Densification of aerated powders using positive pressure
AssigneeKerr-McGee Chemical Corporation
InventorsJames William Bates, Thomas Ian Brownbridge
Life of this patent
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Abstract
A process for increasing the bulk density of an aerated powder is provided. The powder is placed in a container. The container is then closed and the gas pressure within the container is increased to a level above atmospheric pressure and at a rate sufficient to cause the powder to compact before a substantial portion of said pressurization gas diffuses into said powder. In one embodiment, the process is utilized to increase the bulk density of an aerated, free-flowing titanium dioxide pigment. Apparatus for carrying out the process is also provided.
Claims3
A process for preparing a slurry, comprising:
- processing a powder, in a fluid energy mill;
- prior to allowing said powder to fully settle, increasing the bulk density of said powder by deaerating said powder by placing said powder in a container;
- and injecting a pressurization gas into the area of said container containing said powder such that the gas pressure in the area of said container is increased to a level above atmospheric pressure at a rate sufficient to cause said powder to compact before a substantial portion of said pressurization gas diffuses into said powder;
- removing said compacted powder from said container, and
- dispersing said densified powder into a liquid medium.
A process for preparing a concentrated titanium dioxide pigment slurry, comprising:
- milling a titanium dioxide pigment;
- prior to allowing said titanium dioxide pigment to fully settle, increasing the bulk density of said pigment by:
- placing said pigment in a container;
- and
- injecting a pressurization gas into the area of said container containing said pigment such that the gas pressure is increased to a level above atmospheric pressure at a rate sufficient to cause said pigment to compact before a substantial portion of said pressurization gas diffuses into said pigment;
- and
- removing said compacted titanium dioxide pigment from said container;
- and dispersing said deaerated pigment in a liquid medium.
Dependencies are inferred from the claim text.