ANTHRACITE

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 multi-media filters. At 56 lbs./ft. 3 it will hydraulically classify and remain above heavier medial such as Filter Sand or Manganese Greensand providing a prefiltration 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 - 56 lb./c. ft. 3
  
• Effective Size - #1 (0.6-0.8 mm), #1 - 1/2 (0.85-0.95 mm), #2 (1.7-2.0 mm)
  
• Uniformity Coefficient - #1 (1.5), #1 - 1/2 (1.6), #2 (1.5)
  
• Mesh Size - #1 (14 x 30), #1 - 1/2 (10 x 20), #2 (14 x 12)
  
• Sphericity - 0.6
  
• Hardness - 3.0-3.8 (Moh's Scale)
  
• Acid Solubility - <1%
  
• Caustic Solubility 0 <1%
  
• Apparent Specific Gravity - 1.65
  
• Meets American Water Works Association
  
• Standard - B100-89
  

Conditions For Operation:

• Bed Depth - 24 - 36 in.
  
• Backwash Rate - #1 (12-19 gpm/ft.2), #1 -1/2 (18-25 gpm/ft.2), #2 (use air scour)
  
• Backwash Bed Expansion - 30-50% of bed depth
  
• Service Flow Rate - 5 gpm/sq. ft. or higher depending upon local conditions.