Using ring roller mills for processing rCB is a vital breakthrough in the high-value recycling of waste resources. The global tire circular economy and “dual carbon” strategies are currently advancing. Pyrolytic carbon black is the primary solid product derived from waste tire pyrolysis. To replace commercial blacks like N330, rCB urgently requires eco-friendly purification. Specifically, it needs ultrafine grinding to fully restore its reinforcing properties. Ring roller mills have become the core equipment for this fine grinding task. They feature dry continuous operation and ensure very low metal contamination. Further benefits include controllable particle size and moderate energy consumption.
1. Characteristics of Pyrolytic Carbon Black and Grinding Challenges
| Characteristic | Impact on Powder Equipments | Advantages of ring roller mills |
| High impurity content (Ash Content 10-30%, containing Zn, Fe, S, etc.) | Prone to equipment wear; Affects rubber performance | Use highly wear-resistant alloy/ceramic materials to reduce iron wear; Magnetic separation can be configured upstream. |
| Soft agglomerates | Difficult to disperse; Affects specific surface area | Ring roller mill effectively de-agglomerates through a combined compression and shear force field, avoiding the elastic rebound issue commonly found in jet mills. |
| Loose, Porous Structure | Prone to over-grinding into amorphous carbon; Reduces reinforcing properties | Adjustable grinding pressure system (spring/hydraulic) controls crushing intensity, preserving primary particle structure. |
| Heterogeneity & Combustibility | Risk of dust explosion (Minimum Ignition Energy < 10 mJ) | Equip with nitrogen protection, explosion vents, static grounding to comply with GB 15577 explosion-proof standard. |
| High moisture fluctuation (typically 3~8%) | Prone to adhesion, clogging classifiers | Moisture Control Recommendation: Some models support micro-steam control systems (approx. 3-9%) for conditioning. |
Core Role of the Ring Roller Mill in Fine Grinding rCB
Deagglomeration and Particle Size Reduction
Post-pyrolysis, rCB forms hard agglomerates (D50 ≈ 50–100 μm) and needs to be ground to D50 = 20–40 μm (close to N330 carbon black). The ring roller mill effectively breaks down agglomerates and releases primary carbon black particles through the repeated rolling and shearing action of multiple grinding rollers. Its built-in variable-frequency turbo sınıflandırıcı provides real-time particle selection, ensuring a concentrated final product particle size distribution (Span < 1.3).
Enhancing Specific Surface Area and DBP Absorption
After grinding, the specific surface area of rCB increases from 40–60 m²/g to 70–90 m²/g. The DBP absorption value rises from 80–100 mL/100g to 110–130 mL/100g, approaching the level of commercial carbon black (N330: 125 mL/100g). These properties directly determine its reinforcing effect, tensile strength, and wear resistance in rubber compounds.
Low Contamination Safeguards Rubber Performance
Commercial carbon black requires iron content < 50 ppm to avoid catalyzing rubber aging. Some ring roller mill manufacturers employ a design with no screws or bearings in the grinding chamber, coupled with high-chromium alloy grinding rollers (Cr ≥ 26%). This can control iron migration to 30–50 ppm, meeting the demands of high-end applications.
Integrated Dry-Process System
A typical rCB fine grinding production line is illustrated below:
Waste Tire Pyrolysis → Coarse rCB Cooling → Magnetic Iron Removal → Ring Roller Ultrafine Grinding → Sınıflandırma → Finished Product Collection
(Optional) Dry Surface Modification (Silane/Fatty Acid Coating)
The entire production process is water-free and solvent-free, avoiding secondary pollution. The modified rCB shows significantly improved dispersion in the rubber matrix, increasing tensile strength by 15–20%.
