Process for treating waste slags
AssigneesTokuyama Soda Kabushiki Kaisha, Sumitomo Metal Industries, Ltd.
InventorsKatsukiyo Marukawa, Setsuo Okamoto, Kazunari Yamada, Masahisa Iba
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Abstract
In the treating of waste slags produced in the desulfurization and/or dephosphorization of molten pig iron with alkali carbonates, the alkali is recovered by extracting said waste slags with hot water while feeding carbon dioxide gas to form an extraction solution having a pH of 9.0-11.5 and recovering alkali carbonates from said extraction solution. The extraction solution contains little sulphur and silicates, from which alkali carbonates can be easily recovered with high yield therefrom.
Claims17
A process for treating waste slags produced in the desulfurisation and/or dephosphorisation of molten pig iron with alkali carbonates, which comprises treating said waste slag with hot water while feeding carbon dioxide gas to form an extraction solution of alkali carbonate having a pH of 9.0-11.5 and recovering alkali carbonates from said extraction solution.
The process of claim 6 wherein a 5-30% (V/V) CO.sub.2 gas containing gas is fed in an amount of 2,000-20,000 Nm.sup.3 per ton of waste slag for said extraction treatment.
The process of any one of claims 8, 9, 12 and 13 wherein said concentration is effected by feeding a waste hot gas produced in an iron mill into a spraying tower concentrator and feeding the filtrate into said tower.
Dependencies are inferred from the claim text.