【作者】 刘素兰； 张显鹏； 崔传孟；

【Author】 Liu Sulan, Zhang Xianpeng, Cui Chuanmeng(School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China)

【机构】 东北大学材料与冶金学院；

【摘要】 研究了不同温度和气氛下焙烧,铀的价态变化。实验结果表明,焙烧温度高于450℃样品中U6+减少,450℃时样品中U6+略增加。 B-3样品固定700℃焙烧,CO气氛下U6+占样品中总铀量的百分数由16．5％降到4．1％,而空气条件下由16．5％降到6．2％,表明还原气氛焙烧更有利于降低样品中的U6+。试验结果与热力学分析结果一致。研究了焙烧后的硼精矿加压碳酸钠水溶液浸出过程,通入的气氛、加入的碱量和氧化剂量对铀的浸出率的影响。实验结果表明,铀的浸出率随气体中O2的增加而提高。相同气氛下,随溶液中碱量和固体氧化剂量的增加铀的浸出率提高。以含铀的硼精矿为原料,碳碱法制取硼砂过程,铀的浸出率最高时为62．5％,溶液中铀的含量仅为0．500mg／L,仍没有回收价值;当铀的浸出率最低时为8．12％,残渣中铀含量为100．0mg／kg,不超过排放标准。更多还原

【Abstract】 After dressing the iron-concentrate and boron-concentrate were got, which contain a little uranium. The boron-concentrate is good material for preparation borax, but it contains a little uranium, therefore it is important to investigate the behavior of uranium during carbonate-alkaline leaching boron-concentrate for borax preparation. The temperature and atmosphere of roast change the valence of uranium. U6+ percentage decreases when the roast temperature is higher than at 450℃ while the temperature is 450℃, the percentage increases. For B-3 sample, U6+ percentage decreases from 16.5% to 4.1% and 6.2% respectively at air and carbon monoxide atmosphere when the roast temperature is 700℃. It shows that carbon monoxide atmosphere avails to decrease U6+ of sample. It is coincident with thermodynamic analysis. The leaching rate of uranium changes with the oxygen content of gas, alkalinity and solid oxidant. During the boron-concentrate leached, the uranium content of solution is 0.500 mg/L, when the leaching rate is 62.5%; while the uranium content of residue is 100 mg/kg when the leaching rate is 8.12%.更多还原