1. Raw Material Pretreatment, Laying a Solid Foundation for Coal Powder Preparation
The raw materials for coal powder preparation are mainly bituminous coal, anthracite, lignite, etc. After the raw coal enters the factory, double pretreatment is required to avoid impurities and large pieces of materials affecting subsequent processing. First is raw material screening, which removes gangue, iron blocks, wood chips and other impurities from raw coal through a vibrating screen to prevent impurities from wearing equipment and affecting the purity of coal powder; second is crushing treatment, for raw coal with a particle size larger than 50mm, a jaw crusher and a hammer crusher are used to crush it to a particle size range of 0-30mm, which meets the feeding requirements of grinding equipment, improves subsequent grinding efficiency and reduces equipment energy consumption at the same time.
2. Core Grinding Link, Determining the Fineness and Quality of Coal Powder
Grinding is the core process of coal powder preparation, which aims to process the pretreated raw coal into fine powder meeting the requirements of industrial combustion (usually the fineness is 80-200 mesh, which can be adjusted according to industry needs). In this link, special grinding equipment for coal powder preparation must be selected. The crushed raw coal is sent into the mill, and the materials are ground into powder through the extrusion and grinding action of grinding rollers and grinding discs. During the grinding process, the operating parameters of the mill must be strictly controlled, the grinding pressure and speed are adjusted according to the hardness and water content of the raw materials, and drying is carried out with a hot air system at the same time, the water content of coal powder is controlled at 1-2% to avoid caking of coal powder and affecting subsequent transportation and combustion.
3. Precise Classification, Screening Qualified Coal Powder Finished Products
The ground coal powder contains particles of different particle sizes, which need to be accurately screened by classification equipment to ensure the uniformity of the particle size of the finished coal powder, which is the key to ensuring full combustion of coal powder. The classification link mainly uses a powder separator, which uses the centrifugal force and gravity of the air flow to separate the fine powder with qualified particle size from the unground coarse powder: the qualified fine powder enters the collection system with the air flow, and the unqualified coarse powder is returned to the mill for secondary grinding through the reflux device until the particle size meets the requirements. The accuracy of the classification equipment directly affects the quality of the finished coal powder. Enterprises need to select a suitable high-efficiency powder separator according to the coal powder fineness requirements to improve classification efficiency and accuracy.
4. Collection and Storage, Ensuring the Safety of Coal Powder Transportation and Use
The qualified coal powder after classification enters the pulse bag filter for collection with the air flow. The dust remover separates the coal powder from the air flow through filter bag filtration. The collected coal powder falls into the unloading device and is transported to the coal powder silo for storage through a screw conveyor. As the terminal equipment of coal powder preparation, the coal powder silo must have good sealing, moisture-proof and explosion-proof performance: the silo body is equipped with temperature and pressure monitoring devices to monitor the internal state in real time; equipped with an arch breaking device to prevent coal powder from arching and blocking; connected with an inert gas protection system at the same time to avoid safety accidents caused by spontaneous combustion of coal powder due to oxidation. The stored coal powder can be directly sent to combustion equipment such as boilers and kilns through a pneumatic conveying system to realize continuous production.
5. Core Control Points of Coal Powder Preparation Process
Water content control: Control the water content of raw coal and coal powder throughout the process. The water content of raw materials before grinding should be controlled below 10%, and the water content of finished coal powder ≤2% to prevent caking and equipment failure;
Particle size refinement: Adjust the grinding and classification parameters according to industry needs to ensure uniform particle size of coal powder, avoid excessive coarse powder affecting combustion efficiency and excessive fine powder increasing dust risk;
Safety protection: Coal powder is a flammable and explosive material. The whole process needs to adopt a negative pressure operation system, equipped with complete dust removal, explosion-proof and fire-fighting equipment, and regularly clean the equipment and pipelines to prevent coal powder accumulation;
Continuous operation: The production capacity of the equipment in each process must be matched to ensure the continuous operation from raw material pretreatment to coal powder storage, reduce downtime and improve overall production efficiency.
If you require grinding, crushing, or sand-making equipment, please feel free to inquire online or by phone (+86-21-58386186). Shanghai Shibang will customize production line configurations tailored to your specific needs based on output volume, processed materials, and desired particle size distribution.
