The Environmental Footprint of Abandoned Asbestos Mines in Zimbabwe, Opportunities for Repurposing and Recovery of Mg And Other Metals from Gaths Mines

Abstract

Asbestos mining in Zimbabwe left vast tracts of unrehabilitated land characterised by heaps of potentially carcinogenic tailings dumps. The research sought to trace the abandoned mines' environmental footprint, establish the tailings' tonnage, and explore the possibility of resuscitation against repurposing one of the prominent Gaths Mines for recovery of metals from the tailings. The mine has been under closure for two decades. the research findings indicated that over 2600km2 of land has potentially been contaminated by asbestos tailings within the abandoned Gaths Mines. The research concluded that resuscitating Gaths mines for asbestos extraction was not feasible given the international scrutiny on asbestos as a hazardous substance. However, after confirming that the Gaths mines hosts over 140 million tonnes of asbestos with 40.3% Mg content and traces of platinum group metals and Al among other recoverable metals, the research concluded that repurposing the site was feasible. The overall estimate for the capex for a 50 000t/pa Mg Plant 25-year project was estimated at US$416,7 million against an estimated net cash flow of US$1 billion. The NPV for the project was estimated to exceed US$95,5 million at a discount rate of 10%. The project’s Internal Rate of Return was estimated at 16.14%. Overall, the research concluded that the site can potentially be converted from a liability to a legacy that will transform the host communities toward the creation of a sustainable city in Mashava, Zimbabwe.