Comparison with Other Grinding Equipment (for rCB)
| Equipment Type | Applicability | Advantages | Disadvantages | Recommended |
| Raymond Değirmeni | Not Suitable | Low cost | Coarse particle size (≤325 mesh), high metal contamination, cannot deagglomerate | No |
| Ball Mill | Limited Applicability | Can handle high-impurity rCB | Severe iron contamination (>200 ppm), over-grinding, high energy consumption | No (Prohibited for rubber) |
| Jet Değirmeni | Usable | No contamination, good particle shape | Extremely high energy consumption (>180 kWh/t), low capacity, unsuitable for high-ash rCB | Only for high-end, small-batch |
| Halkalı Silindirli Değirmen | Preferred | Moderate energy consumption (80-120 kWh/t), strong deagglomeration capability. Can integrate modification, mature explosion-proof design | Single unit capacity ≤8 t/h, requires multiple units in parallel for expansion | Highly Recommended |
Real-World Application Cases
The table below summarizes typical application vakalar of ring roller mills in the rCB field. It covers representative projects from both domestic and international markets. Key highlights include specific technical solutions, processing capacity, and product performance. The table also details the significant economic benefits of these projects.
| Project Location / Enterprise Type | Technical Solution | Product Specifications | Application Field | Economic Benefits / Technical Results |
| European Carbon Black Regeneration Enterprise | Environmental Key Points (including repeatable calculation + consumption grading) | D50 = 30 μm, BET = 85 m²/g, Fe ≤ 45 ppm | Truck Tire Bead Section | Estimated 20% less N330 black required Raw material cost reduced by 18% Tire rolling resistance reduced by 5%, complies with EU REACH regulations |
| China Fuyao Da Environmental Technology Co., Ltd. | Carbon Black: Dry Process Surface Modification Integrated Production Line | D97 ≤ 63 μm, DBP ≥ 115 mL/100g, Ash ≤ 12% | Engineering Rubber Products (Oil Seal, Gasket) | Annual capacity 12,000 tons Finished product price 6000 RMB/ton (vs. raw material 2000 RMB/ton) Value addition up to 200% |
| Shandong Tire Recycling Base | Multi-unit Carbon Black Plant Model: Dry Process Integrated System | Iron Content ≤ 50 ppm, Particle Size Distribution Span < 1.25 | Commercial Vehicle Tire Tread Section | Achieved 20% substitution of new carbon black in the tread compound Passed material certification by OEMs Effectively improves tire wear performance |
| Jiangsu New Material Company | Carbon Black: Nitrogen Protection + Desulfurization & Dedusting (Fully Enclosed) | Moisture ≤ 0.5%, BET Surface Area 75-90 m²/g | High-Performance Rubber Seals, Vibration Damping Parts | Meets automotive Tier 1 supplier standards for electric vehicles Reduces reliance on conventional imports Annual savings on import substitution exceed 8 million RMB |
| Southeast Asia Renewable Resource Industrial Park | Tyre Pyrolysis Three-Stage Process (Adapts to high steel content feedstock) | Feed steel content ≤ 8%, Finished Product D50 = 35±2 μm | Tire Tread for Global Retreading Market | Resolves local carbon black supply gap Improves ecological chain, reduces pollution Shortens payback period to 2 years |
Conclusion
The application of ring roller mills in fine grinding pyrolytic carbon black not only addresses industrial bottlenecks such as rCB agglomeration, impurities, and performance instability but also completes the circular economy loop of “waste tires → high-value carbon black → green tires.” Its dry, efficient, low-pollution, and scalable technological pathway makes it the most economically and technically feasible mainstream equipment in the current field of rCB deep processing. As global tire recycling regulations tighten (e.g., the EU’s ELT Directive) and the rubber industry’s demand for carbon reduction grows, the application prospects for ring roller mills in the rCB sector will continue to expand.
Destansı Toz
Epic Powder Roller Mill — Redefining efficiency in dry fine powder processing. With an output more than double that of traditional Raymond and jet mills, it delivers superior product fineness, excellent size control, and remarkable stability.
- High Output & Adjustable Fineness — Capable of producing powder from D97: 3–8μm up to 10–40μm. Compatible with multi-stage classifiers for simultaneous multi-size production.
- Easy & Clean Setup — No major civil engineering required. Fully enclosed system ensures all fine powder is collected, meeting dust emission standards with zero environmental pollution.
- Wide Industry Application — Ideal for grinding calcium carbonate (calcite, marble, limestone, chalk), barite, kaolin, dolomite, magnesite, alumina, ultrafine cement, slag, steel slag, and more.
Large output. Eco-friendly. Multi-grade ready. — Your advanced solution for modern mineral powder production.
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