With the rising demand of steel, the pig iron production increases steadily. The negative effects of sulfur in different applications of steel are finally resulting in very low sulfur contents in the produced steel. Today the slags, which accure during the desulfurization process of pig iron, are treated and partly reused in different industrial applications. 30 % of this slag has to be dumped, because of the high sulfur content, although there is a huge amount of metallic iron in this residue. To achieve a better understanding of the recycling concept, the desulfurization process was simulated through hot stage microscopy trails. During this procedure the sulfur forms sulfur dioxide and evaporates from the sample. The specimens were prepared and analyzed by scanning electron microscopy in combination with EDX analyses, which shows the distribution of elements over the sample surface. For experiments with higher amounts of desulfurization slag a “Top Blown Rotary Converter” was used. Furthermore process parameters and the influence of additives were investigated during these trails. The result of this master thesis shows a new possibility to treat desulfurization slags and to recycle them during the production of iron and steel.