## 3 Metal Melting: Experimental Setup and Data Collection  
In the production processes in foundries, the control of the melting metals process is set as an imperative in order to obtain the desired chemical composition and temperature of the molten metal. The quantity of alloying elements and the corresponding energy sources represent the potential control objects. Metal melting (Figure 2) is a complex process because of the complex interaction between the process parameters such as thermal loss and the dynamics of non-linear chemical reactions. In this case, the process of obtaining white cast iron was monitored and data acquisition during its monitoring was carried out. Data collection was carried out in real industrial conditions in the foundry. In the induction furnace with a capacity of eight tons, at a temperature of 1500 \({}^{\circ}\)C, white cast iron melts. In one shift, two batches are melted in total. The induction furnaces operate on the principle of using a strong magnetic field formed by passing the electric current through a coil, wound around the material that melts. The effect of the induced current in the metal is the heating and melting of the metal. The electromagnetic force simultaneously causes the mixing of the melted metal.  
The furnace is never discharged completely during the melting process, but it remains about 30% of the total capacity, i.e., 2.5 tons of molten metal. The chemical composition of molten metal that remains in the furnace is known from the previous chemical analysis of molten metal. In the induction furnace, which has two-thirds of the empty space, it is added 5 tons of steel waste with a known chemical composition. After melting, a chemical analysis is carried out, followed by alloying if necessary, and then a new analysis and new alloying if necessary, until the desired chemical composition is achieved. Chemical analysis is carried out on a quantometer Applied Research Laboratories 2460 (Figure 3).  
Figure 3: Quantometer Applied Research Laboratories 2460 for chemical analysis.  
Figure 2: Metal melting process.  
In the concrete case, four chemical elements were monitored: carbon (C), chromium (Cr), silicon (Si) and manganese (Mn), which are significant for the qualitative characteristics of the casting part for which the production of white cast iron is intended. After melting 300 batches, the same number of data sets were formed and are organized into four groups. The first group (Figure 4) consists of a chemical composition of 2.5 tons of molten metal that remains in the furnace after the melting process (C (%), Si (%), Mn (%) and Cr (%)).  
The second group (Figure 5) of data consists of a chemical composition of five tons of steel waste that is added into the furnace ((C (%), Si (%), Mn (%) and Cr (%)).  
The third group (Figure 6) of data represents the amount of alloying additives that is added during the alloying process (FeMn (kg), carburizing agent (kg), FeSi (kg) and FeCr (kg)).  
Finally, the fourth group (Figure 7) of data represents the chemical composition of melted iron after the alloying process (C (%), Si (%), Mn (%) and Cr (%)).  
Figure 4: Chemical composition (C, Si, Mn i Cr) of 2.5 tons of molten metal in furnace.  
Figure 5: Chemical composition (C, Si, Mn and Cr) of 5 tonnes of steel waste.