摘要 |
Synthetic, granular filter particles which are of substantially uniform size, of controlled density, and water-wettable. A method is provided for manufacturing such particles in uniform sizes ranging from about 1/16 to about 3/8 inch and at controlled densities ranging from a specific gravity of about 1.04 to about 1.5. The particles comprise hollow silica beads dispersed in a matrix of cured cement. In deep bed, multi-layer liquid filters, the particles can be utilized as the upper strata of the filter and act as a barrier for particles that would normally plug a deep bed filter having conventional, natural materials, such as sand in the lower strata. Alternatively, all of the strata of the deep bed filter may be comprised of the particles of the present invention in substantially uniform, controlled sizes and densities, the size of the particles decreasing and the density of the particles increasing in the direction of flow through the filter bed.
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