## 1 Introduction
\[2\mathrm{C}_{(\mathrm{s}),\mathrm{refractory}}+\ \mathrm{O}_{2(\mathrm{g})}\ \rightarrow\ 2 \mathrm{CO}_{(\mathrm{g})} \tag{1}\]  
\[\mathrm{C}_{(\mathrm{s}),\mathrm{refractory}}+\ \mathrm{MgO}_{(\mathrm{s})}\ \rightarrow\ \mathrm{CO}_{(\mathrm{g})}+\ \mathrm{Mg}_{(\mathrm{g})} \tag{2}\]  
\[2\mathrm{Mg}_{(\mathrm{g})}+\ \mathrm{O}_{2(\mathrm{g})}\ \rightarrow\ 2 \mathrm{MgO}_{(\mathrm{s})} \tag{3}\]  
The primary factor contributing to localized corrosion and consequent erosion of the BOF refractory lining is the complex interaction within the MgO-C-slag-metal phase system. This complex interaction, enhanced by the formation of carbon monoxide bubbles, plays a major role in initiating and accelerating the deterioration process observed in such industrial environments. Inhibition of local corrosion is observed in the ternary MgO-C-slag-metal system due to the formation of CO bubbles at the phase interface [49; 50]. During this time, the forming of gas bubbles at the MgO-C-metal interface enhances local corrosion. Equation (4) describes the fundamental chemical reaction that forms carbon monoxide, representing the key reactants and products involved. It can be observed that the iron oxide FeO in Equation (4) is produced as a result of the chemical reaction shown in Equation (5). Iron oxide (FeO) is then transferred from the slag-metal phase boundary to the slag-refractory phase boundary where it reacts with carbon to form carbon monoxide bubbles according to the following equations [51]:  
\[(\text{FeO})+\text{ C}_{(\text{s}),\text{refractory}}\rightarrow\text{ Fe}_{(1)}+\text{ CO}_{(\text{g})} \tag{4}\]  
\[[\text{O}]+\text{ Fe}_{(1)}\rightarrow(\text{FeO}) \tag{5}\]  
The effect of the flow of molten slag and steel is another factor affecting the wear rate of the MgO-C refractory. The slag film's movement is a consequence of the intense swirling and turbulent flow induced by high-intensity oxygen blowing [52; 53; 54]. This process represents a significant factor contributing to the local corrosion of the BOF refractory lining. Slag film motion increases dissolution (erosion) of the MgO-C refractory and acts as an abrasive on the BOF refractory lining [55; 56; 57]. Applying gunning refractory mixtures is an effective method to extend BOF lining service life and maximize heat per campaign. Gunning minimizes downtime due to lining repairs and ensuring process continuity [8]. Slag coating, slag splashing, and refractory gunning are crucial for maintaining refractory integrity in BOFs. Repair procedures protect the MgO-C refractory lining in BOF from mechanical and corrosive wear. Furthermore, these procedures assist in the extension of the life of the refractories, thereby prolonging the BOF campaign [58]. Current BOF lining lifetimes range from 3000 to 20,000 heat per campaign. This very wide range is due to the technological parameters of the BOFs and to the different approaches taken by steelmakers to the treatment of the BOF refractory lining. A combination of slag coating, slag splashing, and gunning of refractory mixtures seems to be a complex and effective repair and care method of MgO-C refractory lining treatment at present. However, it is important to note that no matter the treatment method, each lining has a definite level of service life beyond which the use of any given repair method becomes economically ineffective. The research was designed with the specific objective of investigating a topic area which has not yet been identified in the available scientific literature. This paper focuses on the purposeful management of the rotation of the copper tip and nozzles of an oxygen lance during its replacement relative to its original position. The research is concerned with the effect of this rotation on the wear of the MgO-C refractory lining of the BOF in the area of the trunnion ring, in conjunction with the consumption of gunning mixtures in the studied area.