三水-一水软铝石型铝土矿溶出矿浆流变性研究

Research on Rheology of Digested Slurry for Gibbsite-Boehmitic Bauxite

以难处理三水-一水软铝石型高硅铝土矿为研究对象,采用Thermo公司生产的RS600型流变仪,研究了温度、固体含量及絮凝剂对上述铝土矿溶出赤泥浆体流变性的影响。结果表明:与原矿浆及预脱硅矿浆相反,溶出赤泥浆粘度随温度的升高而降低;当固体含量(质量分数)低于16%时,溶出矿浆为牛顿流体,其粘度随固体含量的升高而升高;当固体含量高于16%时,溶出矿浆为宾汉姆流体,屈服应力与粘度都随固体含量的升高而升高;沉降槽中,在靠近清液层的上部沉降区域,固体含量较低,此时的赤泥浆属于一般的牛顿流体,赤泥沉降速度可以采用传统的斯托克斯沉降公式计算,而在沉降槽中部或底部,赤泥变为宾汉姆流体,沉降速度应该采用宾汉姆流体的沉降速度公式计算;由于溶出赤泥浆的塑性粘度及屈服应力都不太大,添加减阻剂对溶出矿浆过程的节能不会产生明显的效果;溶出赤泥浆体的粘度随着絮凝剂添加量的增加而增加,其输送难度也随之提高。

Taking refractory gibbsite-boehmitic high silicon bauxite as research subject,the effects of temperature,silid content and flocculant on rheology of red slurry digested by above bauxite were investigated by RS600 rheometer produced by thermo corporation.The results showed that the viscosity of digested slurry decreased with the increase of temperature,which is contrary to that of raw pulp and predesilicated slurry.When the solid content（mass fraction） was lower than 16%,the digested slurry was Newton fluid whose viscosity increased with the increase of the solid content.When the solid content was higher than 16%,the digested slurry was Binham fluid,in which both yield stress and viscosity increased with the increase of the solid content.The solid content was lower in the upper settling zone close to supernatant liquid layer in precipitation tank,the red slurry belonged to conventional Newton fluid and the settling rate of red slurry can be calculated by traditional stokes settling formula.While in the middle or botton part of the precipitation tank,the red slurry changed into Binham fluid,and the settling rate should be calculated by the settling rate formula of Binham fluid.Adding drag reducer had little effect on the energy saving of digested slurry process due to lower plastic viscosity and yield stress of digested red slurry.The viscosity of digested red slurry increased with the increase of the adding amount of flocculant and the transport difficulty increased correspondingly.