Making transport and disposal of mining tailings more efficient

In mining industries, management of mining tailings is one of the challenging aspects of the mining operations. An effective transport and disposal of mining tailings can be carried out with the understanding of its behaviour and properties. In order to establish the behaviour of the tailings, its characteristics have to be determined. Some of the tailing characteristics are chemical composition, physical composition, crust formation, behaviour under pressure, settling and drying time. Out of these various characteristics, the research focus is primarily on understanding the settling characteristic of the mining tailings.

Mining tailings/slurries often behave as non-Newtonian fluids. In non-Newtonian fluids, the viscosity (the measure of a fluid's ability to resist gradual deformation by shear stresses) is dependent on shear rate.

If large particles are present in mining tailings, they separate from tailings and cause transport to change from what is a homogeneous flow. When there are fine, suspended particles in the slurries, the slurries act as homogeneous fluids. However, these mining slurries contain a few large particles, causing inhomogeneity. This inhomogeneity makes it challenging for the mining operations.

And this is where Lavanya Sethuraman, a researcher with the IITB-Monash Research Academy, is hoping to make a difference. Lavanya's project is titled 'Solid settling in sheared non-Newtonian fluids', and she is conducting computational experiments with rheology data using different viscosity functions, to examine the effect of shear rate on settling. (Rheology is the science of flow and deformation of matter and describes the interrelation between force, deformation and time.)

Fig 1: Slurry Pipeline ( Picture courtesy: Creative commons library)

The IITB-Monash Research Academy is a pioneering joint-venture research partnership between two leading institutions in India and Australia. It offers research scholars like Lavanya the opportunity to study for a dually-badged PhD from both IIT Bombay in India and Monash University in Australia. Students spend time at both countries over the course of their research, and many of them work on projects that are strongly-interdisciplinary in nature and with an applied research focus.

Says Prof Murali Sastry, CEO of The Academy, "A large number of multi-national companies have set up R&D centres in India. It is important that IIT Bombay and Monash University are connected to the research agenda that is being crafted in these R&D Centres. Given its strong industry-facing intent, the IITB-Monash Research Academy is an important vehicle that will help achieve this connection."

Says Lavanya, confidently, "My research work answers the fundamental question: How rapidly do particles settle and how does shear rate affect this? Once we know this, it will be possible to overcome the challenges faced by non-Newtonian fluid transportation."

The mining industry will be watching keenly. And so will we.

Research scholar: Lavanya Sethuraman, IITB-Monash Research Academy

Project title: Solid settling in sheared non-Newtonian fluids

Supervisors: Prof Shivasubramanian Gopalakrishnan, Prof Rajneesh Bhardwaj, Prof Murray Rudman, Dr Andrew Chryss (Industrial supervisor, CSIRO)

Contact details: lset4@student.monash.edu

This story was written by Mr Krishna Warrier based on inputs from the research student and IITB-Monash Research Academy. Copyright IITB-Monash Research Academy.