膜电解钒酸钠溶液制备五氧化二钒

Preparation of Vanadium Pentoxide from Sodium Vanadate Solution by Membrane Electrolysis

钒渣提钒的传统方法钠化提钒工艺以铵盐为介质实现钒酸钠阴阳离子的解离,但是会产生大量的氨氮废水和硫酸钠固废,使得钒产品制备过程环境污染严重,工艺复杂,成本高。基于此,提出了膜电解技术处理含钒浸出液,使钠离子扩散到阴极,钒保留在阳极,随后通过水解沉钒,煅烧获得五氧化二钒产品,阴极液蒸发浓缩回收氢氧化钠的工艺技术。系统考察了电解电压、电解时间和沉钒温度等的影响规律,在电压5 V、电解时间135 min的条件下,可分离回收浸出液中85%的钠;电解后的浸出液在120℃加热90 min,沉钒率可达99%,获得的五氧化二钒产品满足行业标准要求。

The traditional method of vanadium extraction from vanadium slag is sodium vanadium extraction process,which uses ammonium salt as the medium to achieve the dissociation of anion and cation of sodium vanadate,but it will produce a large amount of ammonia nitrogen wastewater and sodium sulfate solid waste,resulting in serious environmental pollution,complex process and high cost in the vanadium product preparation process.Based on this,a technology of membrane electrolysis was proposed to treat vanadium-containing leachate,which allows sodium ions to diffuse to cathode,while vanadium remains in anode.Vanadium pentoxide product was obtained by hydrolysis,precipitation and calcination,and sodium hydroxide product was recovered by evaporation and concentration of catholyte.The effects of electrolytic voltage,electrolytic time and vanadium precipitation temperature were investigated systematically.The results show that under the condition of voltage of 5 V and electrolytic time of 135 min,85%sodium in the leachate can be separated and recovered.The leaching solution after electrolysis was heated at 120℃for 90 min,the vanadium precipitation rate can reach 99%.The obtained vanadium pentoxide products meet the requirements of industry standards.