Thermal studies in CuO-Cu_2O-SnO_2 system at two oxygen pressures, as observed by DTA/TG experiments

摘要

This study reports experimental investigations by DTA/TG analysis of (1-x)SnO_2-xCuO compositions, up to 1773 K and at two oxygen partial pressures (i.e. air and argon). In air, DTA/TG results showed thermal effects due exclusively to CuO presence in the initial mixture. No binary compounds were formed. The reduction process of CuO to Cu_2O 1273 K as well as the formation over 1373 K of the liquid phase, have been evidenced. In argon atmosphere, CuO to CuO reduction reaction is shifted toward 1205 K, while the liquid phase appears in the studied mixtures over 1473. The formation of an eutectic composition between SnO_2-Cu_2O, melting at 1491 K, coordinates: 0.932Cu_2O+0.068SnO_2, has been experimentally established in argon.