PbO-“CuO_(0.5)”和PbO-“CuO_(0.5)”-“FeO1.5”渣体系与金属相平衡的实验和热力学建模

Experiment and thermodynamic modelling of phase equilibria in PbO−“CuO_(0.5)”and PbO−“CuO_(0.5)”−“FeO_(0.5)”slag systems with metal

为了支撑现有以及新兴火法冶金工艺的改进和研发,作为PbO-ZnO-Cu_(2)O-FeO-Fe_(2)O_(3)-CaO-SiO_(2)-Al_(2)O_(3)-MgO-S-(微量As,Sn,Sb,Bi,Ag,Au,Ni,Cr和Co)19种元素多组分渣/锍/合金/黄渣系统热力学研究的一部分,对PbO-“CuO_(0.5)”和PbO-“CuO_(0.5)”-“FeO_(1.5)”体系在金属铜以及铅铜合金饱合条件下的相平衡进行研究。试样采用高温平衡加淬火处理,并使用电子探针(EPMA)直接测量渣相、固体氧化物相和金属相的成分以确定体系的相平衡。通过实验获得铅黄(PbO)、尖晶石((Fe,Cu)Fe_(2)O_(4))、赤铜矿(Cu2O)、铁氧体铅(Pb_(2+x)Fe_(2)O_(5+x))、磁铁铅矿(Pb_(1+x)Fe_(12-x)O_(19-x))、铜铅矿(Cu2PbO_(2))和赤铜铁矿(CuFeO_(2))在688~1000℃的初晶相区相平衡广数据。PbO-“CuO_(0.5)”系统的实验结果表明,铜铅矿(Cu2PbO_(2))发生不一致熔化,而非如之前的研究表明它在低于二元共晶温度的情况下分解形成铅黄(PbO)和赤铜矿(Cu2O)。基于过去和现在的实验研究结果,采用FactSage热力学计算软件包导出一组描述系统中所有物相的自洽热力学模型参数。

The phase equilibria of the PbO-“CuO_(0.5)”and PbO-“CuO_(0.5)”-“FeO_(1.5)”slag systems in equilibrium with solid metallic copper and/or liquid metallic lead-copper alloy were studied as part of the investigation of the 19-element PbO-ZnO-Cu_(2)O-FeO-Fe_(2)O_(3)-CaO-SiO_(2)-Al_(2)O_(3)-MgO-S-(As,Sn,Sb,Bi,Ag,Au,Ni,Cr,Co as minor elements)multicomponent slag/matte/metal/speiss system,supporting the operation and development of the existing and emerging pyrometallurgical processes.In the experimental portion of this study,samples underwent high temperature equilibration followed by quenching,after which the compositions in the liquid slag,solid oxide and metallic phases were directly measured by electron probe microanalysis(EPMA).Phase equilibria data on the massicot(PbO),spinel((Fe,Cu)Fe_(2)O_(4)),cuprite(Cu_(2)O),lead ferrite(Pb2+xFe2O5+x),magnetoplumbite(Pb_(1+x)Fe_(12-x)O_(19-x)),copper plumbite(Cu_(2)PbO_(2)),and delafossite(CuFeO_(2))primary phase fields were obtained between 688 and 1000℃.A key finding of the experimental study of the PbO-“CuO_(0.5)”subsystem was that the copper plumbite(Cu_(2)PbO_(2))phase melted incongruently,contradicting previous studies that suggested it apparently decomposed below the binary eutectic temperature to form massicot(PbO)and cuprite(Cu_(2)O).Based on the results of past and present experimental studies,a self-consistent set of thermodynamic model parameters describing all phases in the system was derived using the FactSage software package.