International mineral trade on the background of due diligence regulation: A case study of tantalum and tin supply chains from East and Central Africa

摘要

Over the past eight years, due diligence has become an increasingly important component of supply chain management for "conflict minerals" such as tantalum and tin. The due diligence concept has been incorporated into regulatory requirements and industry standards as far as mineral sourcing from the Democratic Republic of the Congo (DRC) and the wider East-Central African Great Lakes region is concerned. The present study investigates how this development is reflected in the trade data of tantalum and tin ore concentrates sourced from the region. The analysis is based on international import data reported by smelter countries covering the 2006-2017 period and calibrated against a supply chain framework of regionally aggregated tantalum and tin producer and transit countries. International imports of tantalum and tin ore concentrates from the Great Lakes region show correlated trends for both commodities comprising a pre-regulatory period from 2006 to 2009, a transitional period of initial due diligence implementation from 2010 to 2012, and an on-going period of streamlined due diligence implementation starting in 2013. Tantalum and tin import reductions in 2010-2011 correlate in time with publication of the conflict mineral section of the Dodd-Frank act in the United States, a temporary ban of artisanal and small-scale mining in the DRC and a de facto embargo established by a number of international mineral buyers. Following a two-year transitional period, international tantalum and tin ore concentrate imports from the region progressively recover towards and beyond pre-Dodd-Frank act levels. The market structure of smelter countries sourcing tantalum from the region changes from a China-dominated monopsonistic situation prevailing from 2006 to 2012 towards a less concentrated international market in 2013-2017. This development correlates with the region's increasing world market share in tantalum mine production. In contrast, tin supply chains reflect an oligopsonistic market that does not change systematically through time. While aggregated international import and regional export data for tantalum and tin ore concentrates used to show strong discrepancies in the past, these data are in good agreement from 2013 onward. Mineral origin declarations show progressively increasing geological and logistical plausibility likely reflecting a reduction of antra-regional smuggling and more accurate chain of custody documentation. As such, international mineral trade data become more consistent with on-going implementation of due diligence.