Copper powder has widespread usage in various industries. For example, its oxide free state is utilized in producing contemporary microchips. The preprocessing of oxidized copper powders for use in microelectronics takes place by reducing them with hydrogen. This treatment leads to agglomeration of the powder. In the course of this work, the reasons behind the powder¿s agglomeration will be investigated. Starting from the oxidation mechanism and the reduction mechanism derived from it, the causes of agglomerate formation are examined and investigated through laboratory experiments. The findings are assessed based on powder texture and color, as well as by images captured using a scanning electron microscope (SEM). The SEM images show a structural alteration in the fine fraction, indicating low-temperature sintering of nanoparticles. The sintering is caused by thermally introduced energy, as well as energy from the exothermic reduction reaction. As a result, the pronouncedness of agglomerates increases with increasing temperature and experimental duration. Furthermore, optimal operating conditions were identified, providing a good basis for the industrial implementation of the process.