【摘要】 以化学平衡法在N_Al2O3≤0.16,N_MgO≤0.30,N_CaO≤0.30范围内于1600和1650℃测定了CaF₂基电渣熔渣中MgO活度,研究了MgO,Al₂O₃和CaO对MgO活度的影响。绘制了CaF₂-MgO-Al₂O₃系和CaF₂-MgO-CaO-Al₂O₃(N_Al2O3=0.07)系MgO等活度线的组成图。α_MgO随N_MgO增加而增大。Al₂O₃于1600℃是强烈降低γ_MgO的物质;而在1650℃,当N_MgO<0.15时,Al₂O₃却是提高γ_MgO的物质;N_MgO为0.16附近存在Al₂O₃对α_MgO影响不敏感区。更多还原

【Abstract】 An investigation was made of the activity of MgO, α_MgO, in molten electrorefining slags with CaF₂ base of the concentrations N_Al2O3≤0.16, N_MgO≤0.30 and N_CaO≤0.30 at 1600 and 1650℃, and of the influence of MgO, Al₂O₃ and CaO contents on it as well. The diagrams of iso-activity for systems CaF₂-MgO-Al₂O₃ and CaF₂-MgO-CaO-Al₂O₃ (N_Al2O3=0.07) were constructed. It was found that the α_MgO increases rapidly with the increase of N_MgO. However, the behaviour of Al₂O₃ is quite changeable, at 1600℃ it decreases violently the activity coefficient of MgO, γ_MgO; at 1650℃ acts as one to increase γ_MgO if N_MgO<0.15 and is insensitive to α_MgO in the limits of N_MgO about 0.16. In the present study, α_MgO referred to solid as a function of component contents in the system CaF₂-MgO-Al₂O₃ at 1600 and 1650℃ may be expressed as follows: At 1600℃ α_MgO=2.89N_MgO-2.07N_MgO²+0.081N_MgO³-(55.23N_Al2O3-644.3N_Al2O3²+2427N_Al2O3³)N_MgO-56.12N_Al2O3N_MgO²+373.1N_Al2O3N_MgO³ At 1650℃ α_MgO=0.898N_MgO+2.73N_MgO²-2.42N_MgO³+(60.8N_Al2O3-120.8N_Al2O3²+350N_Al2O3³)N_MgO-77.5N_Al2O3N_MgO²+ 1036N₍Al₂O₃N_MgO³ In system CaF₂-MgO-CaO-Al₂O₃(N_Al2O3=0.07), CaO is found to be increasing γ_MgO at 1600℃ and varied its effect at 1650℃ with various N_MgO. The expres-sion of α_MgO at 1650℃ in this system may be shown as: α_MgO= 4.67N_MgO-30.7N_MgO²+70.1N_MgO³- N_CaO(17.5N_MgO-208.4N_<sub>MgO²+521N_MgO³)更多还原