Granted Patent B2

US 6,843,282 · App. 10/802,244 · Granted Jan 18, 2005

Abstract

Claims (12)

1. 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.

2. The process of claim 1 wherein said powder is titanium dioxide pigment, and said liquid medium is water.

3. 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.

Assignments (12)