Single Superphosphate — SSP
Single Superphosphate Plant Acidulation, Curing & Off-Gas Scrubbing Support
Digesting the Chemistry & Industry Role
Single Superphosphate (SSP) is the oldest and simplest phosphate fertilizer. It is produced by reacting ground phosphate rock with sulfuric acid. SSP provides phosphorus, sulfur, and calcium — making it valuable for sulfur-deficient soils.
Despite being a mature technology, SSP remains economically competitive in many markets due to low capital cost, simple process, and the ability to use lower-grade phosphate rock compared to DAP/MAP production.
Successful SSP plant operation depends on managing rock-to-acid reaction ratios, optimizing pile curing dynamics to reduce free acidity, and ensuring high-efficiency off-gas scrubbing for fluorine containment.
The Production & Conversion Sequence
Acidulation Mixing
Finely ground phosphate rock and 65-75% sulfuric acid are metered and intensely mixed in a continuous paddle mixer.
Slurry Digestion Den
The liquid slurry is discharged onto a slow conveyor den where it reacts and solidifies into a solid block over 15-30 minutes.
SSP Excavation
A rotary cutter at the end of the den cuts the solid block into fine powder, which is conveyed to the curing shed.
Shed Curing
The green SSP is stored in large piles for 2–4 weeks to complete the rock digestion and allow excess moisture to evaporate.
Optional Granulation
Cured powder SSP is crushed, granulated in a rotary drum with steam and binder, dried, and screened for bagging.
Key Equipment & Machinery Assets
Continuous Den Mixer
High-shear double-shaft mixer designed for rapid, uniform contact between rock dust and sulfuric acid.
Continuous Solidification Den
Slow-moving conveyor slat den allowing the react slurry to solidify and gaseous fluorine to vent.
Fluorine Scrubbing Towers
Multi-stage gas cleaning system designed to capture hydrofluoric acid and silicon tetrafluoride.
Curing Shed Cranes
High-capacity overhead crane and scraper systems managing heap turning for complete curing.
SSP Granulator
Rotary drum or pan granulator adding water/steam to form hard, transportable superphosphate granules.
Commissioning Challenges & Startup Risks
Hurdle 01
Acidulation ratio (acid to rock) must be precisely controlled — too much acid creates a wet, sticky product; too little leaves unreacted rock.
Hurdle 02
Curing time and conditions affect final product quality — incomplete curing leads to high free acid content.
Hurdle 03
Granulation of SSP requires careful control of moisture and temperature to achieve target granule hardness and size.
Operated. Started. Optimized.
Kafaah's team has operational experience with SSP production, including acidulation optimization, curing management, and granulation performance improvement.
We troubleshoot chemical formulation imbalances, design dust mitigation and scrubbing systems, and help facilities upgrade powder operations to granular production.
Related Advisory & Engineering Services
Technical Troubleshooting
Production loss, quality deviation, equipment failure. We have seen most problems before — and resolved them. Rapid diagnosis using chemical-specific methodology.
Production Optimization
Process audit, energy balance review, yield improvement, unit cost reduction. We measure before and after — results are not estimated, they are documented.
Operator Training
Plant-specific training programs in Arabic and English. Developed by engineers who have operated these plants — not generic training consultants.
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