Clack Anthracite is a select coal, mined and processed for use inwater filtration. It is ideal for single bed, dual bed or multi-mediafiltration systems.
Although its potential for water treatmenthas been recognized since ancienttimes, anthracite coal was not used forthis purpose until the beginning of the20th century. Crushed Anthracite makesan excellent medium density filtrationmedia. Clack Anthracite is mined from thefinest Pennsylvania coal. It is specificallyselected for water treatment, and duringits production goes through several sizinginspections. Representative samplesare randomly chosen for a completelaboratory quality control analysis foreffective size, uniformity coefficient,specific gravity, acid solubility andhardness.Because of its angular shape, some of thesediment penetrates deeper into the bed.When compared to equivalent filter sands,this means longer filter runs and less headloss. Backwash rates are also reduced.Because of its unique density, ClackAnthracite can be used in multi-mediafilters. At 50 lbs/ft , it will hydraulicallyclassify and remain above heaviermedia such as Filter Sand or ManganeseGreensand, providing a prefiltration layer.
Higher service flows and longer filterruns than equivalent sand filters
Close attention to gradation, hardnessand purity assures consistent andreliable performance
Unique density allows ClackAnthracite to be combined withother filtration media in multi-mediafilters
Lower uniformity coefficient has lessoversized and undersized particlesresulting in a highly uniform bed
Bulk Density: 50 lbs./cu. ft.
Hardness: 3.0-3.8 (Mohs scale)
#1 Anthracite: 0.6-0.8 mm
#1 Anthracite: 0.85-0.95 mm
#2 Anthracite: 1.7-2.0 mm
#1 Anthracite: <1.7
#1 Anthracite: <1.7
#2 Anthracite: <1.6
#1 Anthracite: 14x30
#1 Anthracite: 10x20
#2 Anthracite: 4x12
Acid Solubility: <1%
Caustic Solubility: <1%
Apparent Specific Gravity: 1.6 gm/cc
Meets AWWA Standard B100-96
CONDITIONS FOR OPERATION
Bed depth: 24-36 in., 10-18 in multibedfilters
Freeboard: 50% of bed depth (min.)
Service flow rate: 5 gpm/sq. ft.or higher depending upon localconditions
Backwash flow rate:
#1 Anthracite: 12-18 gpm/sq. ft.
#1 Anthracite: 18-25 gpm/sq. ft.
#2 Anthracite: use air scour
Backwash bed expansion: 20-40% ofbed depth