Slag Systems in Copper Recycling from Cu-Mg Scraps

摘要

Ever increasing metal consumptions starting with the industrial revolution, caused improper and irresponsible utilization of raw material sources. Initially, recycling concepts were purely based on economic motives. Today, however, it covers much broader concepts along with local economic views, such as globalization and environment. The rate of recycling from secondary raw materials is on the rise, and, therefore, not only the primary sources are conserved by the energy savings per unit ton of metal but also the secondary raw materials are rendered to be useful. For instance, the recycling ratio is more than 40% in terms of copper today. This study aims at determining a suitable slag system for the recycling of Cu-Mg scraps in order to obtain a slag with high fluidity. Oxygen and hydrogen absorption of these alloys, as well as the choice of refractories, represent major importance during the pyrometallurgical valorization of Cu and Cu alloys. The optimum experimental conditions for the valorization of Cu-Mg scraps (0.59% Mg) were found to be 1200℃; a slag composition of 16% CaO, 49% FeO, 35% SiO_2 + B_2O_3; chrome-corundum refractory brick with a ceramic-chemical bonding, and 30 minutes of reaction period. Characterization studies revealed that the slags produced did not contain free silicates [(Fe,Mg)_2SiO_4], that their soluble impurity content was below the limits, and that they displayed a glassy appearance.