(1. 南華大學 環(huán)境保護與安全工程學院，衡陽 421001；
2. 南華大學 放射性三廢處理與處置重點實驗室，衡陽421001；
3. 南華大學 鈾礦冶生物技術(shù)國防重點學科實驗室，衡陽 421001)
摘 要: 針對低品位鈾尾礦因脈石含量高、物相賦存狀態(tài)復(fù)雜而造成的鈾浸出率低的問題，提出添加輔助氧化劑破壞脈石結(jié)構(gòu)而實現(xiàn)強化浸出鈾的思路。采用單因素實驗法對比常規(guī)酸浸和3種氧化劑(H2O2、MnO2 和Fe3+)強化酸浸對鈾浸出率的影響。結(jié)果表明：當浸出溫度、硫酸濃度和液固比分別為30 ℃、1 mol/L和20:1時，采用常規(guī)酸浸6 h后鈾的浸出率僅為78%，而在相同的浸出條件下，強化酸浸1.5 h鈾的浸出率可達到95%。浸出渣的XRD及SEM-EDS分析結(jié)果表明，H2O2及MnO2均能破壞脈石晶體結(jié)構(gòu)，減少顆粒團聚，但添加MnO2后生成新的硅酸錳鹽晶體，F(xiàn)e3+不能破壞脈石結(jié)構(gòu)，但其氧化作用在一定程度上能加快鈾的浸出。
關(guān)鍵字: 鈾尾礦；浸出；氧化；脈石
（1. School of Environment Protection and Safety Engineering, University of South China, Hengyang 421001, China;
2. Key Laboratory of Radioactive Waste Treatment and Disposal, University of South China, Hengyang 421001, China;
3. Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China）
Abstract:In view of low extraction rate of uranium caused by high gangue content and complex occurrence state of phases existing in low-grade uranium tailings, adding suitable oxidants in leaching process to destroy the gangue crystal structure were proposed to enhance the uranium extraction. The effects of traditional acid leaching and intensified leaching with three oxidants (H2O2, MnO2 and Fe3+) on uranium extraction were investigated using single-factor experiments. The results show that uranium extraction ratio is only 78% after 6 h in traditional leaching at temperature, sulfuric acid concentration and liquid-solid ratio of 30 ℃, 1 mol/L and 20:1, respectively, while the extraction ratio reaches 95% after 1.5 h in intensified leaching under the same leaching conditions. H2O2 and MnO2 can decompose the gangue crystal structure and reduce the particle agglomeration. However, manganous silicate forms when MnO2 is used as oxidants. The ferric iron has no effect on destroying the gangue crystal structure, but it can improve the uranium extraction ratio depending on its oxidation influence.
Key words: uranium tailing; leaching; oxidization; gangue
