Pathway of Sucrose Oxidation in Manganese (Pyrolusite) Nodule

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• 作者：Ayon Bala Baral ; Barsha Dash ; Malay K. Ghosh ; Tondepu Subbaiah ; Manickam Minakshi
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2015
• 出版时间：December 16, 2015
• 年：2015
• 卷：54
• 期：49
• 页码：12233-12241
• 全文大小：605K
• ISSN：1520-5045

文摘

Polymetallic sea nodules are the potential resources of copper, cobalt, manganese, and nickel. The exploration and exploitation of manganese nodules are necessary to meet the future demands of Mn in the world. This work describes the valuable extraction of Mn through an innovative approach of using sucrose as a reductant. The metal extraction from the nodule leaching was studied in ambient temperature (27 掳C) and at an elevated temperature 90 掳C with and without agitation. In both cases, 99.9% of Mn was extracted while the extraction time appears to be significantly low (2 h) at 90 掳C but it requires a longer time of 24 h at 27 掳C. The optimum sucrose concentration selected was 7% (w/w) of nodule for maximum metal extraction. With use of 10% (v/v) H₂SO₄, 7% (w/w) sucrose at 90 掳C, and solid to liquid (S/L) ratio of 1:10 the achieved metal recovery figures were the following: Mn >99%, Ni 98%, Cu 87%, Co 83% in 2 h. The oxidation pathway of sucrose is outlined in this study with the aid of mass spectrometry during reductive leaching of ocean bed nodule. Sucrose in acidic environment generates 1- or 6-monoacid of sucrose with ions of m/z (mass-to-charge ratio) 355 and 127, 5-hydroxymethylfurfural (5HMF). A dehydrated glucose complex (m/z 325) was generated at elevated temperature. These released organics act as reductant for the leaching of Mn²⁺ from MnO₂. Glucaric acid (m/z 211) is generated as the end product of the sucrose oxidation in the solution.