Nowadays, people should pay more attention on the environment problems that had advent along with the development of rare earth metallurgy industry. A large number of water pollutant, air pollutant and solid pollutant were discharged in the process of synthesis of rare earth compound by precipitation and roasting process. In order to solve the industry pollution problems, a new technology route was developed for the preparation of lanthanum oxide using lanthanum chloride as raw material by oxy-hydrogen flame route. The experiment results showed that lanthanum chloride could directly convert to lanthanum oxide under high temperature by the combustion of mixture gas of hydrogen-oxygen that provided by oxy-hydrogen generator continuously. The phase composition of obtained product was characterized by XRD and the conversion rate of lanthanum chloride and the reaction mechanism were discussed.

With lanthanum chloride solution as raw material, and use the hydrogen peroxide of clean and pollution-freeobtained from oxidation reaction as auxiliary reagent, and with the carrier gas together form spray pyrolysis to obtain lanthanum oxide. On the one hand, in the hydrogen peroxide system, the temperature of direct pyrolysis reaction of lanthanum chloride solution decreased obviously, The reaction temperature is decreased from 1280°C to 1000°C or less. That reduce the energy consumption and simplify the requirements of pyrolysis equipment technology. The production process does not use NH3.H2O and NaOH to precipitate. It does not produce the traditional process of NH4+, Na+ to pollute water. It can greatly reduce the damage to the environment, and can product with high yield, high purity of the rare earth oxide. This method not only applies to the pyrolysis of the rare earth chloride solution, also applies to metal chloride solution, such as FeCl3, AlCl3, NiCl2. It was shown that the reaction temperature has been effectively reduced, VLaCl3: VH2O2 with 1: 1.5 can get high purity of La2O3.