• Industrial filter cloth | Horizontal vacuum belt filter, harmless treatment of phosphogypsum
  Filter machine type: Horizontal vacuum belt filter
  Application Industry: Harmless Treatment of Phosphogypsum
  Handling material description: Phosphogypsum mixed with lime, with a pH value around 9.0.
  Filter cloth model: 15P

The pace of phosphochemicals expansion far outstrips the industry's ability to keep up with the evolving capacity for byproduct management. For every unit produced, 1  Tonnes of phosphoric acid, often occurring as a byproduct 4.5–5.5 Tonnes of phosphogypsum are particularly prominent in wet-process phosphoric acid systems. Large-scale stockpiling of phosphogypsum not only encroaches on land but also poses significant environmental risks, including fluorine, heavy metals, and acidic leachate. Therefore, “ Harmless and resourceful ” Becoming a core issue driving policy and industry transformation.

Among the many technological pathways, Horizontal Vacuum Belt Filter Machine Horizontal Vacuum Belt Filter ， HVBF ） +  Xadia Citius High-Performance Industrial Filter Cloth , considered one of the most stable, economical, and versatile solutions for the dehydration, washing, and solid-liquid separation processes in phosphogypsum treatment. It not only affects the moisture content of the filter cake but also plays a critical role in pollutant retention efficiency, filtrate water quality, equipment lifespan, and the cost of subsequent resource recovery and utilization.

This article comprehensively analyzes the critical role of industrial filter cloths in the harmless treatment of phosphogypsum, covering everything from process logic and equipment features to filter cloth selection strategies.

01  Why is it said “ Filtering Stage ” Is it the key to the success or failure of phosphogypsum treatment?

Phosphogypsum has a complex composition and typically includes:

• Free acid ( H ₂ SO ₄ ) And soluble phosphorus
• F ⁻ 、 As 、 Cd 、 Cr Heavy metal ions, etc.
• Fine particles with uneven particle size distribution
• Highly adhesive, poor filterability

These characteristics collectively constitute the industry's pain points:

( 1 ) High filtration difficulty: Fine particles, prone to clogging the filter cloth

Granularity D50 Only 10–30 μm , some are even finer; if the filter cloth pore size and weave structure are chosen improperly, it can easily lead to the formation of “ Pasted Cloth ”— Flux drops sharply, and filter cloths frequently become unusable.

( 2 ) Moisture content difficult to reduce

Reutilization pathways such as stockpiling, calcination, and blending with building materials generally require specific moisture content levels. ≤ 10–15% . Filtration efficiency directly affects the threshold for resource utilization.

( 3 ) Washing efficiency affects the degree of harmlessness.

The synergistic interaction between the wash water and the filter cloth determines the impurity removal rate, but if the filter cloth is unevenly distributed or lacks sufficient hydrophilicity, it will lead to increased washing volume and higher costs.

( 4 ) The quality of the filtrate determines the environmental protection costs.

If soluble phosphorus, fluorine, and impurities cannot be effectively removed, the subsequent wastewater treatment costs will significantly increase.

Therefore, industrial filter cloth is not just a material—it is, in fact, “ The core components of equipment performance ”。

02  Horizontal vacuum belt filter: One of the most suitable solid-liquid separation equipment for phosphogypsum systems

HVBF It is widely used in the phosphogypsum project because it meets “ Continuous, high-capacity, and enhanced washing ” The characteristics.

( 1 ) Continuous operation, suitable for large-scale phosphate chemical production lines

• High hourly processing capacity, reaching up to tens of tons. —— Hundreds of tons of wet materials.
• The filter cake continuously moves across the surface of the filter belt, ensuring stable production capacity.

( 2 ) Negative-pressure filtration ensures rapid cake formation.

• Negative-pressure filtration enables the slurry to quickly form a filter cake, making it suitable for fine-particle systems like phosphogypsum.

( 3 ）Multi-stage countercurrent washing enhances the level of harmlessness

• Configurable 2–5 Class A Spray System
• High utilization rate of wash water
• Soluble phosphorus, fluorine, soluble salts, and more are significantly reduced.

(4) The filter cloth determines the filter machine. 60% Performance

Includes:

• Filter cake forming speed
• Moisture Content
• Washing uniformity
• Filtrate Transparency
• Machine Stability
• Maintenance costs

And this is precisely where industrial filter cloth proves its value.

