VRM & Ball mill combined cement grinding solution
Capacity: 700 ~ 5,000 TPD
Main Grinding Equipment: vertical roller mill, ball mill
Material: cement clinker
Working Process: cement combined grinding system
Solution: EPC service providing including design, procurement, construction, and trial operation
Solution Introduction
A cement clinker grinding unit comprises cement grinding mills and related equipment to grind cement clinker and get finished cement. As the name indicates, In the VRM & ball mill combined grinding system, the grinding mill is a vertical roller mill and a ball mill. Other equipment includes a combined separator, cement ball mill, and O-sepa separator.
Four mainstream grinding systems according to the cement mills using
Vertical roller mill final grinding system
Roller press and ball mill combined grinding system
Vertical roller mill & ball mill grinding system
Process of Cement clinker grinding plant with VRM & Ball mills
The VRM & ball mill combined grinding system is a closed circuit system. The vertical roller mill is adopted as a pre-grinding equipment with a separate ventilation system. The gas extracted from the ball mill is used as the primary air of the O-Sepa separator, and the secondary and tertiary air is ambient air.
VRM Pre-grinding
The vertical roller mill first pre-grinds the clinker and mixed materials.
Screening and Re-grinding
An inclined internal screening mechanism is installed in the mill following the pre-grinding of the clinker. The screening device stops the large pieces of material that escape and sends them back to the vertical mill for grinding and rolling.
Ball mill primary grinding
After smaller materials are screened, the fine powder is sent to the ball mill. There, it undergoes rolling and shearing, which reduces the material’s size and increases its number of cracks, 30% of which are smaller than 80um. The combined material produces ideal grinding conditions for the ball mill once it enters.
Classifying by O-sepa separator
The O-Sepa separator with downflow built into the top of the vertical mill uses powerful airflow to lessen the layer of powdery material on the grinding disc of the vertical mill.
Ball mill secondary grinding
After being selected for powder, the eligible materials go into the completed product warehouse, while the coarser materials go into the ball mill to be ground even more.
Features of the VRM & ball mill combined grinding system
The process is relatively complex, and the equipment investment is comparable to that of the fourth system, but the civil engineering cost is relatively less because the vertical mill can be arranged outdoors. In addition, the maintenance of the vertical mill is less than that of the roller press, so the operating rate is higher.
1) The clinker is pre-ground in the vertical mill. Following the pre-grinding, there are numerous cracks and the particles are sheared and rolled. The mixture produces ideal grinding conditions for the ball mill once it enters, significantly increasing the system’s grinding capacity.
2) The vertical mill uses both static and dynamic rings to guarantee the material layer’s thickness.
3) The ball mill’s output can be increased by simply selecting the sieve gap following the grinding efficiency parameters to ascertain the particle size entering the mill.
4) The classifying system is different from the screening of ordinary high-fine grinding. The primary distinction is that it falls under the category of dynamic active separation, has improved classification accuracy and efficiency, is easy to modify, and has no effect on the mill’s ventilation area.
5) The cement particle size distribution and particle morphology are more reasonable as a result of this combined grinding, which also solves important common technical issues with the reasonable matching of particle characteristics with surface energy, mechanical energy, and chemical energy. Its gelling efficiency is also greatly improved, and the chemical and mechanical energy activation of siliceous and siliceous aluminum industrial solid waste are combined organically.
Clinker grinding mills
Vertical Roller Mill
The vertical roller mill developed by SINOMA Zibo has the features of optimum design with a reliable structure. It integrates drying, grinding, classification, and transportation and can be completed in one piece of equipment. The TRM vertical roller mill series are widely applied in grinding cement raw meal, cement, coal, petroleum coke, desulfurized limestone, various metallurgical slag including steel slag, nickel slag, dry grinding of ceramic raw materials, machine-made sand, furnace slag, fly ash, iron ore, etc.
Advantages
Simple processes, drying, grinding, and classifying can be accomplished in one piece of equipment.
Compact layout and lower construction investment.
Higher grinding efficiency, lower power consumption, and lower wear ratio.
With high drying capacity, raw material with up to 20% moisture can be dried within the VRM grinding process.
Cement Ball Mill
Ball mills are widely used in cement, metallurgy, power generation, ceramics, and other industries. Ball mills have strong adaptability to a variety of raw materials, low failure rate, stable operation, and high reliability.
Features
Available drive methods include central drive, lateral drive, and complex drives.
Available bearing types are either sliding shoe bearings trunnions or a combination of both.
Discharge of the ball mils is at the end or in the middle of the ball mill.
Cement ball mill configuration
| Specification (m) | Grinding method | Drive type | Grinding chamber qty | Speed (p/min） | Capacity（t/h) | Bearing type | Main motor power (kw) |
|---|---|---|---|---|---|---|---|
| Φ3.2×13 | open circuit | edge | 3 | 17.89 | 50-52 | double slide shoes/main bearing | 1600/1800 |
| Φ3.5×13 | open circuit | center edge | 3 | 17 | 70-80 | double slide shoes/main bearing | 2000 |
| Φ3.8×13 | open circuit | center | 2/3 | 16.3 | 130 (roller press) | double slide shoes/main bearing | 2500 |
| Φ4.0×13 | open circuit | center | 2/3 | 15.95 | 75 | double slide shoes/main bearing | 2800 |
| Φ4.2×13 | open circuit | center | 2/3 | 15.6 | 90 | double slide shoes | 3550 |
| Φ4.2×13.5 | open circuit | center | 2/3 | 15.6 | 95 | double slide shoes | 3550 |
| Φ4.2×14.5 | open circuit | center | 2/3 | 15.3 | 100 | double slide shoes | 3800/4000 |
| Φ4.4×15 | open circuit | center | 2/3 | 15.3 | 110-115 | double slide shoes | 4000/4200 |
| Φ4.6×14 | open circuit | center | 2/3 | 15 | 90 | double slide shoes | 4250 |
| Φ5.0×15 | open circuit | center | 2/3 | 14.4 | 150 | double slide shoes | 5800/6000 |
For the configuration of the whole process, contact us!
