Metal oxide prodn. by combustion of halogen cpd., and fuel - without excess oxygen, to prevent free halogen formation

摘要

In the prodn. of metal oxides (I) by combustion of halogenated metal cpds. (II), esp. metal chlorides (IIA), with supply of a fuel gas (III), combustion is carried out with excess O2, pref. with a lack of O2. O2-enriched air or pure O2, opt. mixed with steam, can be used for combustion. After sepg. (I) and scrubbing to remove the acid, the waste gas can be subjected to recombustion or recycled. Pure H2 is used as (III). The amt. of reactants supplied to the combustion chamber is controlled according to the reducing or oxidising constituents of the waste gas. The formation of free halogen (C12), which is costly to remove, is avoided. The process is useful, e.g., for the prodn. of SiO2 from SiCl4.