ANTHRAZORB™

A dual-media filter bed is only as good as the anthracite sitting on top of it. If the media is soft, it generates fines during backwash and those fines migrate into the sand layer and eventually into the treated water. If the particle size distribution is wide, the bed does not stratify correctly after backwash and stratification is exactly what gives dual-media filters their performance advantage over single-medium sand beds.

ANTHRAZORB™ is our purpose-built filter-grade anthracite sourced from deposits with fixed carbon between 85% and 92%, processed through selection, crushing, washing, and precision screening to the effective size gradations that multi-media water treatment systems require.

The mechanism that makes dual-media filters outperform single-medium sand beds is density stratification. After every backwash cycle, the lower-density anthracite layer (750–900 kg/m³) settles above the higher-density sand layer (~2,600 kg/m³) restoring the coarse-to-fine bed structure that drives efficient suspended solids capture. If the anthracite generates excessive fines, or if its particle size distribution is wide enough to intermix with the sand layer, stratification breaks down and filtration performance degrades. ANTHRAZORB™ is processed specifically to prevent both failure modes.

Angular grain structure maximises void space and filtration surface area. High hardness keeps fines generation minimal through repeated backwash cycles. Chemical inertness across the full pH range means it does not degrade in aggressive influent chemistry. EN-12909 compliant. In well-maintained filter systems, ANTHRAZORB™ delivers a 10–15 year service life.