Process for making finely divided solids
AssigneeGeneral Technology Applications, Inc.
InventorsAlbert F. Hadermann, Paul F. Waters, Jerry C. Trippe
Life of this patent
Estimating the term…
Abstract
Solid particles of microscopic size are mixed in a nitrogen atmosphere at conditions of pressure and temperature such that at least a monolayer of nitrogen molecules is adsorbed on the particle surfaces but at conditions at which liquid nitrogen cannot exist in the mixture.
Claims24
A process for mixing unlike microscopic solid particles comprising:
- dispersing said particles in cold nitrogen gas at conditions of temperature and pressure whereat at least a monolayer of nitrogen molecules is adsorbed on the surface of said particles;
- physically admixing said particles for a time sufficient to obtain substantial homogeneity throughout the resulting mixture while maintaining the temperature and pressure such that said adsorbed layer of nitrogen is retained on the particle surfaces but that no liquid nitrogen may exist within the mixture;
- and thereafter
- removing said adsorbed nitrogen layer from the particle surfaces either by raising the temperature or by lowering the pressure, or both.
A process for making a pyrotechnic composition of magnesium and a tetrafluoroethylene fluorocarbon polymer, comprising:
- chilling finely divided particles of said tetrafluoroethylene fluorocarbon polymer to a temperature whereat at least a monolayer of nitrogen molecules can be adsorbed on the surfaces of said polymer particles;
- dispersing said finely divided polymer particles by agitation in cold nitrogen;
- chilling finely divided magnesium particles by direct contact with cold nitrogen;
- mixing the polymer and magnesium particles in a nitrogen atmosphere for a time sufficient to obtain a substantially uniform distribution of the magnesium and polymer particles in the resulting mixture;
- maintaining the temperature and pressure during the mixing step such that at least a monolayer of nitrogen is adsorbed on the surfaces of said polymer and magnesium particles but that no liquid nitrogen is in contact with said polymer and magnesium particles during mixing;
- and
- warming said mixture while maintaining it in a nitrogen atmosphere and forming the mixture into desired shapes by application of heat and pressure.
The process of claim 5, wherein magnesium comprises more than half of said mixture by weight.
In a process for mixing microscopic solid particles of two or more unlike substances together, the improvement comprising:
- conducting said mixing in a nitrogen atmosphere at conditions of temperature and pressure whereat at least a monolayer of nitrogen molecules is adsorbed on the particle surfaces but whereat no liquid nitrogen is present during the mixing.
A process for mixing microscopic solid particles of two or more unlike substances comprising:
- dispersing particles of each of said substances in cold nitrogen at conditions of temperature and pressure whereat at least a monolayer of nitrogen molecules is adsorbed on the surfaces of said particles;
- physically admixing said particles for a time sufficient to obtain substantial homogeneity throughout the resulting mixture while maintaining the temperature and pressure such that said particles retain said adsorbed layer of nitrogen but that no liquid nitrogen is present with said particles during mixing;
- and
- allowing the mixture to warm while maintaining it in a nitrogen atmosphere.
Dependencies are inferred from the claim text.