The ZJ slag slurry pump plays a core role in conveying solid particle-containing slag slurry media during raw coal classification, and its functions are closely related to the process flow of raw coal classification. The following explanations are provided regarding the raw coal classification process, the characteristics of the ZJ slag slurry pump, and its specific roles:
I. Overview of Raw Coal Classification Process
Raw coal classification is the process of separating mined raw coal according to characteristics such as particle size and density, commonly seen in coal washing plants. The process typically includes:
Screening: Using equipment like vibrating screens to divide raw coal into lump coal, fine coal, etc., based on particle size.
Washing: Removing gangue and impurities from raw coal using water or heavy media (e.g., magnetite powder) to separate clean coal from waste.
Coal slurry treatment: The coal slurry (containing fine coal particles and impurities) generated during washing needs to be processed for recycling or discharge.
II. Characteristics and Application Scenarios of ZJ Slag Slurry Pump
1. Structural and Performance Features
Wear-resistant design: The pump body and impeller are made of wear-resistant materials such as high-chromium cast iron, suitable for conveying slurries containing hard particles like coal slag and gangue (particle size can reach 10-50mm).
High head and large flow rate: The head range is typically 20-130m, and the flow rate can reach 50-1500m³/h, meeting the transportation needs of long-distance and high-concentration slurries in the washing system.
Impact resistance: It can withstand the high-speed impact of particles in the slurry, reducing equipment wear and extending service life.
2. Application Scenarios in Raw Coal Classification
The ZJ-type slag slurry pump is mainly used in the coal slurry treatment system and heavy medium circulation system.
The specific applications of slurry pumps in the coal washing process are as follows:
1. Combined medium pump: pump the medium suspension that meets the specified density in the combined medium barrel into the trough of the shallow trough heavy medium separator for raw coal selection.
2. Dilute medium pump: pump the dilute medium suspension in the dilute medium tank into the magnetic separator for magnetic separation, and the concentrate (medium) after magnetic separation is recovered to the combined medium tank.
3. Cyclone feed pump: pump the coal slurry water in the coal slurry bucket to the coal slurry concentration cyclone for separation.
4. Water pit pump: pump the ground water into the diluent barrel.
5. Circulating water pump: pump the clarified water in the concentration tank to the washing system for de-medium spraying of the de-medium screen and system water replenishment.
6. Underflow pump: pump the concentrated high-concentration coal slurry water in the concentration tank to the coal slurry mixing tank of the washing water system.
7. Filter press feed pump: pumps the high-concentration coal slurry water in the coal slurry mixing tank into the filter press to separate the coal slurry from the water.
8. Filtrate pump: the filtrate after the filter press treatment is recovered into the filtrate tank and pumped to the concentration tank by the filtrate pump.
III. Specific Roles of ZJ-type Slag Slurry Pump in Raw Coal Classification
1. Conveying Slag Slurry after Washing
Scenario: After raw coal is washed with water or heavy media, the generated coal slurry (containing fine coal particles and gangue powder) needs to be transported to a thickening tank or filter press for solid-liquid separation.
Role: The ZJ-type pump transports high-concentration slag slurry (solid content can reach 30%-50%) from washing equipment (such as jiggers and heavy medium cyclones) to subsequent treatment links, ensuring the continuity of the classification process.
2. Maintaining Circulation of Heavy Medium Suspension
Scenario: In the heavy medium coal washing process, magnetite powder is mixed with water to form a suspension, which separates coal from gangue through density differences.
Role: As a circulation pump, the ZJ-type pump transports the suspension from the medium tank to the cyclone and recovers the suspension after washing, reducing medium loss and maintaining the stable operation of the system.
3. Assisting in Recovery of Fine Coal Particles
Scenario: Fine coal slime (particle size <0.5mm) generated during classification needs to be recovered through processes like thickening and filtration to avoid resource waste.
Role: The ZJ-type pump transports the coal slurry to a thickener or sedimentation tank. By controlling the flow rate and head, it ensures effective sedimentation of fine coal particles, providing conditions for subsequent dewatering (such as plate-and-frame filtration).
4. Achieving Graded Transportation and Distribution of Slag Slurry
Scenario: According to raw coal classification requirements, slag slurry may need to be transported to different processing equipment (such as screening machines and washing tanks of different specifications).
Role: Through the head adjustment of the ZJ-type pump, slag slurry is distributed to different workstations, meeting the transportation needs of multiple links and paths in the classification process.
IV. Selection and Process Matching of ZJ-type Slag Slurry Pump
In raw coal classification, the selection of ZJ-type pumps needs to consider the following parameters:
Medium characteristics: Slag slurry concentration, particle size, and hardness (e.g., gangue content).
Process flow rate: The amount of slag slurry generated per unit time in the washing system.
Transportation distance and height: Determining the head requirement of the pump (such as the drop from the washing workshop to the thickening tank). For example, when handling high-concentration coal slurry, a ZJ-type pump with a larger impeller diameter and lower rotation speed should be selected to reduce wear and avoid blockage.
V. Summary
The ZJ-type slag slurry pump is a key equipment connecting washing, transportation, and treatment links in raw coal classification. Its core role is to efficiently transport solid-containing slag slurry and ensure the continuity and stability of the classification process. Through wear-resistant design and performance matching, this pump can adapt to the high-load and strong-wear working conditions in raw coal classification, while assisting in resource recovery and environmental protection discharge (such as recycling of coal slurry). For further details on specific process parameters or equipment selection, detailed analysis can be conducted based on on-site working conditions.
