Phosphogypsum mainly comes from the production process of wet phosphoric acid and is one of the main wastes of the phosphorus chemical industry. The random discharge and storage of phosphogypsum has seriously damaged the ecological environment, not only polluting groundwater resources, but also causing waste of land resources. China has established a series of laws and policies to regulate the treatment and utilization of phosphogypsum, requiring enterprises to treat and utilize it and not to discharge it at will. These policies have promoted the development and application of comprehensive utilization technology of phosphogypsum. Disposed phosphogypsum can be used in many fields such as agriculture, building materials, environmental governance, ceramics and daily chemicals.
Project advantages
1.Environmental protection: After the treatment of phosphogypsum, the solubility of heavy metals and toxic substances in phosphogypsum can be reduced, reducing environmental pollution.
2. Solid waste resource utilization: After the treatment of phosphogypsum, it can be used as construction or roadbed materials, etc., and has a wide range of application prospects.
3. Economic benefits: The implementation of phosphogypsum treatment technology reduces the cost of raw materials and increases the added value and competitiveness of products.
4. Development opportunities: The support of environmental protection policies provides more development opportunities for enterprises
(1) Feeding & Calcining System
Phosphogypsum is loaded to the box feeder by a forklift, and then conveyed to the steam tube calcining kiln by a belt conveyor, a metering belt, and a shaftless screw. It is calcined with supersaturated water vapor at 240℃. The calcined product goes to the grinding system, and the exhaust gas is discharged into the atmosphere through the exhaust fan chimney after dust removal by a bag dust collector.
(2) Dosing System
The calcined material is sent to the cooling bin and the adjustment bin by a screw conveyor and a bucket elevator. A variable frequency feeding device is installed under the bin. After adjusting the proportion, it is sent to the pre-grinding bin by a screw conveyor and a bucket elevator.
(3) Gypsum Grinding System
A variable frequency unloading device is installed under the pre-grinding bin. The gypsum powder is sent to the gypsum mill by a screw conveyor. The ground material is sent to the finished product bin by a bucket elevator. A discharging screw is installed under the finished product bin. A packaging machine can be installed for packaging and sale, or the powdered material can be directly transported and sold in bulk by a truck.
| Annual Capacity (Ten Thousand Tons) | 5 | 10 | 15 | 20 | 25 | 30 | 40 | 50 |
| Main Equipment | Main equipment models,and technical &economic index | |||||||
| Phosphogypsum Rotary Kiln | Φ2.0×24m | Φ2.4×24m | Φ2.8×26m | Φ3.0×26m | Φ3.2×26m | Φ3.4×28m | Φ3.6×28m | Φ4.0×28m |
| Phosphogypsum Ball Mill | Φ1.2×4.5 | Φ1.5×5.7 | Φ1.83×5.5 | Φ2.1×6.5 | Φ2.2×6.5 | Φ2.4×7 | Φ2.4×8 | Φ2.6×8 |
| Bag Filter | PPC96-6 | PPC96-8 | PPC128-6 | PPC128-9 | PPC96-2X9 | PPC128-2X7 | PPC128-2X9 | PPC128-2X12 |
| Production Raw Material Requirements | calcium sulfate dihydrate content(dry basis):≥90%,adhesion water content ≤15% water-soluble magnesium oxide (dry basis)≤0.5%.PH value 6-8. chloride ion content(dry basis)≤500mg/kg | |||||||
| Calcination Temperature/℃ | 150 | |||||||
| Steam Consumption Index(kg/t gypsum powder) | 500±50 | |||||||
| Power Consumption Index(kW.h/t gypsum powder) | 25±5 | |||||||
| Phosphogypsum:Gypsum Powder | 1.4:1 | |||||||
| Solidification Time | Initial solidification≥8min,termination of solidification≤30min | |||||||
| Fineness | ≤5% | |||||||
| Strength (Mpa) | 2 hours flexural strength≥3.0MPa;compressive strength≥6.5MPa; | |||||||
| Three-phase Control | Dihydrate gypsum is less than 3%,hemihydrate gypsum is greater than 84%, and soluble anhydrous gypsum is less than 3%; | |||||||
| Emission Concentration/(mg/m³) | ≤30 | |||||||
| Annual Working Day/days | ≥300 | |||||||
| Overhaul Cycle/Year | 3 | |||||||
| Applicable Fuel | Steam,natural gas,pulverized coal | |||||||
