Influence of freeze–thaw cycles on mechanical responses of cemented paste tailings in surface storage

ABSTRACT

Surface cemented paste tailings disposal (SPD) has become a useful practice in many mines around the world. The method is a sustainable tailings management that returns tailings to fill the surface cavities and subsidence caused by mining operations, thereby maximising the safety, efficiency and environment of tailings management. This study was conducted to manifest the mechanical responses of the SPD cover layer induced by freezing and thawing cycle (FTC). It shows that with an increase of FTCs, lots of microcracks are formed, scaled and spalled on the sample's surface. The uniaxial compressive strength (UCS) and ultrasonic pulse velocity (UPV) of SPD specimens decrease with increasing FTCs. The reduction of the specimen with a higher cement-to-tailing ratio and longer curing age is smaller than that with lower cement content. The logarithm equation can be available to estimate the UCS values of SPD with the measured data of UPV. The results may be helpful to better understand not only SPD for sustainable tailings management but also the enhancement of the rehabilitation of subsidence in mine regions.

KEYWORDS:

• Surface cemented paste tailings disposal
• freezing and thawing cycles
• uniaxial compressive strength
• ultrasonic velocity

Acknowledgments

The first author also would like to acknowledge China Scholarship Council as financial support for my visiting work at University of Ottawa.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Key Technologies Research and Development Program[2018YFC0808403].