Filtration grade anthracite for use in dual and multi-media filters.
Water containing moderate to high levels of suspended solids will quickly blind a sand filter. Adding a layer of appropriately sized filtration anthracite on top of the sand traps the larger solid particles leaving the sand to deal with the finer solids without being blinded. After backwashing to remove the retained solids the lower density anthracite reforms a discrete layer above the sand.
Dual media filtration with anthracite and sand is particularly suited to the treatment of surface waters which employ a coagulation step. The angularity of the anthracite particles provides a high voidage bed with high solids holding capacity to remove any carried over floc prior to sand filtration. Dual media sand/anthracite filters can increase service times between backwashes by more than twenty times that of a single media sand filter treating the same water.
Anthracite filter media may also be used in applications where silica pick-up is to be avoided such as boiler waters.
CAS Filtration Anthracite is certified to NSF ANSI 61.
CAS Filtration Anthracite is produced to comply with BS EN 12909 “Products used for treatment of water intended for human consumption – Anthracite”
Sizes Available: Anthracite is produced in the following size ranges:
| No. 1 | 0.60 – 1.18mm | No. 1S | 0.80 – 1.6mm |
| No. 2 | 1.18 – 2.50mm | No. 2S | 1.40 – 2.50mm |
| No. 3 | 2.5 -4.0mm | ||
| No. 4 | 5.0 – 10.0mm |
Other grades available on request
Backwash curve for Grade 2 anthracite
