Method and Apparatus for Production of Powders

Apparatus and method are disclosed for producing oxides of metals and of metal alloys. The metal or alloy is placed in an oxygen atmosphere in a combustion chamber and ignited. Products of the combustion include one or more oxides of the metal or alloy in powdered form. In one embodiment of the invention a feeder is provided whereby material to be oxidized by combustion can be advanced into a combustion chamber continuously. A product remover receives the powder product of the combustion

Method for Production of Powders

Apparatus and method are disclosed for producing oxides of metals and of metal alloys. The metal or alloy is placed in an oxygen atmosphere in a combustion chamber and ignited. Products of the combustion include one or more oxides of the metal or alloy in powdered form. In one embodiment of the invention a feeder is provided whereby material to be oxidized by combustion can be achieved into a combustion chamber continuously. A product remover receives the powder product of the combustion

Method and apparatus for production of powders

Apparatus and method are disclosed for producing oxides of metals and of metal alloys. The metal or alloy is placed in an oxygen atmosphere in a combustion chamber and ignited. Products of the combustion include one or more oxides of the metal or alloy in powdered form. In one embodiment of the invention a feeder is provided whereby material to be oxidized by combustion can be advanced into a combustion chamber continuously. A product remover receives the powder product of the combustion

Multiphase oxidation of metals

The burning of metals in enriched oxygen atmospheres includes multiple phases and, therefore, satisfies the definition of being a heterogeneous system. For a reaction to be considered heterogeneous, however, the site of the chemical transformation must be at an interface. While the Wagner theory of metal oxidation gives satisfactory mechanisms for this type of reaction for solid metals, no comparable theory is available for metal oxidation when the temperature is above the melting point of the metal. Similitude theory is applied to metal combustion under conditions of the NASA/ASTM flammability test system in order to identify rate-controlling regimes and conditions of heterogeneous reaction. Above 4 MPa, the observed burn rate for iron is proportional to the sample dimension, L, as L-0.7. Analysis shows that the heat transfer rate between the reaction surface and the solid rod is proportional to L-0.5 and may, therefore, be the rate-determining process for the system.</p