A red mud slurry residue from a bauxite processing plant is to be pumped from the plant to a disposal pond, at a rate of 1000 gpm, through a 6 in. ID pipeline that is 2500 ft long. The pipeline is...

A red mud slurry residue from a bauxite processing plant is to be pumped from the plant to a disposal pond, at a rate of 1000 gpm, through a 6 in. ID pipeline that is 2500 ft long. The pipeline is horizontal, and the inlet and discharge of the line are both at atmospheric pressure. The mud has properties of a Bingham plastic, with a yield stress of 250 dyn/cm2 , a limiting viscosity of 50 cP, and a density of 1.4 g/cm3 . The vapor pressure of the slurry at the operating temperature is 50 mmHg. You have available several pumps with the characteristics given in Appendix H.

(a) Which pump, impeller diameter, motor speed and motor horsepower would you use for this application?

(b) How close to the disposal pond could the pump be located without cavitating?

(c) It is likely that none of these pumps would be adequate to pump this slurry. Explain why, and explain what type of pump might be better.