Raymond mill processes coke

• Publication time：2025-07-30
• Click：0

Raymond Mill and Coke

Coke is the product of bituminous coal subjected to high-temperature dry distillation at 1000°C. It contains 85%-90% carbon, has low volatile matter content (1%-3%), and a high calorific value of 29-30 MJ/kg. In iron and steel smelting, it serves as both a heat source and a reducing agent, with approximately 0.4-0.6 tons of coke required to produce 1 ton of pig iron. In the foundry industry, it facilitates metal melting and casting. In the chemical sector, it can be used to produce calcium carbide, synthetic ammonia, and other products. Coke is categorized into types such as metallurgical coke, foundry coke, and chemical coke, with strict requirements for indicators like strength, sulfur content, and particle size. Raymond mills can grind coke to a fineness of 80-400 mesh, meeting the needs of various applications.

Advantages of Using a Raymond Mill for Coke Grinding

Raymond mills are specifically designed for materials with medium to low hardness, with a Mohs hardness applicability of ≤7, which aligns with the characteristics of coke. They utilize high-chromium alloy grinding rollers/rings, increasing wear resistance and service life by 40%. By adjusting the speed of the classifier, coke can be ground to a fineness of 80-400 mesh. The product line is extensive, with small models (3R/4R) having a capacity of 0.5-5 t/h and large models (5R/6R) a capacity of 5-20 t/h. In the 80-300 mesh fineness range, Raymond mills offer significant cost-performance advantages. Compared to ball mills, they consume less energy, occupy less space, and have lower labor costs. Compared to vertical mills, they have lower investment costs and simpler maintenance. Compared to jet mills, they are more cost-effective and have higher productivity. Their sealed air circuit system, combined with a baghouse dust collector, achieves a dust recovery rate of up to 99.5%.

Process for Grinding Coke with a Raymond Mill

Preprocessing Stage: This includes crushing and screening, as well as drying and conditioning. Lumpy coke (≤300mm) is initially crushed by a jaw crusher to ≤30mm, with impurities removed by a vibrating screen. When the moisture content of the coke exceeds 5%, a rotary dryer is used to reduce it to below 3% at a temperature of 150-200°C.

Grading and Classification Stage: The material enters the grinding chamber via an electromagnetic vibrating feeder. Under the action of centrifugal force, the grinding rollers press against the grinding ring to pulverize the material. Qualified fine powder is propelled by a fan into the classifier for classification. Coarse powder falls back to be reground, with a screening efficiency of over 99%. Real-time monitoring of the fan's air volume (1000-15000 m³/h) and the negative pressure in the grinding chamber (-500 to -1000 Pa) is essential.

Product Collection and Environmental Protection: A two-stage powder collection system of "cyclone separator + pulse baghouse dust collector" is employed, which offers high separation efficiency and ensures that the dust content in the exhaust gas is less than 30 mg/m³. When processing materials with high volatile matter content, a nitrogen protection system is installed to maintain the oxygen concentration below 8%.

Key Points for Grinding Coke with a Raymond Mill

Maintenance Strategy: Establish wear records for the grinding rollers/rings and promptly replace worn parts. Use lithium-based grease (NLGI 2#), with the roller bearings lubricated every 8 hours and the gearbox oil changed every 500 hours. This ensures the bearing temperature rise is less than 40°C and the gearbox oil temperature is less than 60°C.

Solutions: If the production capacity suddenly drops by more than 30%, check the spring pressure and clear accumulated powder from the air ducts. If the finished product is too coarse, increase the classifier speed or replace the blades. If the machine experiences abnormal vibration, calibrate the feeder's frequency converter and tighten the bolts.

Explosion Protection: For coke varieties with a volatile matter content of over 5%, equip the mill with explosion-proof motors (Ex d IIB T4), temperature sensors, and CO concentration detectors to automatically activate a nitrogen purging system.

Summary

The Raymond mill is an efficient piece of equipment for grinding coke, suitable for achieving a fineness of 80-400 mesh. The machine features wear-resistant components, allows for controlled classification of fineness, and has a capacity of 0.5-20 t/h, along with low energy consumption and excellent sealed dust collection. Compared to other types of equipment, the Raymond mill offers superior cost-performance in the 80-300 mesh fineness range, making it a preferred choice.