Fusaji Ozawa

Thermal decomposition of organic basic aluminium salts—formate and acetate

Abstract The thermal transformation of anhydrous alumina by the decomposition of the formate and acetate of basic aluminium has been examined by thermal analysis (TG and DTA), infrared spectrophotometry and X-ray diffraction studies. It is found that under an atmosphere of air the organic basic aluminium salts decompose to anhydrous amorphous alumina which transforms to α-alumina via γ-, δ- and θ-aluminas

Thermal decomposition of zirconium hydroxide

Abstract The thermal decomposition of zirconium hydroxides prepared from aqueous ammonium hydroxide solutions on the addition of potassium fluorozirconate, K 2 ZrF 6 , under various conditions has been examined by thermogravimetry, differential thermal analysis, X-ray diffraction study and infrared spectrophotometry. As a result, it is found that the thermal decomposition of zirconium hydroxide proceeds according to In this process, the transformation of amorphous ZrO 2 to either the metastable tetragonal or monoclinic form depends on the composition of the original starting material as an hydrated oxyhydroxide, ZrO 2− x (OH) 2 x · y H 2 O where x ⩽ 2 and y ⋍ 1.

Thermal decomposition of ammonium uranates precipitated from uranyl nitrate solution with ammonium hydroxide

Abstract Thermal decomposition of ammonium uranates precipitated from uranyl nitrate solutions on addition of aqueous ammonium hydroxide under various conditions has been examined by thermogravimetry (TG), differential thermal analysis (DTA), infrared spectroscopy and X-ray diffraction study. The TG curves of all precipitates show the weight-loss corresponding to the calculated value as UO 3 ·NH 3 ·H 2 O. The DTA curves of the precipitates give the endotherms at about 130, 210 and 590 °C and the exotherms at 340–420 °C. As a result, it is found that ammonium uranates thermally decompose to amorphous UO 3 at about 400 °C, and transform to U 3 O 8 via β-UO 3 .

Thermal Transformation of Aluminium Hydroxide to Alumina

The thermal transformation of crystalline and gelatinous aluminium hydroxide by thermogravimetry (TG), differential thermal analysis (DTA), X-ray diffraction study and infrared spectrophotometry.