Analysis of material flow among multiple phases of cobalt industrial chain based on a complex network

In recent years, with the continuous growth of consumer electronic products and the vigorous development of the new energy vehicle industry, the demand for global cobalt resources has increased sharply. The increasing demand is putting enormous pressure on the sustainable development of cobalt resources and exposing them to the risk of supply shortages. At present, most of the researches on cobalt resources are limited to trade between countries or to resource flows within individual countries, and fail to consider the flow of cobalt resources from the international and domestic perspectives as a whole. To observe the cobalt resources in global flows and analyses cobalt resource dependence at the global and national levels, this article systematically combs the various cobalt element forms by using the concept of the industrial chain. Additionally, it constructs a trade related global cobalt element material flow network model of each phase in the cobalt industrial chain, using the cobalt production data and products containing cobalt trade data in 2016, 2018 and 2020, based on complex network and material flow analysis. This article used network indicators to analyze the important trading countries (regions), and trading hubs for the cobalt. And then it used the Herfindahl-Hirschman Index to measure the concentration of importing and exporting markets in each phase of the cobalt industrial chain. For the important trading countries (regions), this article further calculated the degree of resource dependence between industrial chain phases within each country (region) and classified them accordingly. The results showed that the important trading countries (regions) of cobalt resources have been occupied by specific countries in recent years. Most of the important trade hub countries (regions) for cobalt are the countries (regions) experiencing rapid economic development. The export trade has a higher degree of monopoly than import trade in the cobalt industrial chain. According to the degree of dependence between the industrial chain phases, the important trading countries (regions) can be divided into four categories, the overall dependence of the industrial chain phases in countries (regions) with higher levels of economic development will be deeper. According to the results, some suggestions were put forward for the sustainable development of cobalt in different countries, including extending the industrial chain, establishing and improving national recovery systems.