炼钢 ›› 2016, Vol. 32 ›› Issue (6): 15-18.

• 转炉及电炉冶炼 • 上一篇    下一篇

生白云石在转炉炼钢渣中的溶解研究

  

  1. 1.武汉科技大学 钢铁冶金及资源利用省部共建教育部重点实验室,湖北 武汉430081;
    2.武汉钢铁股份有限公司 炼钢总厂,湖北 武汉 430083)
  • 接受日期:1900-01-01 出版日期:2016-12-05

Study on dissolution mechanism of dolomite in LD slag

  • Accepted:1900-01-01 Online:2016-12-05

摘要: 根据转炉炼钢使用生白云石代替轻烧白云石造渣的实际需求,进行了生白云石和轻烧白云石在转炉炼钢渣中的溶解试验,通过扫描电镜观察和能谱分析,对比分析了生白云石和轻烧白云石的溶解机理,并开展生白云石代替轻烧白云石造渣的生产实践。结果表明:生白云石和轻烧白云石在炼钢渣中的溶解机理不同,生白云石在炼钢高温下首先发生分解反应碎裂,形成MgO,CaO微粒,再和熔渣发生溶解反应,同时由于CO2气泡的搅拌作用,其溶解速度明显快于轻烧白云石。在转炉炼钢温度下,生白云石中碳酸盐的分解是一步完成的。使用生白云石造渣,炼钢脱磷率由83.2 %提高到84.1 %,增硫质量分数由78×10-6降到71×10-6,终渣性质也有利于炉衬维护,熔剂成本降低2.98元/t。

关键词: 转炉炼钢, 生白云石, 轻烧白云石, 溶解

Abstract: According to the actual needs of using dolomite instead of doloma slagging in converter steelmaking, the dissolution experiment of the dolomite and doloma in converter steelmaking slag was carried out. By scanning electron microscopy and energy spectrum analysis, the dissolution mechanism of dolomite and doloma were compared and analyzed, and the industrial test of slagging with dolomite instead of doloma is carried out. Results show that the dissolution mechanism of dolomite is different to doloma in LD slag. Dolomite firstly occurs pyrolysis reaction in steelmaking temperature, then it becomes MgO, CaO tiny particles and take dissolves reaction with liquid slag. Moreover,  because of the stirring effect of CO2 bubbles, dolomite dissolve faster than doloma. Dolomite is found to decompose into CaO, MgO and CO2 in one step at the converter steelmaking temperature. By using dolomite slagging, dephosphorization rate increases from 83.2 % to 84.1 % and sulfur mass fraction increment reduce from 78×10-6 to 71×10-6. Final slag properties also conducive to the maintenance of furnace lining, and the cost of steelmaking flux decrease 2.98 yuan/t.

Key words: LD steelmaking, dolomite, doloma, dissolution