The research group said the system operates in low pH conditions (acid) and groundwater pressures of at least 20bar (to depths of around 200m below ground level). It is an end-to-end sensor, hardware and software solution that features robust, solid-state electrochemical sensors for measuring multiple chemical properties in embedded aqueous applications.
Button-sized sensors include a reference electrode to measure oxidation-reduction potential and pH. Third-party conductivity, pressure, depth and temperature sensors have also been integrated into the design.
At this time, the systems are hard-wired for data and power transfer between the local surface communication gateway and sensor pack; gateway data is transmitted to an online server using wireless options. It can take measurements every few seconds, and the data sent to the server can then be viewed live, and securely, from anywhere.
CSIRO's industry trial project lead Daniella Caruso pointed out that effective groundwater management is vital for in-situ recovery (ISR) and other mining sites to operate safely and compliant with regulations, as well as to protect the environment and local communities.
"However, the current best-practice method for ISR operations relies upon a manual ‘pump and test' method that has significant challenges, [including] high installation and labour costs, high maintenance requirements and lengthy processing times that delay corrective actions and can put the environment at risk," Caruso said.
"To date, there is no embedded automated groundwater monitoring system that exists for ISR operations."
The agency is now testing 10 SENSEI sensor packs, alongside Heathgate Resources, Boss Resources and National Energy Resources Australia (NERA), at Heathgate's Four Mile West uranium mine in far-north South Australia. If the first trial is successful, 16 more sensor packs will deploy next April in a 12-month trial.
"The objective is to test the sensors in controlled conditions alongside current manual monitoring techniques," Heathgate Resources HSSE regulatory and compliance superintendent Kathryn Levingstone said.
"And with government support - subject to it all going well - have it recognised it as an approved or best-practice technology," she added.
"We are already receiving measurements from the wells, so that's given us confidence we're measuring and collecting data, which is exciting," Caruso added, noting that CSIRO hopes SENSEI will reduce operational costs and help Australian mining companies be more globally competitive.
Looking ahead, CSIRO is exploring opportunities to partner with other mining and METS companies to conduct more commercial field trials of SENSEI in a variety of applications, including remote and abandoned mining sites, and to monitor mine tailings, treatment plant water quality, mineral leaching and more.
