大洋多金属结核合成Li1＋xMn2-xO4的热力学行为

Thermodynamic Analysis on Li_(1+x)Mn_(2-x)O_4 Synthesis from Ocean Multi-metal Nodule

研究用LiOH·H2O与多金属结核合成Li1＋xMn2-xO4过程中矿物的热力学行为。根据热力学数据△G和△H的计算结果，多金属结核中的锰矿物、针铁矿在加热过程中均会分解，针铁矿稳定性较锰矿物差。多金属结核中的铜镲元素虽吸附在锰矿物中，但加热时不能与锰矿物形成复合氧化物。铜钴镍均能与针铁矿形成复合氧化物，在172-760°范围内铜铁复合氧化物能稳定存在，但含量小于1％。镍铁复合氧化物在25-500°C范围内能稳定存在，当温度大于500℃时会完全分解。钴铁复合氧化物在25-1000℃范围能稳定存在，性质最稳定。260-436°C温度段为形成复合氧化物的主要阶段，XRD图中出现了复合氧化物的前两强峰，热力学分析结果与实验结果相符合。

The thermodynamic performance of various minerals in ocean multi-metal nodule in the process of Li1＋x Mn2-xO4 synthesis with LiOH·H2O and ocean multi-metal nodule as raw material is investigated. It is shown by the calculation results of the thermodynamic data AG and AH that manganese ore and goethite in multi-metal nodule will be decomposed and goethite is more unstable at calcinations process. Cupper, cobalt and nickel absorbed by multi-metal nodule can not form composite oxide with manganese ore, but can form composite oxide with goethite. From 172°C to 760°C, the composite oxide of cupper-iron is stable and the content is below 1%. From 25°C to 500°C , the composite of nickel-iron is stable and will be decomposed above 500°C . From 25°C to 1000°C , the composite of cobalt-iron is stable. The composite oxides are formed from 246°C to 436°C . There are two main peaks in XRD diagram. The thermodynamic result is agreement with experiment result.