A System Dynamics Model Assessment of the Supply of Niobium and Tantalum Using the WORLD6 Model

Abstract

The mining, secondary extraction, supply, market price and recycling of the metals tantalum (Ta) and niobium (Nb) were modelled using the WORLD6 model. The ultimately recoverable resource estimates resulted in significantly larger amounts than earlier studies with a best estimate of the ultimately recoverable resources of about 2 million ton of tantalum and 95 million ton of niobium. There is uncertainty in the resource estimates and they vary in the range from 0.790 million to 2 million ton of tantalum and from 52 million to 160 million ton of niobium. Niobium deposit contents were assessed with respect to extractability, and 56% seems to be extractable. The WORLD6 model outputs show that the use efficiency of these metals will be low unless the degree of recycling will be significantly improved. A sensitivity analysis was done with respect to resource size and different future demand levels, with significant supply sustainability impacts for niobium from resource size, but little impacts for tantalum. We show that for the amount resource available, price and demand dynamics will have greater impact on supply than resource size above 50 million ton of niobium. Peak production is estimated to take place 2020–2055 for tantalum and niobium. The model suggests that there will be soft scarcity in niobium and hard scarcity in tantalum after 2020–2030 with the present regime of recycling. The niobium and tantalum extraction and ore grades were modelled with good success when tested against observed data.