转炉及KR循环利用钢包热态铸余渣工艺试验

为了达到节能降耗的目的,在转炉及KR进行钢包热态铸余渣循环利用的工艺试验。对比分析了转炉及KR循环利用钢包热态铸余渣前后的成渣效果和冶金效果。结果表明,在不需要对现有装备进行改造的情况下,常规炉次每炉加入约30 kg/t的钢包热态铸余渣,可节约消耗钢铁料12 kg/t、石灰4.31 kg/t、烧结矿4.87 kg/t、氧气1.83 m3/t,缩短冶炼时间3.24 min/炉,节省冶炼成本39.43 元/t(钢),降低终点a[O]含量,提高终点脱磷率,在提高钢水质量和冶炼效率、降低炼钢成本的同时,减轻了钢包铸余渣排放对环境的污染,经济效益和社会效益良好。为减小钢包铸余渣中硫含量高对转炉冶炼效果的影响,可采用将钢包热态铸余渣返回KR进行铁水预处理的方式加以循环利用,每罐铁水中加入约27 kg/t的钢包热态铸余渣后,石灰等脱硫剂用量减少82.2%,铁水预处理时间缩短1 min,温降减少4 ℃,回磷率降低2个百分点,脱硫率达到69.4%,同样取得了良好效果。

Process test of recycling ladle hot casting residual slag in converter and KR

In order to achieve the purpose of energy saving and consumption reduction, the recycling process test of ladle hot casting residual slag was carried out in the converter and KR. The slag forming and metallurgical effects before and after the recycling of ladle hot casting residual slag in the converter and KR were compared and analyzed. The results showed that, without modification of the existing equipment, adding about 30 kg/t ladle hot casting residual slag in each conventional furnace could save 12 kg/t of iron and steel material, 4.31 kg/t of lime, 4.87 kg/t of sinter and 1.83 m3/t of oxygen, shortened the smelting time by 3.24 min for per furnace, saved the smelting cost of 39.43 yuan/t steel, reduced the end-point a[O] content, improved the end-point dephosphorization rate, and improved the molten steel quality and smelting efficiency, while reduced the cost of steelmaking. The environmental pollution caused by the discharge of ladle casting residual slag was also reduced, and the economic and social benefits were good. In order to reduce the influence of high sulfur content in ladle casting residual slag on converter metallurgical effect, the ladle hot casting residual slag could be recycled by returning to KR hot metal pretreatment, about 27 kg/t ladle hot casting residual slag was added to each hot metal tank, the amount of desulfurizer such as lime was reduced by 82.2%, the hot metal pretreatment time was shortened by 1 min, the temperature drop was reduced by 4 ℃, the rephosphorization rate was reduced by 2%, and the desulfurization rate was 69.4%, and good results were achieved.