Construction of Knowledge Graphs for the Constituent Elements and Mineralization Process of Urban Minerals: A Case of Iron and Steel Resources

Urban minerals are secondary resources with economic value that can be recycled and utilized, including iron and steel, non-ferrous metals, rubber, and others. Accurately estimating the quantities of various components is a critical element in the urban mining operations that support sustainable resource management. To achieve this, ontology construction was employed to systematically define and structure the relationships among different entities in the domain. Knowledge graphs were developed to identify the constituent elements and mineralization process of iron and steel, contributing to improved sustainability in urban resource utilization. The knowledge graphs were constructed using a top-down approach and stored in a Neo4j database. When a knowledge graph of iron and steel components is constructed, the iron and steel products are classified into 5 major categories and 14 subcategories. The knowledge graph of the iron and steel mineralization process is divided into five iron and steel mineralization stages and combines industrialization and urbanization to represent the factors that play a role in the iron and steel mineralization process. By leveraging ontology construction, the knowledge graph can improve the efficiency of refining and analyzing data in urban mineral-related fields. This, in turn, provides an essential data basis for establishing a circular economic system for iron and steel industry resources and advancing sustainability-oriented urban mining practices.