Abstract
The solubility of oxygen in mattes of various compositions was determined based on the study of the equilibrium of the copper–lead matte–gas phase system. The experiments were conducted with different compositions of synthetic matte with copper content ranged from 25% to 45%. The behaviour of iron and lead compounds and their effect on the oxygen content in copper–lead matte were studied. The pattern of oxygen solubility was established and factors affecting the formation of quantitative ratios of the forms of oxygen in copper–lead mattes were identified. We put forward a statement that oxygen in copper–lead matte dissolves in the form of wustite (FeO) and magnetite (Fe3O4). The content of Fe3O4 is directly dependent on the content of FeS in copper–lead matte and strongly correlated with it. An increase of the content of non-ferrous metals in copper–lead matte leads to a reduction of the content of FeS and consequently of that of Fe3O4. The research revealed that unlike the copper-rich mattes, the main characteristics that determine the properties of copper–lead mattes are the content of copper, lead and oxygen, as well as the quantitative ratio of the forms of iron. Regression equations were constructed to predict the content of FeO and Fe3O4 in copper–lead mattes depending on their composition.