The least energy and water cost condition for turbulent, homogeneous pipeline slurry transport

•Long distance slurry are intensive users of water and energy.•Water and energy costs are analyzed to find lowest cost transport conditions, given the solid throughput.•It is shown that the minimum possible transport velocity minimizes the total transport cost.•The resulting criterion is independent of the presence of energy dissipation points in complex topographies.

The efficient combined use of water and energy in long distance slurry pipelines is analyzed in light of the total cost function resulting from an energy and mass balance. Given a system throughput and a set of common slurry and flow properties associated with long distance cross country pipelines such as Krieger-type rheology and smooth wall turbulent flow with small yield-to-wall stress, the minimum cost condition is obtained at the minimum feasible transport mean velocity. This condition has been found irrespective of the particular value of the dissipation-to-pump station location difference, provided the required pumping power is positive.