絮凝氧化铁悬浮液流变性质研究

应用LVDV-Ⅲ+型可编程流变仪测定了微米级氧化铁悬浮液絮凝处理后的流变特性,考察因素包括悬浮液固相质量浓度、pH值、絮凝剂添加量、搅拌速度。结果表明,悬浮液浓度不同,其流变性能也表现出不同,在相同剪切速率下,高质量分数悬浮液的表观粘度和剪切应力都大于低质量分数悬浮液的表观粘度和剪切应力;pH对絮凝悬浮液流变性有重要的影响。絮凝悬浮液粘度随pH的增加先增大后减小,絮凝剂聚合氯化铝添加量为80 mg的条件下,pH=6.14时表观粘度最大;絮凝剂浓度的不同,对于悬浮液流变性能的影响也不同,在相同剪切速率下,添加高浓度絮凝剂悬浮液的表观粘度和剪切应力都大于添加低浓度絮凝剂悬浮液的表观粘度和剪切应力,增加絮凝剂浓度对提高悬浮液粘着性能具有积极意义;对悬浮液搅拌强度不同其流变性能也表现出不同,在相同剪切速率下,悬浮液的表观粘度和剪切应力随着测试前对它搅拌强度的增加表现出先增大后减小。

Study on the Rheological Property of Flocculation Treated Fe2O3 Suspension

The rheological property of flocculation treated micron ferric oxide suspension was measured by LVDV-Ⅲ + type programmable rheometer.The factors investigated included the mass concentration of the solid phase,the pH value,the flocculant dosage and the stirring speed.The results showed that the rheological property changed with the concentration of the suspension,the apparent viscosity and shear stress of the high mass fraction suspension were greater than those of the low mass fraction suspension in the same shear rate.The pH value had an important influence on the rheological property of flocculated suspension.The viscosity of suspension first increased and then decreased with the increasing of pH,the maximum viscosity occurred at pH = 6.14 when the amount of flocculant PAC was 80mg.Flocculant concentration also affected the rheological property of suspension,the apparent viscosity and shear stress of suspension adding high concentration flocculant were greater than those of suspension adding low concentration flocculant in the same shear rate,increasing flocculant concentration had a positive significance to improve the adhesive properties of the suspension.The rheological property also changed with the stirring strength,in the same shear rate,the apparent viscosity and the shear stress of the suspension first increased and then decreased with the increasing of stirring strength.