Operating a concentrating table isn't a "set it and forget it" process. Feed characteristics change, material density varies, and optimal separation requires constant fine-tuning. But knowing when you can safely make adjustments during operation—and when you must shut down and lock out—can mean the difference between efficient operation and a trip to the emergency room.
The Golden Rule: Hands Away from Moving Parts
Here's the fundamental principle that guides all adjustment decisions: If the adjustment requires your hands, tools, or body near moving parts, the table must be shut down and locked out. No exceptions, no shortcuts, no "just real quick" moments.
Some adjustments are designed to be made during operation using external controls. Others require you to shut down completely. Understanding the difference keeps your team safe.
Adjustments You CAN Make During Operation
These adjustments can be performed while the table is running because they're designed with operator safety in mind:
Side Tilt Adjustment (Hand Wheels)
What it controls: The downward slope of the deck from the backboard side to the tailings side.
How to adjust safely: Your concentrating table has hand wheels at the feed corner that control the tilting mechanisms. These can be turned during operation to make fine adjustments to side tilt.
Safe practice:
- Stand clear of the deck and moving components
- Turn the hand wheel gradually and watch material flow across the deck
- Keep hands on the hand wheel only, never reaching toward the mechanism or deck
Side tilt is your most frequent adjustment. Higher side tilt causes more material to discharge off the tailings side; lower side tilt does the opposite. This adjustment compensates for minor fluctuations in feed characteristics.
Feed Rate and Water Flow
What it controls: The amount of material entering the table and the wash water distribution.
How to adjust safely: Feed gates and water control valves are designed for adjustment during operation.
Safe practice:
- Use external controls only—never reach into the feed box
- Make gradual changes and monitor all three product streams (concentrate, middling, tailings)
- Adjust feed and water together for optimal separation
Feed and water adjustments work together. Optimal separation requires constant monitoring and minor tweaking throughout the shift.
Adjustments That REQUIRE Shutdown and Lockout
These operations require you to shut down the table, isolate all energy sources, and implement proper lockout/tagout procedures:
End Elevation Adjustment (Turnbuckles)
What it controls: The upward slope of the deck from the motion end to the concentrate end.
Why lockout is required: Adjusting turnbuckles requires working with wire rope assemblies. Attempting to adjust while the table is moving is unsafe and impractical.
Safe procedure:
- Shut down the table using normal procedures
- Isolate electrical power and apply lockout devices
- Use correct tools to adjust turnbuckles in the wire rope assemblies
- Make small incremental changes
- Keep clear of suspended decks and wire ropes during adjustment
- Remove lockout devices and test operation
End elevation is generally a semi-permanent adjustment. Once established for a particular feed, it rarely needs changing unless feed conditions change substantially.
Belt Tension Adjustment
Why lockout is required: Adjusting belt tension requires working near the motor and drive system with moving belts under tension.
Safe procedure:
- Shut down the table using normal procedures
- Isolate electrical power and apply lockout devices
- Verify the head motion is completely stopped
- Adjust motor position using the motor base bracket adjustment bolt
- Check belt tension (should have approximately 1/4 inch deflection when pressed)
- Remove lockout devices and test operation
Never attempt to adjust belt tension while the motor is running or could accidentally start. Drive belts under tension can cause severe hand and finger injuries.
Deck Removal or Riffle Maintenance
Why lockout is required: Any work on the deck surface requires your hands in areas where the deck moves during operation.
Safe procedure:
- Complete shutdown and lockout/tagout
- Verify all motion has stopped
- Support the deck properly before removing any attachments
- Use appropriate lifting equipment—decks are heavy and awkward
- Follow your operation manual for proper removal sequence
Deck work is some of the most hazardous maintenance you'll perform. Rushing or skipping lockout procedures during deck changes has caused serious crushing injuries.
Head Motion Service
Why lockout is required: The head motion contains rotating shafts, gears, and precisely balanced counterweights. Any internal work is extremely hazardous without proper lockout.
Safe procedure:
- Shut down and lock out all electrical power
- Allow the head motion to come to complete rest
- Verify no stored energy in springs or mechanisms
- Follow manufacturer procedures for cover removal and service
- Never reach into the head motion while any part could move
Head motion service should only be performed by trained personnel following detailed procedures. The internal components are under stress and can cause serious injury if mishandled.
Swivel Connector Replacement
Why lockout is required: Swivel connectors are under load from the suspended deck assembly and connect to moving components.
Safe procedure:
- Shut down and lock out the table
- Properly support the deck to relieve load on the swivel connector
- Use correct tools and follow torque specifications
- Never work under unsupported suspended loads
- Verify proper installation before removing supports
Swivel connectors are critical wear items—keep replacements in stock so you're ready when weekly inspections reveal wear.
Understanding Lockout/Tagout Basics
When shutdown and lockout are required, follow your facility's procedures. At minimum: shut down normally, isolate all energy sources, apply lockout devices (each person applies their own lock), verify isolation, and only remove locks when work is complete, and all personnel are clear.
If you're unsure whether an adjustment requires lockout, shut down, and lock out. It's always safer to lock out unnecessarily than skip it when needed.
Making Adjustments Part of Your Safety Culture
Safe adjustment practices require more than just knowing the rules:
Communicate clearly: Before making any adjustment, let nearby personnel know what you're doing. This prevents surprises and ensures help is available if needed.
Work deliberately: Rushed adjustments lead to mistakes. Take your time, think through each step, and never let production pressure push you into unsafe shortcuts.
Document problems: If you notice an adjustment is becoming difficult, requires more force than normal, or doesn't respond as expected, report it. These are early warning signs of mechanical problems.
Train thoroughly: New operators should never make adjustments without supervision until they've demonstrated complete understanding of safe procedures.
Keep Your Adjustment Tools Ready
Having the right tools on hand makes adjustments safer and more efficient. Stock critical adjustment tools and spare parts so you're never tempted to improvise with wrong-sized wrenches or makeshift tools.
For technical support or safety questions about your Deister equipment, contact us at 1-800-926-6453 or contact us.
