Separation of thorium from zirconium carbide waste is reported. The waste typically contains zirconium, yttrium, uranium, and thorium, along with other impurities including rare earth elements (REEs), iron, calcium, aluminum, hafnium, and titanium. The first step in the separation was selective leaching of zirconium, uranium, and most other impurities with HNO₃–HF, leaving thorium and REEs as insoluble fluorides. The effective parameters such as HNO₃ and HF concentrations, temperature, and time were optimized for achieving the maximum leaching of zirconium and the minimum leaching of thorium, using central composite design and a multiple response optimization algorithm. Thorium and REEs were leached from the residual solid with H₂SO₄, followed by their precipitation with ammonia, dissolution of the precipitate in HNO₃, and extraction of thorium with tri-n-octylamine–kerosene. The factors affecting the extraction of thorium were optimized with respect to HNO₃, TOA, diluent, V_org/V_aq, and extraction time. Using the above sample preparation and extraction methods, thorium could be extracted with an efficiency of 95.6%.

中文翻译：

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从碳化锆废物利用三叔钍的分离通过液-液萃取ň -octylamine选择性溶剂酸浸后

据报道，从碳化锆废料中分离出。废物通常包含锆，钇，铀和or，以及其他杂质，包括稀土元素（REE），铁，钙，铝，ha和钛。分离的第一步是用HNO ₃ -HF选择性浸出锆，铀和大多数其他杂质，剩下的as和REEs为不溶性氟化物。使用中央复合设计和多响应优化算法，对有效参数（例如HNO ₃和HF浓度，温度和时间）进行了优化，以实现最大的锆浸出和最小的or浸出。用H ₂ SO ₄将和REE从残留的固体中浸出，随后可以通过与氨，在HNO沉淀的溶解沉淀₃，和钍与三提取Ñ -octylamine煤油。针对HNO ₃，TOA，稀释剂，V _org / V _aq和萃取时间对影响th萃取的因素进行了优化。使用以上样品制备和提取方法，th的提取效率为95.6％。