A tailings storage facility (TSF) is an engineering structure with an earth dam that stores process waste known as tailings, a mix of ground rock, water and residual reagents. Its potential failure would be disastrous for the environment, people and business. Polyus is the first company in Russia to introduce an automated system to make such failures less likely.
The team is now able to better control the condition of TSF hydraulic structures in real time, monitor the slightest deviations and forecast and eliminate safety risks to such structures.
Such a responsible approach complies with the requirements of the Global Industry Standard on Tailings Management adopted in 2020 by the International Council on Mining and Metals (ICMM) and the United Nations Environment Program (UNEP). Polyus was involved in the development of the Standard and has implemented it across its operations.
Implementation
Polyus currently has six TSFs in operation, with two more soon to be commissioned. Each TSF is controlled by the Company and the government. The state regulatory authorities supervise construction, operation, capital maintenance, mothballing and closure.
The Company regularly reports to the Russian technical regulator (Rostekhnadzor). Safety is continuously monitored by people on site as legally required. In addition, TSFs are checked by independent expert auditors once every few years. The problem with the previous system was that all information was collected on paper.
The new Hydraulic Structures Safety and Management Monitoring System aggregates all TSF data, which is available in real time across all levels, from hydraulic engineers to the general director. Sensor data and visual observations made by hydraulic engineers are delivered directly to the relevant system dashboards.
Polyus was the first Russian company to introduce such a system as part of a pilot project at its largest mine — Olimpiada, Krasnoyarsk Territory.
How the system works
The monitoring system consists of several elements.
- Visual observations
Hydraulic engineers walk around the huge TSF and record potential defects: leaks, fractures, pipe breaks, soil erosion, etc. Each identified defect is recorded in the system and ranked by severity.
- Instrumental observations
These are based on instrumentation and sensors. For example, groundwater in the TSF dam is measured with piezometers inserted in special holes. The movement of the dam is monitored with survey markers, which consist of secured steel nails with a clear link to particular coordinates.
All monitoring parameters have variance thresholds. If the water level in the piezometers is higher than critical, this means there are structural or process flaws. A 1 mm displacement of the mark over a month is acceptable. However, a 10 mm displacement is an indication that this is a defect on a particular section of the dam.
In addition, analysis of tailings and TSF water, as well as other necessary information, is also sent to the system.
- Defect response and mitigation
All registered defects must be mitigated. The system forms an action plan for each defect that assigns responsibilities and sets timelines. This makes it possible to track the implementation status of the plan.
- Committee inspections
The system also records the reports and results of all inspections made by corporate committees as legally required, such as pre-flood and post-flood checks. Internal audits as well as ones performed by Rostekhnadzor also enter the system.
Results
Project implementation enabled Polyus to automate the TSF monitoring management process and respond more promptly to identified defects.
The new system places all parties involved in TSF management in a single information field with access to a large, updated database. The efficiency of accessing information on near misses is improved, as notification of a problem instantly appears in the observation logs. It is immediately available and is marked in red and can be viewed in real time.
Plans and outlook
The Company intends to scale up the system across the other TSFs, which may take another two years. At the same time, it will continue to improve the system by fixing bugs, which inevitably appear when using software, making it more user-friendly and developing new functionality. Polyus will also continue to upgrade the system with automated sensors. Finally, the Company plans to test additional control and monitoring systems that are not yet legally required. This will further enhance TSF safety.
For more details, see the RBC article: https://trends.rbc.ru/trends/industry/cmrm/64d214719a7947491e6c51e6