电弧炉粉尘直接还原炉渣氧化和脱硫能力计算热力学

Calculation thermodynamics for slag abilities of oxidation and sulfur-removing in electric arc furnace dust reduction process

电弧炉炼钢粉尘中含有多种重金属 ,若填埋弃置会对环境造成污染 .将粉尘与还原剂碳粉混合制粒后返回电弧炉 ,并补充硅铁还原粉尘中难还原的金属 ,有价金属还原后回收于钢液中 ,不仅能生产不锈钢或特种钢 ,而且能保护环境 .制粒时使用木质磺酸钙作为粘结剂 ,而木质磺酸钙中含有硫 ,可能影响钢材质量 ,影响程度取决于冶炼过程中炉渣的条件 .经改变初始熔铁、球团、硅铁和石灰加入的量比关系进行实验 ,采用X射线荧光分析仪检测炉渣成分进行计算热力学研究 ,确定了 15 5 0℃时CaO MgO FeO Fe2 O3 SiO2 S体系炉渣中各物质的浓度 (摩尔分数 )和炉渣的氧化与脱硫能力 ,其氧化能力可用n(FetO) =n(FeO) + 6n(Fe2 O3) + 8n(Fe3O4 )表示 ;此外 ,确定了还原过程中脱硫能力与氧化能力、硅铁和石灰的加入量以及炉渣的碱度之间的关系 .通过实验 ,建立了电弧炉粉尘直接还原过程中炉渣体系的计算热力学数学模型 。

There are some heavy metals in the electric arc furnace (EAF) steelmaking dust. It has been listed as a hazardous material because it is harmful to the environment to landfill the EAF dust. The valuable metals in the dust can be recycled by mixing it with reducing agent carbon to make pellets and then returning the pellets to the EAF and adding ferro silicon. Part of valuable metals in the dust is reduced by carbon and part of them reduced by ferro silicon for the economical consideration. The reduced metals get into the steel in the stainless steel or special steel production, which is not only to protect environment but also to recover metals in the way of the direct reduction. But the lignosulfonate was used as the binder in the pelletization and the sulfur in it maybe affects the quality of produced steel, which is dependent on the status of the smelting slag. The experiments were conducted in the way of changing the ratio of start iron, pellets, ferro silicon and lime. The content of the slag was checked by XRF for the calculation thermodynamics study. The active concentrations of materials in the slag, the slag abilities of oxidation and sulfur removing in EAF dust reduction process were determined by thermodynamics calculation study on CaO MgO FeO Fe 2O 3 SiO 2 S slag at 1 550 ℃. The oxidation ability of slag can be expressed as n (FetO)= n (FeO)+6 n (Fe 2O 3)+8 n (Fe 3O 4). The relationship between the sulfur removing ability and the oxidizing ability, the ratio of ferro silicon, lime as well as the basicity of the slag was determined on the study. The calculation thermodynamics model was set up and it could be useful in production. [