension of the solution. The Zeta potential test showed that the four starch had similar effect on the surface Zeta potential of hematite. The increase of pH value and the addition of starch can increase the absolute value of Zeta potential on hematite surface and make the zero electric point of hematite deviate to acidity. Ir spectra showed that starch chemisorbed on hematite surface. The flocculation mechanism of the four kinds of starch to hematite is as follows: starch adsorbed on the surface of hematite, and the hematite is flocculated mainly by the bridge action of starch molecular chain under low alkalinity; Hematite is flocculated under high alkali condition mainly by the bridge action of starch molecular chain and hydrogen bond interaction.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD951

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