1. Overview
Cerium chloride is anhydrous or aqueous mixture and is not good for the eyes, respiratory system, and skin. It is used in petroleum catalysts, automobile exhaust catalysts, intermediates and other industries. It is also used in the manufacture of cerium and other metals.
2. Physical and chemical properties
The chemical formula of cerium chloride is CeCl3. Molecular weight 246.48 Colorless crystals. It's easy to get wet. The melting point is 848 °C, the boiling point is 1727 °C, and the relative density is 3.920. Soluble in cold water (hot water decomposition), ethanol and acetic acid. It can react with ammonia, strong alkali, ammonium oxalate, acids, sulfides, and can be decomposed by oxygen or water vapor to produce cerium oxide.
3. Preparation method
Cerium carbonate is dissolved in hydrochloric acid solution, evaporated and dried, the residue is mixed with ammonium chloride and calcined with red heat, cerium oxalate is burned in a hydrogen chloride gas stream, and cerium oxide is burned in a carbon tetrachloride gas stream.
Direct chlorination of rare earth oxides with ammonium chloride to synthesize anhydrous chloride is a new green method. This method has high efficiency and novel process, but it is not easy to solve the corrosion problem of high-temperature chlorination equipment. Under low-temperature roasting conditions, NH4Cl reacts directly with CeO2 through secondary decomposition and chlorination.
4. Product identification
The chlorination rate (A, %) was determined using the EDTA volumetric method. Hexamethyltetramine was used as buffer solution and xylenol orange as indicator, titrated with EDTA standard solution, and the endpoint was purple-red to bright yellow. Averages were obtained by three parallel titrations. An anhydrous chloride crystalline phase was determined using an X-ray diffractometer. The pipe pressure is 40kV, the pipe flow is 100mA, Cuka (λ = 0.15406).