钒渣无盐焙烧产物冷却方式对物相转型及钒提取率的影响  

Effects of cooling method on phase transformation and vanadium extraction during non-salt roasting of vanadium slag

作　　者：张晴 王玲 翟婷好[1] 马保中 王成彦 ZHANG Qing;WANG Ling;ZHAI Ting-hao;MA Bao-zhong;WANG Cheng-yan(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Beijing Key Laboratory of Green Recycling and Extraction of Rare and Precious Metals,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]北京科技大学稀贵金属绿色回收与提取北京市重点实验室,北京100083

出　　处：《中国有色金属学报》2023年第8期2678-2690,共13页The Chinese Journal of Nonferrous Metals

基　　金：国家重点研发计划资助项目(2022YFC2904201)。

摘　　要：钒渣高温焙烧产物的冷却方式与后续钒提取率及实际生产效率密切相关。本文采用XRD、SEM+EDS、XPS、BET等表征方法,对比分析了钒渣无盐焙烧-硫酸浸出提钒工艺中空气缓慢冷却及水淬冷却焙砂在物相及钒价态转化、微观形貌、比表面积等方面的差异,并对比分析钒的硫酸浸出效率。结果表明:焙烧温度是影响钒渣物相转化及新物相结晶分异的关键因素,当焙烧温度为900℃时、保温2 h后,钒渣原料中钒尖晶石、橄榄石及玻璃相完成物相转化,生成赤铁矿(Fe_(2)O_(3))、铁板钛矿(Fe_(2)TiO_(5))、二氧化钒(VO_(2))、钒酸盐相(Ca_(2)V_(2)O_(7)、Mn_(2)V_(2)O_(7)、Mg_(2)V_(2)O_(7))和二氧化硅(SiO_(2)),并充分结晶分异。在700~850℃焙烧阶段,缓慢冷却有利于物相进一步转化及钒酸盐的迁移和聚集,缓慢冷却焙砂的钒浸出率较水淬冷却焙砂的高3%~4%。在900℃以上高温焙烧阶段,冷却方式对钒物相转型及钒浸出率影响很小,钒浸出率分别为93.15%、92.89%。在该温度下水淬冷却可在保证钒浸出率的前提下提高生产效率。The cooling method of vanadium slag roasting products is closely related to the subsequent vanadium extraction and the actual production efficiency.In this paper,the various characterization methods,such as XRD,SEM+EDS,XPS,and BET were applied to investigated the differences between air cooling and water quenching on the phase transformation,vanadium valence,microstructure,specific surface area of non-salt roasting products,as well as the sulfuric acid leaching efficiency of vanadium.The results show that the roasting temperature is the crucial factor to phase transformation of the original phases and crystalline differentiation of the new phases.With the roasting temperature of 900℃and duration time of 2 h,the vanadium spinel,fayalite and glass phases in the vanadium slag transformed completely into Fe_(2)O_(3),Fe_(2)TiO_(5),VO_(2),vanadate(Ca_(2)V_(2)O_(7),Mn_(2)V_(2)O_(7),Mg_(2)V_(2)O_(7))and SiO_(2) in the roasted product.Moreover,these new formed phases realize the fully crystalline differentiation.Summarily,with the medium roasting temperature of 700−850℃,the air cooling will further advance the phase formation and aggregation of vanadate.Accordingly,the leaching efficiency of vanadium in air-cooled product is 3%−4%higher than that in water-quenched product.When the roasting temperature is higher than 900℃,the cooling methods have little effect on the phase transformation and the vanadium leaching efficiency,both leaching efficiencies can reach to 93.15%,92.89%,respectively.The water quenching is feasible on the non-salt roasting products at temperature higher than 900℃,which can improve the productivity while achieve the efficient attraction of vanadium.

关 键 词：钒渣 无盐焙烧 缓慢冷却 水淬冷却 物相转型 酸浸 

分 类 号：TF821[冶金工程—有色金属冶金]