Every year, approximately 28 million tons of used refractories are generated worldwide. The majority of the consumed refractories are used for foreign applications, such as aggregates for road construction (downcycling), or deposited in landfills, while their recycling played a rather subordinate role until now. For ecological and economic reasons, an increased research potential to deal with the application of refractory recyclates was identified in the last few years.

The objective is to research and develop new sophisticated recycling options for used MgO-C refractories allowing both the recycling (re-utilization in similar high-temperature materials) and the upcycling (material upgrading) of refractories in metallurgical processes.

The development of a new generation of coarse-grained high-temperature materials based on MgO-C refractory recyclates with particular functional properties for high-temperature processes in the metallurgy covers two concepts: 1) MgO-C refractories based on recyclates and a pitch- and resin-free environmentally-friendly lignin-collagen binder system with an application as lining material for steel ladles, and 2) Novel metal-ceramic composites based on MgO-C recyclates with an application as electrode material for aluminium fused-salt electrolysis.

The presentation will provide insights into the latest technical results of this long-term project, such as physical (bulk density, open porosity, Brazilian-test) and thermo-mechanical properties (CCS, oxidation resistance, RuL) of MgO-C with the new binder system as well as microstructure (SEM/EBSD), electrical conductivity electrochemical potential, and appliance tests of the MgO-steel anode materials.