硫酸法钛白生产中钛铁矿液相酸解反应的实验研究  

An Investigation on the Liquid Phase Digestion of Ilmenite in Sulfate Process TiO_2 Pigment Production

作　　者：景建林[1] 张全忠[1] 邱礼有[1] 梁斌[1] 

机构地区：[1]四川大学化学工程学院四川省多相流传质与化学反应工程重点实验室,四川成都610065

出　　处：《化学反应工程与工艺》2003年第4期337-343,共7页Chemical Reaction Engineering and Technology

摘　　要：　低浓度硫酸液相酸解钛铁矿可以大幅度减少硫酸法钛白生产中的废酸、废气排放。通过在高液固比、强搅拌下进行的实验研究表明,65%～80%硫酸液相酸解仍具有很好的反应活性。工业酸矿比条件下,采用反应过程中不断加入稀酸或水稀释的方法,增加料浆的流动性能和搅拌性能,可以实现液相酸解操作。液-固相酸解的对比实验表明,工业条件下固体产物层对酸解率有很大影响;通过SEM、EDS等表征,发现液相法酸解矿粒表面产物层比固相法要薄,分布更疏松。液相酸解工艺条件优化结果表明,在酸矿比1.4下,用65%～75%硫酸,150～160℃,120min,酸解率高于85%。可以得到总钛浓度116kg/m3,F值为2左右的合格钛液。操作周期缩短到2～3h。Lowering the concentration of digestion sulfuric acid can greatly reduce emissions of spent acid and flue gas in the sulfate process for TiO_2 pigment production. The experiments conducted under a high liquid/solid ratio and a well stirred situation, showed that the reaction activity was considerable high even in 65%~80% sulfuric acid solutions. A liquid-phase digestion operation was realized by continuously adding dilute acid or water to ensure the fluidity of reaction slurry. Mechanic agitation was employed to enhance the mass transfer. Comparing the liquid-phase digestion with solid-phase digestion, the experimental results indicate that the diffusion of reactants through solid product layer significantly affects the digestion degree of ilmenite in a commercial solid-phase digestion operation. The SEM and EDS characteristics show that the product layer over the un-reacted core in liquid phase digestion is thinner and its structure is looser comparing with solid phase digestion. With an industrial acid/ore ratio of 1.4 and an acid concentration of 65%~75%, digestion degrees higher than 85% were obtained at 150℃ ~160℃ within 120 min. Titaniferous solution with a TiO_2 content of 116 kg/m^3 and a F value of 2.0 was obtained, which was suitable for the pigment production. The liquid-phase operation shortened the periodic time to 2~3 hours.

关 键 词：硫酸法 钛白 工业生产 钛铁矿 液相酸解 实验研究 

分 类 号：TQ621.12[化学工程—精细化工]