Barsi, D & Wilson, GW 2026, 'Predicting material properties of commingled waste rock and tailings', in AB Fourie, M Horta, M Oliveira & S Wilson (eds), Paste 2026: Proceedings of the 28th International Conference on Paste, Thickened and Filtered Tailings, Australian Centre for Geomechanics, Perth, pp. 1-13, https://doi.org/10.36487/ACG_repo/2655_44
(https://papers.acg.uwa.edu.au/p/2655_44_Barsi/)
Abstract: Traditional mine waste management practices present numerous issues that may tarnish the view of the mining industry. In the worst of cases, failures of tailings dams or waste rock piles can lead to the loss of life, environmental damage, and large monetary costs that may fall on local governments. Even without failures, typical mine waste facilities occupy large areas of surface land, and contain toxic water and soil that may migrate into the local environment through the groundwater or as wind-blown dust. To maintain and improve the social license to operate, the mining industry needs to continue to improve mine waste management practices.
The co-disposal of waste rock and tailings have been utilised in many configurations, with some success. Commingling is an emerging idea, and a specific type of co-disposal that utilises dewatered tailings and waste rock together in a thoroughly mixed blend. These materials can be deposited at low moisture contents, with low hydraulic conductivity, and with proper compaction they can also maintain high saturation, limiting the influx of oxygen. The result is a physically stable material with low potential for acid generation, and a much smaller surface area required for deposition. Unfortunately, there are few full-scale trials or waste management facilities using this method. One possible issue is that the design of these materials is still in its infancy. This paper explores methods to predict material properties of commingled materials using conventional laboratory techniques. Tailings and waste rock samples have been collected from a dozen metal mines globally to study a variety of materials. It is demonstrated that important material properties can be predicted, allowing for the preliminary design of commingled waste facilities. With such design tools available, more field and full-scale trials can be conducted to further understand and improve this method of mine waste management.

Keywords: commingling, mine waste management, closure