PROCESS FOR PRODUCING TUNGSTEN OXIDE AND TUNGSTEN MIXED OXIDES

摘要

Process for producing a tungsten oxide powder or a tungsten mixed oxide powder of general formula M_xWO₃, wherein M=Na, K, Rb, Li and/or Cs, 0.1≤x≤0.5, comprising the consecutive steps of:a) providing a solution comprising respectively at least one tungsten compound and optionally at least one M-comprising compound in a concentration corresponding to the stoichiometry M_xWO₃,b) atomizing the solution, thus forming an aerosol, into a reaction space,c) reacting the aerosol in the reaction space with a hydrogen/oxygen flame for which the expression 1O_2,primary/0.5H₂≤3 applies, wherein the reaction space is configured such that it comprises two reaction zones with two different velocities of the reaction mixture v₁ and v₂ where v₂=0.3-0.8 v₁ and 0.5≤v₁≤10 Nm/s,d) separating the solid from vaporous or gaseous substances ande) passing a reducing gas stream over the separated solid at a temperature of 450-700° C.;Process for producing a tungsten oxide powder or a tungsten mixed oxide powder of general formula M_xWO₃, wherein M=Na, K, Rb, Li and/or Cs, 0.1≤x≤0.5, comprising the consecutive steps of:a) providing a solution comprising respectively at least one tungsten compound and optionally at least one M-comprising compound in a concentration corresponding to the stoichiometry M_xWO₃,b) atomizing the solution, thus forming an aerosol, into a reaction space,c) reacting the aerosol in the reaction space with a hydrogen/oxygen flame having a lambda value1, wherein: lambda=total oxygen/0.5×hydrogen,d) separating the solid from vaporous or gaseous substances.