2025 Nelsen Corporation Catalog - Catalog - Page 117
#1-1/2 Anthracite 4
Although its potential for water treatment has been recognized
since ancient times, anthracite coal was not used for that purpose
until the beginning of this century. Crushed anthracite makes an
excellent medium density filtration media. Anthracite has been
manufactured from the finest Pennsylvania coal since 1932. It is
specifically selected for water treatment, and during its production
goes through several sizing inspections. Random samples are
chosen for a complete laboratory quality control analysis for
effective size, uniformity coefficient, specific gravity acid solubility
and hardness.
Because of its fractured shape, some sediment penetrates deeper
into the bed. When compared to equivalent filter sands, this
means longer filter runs and less head loss. Backwash rates are
also reduced.
Anthracite, because of its unique density, can be used in multimedia filters. At 56 lbs./ft.³ it will hydraulically classify and remain
above heavier medial such as Filter Sand or Manganese Greensand
providing a pre-filtration layer.
Advantages:
• Higher service flows and longer filter runs than
equivalent sand filters.
• Close attention to gradation, hardness and purity assures consistent
and reliable performance.
• Unique density allows Anthracite to be combined
with other filtration media in multi-media filters.
Physical Properties:
Color .............................................................................................. Black
Density .................................................................................. 50 lbs./ft.3
Effective Size #1-1/2 ......................................................(0.85-0.95 mm)
Uniformity Coefficient #1-1/2 ............................................................(1.6)
Mesh Size - #1-1/2 .................................................................... (10 x 20)
Sphericity...........................................................................................0.6
Hardness ..............................................................3.0-3.8 (Moh’s Scale)
Acid Solubility ...................................................................................
