The purpose of work is the research of behavior of non-ferrous metals, in particular of zinc and lead, for analysis of a capability of utilization of steel-making dust and sludge by recycling in the steel-making vessel (open-hearth furnace, converter, arc electric furnace), and also working out the technology of utilization of steel-making dust and sludge.
For achievement of the purpose it is necessary to solve the following problems:
1) analysis of existing processes of processing of steel-making zinc bearing dust and sludge on foreign and domestic enterprises
2) research of physico-chemical properties of steel-making dust and sludge
3) research of behavior of zinc and lead at an agglomeration, in the blast furnace, in a steel-making vessels
4) explore the possibilities of preparation of steel-making dust and sludge for recycling in steel-making vessel
3 Suspected scientific novelty
Working out of economically effective technology of utilization of zinc bearing steel-making dust and sludge with full usage of all valuable components.
4 Reviews of existing researches
At utilization such sludge in the building industry, in cement production conducts irretrievable losses of valuable components keeping in its. A perspective direction is the making from sludge, which has dehydrated on the traditional scheme, pellets, which will metallize, unburned pellets or briquettes. At processing of metallizated pellets from iron bearing sludge and dust is deleted 75-99 % of zinc and lead, 40-77 % of sodium oxide and 60-85 % of potassium oxide. The combinations of these metals, which are caught from waste gas, could be the charge for non-ferrous metallurgy.
Some industrial processes of metallization of pellets are invented. General for these processes is usage for the metallization aggregate of a rotated tube-type furnace. These processes differ one from other by technology of preparation of charge, and also availability or absence of a fire grate for a heating and hardening of pellets. These processes are very material-consuming and power-consuming.
5 The present and further researches
The scheme of circulation of non-ferrous metals in steel-making processes was studied. Any loop system results in accumulation of a circulating component and to stabilization of a bearing flow on more high level. We calculate the accumulation of zinc and lead in dust at recycling in steel-making vessel at different contents of zinc and lead. The results of this calculation are shown in figure.
Figure - Results of calculation of behavior of zinc and lead at recycling of dust
Through some number of cycles there is a saturation of dust by non-ferrous metals and it is necessary take out it from a cycle for further processing and extraction of non-ferrous metals. For processing of enriched dust or sludge at plants of non-ferrous metallurgy it is enough to have the contents 12 - 15 % of zinc. However the problem of usage of iron bearing part is not decided. Therefore it is offered to realize the recycling of dust or sludge to content of zinc 12-15 %, further to make processing of sludge with humidity 6-8 % by fluid steel-smelting slag. Thus we will receive the products of zinc sublimation, which are charge for non-ferrous metallurgy and slag enriched by iron and it can be used in charge for blast furnace. At usage of such lumpy product in the blast furnace will economize agglomerate, limestone, the manganese ore, and coke. Thus at usage of one ton of such product will be economize more than 60$.
In further we plane to state the value of investments for realization of offered technology on concrete enterprise (in this case OJSC "Ilich Iron and Steel Works of Mariupol") and to calculate indexes of an economic efficiency of realization of this project.
6 Conclusions
Thus for a solution of a problem of utilization of zinc bearing dust and sludge there is a potential in steel-making production. Offered technology will permit to utilize all valuable components keeping in dust and sludge of steel-smelting furnaces.
8 List of sources
1. Степин Г.М., Мкртчан Л.С., Довлядов И.В., Борщевский И.К. Проблемы цинка в доменном производстве России и пути их решения. Металлург. – 2001, № 10. – С. 39 – 42.
2. Проблемы цинка в доменном производстве / Капорулин В.В., Урбанович Г.И., Невмержщкий Е.В. и др. // Сталь. – 1984, № 11. – С. 9 – 15.
3. Троянский А.А., Клягин Г.С., Ростовский В.И. Технология рециклинга пылевыноса сталеплавильных агрегатов с извлечением цветных металлов // Сталь. – 2002, № 8. – С. 119 – 122.
4. Борисов В.М., Казьмин А.А. Удаление вредных примесей из железосодержащих отходов за рубежом // Бюл. НТИ: Черн. металлургия. – 1981, № 17. – С.15 – 24.
5. Валавин В.С., Юсфин Ю. С., Подгородецкий Г. С. Поведение цинка в агломерационном процессе // Сталь. – 1988, № 4. – С.12 – 17.
6. Ивянский В. А., Довлядов И. В., Михалевич А. Г. Пути повышения степени обесцинкования железорудных материалов в процессе их агломерации // Черная металлургия. – 1988, № 2. – С. 13 – 14.
7. Высокотемпературные процессы переработки шламов металлургического производства / Н.И. Иванов, В.К. Литвинов, В.Ф. Шутикова, Е.Б. Агапитов // Бюл. НТИ: Черная металлургия. – 1989, № 6. – С. 20 – 28.
8. Herlits News, Eriksson Sune, Skogbolg Johny New generation of reduction process based on plasma technology // Rev. Metall. – 1983, № 3. – P. 511 – 520.
9. Пат. 4612041 США, МКИ С22В 4/00. Способ извлечения ценных металлов из железной пыли с высоким содержанием цинка. – Опубл. 16.09.86.
10. Маламуд С.Г., Колесник В.Г., Юрьев Б.П. Разработка способ окускования доменных шламов и мартеновских пылей с извлечением цинка при нагреве в полях СВЧ // Сталь. – 2000, № 1. – С. 3 – 7.
11. Карабасов Ю.А., Юсфин Ю.,С., Курунов И.Ф. Проблемы экологии и утилизации техногенного сырья в металлургическом производстве // Металлург.- 2004, №8. – С.27-33
12. Krishnan E.Radha, Kemner William F. Recycling of dust from electric arc furnaces – an experimental evaluation // 44ht Elec. Furnace Conf. Proc. Vol. 44 Dallas Meet.,Dec. 9-12,1986. – Warrendale, 1987.- C.335-365
14. Evans Larry G., Hogan John C. Recycling ofEAF dust by direct injection // 44th Elec. Furnace Conf. Proc. Vol. 44 Dallas Meet.,Dec. 9-12,1986. – Warrendale, 1987.- C.367-372
15. Melecky Jan Gtuetn, Nova hut, Alois C. Технологическая проверка возможностей гидрометаллургической обработки пыли-уноса из сталеплавильных печей // Hutnik. –1989, № 5. – C. 166 – 176
16. Заявка № 60-251234, Япония, МКС С22В 19/30. Способ извлечения цветных металлов из шламов. Опубл. 13.07.85.