## 1 Introduction  
The experiments presented here for the agglomeration of secondary raw materials of the electric arc furnace (EAF) process are part of the research project Fines2 EAF, which is funded by the European Research Fund for Coal and Steel. The aim of the project is to find an easy and flexible on-site solution for the agglomeration of fine materials, which accrue in low quantities in steel plants. Beyond the technical challenges of agglomerate fine materials, the solution has to be low cost to fulfil the requirement of economic efficiency. Therefore, the stamp press is the central element of the investigated process chain.  
The stamp press has the ability to be easily adapted to different materials compared with the pelletising process, which is also quite common for the recovery of metallurgical waste materials. A benefit compared with pelletising is the lower amount of binding agent and the lack of a drying process, which is necessary after pelletising, thus making the stamp press a more economical solution. Furthermore, the variation of the pressing force and mould size as well as the independence of the grain size are benefits which are important for the diversity of materials found in a steel plant [1; 2].  
The EAF is the main component of the secondary (electric) steelmaking route, which consists of the furnace, a casting plant and a hot rolling mill. In 2017, global crude steel production via the electric steel route was 28.0%, accounting for 472 million tons of crude steel [3]. During the production and processing of steel, a variety of by-products accrue, such as slags, dusts, sludges and scales. These by-products have the potential to be recycled on site but at the moment are not because it is not suitable due to the lack of low-cost methods. Therefore, they are disposed of in landfills or reused outside the steel plant, for example, as construction material. Due to the changes in worldwide environmental policies towards integrated pollution prevention, the regulations for applications outside of steel plants and landfills have become more restrictive [4; 5].  
However, the reuse of these substances is limited both by their particle size and their sometimes poor quality. Heavy metals and hydrocarbons make direct landfilling or recycling difficult [6]. Nevertheless, today, around 10%-67% are landfilled [7; 8]. Therefore, research on other methods for reuse, especially the recycling of residues into EAFs, remains useful:  
* The residues contain a high content of metal oxides, which are an important source for iron production. Other major components of the residues, such as magnesium oxide, can also bring benefits to the process [9].
* The use of residual materials outside the steelworks or their landfills is restricted, more expensive or prohibited due to stricter environmental laws [10; 11].
* There are also opportunities to reduce the cost of required scrap, alloying elements or slag formers, as well as the cost of landfilling, so that even profits can be made.  
Driven by political pressure and the goal of reducing waste and saving primary raw materials by substitution with secondary raw materials, a favourable and flexible agglomeration method must be found. The main aim of the presented work was to produce agglomerates with sufficient physical properties (abrasion resistance and cold strength) to be used in EAFs without material loss during handling. The following section presents a selection of residual materials from a steel mill that were successfully formed into agglomerates using a stamp press.