Tools for hydraulic design of high density tailings pipelines

Abstract

In the hydraulic design of high density tailings pipelines, unlike the hydraulics of Newtonian fluids, one cannot assume a specific flow regime, such as turbulent flow for water or conventional tailings. This must be defined through one or more procedures or criteria, which may not always be in agreement with each other. Therefore, the choice of a particular pipeline diameter will not only depend on the flow rate and velocity, but also on the flow regime.

The challenge is the variability of the tailings slurry rheology, which could show laminar or turbulent properties depending on the physical characteristics of the slurry.

However, before pilot plant or loop testing can begin, it is often necessary to conduct case studies in order to evaluate the potential impact of the various parameters.

The authors consider the Hedström-Moody Diagram to be a very useful graphic tool for case studies such as a specified rheology for a given flow rate in a fixed diameter pipeline, because it enables a practical and intuitive interpretation of the flow behavior. For example, it makes it possible to identify the laminate – turbulent transition zone or to visualize the range in which the effect of roughness over the friction factor can be detected.

The aim of this study is to promote the use of design curves as part of the methodology for the hydraulic design of tailings pipelines.