03  Phosphogypsum-specific industrial filter cloth: Technical requirements are higher than you might think.

Phosphogypsum filtration isn't a matter of just choosing one option. “ A certain type of fabric ” , but rather to Fiber structure, air permeability, filtration efficiency, surface treatment, operational lifespan Wait to present comprehensive requirements.

The following analyzes the core performance indicators that filter cloths must possess, from a professional perspective:

( 1 ) Strong anti-clogging performance —— Reduce paste buildup, increase throughput

Phosphogypsum contains many fine particles with strong adhesion; if the filter cloth has uneven pore size distribution or a rough surface, it can become clogged within hours.

Therefore, the filter cloth must possess:

• Precise control of aperture (multi-layer structure or monofilament available) / Composite structure)
• Optimized surface flatness (reducing slurry embedding)
• It has excellent release properties, allowing for quick material discharge and preventing secondary blockages.

( 2 ) High retention rate, with filtrate clarity meeting standards

Effectively reduce:

• Suspended solids ( SS ）
• Phosphorus, Fluorides
• Impurity particles

Ensure the filtrate has a lower load before entering the wastewater treatment plant.

(3) High washing efficiency

An excellent filter cloth must be able to:

• Promote even distribution of the cleaning solution
• Controlling the direction of moisture migration within the filter cake
• Improve countercurrent washing efficiency and reduce wash water consumption.

( 4 ) Acid-resistant, wear-resistant, and hydrolysis-resistant

Phosphogypsum systems commonly contain:

• pH 2–4 The acidic liquid
• Fluoride ions F ⁻
• High-solids particle friction

The filter cloth must operate stably in this environment for extended periods, without losing strength or becoming brittle.

( 5 ) Low deviation, high bonding strength, long lifespan

In a continuously operating horizontal vacuum belt filter:

• Misalignment of the filter cloth can reduce washing efficiency and compromise equipment stability.
• The strength at the seams must be higher than that of the fabric itself.
• Lifespan directly affects operational costs (typically ranging from several months to half a year).

04  How to Choose the Right Filter Cloth for Phosphogypsum? (Key Parameters and Selection Strategies)

Here is a filter cloth selection framework tailored for the phosphogypsum industry, intended as a reference for system engineers and process engineers:

1.  Mesh Size and Retention Level

• Recommended air permeability range: 100–250 L/dm²·min (Calibrated according to equipment conditions)
• Filtration accuracy: 1–50 μm   Customized based on material particle size within the range.

2.  Structural Form

• Monofilament filter cloth : High flatness, quick cake release, and excellent wear resistance
• Multilayer Composite Filter Cloth : Enhance retention rate and cake-forming speed
• Enhanced Braided Structure : Extend lifespan, reduce deviation

3.  Surface Treatment

Available depending on operating conditions:

• Thermal Setting Stabilization
• Surface smoothing treatment (reducing particle ingress)
• Acid-resistant resin coating (extends service life)

05 Xadias CITIUS The Practical Value of Industrial Filter Cloth in the Harmless Treatment of Phosphogypsum

Drawing on comprehensive industry experience, adopting Xadia Citius High-performance filter cloth +  Stable Horizontal Vacuum Belt Filter Afterwards, it can achieve:

These indicators are “ Harmless treatment ” With “ Resource-based utilization ” The foundation of success.

06  The trend in phosphogypsum treatment: A dual upgrade of equipment stability and filter cloth performance

The future trend of phosphogypsum is heading in the following direction:

• Low-moisture filtration technology becomes the new standard
• The filter cloth from “ Materials ” To “ System-level components ” , needs to be designed to match the equipment
• Continuous and stable operation becomes the key focus in evaluating environmental protection projects.
• Demand for resource-based utilization (building materials, road materials, and gypsum alternatives) is expanding.

In this evolution, Xadia Citius The importance of filter cloth is being reevaluated—it has transitioned from a consumable item to something that determines “ Production capacity, metrics, costs ” The core technology.

Conclusion: Filtration determines the quality of harmlessness, while filter cloth sets the upper limit of the filtration machine.

Phosphogypsum management is a critical juncture for the sustainable development of the phosphate chemical industry today, and in this core process of solid-liquid separation:

• Equipment determines the upper limit of capability.
• The filter cloth determines the performance lower limit and operating costs.

Xadia Citius Industrial filter cloth on horizontal vacuum belt filters has become more than just a passive element. “ Filter medium ” Instead, it is the core technological component of the entire system.

In the harmless future of phosphogypsum ——
Xadia Citius Innovation in filter cloths, optimization of manufacturing processes, and stability of equipment will collectively determine the speed and quality of resource utilization in the industry.