Irkutsk National Research Technical University (Irkutsk, Russia):

V. V. Vlasova, Cand. Eng., Associate Prof., Dept. of Mineral Processing and Environment Protection, E-mail: vlaver64@rambler.ru
E. Yu. Fomina, Cand. Eng., Associate Prof., Dept. of Mineral Processing and Environment Protection

Today the problem of ash-waste storage and low level of ashwaste treatment affects the efficiency of energy economic, because landfills of ash waste needs a proper technological maintenance and large financial supplies. It seems to be a hard task for energy industry to reduce this item of expenses because of the risks of negative effects to environment. The possible solution can be found in wide using of ash and slag waste in the national economy. This article provides the results of developing a technology of extraction of valuable components (in particular – iron) from ash and slag waste of thermal power plants of the Irkutsk region (CHP-9 in Angarsk, NI CHP in Irkutsk). The technological scheme includes preliminary screening to class 1.25 mm, classifi cation and wet magnetic separation. This scheme allows to obtain a concentrate with content of Fe₂O₃: 58.23% for material from CHP-9 and 67.61% for material from NI CHP. According to composition and properties of the obtained magnetite concentrates, we can suggest the directions of their use. One of the possible use is the complete or partial replacement of natural magnetite or other secondary materials (scrap, crushed scale) in the smelting of steel, iron, cast iron and ferroalloys. The experimental smelting of pre-briquetted charge proved the possibility of smelting the cast iron from iron-containing concentrate separated from ash and slag waste from NI CHP. The cast iron smelted within the experiment can be defi ned as cast iron of brand P2 that are commonly used in steelmaking processes. This result proves the possibility of using ash and slag waste as an alternative replacement to natural resources.

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