Patent ID: 7387752
Filing Date: 2008-06-17
Classification: B01D,B28B,C04B,F26B,Y10T

Abstract:
1. A method for producing solid sintered ceramic particles that are substantially round and spherical comprising: preparing a slurry having a solids content of about 50 to about 75% by weight, and comprising water, a ceramic starting material and a dispersant, which ceramic starting material has an alumina content of greater than about 40 weight percent, and which dispersant is added to the slurry in an amount of 0.075 weight percent to 1.0 weight percent by weight of the dry ceramic starting material and is selected from the group consisting of colloids, polyclectrolytes, tetra sodium pyrophosphate, tetra potassium pyrophosphate, polyphosphate, ammonium citrate, ferric ammonium citrate and sodium hexametaphosphate and; feeding the slurry to an atomizer operably connected to a dryer; operating the atomizer to atomize the slurry into droplets; operating the dryer to provide an air inlet temperature in a range of from about 100° C. to about 500° C.; forming solid substantially round and spherical particles by allowing the droplets to pass through the dryer and exit through a discharge of the dryer; sintering at least a portion of the particles discharged from the dryer at a temperature of from about 1000° C. to about 1600° C. for a time at peak temperature of from about 20 to about 45 minutes, wherein sintered, solid, substantially round and spherical particles are formed having an average particle size of greater than about 200 microns, an average bulk density of greater than about 1.40 g/cc, and an average apparent specific gravity of greater than about 2.60.