銅の熔錬に関する研究 (第4報)

珪酸飽和のFeO-SiO₂緩と平衡する皮へのFeOの溶解

抄録

In order to determine the solubility of FeO in Cu₂S-FeS mattes coexisting with the Si0₂-saturated FeO-Si0₂ slag, briquetts of powdered mixture of Cu₂S, FeS and somewhat excess FeO were melted in silica crucibles at temperatures of 1, 200, 1, 250 and 1, 300°C. The components of matte were calculated from the analytical values obtained, and the solubility of FeO was determined as is shown in Fig. 1. Although the FeS-matte containing no Cu₂S dissolves 27.5 pct FeO, the content of dissolved FeO decreases as the matte grade increases, and reaches substantially down to zero for the Cu₂S-matte. The solubility of FeO is practically unaffected by the change in temperature, or by the addition of lime or alumina. The contents of S in the mattes in this case are found between 26.5 and 20 pct as are shown in Fig. 3, and in general these are considerably smaller than those in the matte composed merely of Cu₂S and FeS, especially in the mattes of the lower grade. The decrease in S content with increasing Cu₂S content is comparatively slight as far as the grade of matte is low. Such general trend of the change in S content is analogous to that encountered in practice, and hence considerable contents of FeO are expected to be soluble in actual mattes. In fact, the microscopic examination revealed the dissolution of FeO in actual mattes. Moreover, the presumed FeO content was calculated from the data in practice, and the same general trend with the results obtained in the present investigation could be recognized.