The scientific work deals with the development of a new process route in the pyrometallurgical refining of secondary copper. The purpose of the refining is to process cooper scrap with a purity higher than 95 % to the quality of FRHC-copper. The major difference compared to conventional refining is that the new process route is based on a two-stage refining process and using non-conventional type of slags. Seven different slag systems were examined and compared with regard to their refining properties of nickel, lead, tin, arsenic and antimony. The slags were based on the following systems: Olivin-slag (CaO-SiO2-FeOx), Sulphate-slag (CaSO4-Na2SO4-CaO), Carbonate-slag (Na2CO3-B2O3-CaO), silicon-oxide-boric-oxide-slag (SiO2-B2O3), calcium-oxide-boric-oxide-slag (CaO-B2O3), sodium hexametaphosphate-calcium-oxide-slag (NHMP-CaO) and sodium hexametaphosphate-boric-oxide-slag NHMP-B2O3. and the influence of slag composition and oxygen potential in the removal of mentioned impurities were evaluated. Subsequently the refining criteria, was the concentration of a certain impurity in metal, distribution coefficient and the relative distribution of the elements analysed. Decomposition of the slag components or their evaporation, as well as copper losses play an essential role for industrial use. In addition to the refining properties, the corrosion of the refractory remains a decisive part in practice. Corresponding investigations to this topic are proposed in the last part of the dissertation.