An existing 1800 m long pipeline, which carried waste mica slurry from kaolin processing, is to be recommissioned. The mica solids throughput is to be substantially increased from 5.2 t/h up to a maximum of 9.53 t/h, but with a typical throughput of around 7.5 t/h. Because of this throughput increase, it was unclear whether the existing 80 mm diameter pipe would be adequate. In addition, the pipe route is to be extended by 250m to 2050m, and its elevation at discharge to settling lagoons increased from 66.2 m to 80 m. The pipeline hydraulics of waste mica slurry were investigated for the 80 mm diameter pipe using the Saskatchewan Research Council's (SRC) Two-Layer Flow Model, for the maximum mica solids throughput of 9.53 t/h. The pipe operating velocity was compared with the predicted deposit velocity for several mica concentrations, ranging from 20% to 50% by weight. Estimates were made of the total differential pressure across the proposed 2050 m long pipeline, as well as the power imparted to the slurry by the pump, and the specific energy consumption (SEC). Two pipe diameters were assumed: 80 mm when no mica wall deposit is present, and 70 mm when there is a 5 mm mica wall deposit. This parameter has a significant effect on the determination of the appropriate pipe operating conditions. For the pipe operating velocity to remain adequately above the deposit velocity (and therefore for the heterogeneous flow pattern to prevail in either horizontal or inclined pipe), it was concluded that if the newly commissioned pipeline contains no mica wall deposit, the pipe should initially be operated at a mica concentration of between 20% and 25% by weight, probably with a target mica concentration of about 23%. A 23% mica concentration results in a mica slurry volume flow rate of 35.5 mVh. The corresponding prediction of pump discharge pressure requirement is 20.6 bar, pump power to the slurry 19.4 kW, and an SEC of about 1 kWh. Once a mica wall deposit has formed, and, as a consequence, the pipe diameter reduced from 80 mm to 70 mm, it is considered feasible to pump mica slurry at a higher slurry concentration, up to about 30% by weight. At 30% mica concentration, a mica slurry volume flow rate of 25.8 m-Vh results, with corresponding predictions of pump discharge pressure requirement of 22.8 bar, a pump power to the slurry of 15.7 kW, and an SEC falling to 0.78 kWh.