不同酸处理钛酸锂的转型研究

Study on transformation of lithium titanate modified with different acids

摘要:

详细研究了酸的种类和处理时间对钛酸锂转型的影响. 结果显示当相同酸度的硫酸和盐酸用来对钛酸锂进行改性时，在盐酸介质中钛酸锂更容易转变为锐钛矿和金红石型二氧化钛. 硫酸浓度越高，钛酸锂更容易转变为锐钛矿和金红石型二氧化钛；处理时间越长，更多的钛酸锂可以转变为锐钛矿和金红石型二氧化钛. 硫酸根通过螯合双齿配位于二氧化钛，有利于稳定锐钛矿型晶相；亲电的H+和高电负性的Cl-影响Ti-O键，导致TiO6八面体中的Ti-O键断裂和锐钛矿型二氧化钛发生结构重排形成金红石型二氧化钛. 钛锂离子筛稳定的结构和晶相组成能够保证高效、循环往复地提取锂，从这一点来看，相比于盐酸，硫酸更适合作为洗脱剂来制备钛锂离子筛，并且低浓度的盐酸是更好的选择.

Abstract:

The effects of kinds and concentrations of acid and treatment time on the transformation of lithium titanate (Li2TiO3) have been studied in detail. The results show that it is easier for Li2TiO3 to turn into anatase and rutile TiO2 in hydrochloric acid medium when the same acidity of sulfuric acid and hydrochloric acid are used to treat Li2TiO3 for modification. The change of Li2TiO3 into anatase and rutile TiO2 becomes easier for the higher the concentration of sulfuric acid. In addition, more Li2TiO3 can be converted to anatase and rutile TiO2 under the longer the time of acid-treated. The sulfate radical coordinates with titanium dioxide by chelating double teeth, which is helpful for stabilizing the anatase crystalline phase. The electrophilic H+ and the high electronegative Cl- affect the Ti-O bond, resulting in the destruction of the Ti-O bond in TiO6 octahedrons, and thus promoting the structural rearrangement of anatase to rutile TiO2. From the view point that the stable structure and crystal phase of lithium ion sieve ensuring extraction lithium ion efficiently and circularly, sulfuric acid is more suitable as eluent for the preparation of lithium ion sieve than hydrochloric acid, and sulfuric acid with a low concentration is a better choice.