EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Due to climate change considerations and the rising costs for the emissions of carbon dioxide, the need for finding alternative reducing agents is becoming apparent. Hence, hydrogen is increasing-ly considered and is investigated in this paper. Through the use of hydrogen as a reducing agent for the production of metals, in this case secondary copper, inherent CO2 emissions associated to carbothermic reduction can be avoided. Despite these advantages the use of hydrogen as a possible reducing agent has to be investigated concerning its solubility in liquid copper. The hydrogen can escape while reheating the copper in other aggregates. Hydrogen can form oxyhydrogen gas in converters and anode furnaces which can lead to explosions. Because of this, the major aspect of this research is the investigation of the solubility of hydrogen in a liquid copper melt.

In the experiments the solubility of hydrogen in a liquid copper melt is investigated by varying the amount (partial pressure) of hydrogen in the gas atmosphere within a dedicated equilibration fur-nace. Hence, the dependency of the hydrogen solubility with regard to its partial pressure in the reaction atmosphere at constant temperature of 1673 K after 2 hours is studied. Subsequently, hy-drogen partial pressure, reaction time, reaction temperature and the purity of the copper melt are varied by two values for each parameter. Finally, the results of the measurements can be interpret-ed systematically using design of experiments. The obtained correlations and trends should give answer to the question if the parameters of the experiments (hydrogen percentage, reaction time, reaction temperature, purity of the copper melt) are independent from one another or if interac-tions can be detected.