转炉低成本炼钢相关技术研究及模型开发

发布时间：2017-12-27 19:04

本文关键词：转炉低成本炼钢相关技术研究及模型开发　出处：《北京科技大学》2017年博士论文　论文类型：学位论文

【摘要】：论文针对企业100t转炉渣料消耗高、渣中(T.Fe)含量高等问题,通过转炉终渣返回利用技术、降低转炉终渣(T.Fe)技术、转炉适宜渣料技术研究及其炼钢成本控制模型的开发,对不同钢种磷含量要求,提出终渣多次利用及降低全铁含量的措施,建立适宜渣料量适时加入模型及成本控制模型,为企业降低转炉炼钢成本提供理论依据和实践指导。研究发现炉渣(P2O5)含量控制在3%以内,组分活度变化对钢液成分的影响不大,对脱磷影响较小。对实际生产炉次数据进行模拟计算,明确了终渣连续返回利用的极限条件。对于100 t转炉,留渣3 t以下,CaO/SiO2大于2.5、(P2O5)含量不超过3%的终渣可返回利用,能冶炼出钢磷含量≤0.020%钢种。终渣碱度提高到3.5以上、终点钢液溶解氧提高到0.05%以上、终渣(FeO)含量需提高到20%以上,有利于高(P2O5)含量的炉渣返回利用。明确了终渣中粒铁含量高的原因,提出控制炉渣(Si02)含量、提高出钢温度等措施降低渣中的粒铁含量,转炉终渣的粒铁含量由平均8.1%降至0.5%,吨钢成本降低18.24元。揭示了转炉渣(T.Fe)含量与底吹强度、含铁冷料的加入量和加入时机、脱碳速度和终点碳含量的关系,提出(T.Fe)含量控制措施,实现终点[C]含量在0.06%以上,可将转炉终渣(T.Fe)含量稳定控制在15%以下;出钢碳含量控制在0.1%以上,可将炉渣(T.Fe)含量控制在12.5%以下;对于出钢磷含量≥0.025%的钢种,终渣(T.Fe)最低降至14%以下,吨钢成本减少3.5元。通过理论计算,分析渣料成分、转炉冶炼过程渣料消耗对脱磷的影响,开发了包括合理渣料消耗量的确定、渣料加入时机调整等的转炉适宜渣料控制技术,通过固体钢渣的使用、不同渣料的合理配比并采取促进钢渣平衡的措施,在同等情况下,实现新渣料加入量降低至40 kg/t以下,降低成本6.29元/t,出钢磷含量均满足所冶炼钢种的要求。通过建立适宜渣料适时加入控制,实现了吹炼过程即时优化渣料结构,降低渣料消耗,对100t转炉冶炼出钢磷含量≤0.015%钢种,造渣料消耗由81.85 kg/t降低至69.99 kg/t。建立了转炉冶炼过程钢液及炉渣成分预报模型,结合熔池温度计算,开发了实时钢液磷含量预报模型。出钢碳含量大于0.08%条件下,模型计算冶炼过程碳含量与实际相差0.014%,出钢碳含量±0.02%以内,模型预测的磷含量与实际相差30 ppm。基于转炉终渣返回技术、转炉适宜渣料控制技术及降低转炉终渣铁含量关键技术,开发了转炉炼钢低成本控制模型,实时对转炉炼钢渣料加入进行控制,模型预测吨钢成本和实际成本的最大实际偏差在20元左右,相对偏差小于0.6%,对转炉炼钢控制成本将起到很好的指导作用。
[Abstract]:The enterprise of 100t converter slag and high consumption of slag (T.Fe) content of higher returns, using technology to reduce the slag through the slag (T.Fe) technology, converter slag material technology and its research development for steelmaking cost control model, requirements of different steel grade phosphorus content, put forward the final slag and reduce repeated use the iron content of the measures, establishing the suitable slag amount added to control model and the model for the enterprise to reduce the cost, to provide the theoretical basis and practical guidance for converter steelmaking cost. It is found that the content of slag (P2O5) is less than 3%, and the change of component activity has little effect on the composition of molten steel and has little effect on dephosphorization. The simulation calculation of the secondary data of the actual production furnace has been carried out, and the limit conditions for the continuous return utilization of the final slag have been clarified. For the 100 t converter, slag below 3 T, CaO/SiO2 (P2O5) is greater than 2.5, the final slag content of not more than 3% can be recycled, can tap the phosphorus content of less than 0.020% steel smelting. The final slag alkalinity is increased to more than 3.5, the dissolved oxygen in the final molten steel is increased to more than 0.05%, and the final slag (FeO) content needs to increase to more than 20%, which is beneficial to the recovery and utilization of the slag with high (P2O5) content. The reason of high content of iron in final slag is clarified. Measures such as controlling slag content (Si02) and increasing tapping temperature are put forward to reduce the content of granular iron in slag. The content of iron in final slag of converter is reduced from 8.1% to 0.5%, and the cost of ton steel is reduced by 18.24 yuan. Reveal the slag (T.Fe) content and bottom blowing intensity, iron cold material adding amount and the relationship between the time and the decarburization rate and end point carbon content (T.Fe) content, put forward control measures, realize the end point [C] content is above 0.06%, the end slag (T.Fe) content and stability control below 15% control; tapping carbon content above 0.1%, the slag (T.Fe) content of 12.5% in the control; 0.025% for steel tapping phosphorus content is higher than the final slag (T.Fe), the lowest is below 14%, the cost per ton of 3.5 yuan less. Through theoretical calculation, analysis of slag composition, smelting slag dephosphorization effect on consumption, including the development of the slag slag, determine the reasonable time to adjust the mixture into the appropriate slag consumption control technology, through the use of reasonable ratio, solid slag slag and take different measures to promote the balance of steel slag and in the same circumstances, to achieve a new slag adding amount is reduced to 40 kg/t, reduce the cost of 6.29 yuan /t, tapping p all meet the requirements of steel smelting. Through the establishment of suitable slag added to control, realizes the real-time optimization of slag blowing process structure, reduce the consumption of slag, the phosphorus content of 100t BOF tapping of steel slag is less than or equal to 0.015%, fuel consumption decreased from 81.85 kg/t to 69.99 kg/t. The prediction model of molten steel and slag composition in converter smelting process is set up, and the prediction model of real time steel liquid phosphorus content is developed in combination with the calculation of molten pool temperature. When the carbon content of tapping is greater than 0.08%, the carbon content of the smelting process is 0.014% different from that of the actual process, and the carbon content of tapping is less than 0.02%. The phosphorus content predicted by the model is 30 ppm. The final slag and converter slag return technology suitable control technology and reduce the slag iron content of key technology based on the development of the converter steelmaking cost control model of converter steelmaking slag adding real-time control model to predict the maximum actual deviation cost per ton and the actual cost of 20 yuan, the relative deviation is less than 0.6%. Play a very good role in guiding the cost control of converter steelmaking.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TF713

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