Method of removing dissolved heavy metals from aqueous waste liquids
AssigneeNippon Kokan Kabushiki Kaisha
InventorsKasane Yamashita, Takao Ikehata, Kazuhiko Tate, Keisuke Nakahara
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Abstract
A powder of a slag formed at the time of manufacturing steel is used to remove heavy metals contained in waste water. After the use the slag may be heated to recover the heavy metals adsorbed thereby or the used slag may be formed into solid blocks, ballast or aggregate by admixing with Portland cement or alumina cement.
Claims19
A method for removing at least one dissolved metal selected from the group consisting of mercury and cadmium contained in an aqueous waste liquid which comprises the step of contacting particles of a steel-making converter slag with said waste liquid so as to absorb and fix said metal or metals on said slag particles, and separating said slag particles from said waste liquid, said steel making converter slag is converter furnace slag consisting essentially of 9-20 wt.% of SiO.sub.2, 37-59 wt.% of CaO, 0.1-2.5 wt.% of Al.sub.2 O.sub.3, 5-20 wt.% of FeO, 0.6-8.0 wt.% of MgO, 0.06-0.25 wt.% of S, 1.3-10.0 wt.% of MnO, 0.4-0.9 wt.% of TiO.sub.2 and 1.5-2.3 wt.% of P.sub.2 O.sub.5.
Dependencies are inferred from the claim text.