Project Background: A large mining company in Paraguay faced several challenges in its limestone processing operations, including low efficiency of traditional screening equipment, severe dust pollution, and difficulty in precisely controlling the loss of fine particles. To meet the stringent requirements of downstream construction and industrial applications for specific particle sizes (0.1 mm–2 mm), the customer sought a solution with high output, a high level of automation, and superior limestone air classification accuracy.
Key Challenges:
- Wide particle size range: Precise classification was required within a broad range from 0.1 mm to 2 mm.
- Extremely high capacity demand: A single production line needed to achieve a throughput of 30–40 t/h.
- Wear resistance: Limestone causes a certain degree of abrasion, requiring long-term stable operation and high equipment durability.
Solution: Epic Powder CTC Air Classification System
To address these requirements, Epic Powder supplied its CTC Series Air Classifier (also known as a coarse powder classifier). This system is specifically designed for powder classification in the range of 100 μm (0.1 mm) to 2 mm, effectively bridging the gap between conventional air classifiers (mainly for fine powders) and traditional vibrating screens (with low efficiency).
Key Equipment Features
- Classification principle: After entering the classification chamber, particles are dynamically separated based on the balance between airflow drag, centrifugal force, and gravity.
- High-capacity design: By optimizing the internal rotor structure and airflow distribution, the CTC system can easily handle feed rates exceeding 40 t/h.
- Ceramic wear-resistant technology: For limestone applications, wear-prone internal components can be lined with wear-resistant materials or ceramic liners, significantly extending service life.
Production Process Overview:
- Feeding stage: Raw limestone is conveyed by a bucket elevator and fed into the top inlet of the CTC classifier.
- Air classification: A frequency-controlled classifier wheel rotates at high speed, generating a stable internal flow field.
- Product discharge:
- Qualified product (0.1 mm–2 mm): By precisely adjusting the classifier wheel speed and fan airflow, particles within the target size range are discharged through the product outlet.
- Ultrafine powder separation: Fine particles smaller than 0.1 mm are carried by the airflow into the dust collection system (e.g., a pulse bag filter), preventing pollution and allowing collection as a by-product.
- Circulation system: Coarse particles (>2 mm) are returned to the crushing stage for reprocessing.
Project Results:
After commissioning, the limestone air classification production line in Paraguay exceeded customer expectations, with the following on-site performance data:
| Key Parameter | On-Site Measured Data |
|---|---|
| Feed material | Limestone |
| Product size | 0.1 mm – 2.0 mm (adjustable) |
| Actual capacity | 35 – 38 t/h |
| Energy consumption | ~20% lower than traditional processes |