物質フロー分析及び熱力学的解析に基づくレアメタルリサイクル性評価

本文主要对各种稀有金属的可回收性进行热力学评价。总的来说，考虑了报废（EoL）镍、钴、镍钴基合金、钛、锌和硅产品的回收。在回收过程中，EoL产品中所含合金元素通常作为杂质元素处理，本研究采用热力学方法定量评价其可去除性/可控性。继2014年（H. 26）对EoL镍、钴基高温合金重熔可精炼性的热力学评价之后，通过金属/渣/气平衡实验测量了CaO-Al2O3-SiO2熔渣中NiO和CoO的活度系数，为重熔工艺控制镍、钴基溶剂合金提供基础热力学信息。在EoL高温合金重熔过程中，控制CaO-Al2O3-SiO2渣的碱度接近于统一有利于去除含铁，降低镍和钴的氧化损失。在此基础上，评价了CaO-Al2O3-SiO2渣对Ni-Co-Fe合金成分的可控性。用热力学方法评价了硅渣处理和定向凝固两种工艺的可细化性。考察了亚氧化物蒸发对EoL钛中铝和钒的去除率。在对H.26中EoL锌的可精炼性进行热力学评价的基础上，实验测量了氯渣与锌之间铁和铅的分布。

This study mainly focused on the thermodynamic evaluation on the recyclability of various rare metals. Totally, recycling of end-of-life (EoL) nickel, cobalt, nickel-cobalt based alloy, titanium, zinc, and silicon products was considered. During the recycling, the alloying elements contained in EoL products are always treated as impurity elements, and the removability/controllability of them was quantitatively evaluated using thermodyanmic method in present study.1. Following the thermodynamic evaluation on refinability of EoL Ni- and Co-based superalloys by remelting process carried out in 2014 (H. 26), the activity coefficients of NiO and CoO in CaO-Al2O3-SiO2 slag were measured by metal/slag/gas equilibrium experiments to provide fundamental thermodynamic information for the control of Ni-Co-based solvent alloy using remelting process. Controlling the basicity of CaO-Al2O3-SiO2 slag close to unity is found helpful to remove the contained iron and reduce the oxidation losses of nickel and cobalt during remelting of EoL superalloys. The controllability of Ni-Co-Fe alloy composition using CaO-Al2O3-SiO2 slag was evaluated based on present results.2. The refinability of silicon using slag treatment and directional solidification processes was evaluated by thermodynamic method.3. The removability of aluminum and vanadium from EoL titanium by evaporation of sub-oxides was thermodynamic evaluated.4. Following the thermodynamic evaluation on the refinability of EoL zinc in H.26, the distribution of iron and lead between chloride slag and zinc was experimentally measured.