By Arash Roshdieh – Principal Engineer
Bushfires across the Australian landscape have once again ripped at our hearts and engendering enormous compassion for those who have lost property, livestock, livelihoods, and in some cases, family members. Can we accept that these devastating events are becoming the “New Norm” in our environment and our way of life?
The new climate norm
As we scan our climatic history, it can be acknowledged that Australian weather patterns are shifting, with extreme climatic events occurring frequently. Impacts on catchment characteristics, such as the depletion of natural soil cover and changes in stream morphology, are compelling examples of our changing environment.
These new environmental phenomena, both nationally and globally, drives a need for us to accept where we are, to understand what might become, and to plan carefully to create a sustainable future. A paradigm change in our approach and lifestyles is required to prepare for and cope with a changing climate.
Water management in a challenging climate
At ATC Williams, our focus is on understanding the sustainable management of tailings, water and waste, particularly in mining. We solidly support the mining industry and acknowledge the shift that is occurring in the philosophy and mindset of the Australian mining community to share the responsibility for managing a changing environment.
One emerging issue that the mining industry faces is the availability of water, for use in mining and mineral processing as well as for environmental and land care purposes. Critically, water is high in demand for washing of ores and related hydrometallurgical applications, therefore is of significant value in a mine setting.
While water has historically existed as a scarce commodity for any number of Australian mines, the true cost to divert water from the environment is rarely realised. In more recent times, the unreliability of rainfall, the depletion of existing surface water and groundwater resources and competing community demands serve to highlight not just the financial burden of water, but the risk to the viability of mining projects.
Sustainable water management requires leadership
At ATC Williams, we strongly believe that a congenial relationship can exist between the environment, the community and the mining industry on the subject of water. Sustainable water management – how water is diverted, captured and consumed - is critical. Responsible miners are at the forefront of the water debate, recognising the accountabilities held and responding to the opportunity to demonstrate strong leadership. These miners are aware of their influences on government policy and are demonstrating that a cultural shift in terms of water use and water management is achievable through their efforts and initiatives.
At ATC Williams, we have invested heavily in enhancing our appreciation of water in mining. Advocacy over the past thirty years regarding the beneficial use of tailings thickening, and more recently filtration, demonstrates this commitment. We strive to minimise exposure to significant water loss through evaporation and particularly seepage. We have therefore advanced our understanding of tailings, thickening and filtration, as well as methods of tailings containment, to support an increased focus on water management.
Leading technology trends
ATC Williams is a pioneer of the Central Thickened Discharge (CTD) technology, a means by which thickened tailings are safely and securely stored, but with the ability to maximise recovery of water before it reaches an open containment area. Dry stacking emerged in later years as a viable alternative for some tailings, although typically at a greater cost. Other techniques for tailings management are available, which can be tailored to any mine site, regardless of setting and conditions, to manage the water inventory while also ensuring storage integrity and security.
A series of pending articles will address the trends and technologies for tailings management and storage that proactively reduce water needs for a mining project. We will highlight operational and life-of-mine cost efficiencies while addressing the many benefits to communities and the surrounding environment.
Arash Roshdieh is a Principal Engineer in ATC Williams’ Melbourne office. Arash is a civil/water-tailings engineer, specialising in dry climate hydrology, tailings and water management, and engineering.