Large pores and high turbidity capture capacity
In single-layer filtration using only filter sand, fine sand particles stratify in the upper layer. This results in turbidity
capture occurring primarily near the surface layer, known as surface filtration, leading to limited turbidity removal.
Due to its low bulk density, coarse-grain anthracite naturally segregates into the top bed layer above fine filter sand, enabling high-efficiency multi-layer (dual-media) filtration. This dual-bed architecture significantly enhances suspended solids and turbidity retention, leading water treatment engineers to deploy anthracite extensively in municipal filtration plants nationwide.
Furthermore, anthracite’s angular shape creates large voids and a high specific surface area. This allows for effective utilization of the entire filter bed in [deep bed filtration]. It is also used in [anthracite deep bed filtration], where a single layer forms a thick filter bed.
Higher Water Recovery & Space Savings: Extended filtration cycles reduce backwash wastewater, while faster filtration rates shrink the equipment footprint.
Clogging & Mud Ball Prevention: Anthracite resists blockage from diatoms (Synedra) or cyanobacteria (Microcystin) and prevents mud ball formation on underlying sand layers.
Superior Microfloc Growth & Water Quality: Angular, porous particles naturally agitate incoming water—even without prior mixing—promoting robust microflocs to deliver cleaner output.
Low-Cost Retrofits: Replacing a portion of sand with anthracite upgrades single-layer filters to dual-layer systems without requiring new cleaning equipment or procedures.
Exceptional Chemical Resistance: High carbon purity keeps anthracite insoluble in both acidic and alkaline solutions, making it ideal for harsh industrial environments like soda ash plants.
High-Efficiency Biofilm Carrier: Its high porosity and large surface area foster rapid biofilm development, allowing the media to double as an effective biological carrier.

Anthracite Quality Specifications

Anthracite Standard Product

We can also manufacture products with the specified effective size and uniformity coefficient upon request.
Please be aware that the effective size includes an error margin.

30 L PE bag, 1,000 L flexible container bag
*Pallet loading available upon request.
When placing your order, please specify the [Effective Size] _and [Uniformity Coefficient].

We have been certified as the first factory in Japan for all filter materials (filter sand, anthracite, manganese sand, filter gravel) listed in ‘JWWA A103:2006-2 Water Supply Filter Materials.’ We contribute to safe, robust, and sustainable water supply operations.
Certified products ensure compliance with Ministry of Health Ordinances and JWWA standards, providing peace of mind!
Reduces the effort of individual quality checks by business entities!
If the pipes and others are certified products, make the heart of water purification, the filter material, certified products too!

About Vietnam Hong Gai Coal

Anthracite is the highest-rank coal in the coal classification system, also known as smokeless coal. Globally, coalfields are distributed in countries such as the United States, China, Vietnam, Russia, and South Africa. While Japan once mined anthracite in regions like Amakusa, it now relies entirely on imports from abroad. Among these, Vietnam’s Hong Gai Coal is recognized worldwide for its high rank and superior quali-ty.
Our company operates a factory in Vietnam and also produces high-quality anthracite domestically using Hong Gai Coal as raw material. We ensure it is safe for use in water systems.
Main Properties of Hong Gai Anthracite