1985 Fiscal Year Final Research Report Summary
Development of a Sulfuric Acid Leach Process of Manganese Nodules at Moderate Temperatures
| Project/Area Number |
59850128
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
無機工業化学
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| Research Institution | Tohoku University |
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Principal Investigator |
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| Project Period (FY) |
1984 – 1985
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| Keywords | Hydrometallurgy / Manganese nodule / Copper / Nickel / Cobalt |
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| Research Abstract |
The research works have been performed on a bench-scale test of 0.2 kg and the development of a new process concentrating Ni as <Ni_3> <S_2> . Nodule(CM-17, 0.2 kg, -40 +60mesh, Cu 0.25, Ni 0.39, Co 0.33, Fe 11.7, Mn 18.5 wt%) was leached in a 2N <H_2> <SO_4> of 2L at 373 K for 4hr stirring at 450rpm. The percentages of leached Cu, Ni, and Co were 87.0, 97.0, and 21.0 %, resp. These valued were higher than those in the beaker-scale test. The Cu, Ni, and Co concentrations in the leach liquor were 0.22, 0.35,and 0.07 g/L, respectively. Calcareous mud (Ca <CO_3> 93.6%) was added gradually to the leach solution until the pH reached 3.0 and <Fe^(3+)> and <AL^(3+)> were removed 98 and 21 %, resp. without coprecipitation of Cu, Ni, and Co. Then, scrap iron(Fe 98.4 %) was added to 1L of the mother liguor at 363 K. The recovery of Cu reached 99.5 % and the Cu content in the precipitate was 75 %. A new process for the recovery of Ni and Co as a mixed sulfide of <Ni_3> <S_2> and CoS have been developed with reduced iron powder and <H_2> S at 363 K. The optimum conditions were as follows:358-368 K, 3[Fe]/[ <Ni^(2+)> ] molar ratio 1.25, and <H_2> S flow rate 0.9L/[ <Ni^(2+)> g/L]hr. The recoveries of Ni and Co reached 99.5 and 90 % at 1 hr, resp.
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