A Brief Overview of In-situ Recovery (ISR)
February 21, 2018Analytics in Mineral Processing
March 10, 2020
In the previous article we wrote an introductory overview of In-Situ Recovery (ISR) and recent interest from industry and research organisations for its application in the recovery of metal ores such as copper. With numerous successful ISR operations around the world, especially in uranium deposits, there is considerable information available about the technical challenges of ISR, but none of them are as critical as the challenge of gaining Social License to Operate. Positive engagement and honest science communication with local and regional communities hold the key to long term success of future ISR operations. In this article we briefly look at some of the aspects that impact on social license and how the industry can work with communities to build trust and gain support.
In the early nineteen seventies companies started testing the concept of ISR for uranium extraction in Kazakhstan. In 2010, according to the World Nuclear Association, there were 19 operating ISR uranium mines in Kazakhstan. Furthermore, it is reported that in 2016 48% of the world’s uranium was extracted using ISR. Australian examples of ISR uranium operations include Beverley operated by Heathgate Resources, and Honeymoon (figure 1) operated by Boss Resources.
ISR involves introducing reactive fluids into an underground metal resource, allowing those fluids to react with the metal of interest, extracting the fluid carrying the dissolved metals, and liberating the metal into its solid form. The key factor that would cause immediate concern with any reasonable person is the fact that a reactive fluid is introduced into an underground system. Objectively this raises a few questions. How does the fluid gain access into the resource? Where does the fluid go? Would it impact on regional groundwater supply? What does this mean for the use of that water in residential and agricultural circumstances? These are serious questions that need serious scientific assessment and clear and concise communication with local stakeholders.
Understanding and controlling subsurface fluid flow is essential to ISR operations. This is beneficial to both the operator and the local communities. It means that valuable resources are not lost because of inefficiencies, and it follows that sensitive subsurface environments and resources are not negatively impacted. It is absolutely essential to identify the critical technology and science components specific to an operation early during the social engagement process and to communicate them clearly, effective, and honestly with local stakeholders. Ultimately the relationships between communities and operators looking to develop new operations rest on trust for and from both parties.
During their presentation at the ISR symposium at CSIRO Waterford, June 2017, Excelsior Mining outlined the nature of their copper deposit at Gunnison, Arizona, and how scientific research developed confidence in their extraction strategy and helped build trust with local communities who felt involved and informed about the process. The ore body is naturally fractured, with the unmineralised section being naturally impermeable. This implies a naturally targeted pore system where fluids are directed only to the underground rock containing valuable metals. Additionally, the ore body is overlain by a carbonate formation, which essentially behaves as a barrier for any fugitive reactive fluids. During social engagement Excelsior Mining successfully demonstrated their ability to control injected fluids with a practical demonstration using sand in a clear perspex container and two tubes representing injection and extraction wells.
A proposed ISR development near Kapunda, South Australia (figure 2), by Terramin in cooperation with Environmental Copper Recovery (ECR) is widely welcomed by the local community, who sees it as an opportunity for the development of tourist attractions and additional income to local businesses.
Social license is critical for the success of ISR developments and each development site will have its own unique set of social circumstances to consider. Thorough investigation of the technology and science challenges for any given operation not only improves the likelihood of technical and economic success, but also long term support from local and regional communities.