A number of recent economic modelling studies have attempted to analyse resource efficiency and the circular economy. However, modelling analysis in this area is relatively underdeveloped. In particular, many CGE models are unable to provide significant insight given their aggregated sectoral coverage. Here we describe the development of the Environmental Global Applied General Equilibrium (ENGAGE-materials) model created to consider the economic and sectoral effects of potential policies on a circular economy and resource efficiency, which affect materials and resources at the stages of extraction, production and recycling. Our policy scope is global with a special emphasis on China and Europe, as both regions have dedicated policies in place and indicate their willingness to take the lead. The case of steel is relevant as it is a key material for all economies across the world and offers a range of interesting features for circularity and sustainability. ENGAGE-materials models iron ore mining, primary production of iron and steel, secondary production of iron and steel, and steel scrap recycling at the global level. We utilise this technology rich framework to provide preliminary results on scenarios comprising economic insights into a saturation effect and straightforward policy such as doubling the availability of secondary steel.