PURPOSE: To efficiently recover graphite, granulated iron, and sodium carbonate, by treating a molten ferrous alloy with sodium carbonate to form slag and by subjecting the slag to dissolution and extraction by the use of an alkali liquor so as to separate the slag into suspended ore content, settled ore content, and extract.
CONSTITUTION: The molten ferrous alloy is treated with sodium carbonate to form slag, and the slag is treated with water of ≥pH7 or alkali liquor, which is separated into suspended ore content, settled ore content, and extract. The settled ore content is subjected to magnetic separation to undergo recovery of granulated iron, and the remaining sludge is utilized as reclamation material, etc. Further, the extract containing the suspended ore content is filtered and separated into solid matter and extract, and sodium carbonate is recovered from the extract. On the other hand, the solid matter is subjected to flotation to undergo separation into tailings and crude kish graphite. Then, iron content, silicic acid content, etc., are eluted and removed from the crude kish graphite by means of acid treatment and, if necessary, acid treatment is carried out twice or more, so that refined kish graphite can be obtained.
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HIDAKA CHIKARA
TANAKA KOGYO