Liming Heavy Industry LM Vertical Coal Mill Empowers Energy Saving and Efficiency Improvement in the Asphalt Mixing Plant Industry

Asphalt, as an excellent road pavement material, is widely used in road construction. Heating is an essential procedure in asphalt production. Coal powder has become the primary fuel for modern asphalt mixture production. With the gradual depletion of coal resources in China, coal processing and utilization are developing toward refinement. Following national policies, clean coal powder preparation projects extend the value of the coal industrial chain, promote the utilization of clean energy, and achieve sustainable green development.

Drawing on over 30 years of R&D and manufacturing experience, Liming Heavy Industry has launched a complete solution equipped with the LM vertical coal mill clean coal powder preparation system, providing customers with customized new-type, safe and efficient clean coal powder production lines. The system is applicable to various materials such as anthracite, bituminous coal and lignite. The finished coal powder features uniform particle size and sufficient combustion. With outstanding safety, environmental performance, high output and low energy consumption, as well as high-standard system configuration, Liming Heavy Industry’s clean coal powder preparation system has won wide recognition from numerous customers.

This project is a fuel pulverizing production line for the asphalt mixing plant of a well-known large construction enterprise. After comprehensive and in-depth investigations in the early stage of the project, the customer finally selected one set of LM vertical coal mill specially dedicated for clean coal powder preparation from Liming Heavy Industry.

The entire pulverizing production line, from front-end feeding to final discharging, is fully designed by Liming Heavy Industry. The production site features compact layout, reasonable design, neat and tidy environment as well as green and eco-friendly operation, realizing standardization, large-scale production and intelligent operation.

Processing Material: Coal

Finished Fineness: 200 mesh

End Application: Asphalt Mixing Plant

Adopted Equipment: Liming Heavy Industry LM Vertical Coal Mill

The complete system of Liming Heavy Industry LM Vertical Coal Mill serves as the core of the project. It integrates crushing, grinding, drying, classification and conveying into a single unit. The integrated drying and pulverizing design realizes the one-step process of grinding and drying simultaneously. This large-scale grinding equipment adopts mature and reliable technological design. Equipped with a five-stage safety explosion-proof system including CO-O₂online monitoring, grinding roller hydraulic devices and an automatic control system, the entire pulverizing process is environmentally friendly, safe, efficient, intelligent and high-yielding. Customers can make diversified selections according to requirements on output, fineness, investment and other aspects.

Raw coal from the stockyard is screened through a grid screen and then conveyed to a steeply inclined belt conveyor or elevator. After iron removal by an electromagnetic iron separator, the raw coal is delivered into the raw coal silo for storage. Once the pulverizing system is fully started, the rod valve at the bottom of the raw coal silo is opened, and the sealed metering belt coal feeder is activated. Raw coal is fed into the LM Vertical Coal Mill for drying and grinding. Hot air or waste gas from the hot blast stove is drawn into the vertical mill by the system fan. It conducts sufficient heat exchange with the raw coal being ground inside the mill, then carries coal powder to the separator for classification. Coarse coal powder that fails to meet the fineness requirement falls back onto the grinding table for re-grinding, while qualified fine coal powder is conveyed by airflow into the explosion-proof pulse bag filter for collection, and then discharged into the coal powder silo via an air lock valve. Impurities contained in raw coal, such as gangue and metal blocks, are discharged out of the mill through the wind ring and slag discharge port. A CO-O₂online monitoring system is configured throughout the process. When processing coal with high volatile content, safety measures such as nitrogen protection and automatic CO₂ fire extinguishing system can be equipped.

Technical Advantages of Complete LM Vertical Coal Mill System

Leading Technology

The LM vertical mill features a simple process flow, integrating crushing, drying, grinding, powder selection and conveying into one unit. It boasts a compact layout and can be installed outdoors.

Low Operating Cost

The equipment is easy to operate. It adopts an automatic forced thin oil lubrication system and is equipped with a hydraulic roller tilting device. During maintenance, the grinding roller can be hydraulically flipped out of the mill, providing ample maintenance space for easy upkeep and low operating costs.

High Degree of Automation

Equipped with an automatic control system, it supports remote operation, interlock protection, reliable operation and simple operation.

High Efficiency & Environmental Friendliness

The entire production line operates under negative pressure. Adopting an explosion-proof plenum pulse dust collector, it causes no dust emission, features low noise and low energy consumption, and complies with the latest national environmental protection standards.

Large Output, High Efficiency and Strong Drying Capacity

Vertical milling delivers large output, high efficiency and low energy consumption. Hot air can be directly introduced into the mill to dry raw materials with incoming moisture up to 15%, with finished product moisture controlled below 1%.

Safe and Reliable Operation System

The system is configured with five-stage safety and explosion-proof measures. Its design is safe and reliable, in line with national and industrial specifications.

Industrial Applications of Clean Coal Powder

Application in Industrial Coal-fired Boilers

It can be used as boiler fuel to improve the thermal efficiency of boilers, reduce pollutant emissions during coal combustion, and lower coal consumption costs.

Application in Metallurgical Lime Industry

Lime kilns normally require high temperature for limestone calcination. As fuel processed by special technology, clean coal powder achieves a high burnout rate during combustion and reduces energy waste.

Pulverized Coal Preparation for Blast Furnace Injection

The blast furnace coal injection system is widely applied in power, iron and steel, and metallurgical industries. The use of clean coal powder effectively cuts carbon dioxide emissions and the generation of other harmful gases during blast furnace injection, enabling cleaner and low-carbon industrial production.

Application in Coal Chemical Industry and Coal-based New Materials

Clean coal powder plays a key role in the production of coal-to-liquid fuels and coal-to-chemicals. Through high-temperature gasification and other technologies, coal is converted into liquid fuels and chemical products, realizing efficient utilization of coal resources.