Although electromagnetic valves are not as eye-catching as large equipment such as pumps and crushers in mining (including metal mines, non-metal mines, coal mines, and sand and gravel aggregates), as the core component of fluid automation control, they play an irreplaceable role in ensuring production safety, improving efficiency, and achieving intelligence. Its application runs through multiple links such as mineral processing, tailings treatment, dust removal, hydraulic systems, fire protection, water circulation, and underground safety.
Medium Control in Mineral Processing Technology
Purpose:
Control the precise addition of flotation reagents (such as collectors, frothers, inhibitors);
Adjust the inlet/outlet of the slurry regulating tank;
Control the flushing water or cooling water for reselection and magnetic separation equipment.
requirements
Wear resistant and corrosion-resistant (slurry containing solid particles, acidic and alkaline agents);
Diaphragm or piston structures are often used to prevent blockage;
The materials are mostly PVDF, PP, 316L stainless steel, and FKM or PTFE seals are used.
Example: In copper ore flotation, the solenoid valve is opened at a scheduled time according to PLC instructions, and yellow medicine solution is injected into the mixing tank with an accuracy of ± 2%.
Tailings pond and thickener control system
Function:
Control the opening and closing of the bottom flow discharge valve;
Adjust the return valve to achieve water resource recovery;
Quickly cut off tailings transportation in emergency situations (anti dam break interlock).
Working condition challenge:
High concentration slurry (solid content>40%), high wear and tear;
Outdoor environment (-30 ℃~+50 ℃), high dust.
Solution:
Choose wear-resistant ceramic lined solenoid valve or pneumatic angle seat valve+electromagnetic pilot valve combination;
Protection level ≥ IP67, with anti freezing heat tracing (in cold regions).
Mine dedusting and spray dedusting system
Application Scenario:
Automatic spray at crushing station, screening workshop and belt transfer point;
Dust suppression in underground tunnels.
Control logic:
Linked with dust sensors, automatically activated when exceeding standards;
Timing pulse spray, saving water and energy.
Valve type selection:
Small caliber (DN15-DN25) normally closed direct acting solenoid valve;
Brass or stainless steel valve body, anti scaling design.
⚠️ Attention: Filters should be installed in areas with high water hardness to prevent nozzle and valve core blockage.
Hydraulic and lubrication system (supporting large equipment)
Equipment objects: hydraulic breakers, rock drilling rigs, tunneling machines, hydraulic supports (coal mines).
Function:
Control the on/off or direction switching of hydraulic oil circuit (mostly used for pilot control);
The lubrication system provides timed oil supply (such as centralized lubrication with dry oil).
Technical Requirements:
High pressure (21-35 MPa), anti pollution;
Fast response (<50 ms), long lifespan (>1 million cycles);
Underground safety and fire protection system (especially in coal mines)
Key applications:
Emergency cut-off of gas drainage pipeline;
Start valve of automatic fire extinguishing system (such as foam and water spray);
Oxygen/water supply control for refuge chambers.
Mandatory requirement:
Must pass the Mining Product Safety Mark (MA/KA certification);
Explosion proof rating: Ex d I Mb (for coal mines) or Ex d IIC T6 (for non coal underground mines);
Intrinsically safe (intrinsic safety) signal interface, supporting linkage with monitoring systems.
Case: An intelligent coal mine deployed an automatic spray system controlled by a solenoid valve on the mining face, which was linked with the gas concentration in real time to achieve "instant spraying after exceeding the limit".
Mining water treatment and recycling
Purpose:
Neutralizing agent addition for acid mine drainage (AMD);
Control of sedimentation tank sludge discharge for ore washing wastewater;
Management of inflow and outflow of recycled water pump station.
Special requirements:
Resistant to strong acid (pH<3) or high salt wastewater;
PH/ORP feedback can be integrated to achieve closed-loop control.