1. Introduction of coal gangue
Coal gangue is a solid waste by-product generated during coal mining and washing. Its main components include silicon dioxide (SiO₂), aluminum oxide (Al₂O₃) and iron oxide (Fe₂O₃). Coal gangue has characteristics of low calorific value (usually < 12 MJ/kg), high sulfur content, and easy spontaneous combustion. Long-term storage of coal gangue not only occupies land but also contaminates soil, groundwater, and air. Realizing high-value utilization through powder processing technology has become a key direction for the comprehensive utilization of coal gangue.
2. Advantages of Air classifier in classifying coal gangue
Qingdao Epic Powder Machinery Co., Ltd. has been engaged in the production of powder processing equipment for many years. The air classifier produced by our company has significant advantages in the classification of coal gangue. Combining its technical characteristics with the requirements of coal gangue processing, the specific advantages are as follows:
· High-precision particle size control
Utilize high-speed rotating classification turbine to achieve accurate separation of coarse and fine particles, and the particle size of product can be adjusted in the range of D97:3-45 microns.
· Low energy consumption and efficient processing
Using the principles of air suspension and centrifugal force to reduce mechanical wear and energy consumption. Take an example, our coal gangue customer adopted our ITC air classifier, the energy consumption of gangue classification was reduced by 30%, and the processing capacity was increased to 2,700 tons/hour.
· Closed design, less pollution
Closed design with low dust emission and no chemical pollution during operation. It is suitable for processing materials containing sulfur and heavy metals, e.g: coal gangue, to avoid secondary pollution.
· Multi-size classification
Achieve multi-size classification through multi-stage series or modular design. This can classify coal gangue into different sizes for the production of high value-added products.
| Grading indicators | Grading interval | Typical Uses |
| Fineness | >50mm | Underground backfill / roadbed filling |
| 10-50mm | Concrete aggregate / ceramic granule | |
| <10mm | Permeable bricks / soil conditioners | |
| Calorific value | >10 MJ/kg | Fluidized bed power generation / gasification hydrogen production |
| 5-10 MJ/kg | Fired bricks / cement mixture | |
| Aluminum Silicon Ratio（A/S） | >2 | Mullite fiber / water purifier |
3. Conclusion
Air classifier can not only classify coal gangue into multiple particle sizes, but also achieve fine-grained control of particle size through technical optimization, providing key support for high-value utilization. In a word, air classifier is very important for resource utilization of coal gangue.
As a manufacturer of powder processing equipment with rich experience and technical accumulation, Epic Powder’s products include grinding equipment, grading equipment, modification equipment and related auxiliary equipment. Among them, air classifier includes 5 types: HTS, ITC, CTC, MBS and TDC. We can provide customers with a one-stop solution from equipment selection, scheme design to installation and commissioning, and after-sales service.
If you need grading equipment to grade gangue or other materials, or need other powder processing equipment, please contact our staff directly, and we will provide you with professional services.
Looking forward to contributing to the growth of your enterprise.
