Зміна складу ковшового шлаку та вмісту сірки в чавуні від доменних печей до конвертерів

• Дата: 2023
• Автори: Шевченко, Анатолій, Меркулов, Олексій, Кисляков, Володимир, Двоскiн, Борис, Маначин, Іван
• Формат: Стаття
• Мова: Українська
• Опубліковано: Physico-technological Institute of Metals and Alloys 2023
• Теми: десульфурація; чавун; ресульфурація; ківш; шлак; розподіл сірки; міксер
• Онлайн доступ: https://www.metalsandcasting.com/index.php/mcu/article/view/25
• Назва журналу: Metal and Casting of Ukraine

The article is devoted to the analysis of changes in the sulfur content in the "cast iron-slag" system in the technological chain of steel production with further development of technical solutions and technological methods aimed at eliminating resulfurization of cast iron. The results of the performed calculations are presented, which are based on the actual data of the ArcelorMittal Kryvyi Rih (AMKR) work using a methodical approach, which showed that when in the blast furnace sulfur content in cast iron is reduced from 0.055 % to 0.025 %, the consumption of coke increases by 39.5 kg/t, the productivity of the blast furnace decreases by 4.9 %, the consumption of limestone increases by 9.14 kg/t, the consumption of charge materials per agglomerate increases by 33.2 kg/t. At the same time, the specific costs for reducing the sulfur content in cast iron in blast furnace production are $3.8/t∙0.01%DS. Point probe scanning of bucket slag samples was performed, which showed that in the slag phase, along with CaO∙SiO2∙Al2O3 type systems with different ratios of components containing 0.2–3.5 % sulfur, CaxSiyAlz type systems containing up to 1 % of sulfur, and in "beads" the sulfur content varies no more than 0.1–0.85 % and in the form of sulfides of the type (Fe, Mn)S, mainly MnS, and in the non-metallic inclusions of "beads" a sulfur content of no more than 15–30 %. It is shown that due to the resulfurization of cast iron in pig iron ladles during the release of metal from blast furnaces, one should not rely on the results of the analysis of samples taken from the chutes of blast furnaces to estimate the sulfur content in cast iron poured into ladles. It is shown that, in order to prevent the process of sulfur transition from slag to cast iron, it is recommended to use corrective additives in the slag of CaO-based materials (including granular unfractionated waste from the production of metallurgical lime in the amount of 1.0–2.0 kg/t of cast iron), which increase the sulphide capacity of the slag. The verification of the effect of corrective additives in the form of granular, unfractionated waste from the production of metallurgical lime, applied to the bottom of pig iron ladles in the amount of 1.0–2.0 kg/t of pig iron, before the release of pig iron from blast furnaces, carried out in industrial conditions at metallurgical plants, showed that the increase in sulfur content in cast iron decreased by 1.5–2 times.