| 摘要 |
A blended, stable ball clay/water slurry, wherein: 1. the slurry comprises from about 58 to about 68 weight percent of ball clay, from about 42 to about 32 weight percent of water, from about 50 to about 650 parts per million (by dry weight of ball clay) of soluble sulfate ion, and from about 0.01 to about 1.0 percent of organic polyelectrolyte (weight of active ingredient by weight of dry ball clay) with a molecular weight of from about 1400 to about 6000; 2. the slurry, when freshly made has a five-minute gel viscosity of from about 1,000 to about 10,000 centipose, a ten-minute gel viscosity of from about 2,200 to about 12,000 centipoise, and a twenty-minute gel viscosity of from about 3,500 to about 14,000 centipoise; 3. the twenty-minute gell viscosity of a three-day old sample of the slurry is no more than 50 percent greater than the twenty-minute gel viscosity of the freshly made slurry and is from about 3,500 to about 14,000 centipose; 4. the difference between the twenty-minute gel viscosity of the slurry and its ten-minute gel viscosity is less than about 3,000 centipoise; 5. the difference between the twenty-minute gel viscosity of the sluffy and its five-minute gel viscosity is less than about 4.000 centipoise; 6. the slurry has an initial Brookfield viscosity at 100 r.p.m. of from about 100 to about 600 centipoise; 7. from about 30 to about 45 weight percent of the particles in the ball clay are smaller than 0.5 microns, from about 53 to about 69 percent of the ball clay particles are smaller than 2 microns, and from about 70 to about 85 percent of the ball clay particles are smaller than 5 microns; 8. the ball clay has a specific surface area of from about 16 to about 21 square meters per gram; 9. the slurry has a settling index of at least about 0.9, a flow index of from about 20 to about 30 seconds, a casting rate of from about 30 to about 60 grams, its filtrate has an optical transmission of at least about 60 percent, and dry samples made from the slurry have a mdoulus of rupture of from about 550 to about 700 pounds per square inch; and 10. the ball clay contains from about 50 to about 65 weight percent of silica and from about 20 to about 35 weight percent of alumina, and the silics/alumina weight ratio in the ball clay is from about 2.0 to about 3.0. 71 |
