Smart monitoring solutions offered for tailings dams

Demand for smart monitoring solutions in tailings storage facilities (TSFs) and waste management infrastructure has increased, following governing bodies’ introducing new standards to mitigate TSF failures, says test and measurement solutions specialist TANDM application engineer Stewart Chaperon.

He explains that failure of the lining system of a TSF can cause pollution, while failure of TSF side walls may result in loss of life, a collapse of infrastructure and large-scale environmental damage, as a result of tailings material inundation and contamination.

Hence, smart monitoring technology enables for early detection of leaks in a TSF’s liner system and monitors the strain in the liner.

Technology also helps to ensure that TSFs do not exceed their design limits, thereby mitigating the possibility of undetectable failures.

TSFs are often remote, and the environmental engineer responsible for their management is usually responsible for several sites, thereby stretching an engineer’s responsibility and creating challenges.

“Having data stored in the cloud allows for the constant monitoring of the system without engineers having to go to site to access data. Moreover, using wireless Internet of Things devices can help to reduce cabling costs and installation time,” he adds.

To this end, TANDM released its strain sensors, developed in-house, for the tailings industry in August, consequently allowing the company to extend its offerings to encompass a complete liner monitoring solution.

This holistic solution combines the new strain sensors with temperature sensors and long range wide-area network monitoring devices from monitoring solutions company Move Solutions.

“We also have an additional option to add a visual monitoring system, which uses a smart autonomous camera for remote monitoring of small displacements,” Chaperon points out.

Preventing Failure

TANDM offers distributed fibre-optic sensing (DFOS) technology to help improve safety and aid in the avoidance of TSF failures.

By placing temperature- and/or strain-sensing DFOS cables below the high-density polyethylene (HDPE) liner on a lined TSF, it is possible to determine whether the liner has a leak, which is indicated by a change in temperature and/or strain caused by increasing moisture below the liner.

Strain-sensing cables are placed on top of the liner in a grid pattern to monitor ground movement and sinkhole development below a TSF.

Temperature and strain cables can also be placed along and around the slopes of an existing TSF to monitor for slope movement and excessive water build-up, which is an early warning of slope failure.

Alternatively, temperature-sensing fibre cables can be placed along the pipeline transferring the tailings to the TSF for leak detection purposes.

“TANDM has a proven, robust fibre solution designed for the harsh environments of the mining industry. We combine an interrogator from fibrisTerre with in-house-developed software to record, visually display and compare results,” says Chaperon.

Earlier this year, the company completed an installation of 8 km of strain fibre below a TSF to monitor ground movement and sinkhole development.

The project involved the installation of a newly developed HDPE strain sensor and temperature sensor by TANDM on a waste facility to monitor the operating conditions and health of the liner, with a pressure monitoring system installed on a TSF pipeline for early detection of blockages and pipe failure.

“We aim to educate industry players on various technologies and their applications because the correct implementation, and use of test and measurement equipment, can save you money and time,” Chaperon concludes.