Kaminsky, HAW, Ghuzi, M, Sedgwick, A, Li, Y & Vietti, A 2024, 'The use of methylene blue index in mine and tailings planning', in AB Fourie & D Reid (eds), Paste 2024: Proceedings of the 26th International Conference on Paste, Thickened and Filtered Tailings, Australian Centre for Geomechanics, Perth, pp. 159-170, https://doi.org/10.36487/ACG_repo/2455_12 (https://papers.acg.uwa.edu.au/p/2455_12_Kaminsky/) Abstract: Methylene blue index (MBI) is a powerful chemical probe with a strong affinity for the hydrophilic surfaces of clay minerals. This high degree of affinity means it outcompetes the majority of other cations to fill all cation exchange sites and to cover the clay surfaces. As a result of this affinity and coverage the MBI correlates well with other important properties such as required flocculant dose and Atterberg limits. Furthermore, MBI is easy to measure, requires small volumes of sample and can be used to predict the properties of mixtures of streams. These attributes make it an extremely powerful tool in exploration and mine planning as an understanding of the MBI of a core can be then used to predict properties further downstream. This paper will highlight experience with using MBI in various mining industries to predict settling properties, understand flocculant dose, and predict relative liquid limits of different tailings streams. This paper will also highlight how the authors suggest the use be extended to better understand potential tailings and closure risks during the exploration phase of a mine. Keywords: methylene blue index, clays, tailings, flocculant dose