My guess is that you need to be in turbulent flow regime at the very least, not laminar so work out your Re number and make sure its above I think 4000.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

URANIUM CAKE SLURRY (water, not dust)
Description
MATERIAL:
10-15% by weight Uranium Trioxide (yellow cake). 8% Ammonium Sulfate in water solution. Specific gravity of slurry is 1.8.

Slurry grind suspension from 30% plus 20 mesh to 100% minus 20 mesh.

Grinds to 100% minus 20 mesh. Need extra horsepower because of high specific gravity.

AB MIXER:

Model 6 x 3, toothed impeller/liner, 20 HP, 1800 RPM, 1/8" grid. Dicon recirculates slurry at 25 gpm to 250 gallon tank.

BENEFITs Grinds to 100% minus 20 mesh. Need extra horsepower because of high specific gravity.


--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

Nicolai,

Pneumatic conveying can be a mixture of science and art. I've seen 2,000-9,000 fpm as a minimum velocity recommended to keep materials in suspensions. This value is very dependent on the density of the particles as well as the particle sizes being conveyed. You should account for the entire distribution, not just the [D4,3] average.

Perhaps you should quantify your material (density, particle size distribution) and see if there is any published literature on similar materials if you cannon find your exact one.