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Innovative technology for Geomechanical and Geophysical Stability Analysis in Tailings Dams

Periodic Reporting for period 1 - Medusa (Innovative technology for Geomechanical and Geophysical Stability Analysis in Tailings Dams)

Reporting period: 2019-08-01 to 2020-01-31

The exploitation and use of mineral resources produce large amount of mine tailings that are commonly in slurry form with high water content and compressibility. Tailings slurries, which contain heavy metals, toxic substances and chemicals are typically transported to an impoundment and thereafter consolidated under their own weight and compaction to form a tailing dam. The main concern with such tailing dams is the stability during the mining operation and after tailing reservoir closure. Several studies report a total of 30+ failure events from 2000 to 2015, with catastrophic consequences both on fatalities and on the environment. The rate of failure is calculated to be two orders of magnitude higher than the failure rate of conventional water retention dams. Medusa is an Innovative Flat Plate Dilatometer which determines in a quick, precise, simple and cost-efficient way the most relevant parameters used in Geomechanical and Geophysical Stability Analysis, including shear wave velocity and stress history, allowing preventive identification of slope instability, and static / seismic liquefaction of tailings dams, to alert about critical conditions. The targets of the feasibility study were: 1) Validate the technical feasibility – Optimization of the product fit design for Medusa; definition of the product development plan for Medusa, integration of seismic and seafloor unit; assessment of the manufacturing strategy and costs; definition of the procedures for the product certification and extension of DMT standards to Medusa. 2) Validate the business opportunity – Validation of the market prices; engagement of key clients and define testing plan for the product validation; Executive Business plan.
The work carried out in the Feasibility study consisted in: 1) Optimization of prototype design for Medusa: the mechanical design (DMT blade has been redesigned), electronic design (new electronic board has been redesigned and built and number of output ports for user interaction has been reduced), firmware (updated by external designers to deal with electronic controller), and software (updated, to implement the electronic and firmware improvements to simplify the output of the results) were optimized. 2) Finalization of Medusa’s manufacturing and supply chain. 3) Validation of Medusa DMT prototype in 3 real sites including Zelazny Most (Rudna - Poland), the largest tailings dam in Europe. 4) Market Analysis in the geotechnical testing and in the specific segment of tailing dam monitoring. 5) Business Model including definition of pricing and go-to-Market Strategy. 6) Plan of the activities to reach the market and the investment needed, including product optimization and prototyping of Medusa and Seafloor units, demonstration in real conditions, product certifications, industrialization and market preparation.
Medusa DMT is the only in-situ geomechanical characterization device which determines in a quick, precise, simple and cost-efficient way the most relevant parameters used for stability assessment of tailings dams. Medusa DMT is an automatic, operator-independent and easy to use testing procedure, with exceptional standardization, repeatability and reliability of the test results. Medusa drastically simplify the traditional way to perform soil measurements even with respect to DMT, making it possible to run an automatic and operator-independent testing procedure. Medusa is the most cost-effective solution for soil testing in dams and ponds: 20% less than competition and double speed execution and targets to become the new standard for routine safety tests in tailing dams.The use of Medusa in tailing dams will allow a comprehensive understanding of the mechanical properties of soils and mine tailings, which is critical for the design and operation of a tailing dam and avoid slope instability and failures.
Medusa DMT prototype in operation