材料期刊网

用直接平衡法研究了1500,1550,1600℃Ni液中Y-S平衡关系,测定了钇的脱硫常数lgK_(YS)及Y,S的一阶活度相互作用系数e_S~Y与温度的关系,并进行了有关的热力学计算。由测得的数据算出Ni液中YS的标准生成自由能△G_((Y)S),钇的标准溶解自由能△G_((Y)(l)→[Y]Ni),活度系数γ_Y~o,以及钇的克原子分数自相互作用系数∑_Y~Y和百分浓度自相互作用系数e_Y~Y与温度的关系。 对于反应[Y]_(Ni)+[S]_(Ni)=YS_(s) △G_((Y)S)=-215000+95.53T(cal/mol)脱硫常数: lgK_(YS)=-47000/T+20.86 e_S~Y=-350200/T+179 △G_((Y)(l)→[Y]Ni)=126200-79.31T(cal/mol) lgγ_(Y)=27584/T-15.151 ∑_Y~Y=-127T05/T+69.79 e_Y~Y=-364.8/T+0.2018

Desulphurization equilibria between Y-S in molten Ni at 1500, 1550 and 1600℃ have been determined and studied thermodynamically. The results are summarized as follows: 1. Temperature dependence of desulphurization constant for the formation of Y-S_(S) as the equilibrium phase in the temperature range of 1500—1600℃ is given by lg K_(YS)=47000/T+20.86 2. Temperature dependences of the first activity interaction parameters between Y and S in liquid Ni are determined to be e_S~Y=350200/T+179 in the temperature range of 1500—1600℃. 3. Temperature dependence of the standard free energy of formation of YS_(S) in liquid Ni is derived to be [Y]_(Ni)+[S]_(Ni)=YS_(S) △G°=-215000+95.53T cal/mol 4. Temperature dependence of the standard free energy of solution of Y in liquid Ni is derived to be Y_(1)=[Y]_(Ni) △G°=126200-79.31T cal/mol 5. Temperature dependences of activity coefficient and selfinteraction coefficient of Y in liquid Ni are derived to be lgγ_Y~0=27584/T-15.151 ∑_Y~Y=-127052/T+69.79 e_Y~Y=-364.8/T+0.2018 6. The minimum content of S in equilibria with Y in liquid Ni in the temperature range of 1500-1600℃ are given ~*[％S]=0.002-0.005 and ~*[％Y]=0.005-0.020. The S content raises with Y when exceed this minimum point.