Mining Concrete Spraying Machine
Mining Concrete Spraying Machine is a core explosion‑proof device for underground roadway shotcrete support. It sprays concrete mixture onto surrounding rock surfaces at high velocity to form a concrete support layer.
- Product Introduction
Mining Concrete Spraying Machine is a core explosion‑proof device for underground roadway shotcrete support. It sprays concrete mixture onto surrounding rock surfaces at high velocity to form a concrete support layer. Widely applied in coal mines and metallic & non‑metallic mines, it serves for roadway and chamber surrounding‑rock sealing, rib spalling prevention and surrounding‑rock reinforcement.
Main Classifications
1.By Spraying Process (Mainstream for Coal Mines)
Dry‑mix spraying machine (dry shotcrete)
Dry sand, aggregate and cement are premixed in dry state and conveyed by compressed air; water is added at the nozzle before ejection.
Advantages: Light‑weight unit, long conveying distance, low procurement cost.
Disadvantages: Severe dust generation, high rebound rate, poor water‑cement ratio control. Its application is gradually restricted in coal mines.
Damp‑mix spraying machine (damp shotcrete)
Raw materials are pre‑wetted with a small amount of water, with supplementary water added at the nozzle. Dust emission is moderately reduced, yet rebound rate remains relatively high. It represents a transitional process solution.
Wet‑mix spraying machine (wet shotcrete, current mainstream for promotion)
Pre‑mixed finished wet concrete is fed into the machine, and liquid accelerator is dosed at the nozzle for spraying.
Benefits: Low dust emission, low rebound rate (<10‑15%), stable concrete strength.
Available types include rotor‑type air‑feed wet spraying machines and piston‑pump wet spraying machines. Wet shotcrete trolleys (equipped with mechanical arms and remote‑control function) are deployed for large‑section roadways.
2.By Structural Configuration
Rotor‑type spraying machine
Compact mobile unit, typical models PS5I, PS6I, PS7I. Most common underground equipment, adopting air‑fed material delivery with explosion‑proof motor.
Piston‑pump wet‑mix spraying machine
Pump‑based material conveying, large output capacity, suitable for large‑cross‑section roadways.
Mining wet shotcrete trolley
Self‑propelled articulated chassis, multi‑section mechanical arm, wireless remote‑control. Enables mechanized operation and keeps operators away from spraying faces for improved safety and efficiency. Standard equipment for large‑and‑medium‑sized mines.
3.Power Supply & Explosion‑Proof Requirements
Underground coal‑mine equipment must obtain MA mining safety certification. Explosion‑proof motor voltage options: 380V / 660V / 1140V. Full‑unit explosion‑proof design is mandatory for high‑gas coal mines.
Main Components
Hopper with vibrating screen
Filters oversized aggregate particles to prevent pipeline blockage.
Rotor assembly (for rotor‑type units)
Material cavities and elastic rubber material cavities, classified as wearing parts.
Drive assembly
Explosion‑proof motor and reduction gearbox.
Pneumatic system
Air compressor pipelines and pressure regulating valves.
Material delivery pipeline and nozzle assembly
Wet‑mix models are additionally fitted with accelerator metering pump.
Trolley‑type units
Articulated chassis, hydraulic boom assembly, remote‑control system and hydraulic power station.
Typical Technical Parameters
| Item | Small‑size Rotor‑type PS6I (Damp / Wet Shotcrete) | Mining Pump‑fed Wet Spraying Machine | Wet Shotcrete Trolley |
|---|---|---|---|
| Spraying capacity | 5‑7 m³/h | 10‑30 m³/h | 15‑25 m³/h |
| Max. aggregate size | ≤20 mm | ≤25‑40 mm | ≤25 mm |
| Working air pressure | 0.4‑0.6 MPa | 0.5‑0.7 MPa | 0.5‑0.7 MPa |
| Horizontal conveying distance | 80‑120 m | 60‑150 m | 60‑120 m |
| Motor power | 5.5‑7.5 kW | 37‑90 kW | 45‑110 kW |
| Rebound rate | 15‑25% for damp shotcrete; ＜15% for wet shotcrete | ＜12% | ＜10% |
| Power supply | 380/660V | 660/1140V | 660/1140V dual‑voltage |
Core Comparison: Dry Shotcrete VS Wet Shotcrete
| Comparison Items | Dry‑mix Spraying Machine | Mining Wet‑mix Spraying Machine |
|---|---|---|
| Water adding position | Water added at nozzle | Water premixed outside machine |
| Dust concentration | Extremely high | Low, complying with occupational‑health requirements |
| Rebound rate | 25‑40% | 8‑15%, saves raw‑material consumption |
| Concrete strength | Unstable, hard to control water‑cement ratio | Precise mixing ratio, stable support performance |
| Drawbacks | High occupational‑health hazards | Prone to pipeline blockage, higher equipment cost |
Applicable Working Conditions
Shotcrete support for underground coal‑mine roadways, return‑air roadways and chambers.
Shotcrete support for underground roadways in metallic mines.
Concrete spraying operation for tunnels and water‑diversion tunnels.
Hot Tags: mining concrete spraying machine, China mining concrete spraying machine manufacturers, suppliers, factory
