Use of Mining Waste Classification in the Context of a Circular Economy—A Review

The beneficial use of mining waste aligns with circular economy thinking: saving primary resources can extend their lifetime and maintain availability, reduce the volume of legacy mining waste and its environmental impacts, and develop a resource beneficiation industry that is less energy and water intensive; mining lower grades at larger scale inevitably requires more beneficial reuse. Existing classifications applicable to different types of mine waste were reviewed. These include factors such as the mode of origin during the mining operation, grain size, chemical composition and stability. The result shows that these factors also largely control their civil engineering applications, suitability for end use sectors and potential hazards. Long-term liabilities related to chemical stability were identified as the most difficult challenge. When developing a reuse project, either by the end users or by the mine operator, it is likely that resource screening covering a comprehensive range of factors will be required, as none of the existing schemes individually cover all of the aspects needed to fully assess suitability for beneficial use. In conclusion, there is a need for a systematic and structured approach to classification of mining waste to facilitate reuse as raw materials, such as that presented in our review.