针对钒渣提钒现行工艺存在的不足，项目提出钒渣提钒液先采用分步沉淀法分离回收其中的钒和铬，再用电渗析分离回收钒铬沉淀后液中的碳酸钠和水，从而实现钒渣提钒的循环冶金工艺过程。通过研究含铬钒酸盐溶液中钒沉淀的行为规律，确定水溶液中钒铬相互作用的机理。基于氨性溶液中钒结晶-溶解的平衡规律的研究，解决偏钒酸铵结晶后液返回用于钒富集渣浸出，避免溶液组分溢出的技术难题。选择碳酸铅作为沉钒后液中铬的沉淀剂，根据同时平衡原理，设计碳酸铅→铬酸铅→硫酸铅→碳酸铅依次转化直接从沉钒后液中分离回收铬酸盐的工艺路线。借鉴海水淡化的成功经验，采用电渗析分离回收钒铬沉淀后液中的碳酸钠和水，使之返回循环使用，从而避免钒铬还原渣及硫酸钠/硫酸铵固体混合物在钒渣提钒工艺过程中产生。研究结果对钒渣提钒现行工艺的转型升级，及高铬钒渣中钒铬资源的高效综合具有重要意义。

In view of the shortcomings of traditional process of vanadium extraction from vanadium slag, the project proposed to use step-by-step precipitation separation to separate and recover V and Cr from the vanadium extraction solution, and then use electrodialysis to separate and recover the sodium carbonate and water from the V-Cr precipitated solution to realize the cyclic metallurgy process of vanadium extraction from vanadium slag. The mechanism of V-Cr interaction in aqueous solution was determined by studying the behavior of V precipitation in chromium-containing vanadate solution. Based on the study of the equilibrium law of V crystallization-dissolution in ammonia solution, the technical problem of returning ammonium metavanadate crystallized solution to the leaching of vanadium enriched slag to avoid the overflow of solution components is solved. Lead carbonate was selected as the precipitant of Cr in V precipitated solution. According to the principle of simultaneous balance, the process route of direct separation and recovery of sodium chromate from the solution by sequential transformation from lead carbonate to lead chromate to lead sulfate to lead carbonate was designed. Based on the successful experience of seawater desalination, sodium carbonate and water were separated and recovered from the V-Cr precipitated solution by electrodialysis, and then they were reused in the process of V extraction from vanadium slag, thereby to avoid the production of V-Cr-bearing reducing slag and the solid mixture of sodium sulfate/ammonium sulfate. The research results are of great significance for the transformation and upgrading of traditional process of V extraction from vanadium slag and efficient and comprehensive utilization of V and Cr extraction from high chromium vanadium slag.