Trabajo ganador en el área Gestión y economía minera de Conamin 2024.

Por: Elvis Arias Quispe, docente, investigador y consultor.  

Abstract

This paper examines the feasibility of using recycled polyethylene terephthalate (PET) as reinforcement in shotcrete for support in mining operations, promoting circular economy. The research evaluates the mechanical properties, environmental impact and economic feasibility of this innovation. The results show significant improvements in the mechanical properties of shotcrete with recycled PET, including a 3% increase in tensile strength when replacing 6 kg of recycled PET in one cubic meter of shotcrete instead of 4 kg of synthetic fiber. Energy absorption reached levels comparable to traditional synthetic fiber. In terms of technical and economic feasibility, recycled PET reinforced shotcrete was shown to be technically feasible and, in the long term, cost-effective with a 72% savings in fiber reinforcement costs. Although there may be upfront costs involved in the purchase of the PET crusher and the extruder, the benefits in terms of reduced maintenance, increased durability and reduced environmental costs outweigh these additional expenses, making the investment justifiable and attractive to mining companies that employ shotcrete within their operations.

Environmentally, the use of recycled PET significantly reduces plastic waste and carbon footprint, saving approximately 47.45 tons of CO₂ equivalent annually. Cost savings of US$11.95 per cubic meter of shotcrete are projected, with a payback period of 3 to 6 months. This innovation not only improves the technical performance of shotcrete, but also contributes significantly to the reduction of plastic waste and carbon emissions, aligning with the principles of circular economy and sustainable development in the mining industry.

In conclusion, research on the use of recycled PET as reinforcement in shotcrete for the mining industry has generated promising and significant results in terms of improved properties, positive environmental impact, technical and economic feasibility, contributions to sustainability and future prospects. While there are limitations and areas for improvement, the study lays the groundwork for further innovation and adoption of more sustainable practices in the mining sector, with the potential to generate long-term benefits for business, society and the environment. The paper recommends the large-scale implementation of this technology in the mining industry, highlighting its potential to improve sustainability and efficiency. Further research is suggested to further optimize the properties of recycled PET and to perform long-term economic analysis.