Spinel sludge samples of different age were prepared byallowing spinel to settle in alumina crucibles. During the aging process theconcentration of spinel crystals increased, which resulted in higher viscosityof the sludge. To quantify this process, we suggested functions describingdependence of sludge viscosity on spinel concentration, time dependence ofspinel concentration in the sludge, and the dependence of sludge viscosity onsludge age.
