Tailings are essentially a mixture of coarse solids, water, and fine solids and are a by-product of the extraction process utilized to recover the desired product from a mine ore. When tailings are discharged into a pond, the coarse solids which separate rapidly are used to build the containment structure while the fine solids are left to settle quiescently in the pond so that the resulting water can be recycled back to the process.
Fluid dynamics plays a central role in the successful development of tailings management strategies and technologies. Coanda Research and Development has supported clients in the mining industries through a wide variety of projects in various areas including:
Characterization of Tailings materials
Understanding the relationship between flow phenomena and material properties is essential towards the development and optimization of tailings processes. In general, tailings materials are often the suspension of particles of varying sizes ranging from coarse sand to submicron sized clay particles in a Newtonian liquid, usually water.
Coanda has expertise in multiple areas related to the characterization of tailings streams including:
- Particle size distribution measurements
- Advanced rheological measurements
- Methylene Blue Index measurements
- Mixing processes for Coagulation and Flocculation of Fluid Fine Tailings in the Oil Sand industries
- Scale up of mixing processes for Coagulation and Flocculation
- Elektrokinetic remediation
Evaluation and scale up of Tailings management technologies
A wide suite of technologies is available for tailings treatment, each of them with their own advantages and limitations. Coanda has developed extensive expertise on central fluid dynamic aspects associated with these technologies, including:
Transport of Tailings Materials
The transport of tailings has received unique attention due to the complex non-Newtonian nature of these materials where it is common to observe changes on the material rheology as a function of both shear rate and time. Coanda’s expertise in this area expands from the flow and transport of raw tailings from the pond to the deposition flow behaviour of amended tailings on a designated deposition area and all the stages in between. Examples of particular interest include:
- Modeling of tailings withdrawal behaviour
- Pipe transport of tailings material
- Hydraulic design for pipe transport of raw and flocculated tailings materials
- Modeling of deposition flow behaviour for amended tailings materials
Geotechnical Evaluation of on Amended Tailings Materials
The successful deployment of all the selected tailings management strategies depends on the final geotechnical performance of the amended tailings. Coanda’s in-house expertise on geotechnical measurements has allowed our clients to carry on integrated programs that cover all aspects of the process design and optimization guided by the ultimately needed geotechnical goals.