35+ Years of Expertise in Turnkey Fertilizer Production Solutions

• Conventional route: Powdered single superphosphate (SSP) is granulated using a rotary drum granulator or disc granulator to produce GSSP.
• Direct granulation route: Phosphate mineral powder is directly converted into GSSP through a one-step process. This is an advanced process route and is the focus of the following description.

• Anti-passivation activators: Anti-passivation additives increase the effective contact area between phosphate mineral powder and sulfuric acid, prevent surface encapsulation during the reaction, and accelerate the reaction rate.
• Slurry homogenization: Slurry homogenization improves slurry fineness, eliminates residual encapsulation, and ensures more complete conversion.
• Slurry conditioning: Slurry conditioning prevents excessive viscosity, avoids blockage of spray pipelines, and creates stable operating conditions for spray granulation.

The process mainly consists of the following steps: phosphate mineral powder metering, mixing with sulfuric acid and anti-passivation additives, slurry homogenization, slurry conditioning, spray granulation, drying, cooling, screening, coating, packaging, and off-gas treatment.

Process Advantages

• Elimination of the curing stage
• Reduced capital investment compared with powdered SSP production
• No requirement for SSP curing warehouses
• Lower production cost (approximately CNY100/t)
• Uniform granule size with reduced caking tendency
• Centralized recovery and utilization of fluorine-containing gas
• Significantly improved production environment

Main Equipment

Weighing scale
Belt conveyor
Five-shaft mixing tank
Slurry homogenizer
Granulator
Dryer
Cooler
Screening machine
Coating machine
Packaging machine
Off-gas treatment system

Process Flow Diagram