Raw material criticality in the context of classical risk assessment
The rapid economic development of emerging countries in combination with an accelerating spread of new technologies has led to a strongly increasing demand for industrial metals and minerals regarding both the total material requirement and the diversity of elements used for the production of specific high-tech applications. Several minor metal markets which are often characterized by high market concentrations of raw material production at the country and the company level have shown high turbulences since the beginning of the 21st century. This has led to growing concerns about the security of raw material supply, particularly in established western economies. As a result, numerous studies on supply risks and raw material criticality for different countries and regions were carried out recently. In this paper, we discuss the methodology of raw material criticality assessment within a criticality matrix which is a modification of a classical risk matrix. Therefore, we first provide an overview of the approaches and results of major studies quantifying raw material criticality by means of a criticality matrix. By applying a uniform scaling to the matrices of different recent studies, a direct comparison of results and data interpretation was enabled. As shown in this paper, the close relation between the criticality matrix and classical risk analysis within a risk matrix was overlooked in most studies which may lead to misunderstanding and misinterpretation of the results. We posit that the interpretation of the coordinates within the criticality matrix and the thresholds separating critical and non-critical raw materials need to be revised by means of general risk definitions.