Tailings management is a critical issue in the mining industry, driven by the need for safety, environmental sustainability, and operational efficiency. Traditional methods often struggle with water accumulation and the subsequent risks in tailings storage facilities (TSFs). Addressing these challenges, the concept of Central Thickened Discharge (CTD) has gained popularity. This technique involves discharging slurry in the centre of the disposal area, forming a low conical hill of tailings, which minimises the need for retaining embankments. The slope of the resulting beach is crucial, depending on the discharge flow rate and slurry rheological properties, influenced by the solids concentration and particle size distribution of the tailings.
Introducing Ultra Paste Technology
Ultra Paste (UP) technology combines thickening and filtration to achieve higher solids concentration in the slurry. This method aims to maintain a pumpable and self-distributing slurry at the TSF while allowing for a steeper deposition slope than thickening alone. The development and components of UP are detailed, highlighting its potential advantages over other non-conventional methods like filtration and paste.
Figures 1, 2, 3, & 4 below show flow diagrams of the reviewed options.
Figure 1 – Flow diagram – option 1 – paste and CTD scheme
Figure 2 – Flow diagram – option 2a – ultra paste (PT + FP + mixing) and CTD scheme
Figure 3 – Flow diagram – option 2b – ultra paste (underperformed VBF) and CTD scheme
Figure 4 – Flow diagram – option 3 – filter stack option
Gold Mine Case Study and Comparative Analysis
We can use a hypothetical case study to compare the benefits and costs of various tailings management strategies. The study evaluates UP technology, particularly when coupled with a CTD deposition scheme. It compares UP with a traditional CTD that only uses a thickener and a filter stack option and considers a typical gold mine in a flat topographical environment. The tailings production rate is assumed to be 4 Mtpa for a life of mine of 12 years. A summary of the reviewed options is presented in Table 1.
| Option |
Name |
Solids concentration | In situ density (t/m3) |
Storage volume (Mm3) |
| Option 1 |
PT + CTD |
65% | 1.50 |
32 |
| Option 2a |
PT + FP + mixer + CTD |
72% | 1.50 |
32 |
| Option 2b |
VBF + CTD |
72% | 1.50 |
32 |
| Option 3 |
FS |
80% | 1.60 | 30 |
Table 1 – Summary of the Considered Options
Environmentally Responsible Mining
Figure 5 shows the outcome of the cost analysis of the various options.
Figure 5 – Summary of CAPEX, OPEX and NPV for various Options
The integration of UP and CTD marks a significant advancement in tailings management, offering a balanced and efficient approach. By understanding the advantages and risks, stakeholders in the mining industry can make informed decisions to enhance their tailings management practices, contributing to safer and more sustainable operations. Adopting UP technology can potentially increase the options for tailings management and advance environmentally responsible mining practices.
This innovative approach could improve the stability and safety of TSFs and promote environmental sustainability by reducing water consumption and enhancing water recovery.
Optimal Tailings Management Solutions
The comparative analysis and case study underscore the importance of site-specific considerations and thorough evaluation processes in selecting the optimal tailings management solution.
On this basis, the four main recommendations are as follows:
- No Shortcut Solutions
Each option must undergo thorough design, costing, and evaluation processes to understand its feasibility and effectiveness comprehensively. - Site Topography and Storage Availability
Results heavily depend on site-specific factors, highlighting the importance of topography and the availability of suitable storage sites. - Need for Representative Tailings Parameters
A complete and representative set of tailings parameters is essential for proper comparison. Options should not be prematurely discarded if suitable parameters are not available for analysis. - Balanced Approach
UP technology may offer a balanced approach, providing a viable compromise between various tailings management techniques, transportation efficiency, and environmental considerations. This needs to be assessed in a comprehensive Options Study into various tailings and water management schemes.
– By Arash Roshdieh
Arash Roshdieh is International Operations Manager and Senior Principal Engineer at ATC Williams. As a civil/water-tailings engineer, he specialises in dry climate hydrology, tailings and water management, and engineering.
– Connect with Arash on Linkedin
