Blast furnace slag is a by-product of steelmaking in integrated smelting plants. It has a significant energy efficiency potential for the iron and steel industry by utilizing the high heat content while recycling the product. However, the treatment in state-of-the-art wet granulation plants for the production of slag sand and the subsequent use as secondary raw material in the cement industry does not utilize the thermal energy of the high temperature slag. The process of dry granulation by rotary disk atomization allows the production of granulated slag sand with simultaneous heat recovery. As it is still under development, the aim of this thesis is to demonstrate fundamental dependencies of specific quality characteristics on control and disturbance variables. Therefore, a rotary disk atomization unit in pilot-plant scale was designed and built. The test mode implementation and evaluation were accompanied by a continuous improvement of the plant concept. The considered quality characteristics are the mean particle size, the mass fraction of the produced slag wool and and the flight velocity of the slag droplets during atomization.