Abstract: The deep desulphurization test on low carbon steel (/%: 0. 06C. 0. 20Si, 1. 20Mn, 0. 020Nb, 0. 015Ti) with initial (74 ~ 167) x 10^-6 [S] is carried out by 20% ~40% high magnesium calcium aluminate premelted slag (/% ： 5SiO2, 37CaO, 42Al₂O₃, 13MgO, 3FeO) combined with 60% 〜80% synthetic slag (/%: 10SiO₂, 61CaO, 25Al₂O₃, 4MgO) and adding 5 ~ 10 g/kg Al in a 10 kg induction furnace. Results show that during refining the sulfur content in liquid decreases to lowest value in 10 min, with gradually increasing oxygen activity in liquid and decreasing sulfide capacity of slag in refining process the sulfur distribution ratio between slag and liquid decreases and the phenomenon of definite resulphurization in liquid occurs ； the larger aluminum addition, lower initial sulfur content in liquid and higher sulfide capacity of slag are favorable for desulphurization reaction and to inhabit resulphurization ； the desulphurization effect of 20% high magnesium calcium aluminate +80% synthetic slag is better and with controlling refining slag ingredient (/% ) 50 ~ 60CaO, 5 ~7MgO, 28 ~32Al₂O₃ ~ 8SiO₂ and adding 3 g/kg Al the sulfur content in steel could decrease to 0. 001 6%.

Key words: Desulphurization, Premelted Refining Slag, Sulfide Capacity, Al

摘要： 用10 kg感应炉进行了20%～40%高镁铝酸钙预熔渣(/%:5SiO2、37CaO、42Al2O3、13MgO、3FeO)配加60%～80%合成渣(/%:10SiO₂、61CaO、25Al₂O₃、4MgO)及加5～10g/kg Al对初始(74～167)×10^-6 [S]的低碳钢(/%:0.06C、0.20Si、1.20Mn、0.020Nb、0.015Ti)的深脱硫试验。结果表明,钢液硫含量在精炼10 min内就可到达最低值,精炼过程随着钢液氧活度逐渐升高而渣硫化物容量逐渐降低,渣钢硫分配比减小,钢液有一定的回硫;较大的铝加入量、较低的初始硫含量和较大的渣硫化物容量有利脱硫反应的进行,也可以抑制钢液回硫;20%高镁铝酸钙预熔渣+80%合成渣脱硫效果较好,控制精炼渣成分(/%):50～60CaO、5～7MgO、28～32Al₂O₃、～8SiO₂、Al加入量3 g/kg,钢中硫含量可降至0.0016%。