For the issue of "greater well depth" faced by deep mining activities, the influencing factors on the settling velocity of particle in the hydraulic lifting system have been studied. Based on the settlement mechanism of spherical particle in water, the settling velocity expressions of laminar area, transition area and turbulent area are respectively determined. A sensitivity analysis is carried out in terms of particle size, particle density and water temperature, and the influence of particle shape and its concentration on the settling velocity is discussed. The results show that in the laminar area and transition area, the sensitivities of particle size, particle density and water temperature to the settling velocity vary with the ratio of particle density to the water's; That in the turbulent area, the sensitivities of those influencing factors exhibit as particle density >particle size >water temperature; And that the actual settling velocities of irregular particles are less than those theoretical values of the spheroidal particle of same size. To make the results better fit engineering practice, the particle shape factor is employed to amend the differences between the theoretical values and the actual ones, and Richardson-Zaki formula is adopted in the hindered settling process.

deep mining  /  vertical pipe  /  hydraulic lifting  /  settling velocity