Study on the Oxidative Leaching of Uranium from the Lignite in the CO32-/HCO3- System. (19th December 2017)

• Record Type: Journal Article
• Authors: Ning, Y.; Li, Y.; Zhang, Y.; Tang, P.
• Other Names: Lu Dan Academic Editor.
• Is Part Of: Geofluids. Volume 2017(2017)
• Publication Date: 2017-12-19
• Subjects: Hydrogeology -- Periodicals; Sedimentary basins -- Periodicals; Fluids -- Migration -- Periodicals; Groundwater flow -- Periodicals; Geothermal resources -- Periodicals; Fluid dynamics -- Periodicals; Earth -- Crust -- Periodicals; 551.49
• DOI: 10.1155/2017/7130971
• Languages: English
• ISSNs: 1468-8115

Abstract

Abstract : Na2 CO3 /NaHCO3 mixtures with different oxidants were used to leach uranium in the lignite which was obtained from Lincang, Yunnan province. The experimental results showed that the optimal solid/liquid ratio and C O 3 2 - /H C O 3 - ratio for uranium leaching were 1 : 20 (g/mL) and 2 : 1, respectively. With the increase of carbon concentration from 0.1 mol/L to 1.1 mol/L, the leaching efficiency of uranium increased from 14.64% to 42.39% after 6 h leaching. The oxidants could significantly enhance the uranium leaching efficiency, which was up to 72.23% by injecting O2 at 1.5 L/min after 12 h leaching. The oxidative leaching process of uranium from the lignite was better fitted to the pseudo-second-order reaction model. The sequential extraction results illustrated that the oxidants could effectively enhance the leaching of organic matter bound uranium in the lignite, which was decreased from 76.86 mg/kg to 9.00 mg/kg by injecting O2 . The infrared spectrum analysis demonstrated that the corresponding transmittance at about 3197 cm −1 was prominently reduced after the oxidative leaching, which intimated that the phenolic and alcoholic hydroxyl might be the main functional groups combined with uranium in the lignite.