钒渣亚熔盐法钒铬高效提取分离应用基础研究

Vanadium and chromium is global scarce resources and important strategic metal. Titanomagnetite, associated with rich chromium resource, is one of the major characteristics polymetallic mineral resources in China. Especially in Panxi region, the reserves of high chromium titanomagnetite chrome are huge. High temperature sodium roasting is the main method of extraction vanadium from vanadium slag. However, due to the structure stability of vanadium and chrome spinel phase in vanadium slag, and the mass transfer barrier at the high roasting temperature, the recovery of vanadium is very low and the chromium cannot be recovered, associated with high environment cost. The project proposed using sub-molten salt unconventional medium to intensify the decomposition of vanadium slag. By study the sub-molten salt reaction thermodynamic characteristics of vanadium slag, the kinetics and reaction mechanism, the phase equilibrium and crystallization separation law of vanadium and chromium in strong basic sub-molten salt medium, and the regeneration cycle characteristics of sub-molten salt medium, the sub-molten salt reaction mechanisms and regulation law in intensifying the decomposition of vanadium slag was obtained, and the clean separation new methods and new processes of vanadium and chromium efficient extraction method by sub-molten salt from vanadium slag is established. The vanadium and chromium efficient extraction from vanadium slag is achieved, and the chromium resource efficient synchronous extraction and recovery, and the waste gas and waste water pollution is eliminated from the source. It provides a theoretical basis to improve the comprehensive utilization level of China's titanomagnetite resources, and particularly provides technical support for the development and utilization of high chromium titanomagnetite resources in our country.

钒、铬是全球性的稀缺资源和重要战略金属。钒钛磁铁矿是我国重大特色多金属矿产资源，伴生有丰富的铬资源，特别是攀西地区高铬型钒钛磁铁矿的铬储量巨大。钒渣高温钠化焙烧方法是我国钒钛磁铁矿提钒的主要方法，但因钒渣中钒、铬尖晶石矿相结构稳定，且受限于高温焙烧方法的反应传质障碍，造成钒回收率低，铬无法回收，提钒过程环境代价高。本项目提出采用亚熔盐非常规介质强化钒渣分解新方法，通过研究钒渣亚熔盐分解反应热力学特性、动力学规律和作用机理、强碱性亚熔盐多元体系相平衡和钒铬结晶分离规律、亚熔盐介质再生循环特性等关键科学问题，获取亚熔盐介质强化钒渣分解的反应机制与调控规律，建立钒渣亚熔盐法钒铬高效提取与清洁分离新方法、新过程，实现钒渣中钒、铬资源高效同步提取回收，并从源头削减废气废液污染，为提升我国钒钛磁铁矿资源综合利用水平提供理论依据，特别是为我国大宗高铬型钒钛磁铁矿特色资源开发利用提供技术支撑。

钒、铬是全球性的稀缺资源和重要战略金属。钒钛磁铁矿是我国重大特色多金属矿产资源，伴生有丰富的铬资源，特别是攀西地区高铬型钒钛磁铁矿的铬储量巨大。钒渣高温钠化焙烧方法是我国钒钛磁铁矿提钒的主要方法，但因钒渣中钒、铬尖晶石矿相结构稳定，且受限于高温焙烧方法的反应传质障碍，造成钒回收率低，铬无法回收，提钒过程环境代价高。本项目通过研究钒渣亚熔盐分解反应热力学特性、动力学规律和作用机理、强碱性亚熔盐多元体系相平衡和钒铬结晶分离规律、亚熔盐介质再生循环特性等关键科学问题，获取了亚熔盐介质强化钒渣分解的反应机制与调控规律，在反应温度220 oC实现了钒渣中钒铬的高效共提，钒提取率达到94%，铬提取率达到84%，并通过分步结晶实现了钒酸钠、铬酸钠的高效分离，建立了钒渣亚熔盐法钒铬高效提取与清洁分离新方法、新过程。钒渣亚熔盐法钒铬共提工艺已建成千吨级示范工程，正在进行5万吨示范工程的建设。新工艺实现了钒渣中钒铬的高效共提，并从源头削减了废气废液污染，为提升我国钒钛磁铁矿资源综合利用水平提供理论依据，特别是为我国大宗高铬型钒钛磁铁矿特色资源开发利用提供技术支撑。