With the support of Universidad de Chile’s Center for Mathematical Modeling (CMM), JRI Ingeniería designed a new more economical and secure technology to build tailing dams with high density of the slurries. This method uses waste rock of the mine to erect the embankments, lowering the tailings storage cost between 5% and 15%, which is equivalent to saving for 4 million dollar per year in a mine that produce 100 KTPD of tailings.

“This management is a growing problem for mining, because of costs of operation, the opposition of the stakeholders who live close the deposits and transport systems and the increasing restriction of the Government” explained JRI technical director Juan Rayo.

Operational costs of tailings storage facilities vary between 0.5 and 1.5 dollars per ton, which is near to 10% of total costs of operation in a mining company. A common concentrator used in big mining, which produces about 100,000 tons of tailings everyday, costs between 30 and 40 million per year.

JRI had lowered this numbers in pilot tests and scale prototype. However, they needed a mathematical model to forecast how much tailing will enter the embankment without trespassing it. Then, they called National Prize of Sciences Carlos Conca and the director of Mathematical Modelling in Mining and Metallurgy Laboratory Raúl Gormaz to create it.

“An amount of paste tailings infiltrate up to reach an immovable position. We had these questions: Where is this limit position? What did this position depends on? How much time is needed to get this limit?” remembered Conca.

Analyzing different variables such as the high of the embankments, dimensions of stones, slope angle, and geological characteristics of the paste tailings as viscosity and yield stress, they developed a model to calculate the immovable position of slurry slurry in the body of the dam. After that, the researchers of the company and university designed and verify a more economical technology to with high standard on security.

“Environmental risks are lowered when we have a trustable method to calculate this new type of dam” said international consultant Ramón Fuentes.

“With the experiments, it’s concluded they don’t need to seal the dam. Using waste rocks with the correct grain size is enough” concluded Gormaz.