Dry stacking of high-grade flake graphite tailings: Tanzania

This paper presents some details of the feasibility study for a proposed dry stacked tailings management system for the Mahenge Graphite Project, in Tanzania. Black Rock Mining Limited is focused on developing its Mahenge Graphite Project, which holds the largest high-grade flake graphite resource reserve in Tanzania – the fourth largest graphite resource in the world. Several potential graphite processing operations are being proposed at various locations around the world and tailings management is a unique challenge given the geochemical characteristics of the graphite tailings and the topographical constraints of the site. Dry stacking of the graphite tailings offers a solution which minimises the environmental risks associated with conventional wet tailings and permits water reuse as part of the tailings management process. The project is located in a tropical savannah environment with a distinct difference between wet and dry seasons. Dry stacking offers a unique and innovative approach to minimising potentially large volumes of excess water during periods of high rainfall. At least 80% of the process water can be recycled.