首钢京唐热态渣、钢绿色循环利用体系开发

Development of green recycling system of hot slag and molten steel at Shougang Jingtang

为实现＂全三脱＂工艺少渣冶炼,进一步降低辅料消耗,首钢京唐开发了热态脱硫渣、液态脱碳渣及铸余渣钢直接返回利用工艺。对热态渣、钢的可回收性进行了分析,并通过工业试验验证了工艺的应用效果。结果表明,回收利用5t的脱硫渣,脱硫剂消耗可降低30%-40%,铁水温降相对减少10-15℃,总渣量减少30%-40%,同时可降低铁损,减少对环境的污染;对于脱碳渣,每炉回收热态渣20t,可节约石灰3.2t,若铁水硅质量分数小于0.15%,脱磷炉可不加石灰,钢铁料消耗相应减少2.4kg/t,并且可取消萤石及轻烧的使用,可实现脱磷炉零辅料消耗;对于钢包铸余,通过控制高炉出铁量,将精炼工序RH/LF/CAS产生的热态精炼渣及钢包铸余兑入半钢包,连同半钢一起兑入脱碳炉中进行冶炼,铸余钢回包次数可达到6-8次,实现液态铸余直接回收。

In order to achieve less slag of ＂ Full-Tri-De＂ smelting process and reduce the material consumption of supplementary materials,the new technology of directly recycling the hot desulfurization slag,the hot decarburization slag and the residual slag and steel after casting was developed in Shougang Jingtang.The recyclability of hot steel and slag of ＂ Full-Tri-De＂ smelting process was analyzed,and the application effects were verified by the commercial test.The results showed that the desulfurization agent consumption,the temperature drop of hot metal and the temperature drop of hot metal can be reduced by 30%-40%,10-15℃and 30%-40%,respectively,through recycling of5 tdesulfurization slag.At the same time,the iron loss and the environmental pollution can be reduced.And the average consumption of 3.2 tlime was saved through recycling hot steel slag 20 tper ladle.If the silicon mass fraction in molten iron was lower than 0.15%,lime could not be added to dephosphorization furnace.The consumption of2.4 kg/t iron and steel raw material was correspondingly cut.Meanwhile,light-burned dolomite and fluorite as burden materials were eliminated in dephosphorization furnace,Thus,it can realize the zero consumption of supplementary materials in dephosphorization furnace.According to the residual in ladle after casting,through controlling the blast furnace tapping and putting the hot refining slag produced in the RH/LF/CAS process and the residual slag and steel in ladle after casting into the semisteel ladle,which was used in the smelting in decarburization furnace,the time of recycling casting residual slag and steel can reach 6-8 times and may achieve the direct recovery of liquid casting.