| 摘要 |
<p>In the process for beneficiating a crude kaolin by the method which includes a wet classification step to provide a classified kaolin fraction having a PSD such that at least 50 % by weight thereof are of less than 1/2νm ESD and substantially 100 % by weight are of less than 10νm ESD; and one or more steps wherein an aqueous slurry of the classified kaolin is at least partially dewatered by filtration; the improvement which comprises effecting at least one of said one or more filtration steps, by flowing said aqueous kaolin slurry through a ceramic filter which is characterized by a porous support layer and an overlying porous filtration layer, the ratio between the respective mean pore sizes of the filtration layer material and the base layer material being between about 2 and 50; the pore size in said filtration layer being in the range of from about 1 to 3 νm, and the pore size in the base layer being in the range of from about 4 to 50νm; and said flow through said filter plate being from said filter toward said base layer, and being effected by establishing a fluid pressure differential across the said filter plate.</p> |
