Hydrothermal Treatment of Hydrous Potassium Titanate Fibers and Hydrous Titania Fiber

Abstract

The potassium tetratitanate fiber produced through the reaction between titanium dioxide and potassium carbonate by the KDC process (Kneading-Drying-Calcination) were converted into six different hydrous potassium titanate fibers (X_I to X_VI ) and one hydrous titania fiber (X_VII)by leaching with water.
The X_I (2K₂O⋅11TiO₂⋅3H₂O), X_II (K₂O⋅6TiO₂⋅19/11 H₂O), X_III (K₂O⋅7⋅TiO₂⋅24/11 H₂O), X_IV(K₂O⋅8O₂⋅29/11 H₂O) and X_VII(2TiO₂⋅H₂O) phases were treated with water, potassium hydroxide and sulfuric acid under hydrothermal conditions. Consequently, the X_I, X_II and X_III phases changed into fibrous anatase, potassium hexatitanate, potassium tetratitanate and X_V (K₂O⋅9TiO₂⋅34/11 H₂O), the X_IV2 phase into fibrous anatase, potassium hexatitanate and X_V, the X_VII phase into fibrous anatase, fibrous rutile and potassium hexatitanate. These seven phases were divided into three groups, X_I to X_III, X_IV to X_VI, and X_VII
The initial stage of hydrothermal reaction were predominantly the internal reaction of solids which depended on the structure of starting hydrous materials.