Аннотация. Для более полного использования железных руд Бакальского рудоуправления предложен обжиг во вращающейся печи в присутствии добавок твердого топлива. Исследования особенностей кинетики тепловой обработки образцов в атмосфере воздуха при скорости нагрева 10 град/мин позволили выделить семь технологических стадий: сушка; подогрев; диссоциация карбонатов; окисление ферритов; формирование труднорастворимых силикатов; расплавление, которые сопровождаются изменением их теплового состояния и условий уплотнения. Исследования изменений линейных размеров сидеритовых образцов в процессе нагрева позволили определить условия упрочнения их структуры в выделенных стадиях тепловой обработки. Представлены результаты промышленных испытаний обжига мелкой фракции сидерита класса 10-0 мм во вращающейся печи, отапливаемой природным газом в присутствии добавок кокса. Показана возможность достижения выхода обожженной фракции до 62,07 % при тепловом КПД агрегата 77,27 %. Ключевые слова: сидерит, кинетика кристаллохимических преобразований, кинетика уплотнения, вращающаяся печь, материальный и тепловой баланс.

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The use of wastes from ferrous metallurgy is expanding in response to the growing scarcity and cost of ferrous and nonferrous metals and environmental deterioration. Thus, blast furnace slurry and dust from gas purification systems at steel smelting fur naces contains zinc compounds, which sublimate on high temperature treatment of pellets and metal scrap and are entrained with dusty gases. The zinc content is 1-3% in blast furnace slurry and 5-20% in electro furnace slurry. The iron content in dust and slurry depends on the zinc content and is 30-50%. The basicity CaO/SiO 2 of blast furnace slurry is 1.2-1.3, which is the value required for smelting. The slurry contains 10-12% solid carbon formed by the disinte gration and entrainment of coke. The introduction of slurry and dust in sintering batch at metallurgical plants is limited by the accumulation of zinc in the blast furnace lining, which consequently deteriorates.To use zinc bearing wastes, a separate system is needed for extraction and trapping of the zinc, while the remaining iron is returned to the metallurgical process. Since zinc sublimates above 1100°C only in metallic form and is present in slurry and dust as oxides, it is expedient to extract the zinc by reduction using carbon. In the present work, we investigate the kinetics of simultaneous iron and zinc reduction from dust and slurry pelletized with coke fines. The compo sition of such dust and slurry is different for different enterprises, as we see in the table.The iron content in blast furnace slurry is deter mined by the batch quality. At OAO MMK and OAO Ural'skaya Stal', where the batch consists mainly of local agglomerates with a high content of iron (56-58%) and pellets (63-65% Fe), the slurry contains around 50% Fe. At OAO NTMK, with a considerably smaller proportion of pellets in the batch, the iron con tent is 45%. At Serov Metallurgical Plant, where no pel lets are used in the batch, and the sinter consists of rel atively lean Bogoslovsk ore, it is no more than 30%.The zinc oxide content in blast furnace slurry from Serov Metallurgical Plant and OAO NTMK is higher (5%), since the batch consists of complex zinc rich Severopeschansk and Tagilo Kushvinsk ores. KMA ore, whose concentrates are pelletized, has a lower impurity content and is free of zinc. Therefore, in slurry from blast furnaces whose batch contains 30-50% pellets (OAO MMK, OAO Ural'skaya Stal'), the zinc content is no more than 1%.The basicity (CaO/SiO 2 ) of the blast furnace slurry is close to the mean basicity of the batch (1.2-1.3), and no fluxing is required. The fairly high content of solid carbon in the blast furnace slurry (~10%) is due to the entrainment of the smallest coke fractions from the batch with the furnace's exhaust gases. The presence of reducing agent in the slurry permits significant reduc tion in consumption of the solid fuel (perhaps to zero) for the reduction of iron and zinc oxides when the pellet batch contains blast furnace slurry. The main harmful impurity in the slurry is sulfur (0.4-2.2%).The...

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