The aim of this work is to study the interactions between a coking coal and two types of wastes: plastics from municipal wastes (single and mixed) and lubricating-oils coming from the iron and steel sector. For this purpose, Gieseler plastometry, rheometry and in situ high-temperature 1H NMR spectroscopy can be combined to discern the most suitable wastes for using as secondary raw materials in metallurgical coke production. It was found that there is a relationship between the Gieseler fluidity, the complex viscosity and the percentage of the mobile hydrogen of the blends coal+additive.The Spanish Ministry of Education and Science (Ministerio de Educación y Ciencia), Research Project CTM2004-03254. The Principado de Asturias, "Plan de Investigación, Desarrollo Tecnológico e Innovación de Asturias”Peer reviewed