Concentrated Clay Suspensions Research Articles

Laboratory separation of clays by hydrocycloning

AbstractAlthough seldom appreciated, the hydrocyclone offers several advantages over the more commonly used sedimentation/decantation method for clay separation. Large amounts of relatively concentrated clay suspensions may be separated in a matter of minutes. In addition, no dispersing agents are required and the shear conditions encountered by the suspension during passage through the hydrocyclone lead to particle disaggregation both in the silt and sub-micron size range. Formulae relating design factors of the hydrocyclone to separation performance exist but are of limited value as they are unable to predict the maximum particle size of the clay product or percentage recovery of any particular size of particle. Such data, determined from practical trials, are given for kaolinite, smectite and mixed-assemblage clay suspensions. Design limitations prevent the effective separation of clay products with ‘cut-off’ sizes finer than 5 µm.