含铅固废协同冶炼过程PbO-CaO-SiO2-Fe2O3-ZnO五元渣系相平衡研究

在1 000~1 250 ℃范围内,采用高温平衡-淬冷-EDS方法研究了含铅固废协同冶炼过程PbO-CaO-SiO₂-Fe₂O₃-ZnO五元渣系在空气气氛下的相平衡规律。研究结果表明,渣中存在的主要物相有尖晶石(Zn_xFe_3-yO_4+z)、红锌矿(ZnO)、黄长石(Pb_vCa_2-vZn_wSi₂O₇)、赤铁矿(Fe₂O₃)、磁铁铅矿(PbFe₁₀O₁₆)和硅钙石(Ca_2-tPb_tSiO₄)。在1 250 ℃、1 200 ℃、1 170 ℃、1 130 ℃和1 100 ℃下,PbO-CaO-SiO₂-Fe₂O₃-ZnO体系的液相点分布测试结果与MTDATA6.0软件模拟液相线基本吻合。在1 000~1 250 ℃范围内,随着结晶过程的进行,PbO-CaO-SiO₂-Fe₂O₃-ZnO体系液相成分中Fe₂O₃含量从16.83%减少到7.67%,ZnO含量从7.62%减少到2.98%,(PbO+CaO+SiO₂)含量从75.55%增加到89.36%。

Phase Equilibrium of PbO-CaO-SiO2-Fe2O3-ZnO System During Synergetic Smelting of Lead-Containing Solid Wastes

The phase equilibrium law of PbO-CaO-SiO₂-Fe₂O₃-ZnO system in air atmosphere during synergetic smelting of lead-containing solid wastes was studied by using high temperature equilibrium-quenching-EDS at the temperature range of 1 000~1 250 ℃, with the mass ratios of CaO/SiO₂=0.20 and PbO/(CaO+SiO₂)=5.43. It is found that spinel(Zn_xFe_3-yO_4+z), zincite(ZnO), melilite(Pb_vCa_2-vZn_wSi₂O₇), hematite(Fe₂O₃), magnetoplumbite(PbFe₁₀O₁₆), dicalcium silicate(Ca_2-tPb_tSiO₄) are the predominant phases in the slag. And the liquid-phase point distribution of PbO-CaO-SiO₂-Fe₂O₃-ZnO system at 1 250℃, 1 200℃, 1 170℃, 1 130℃ and 1 100 ℃ are in good agreement with those simulated by MTDATA 6.0. At the temperature range of 1 000~1 250 ℃, contents of Fe₂O₃ and ZnO in the liquid of PbO-CaO-SiO₂-Fe₂O₃-ZnO system fell down respectively from 16.83% and 7.62% to 7.67% and 2.98% during the crystallization process, while the content of (PbO+CaO+SiO2) rises from 75.55% to 89.36%.