Crusher Discharge Chute Wear Patterns: Inspection and Relining Checklist
Crusher discharge chute wear should be read as a pattern across the outlet throat, first-impact zone, rebound walls, sliding transition and receiving-equipment interface. A single minimum-thickness reading cannot tell whether the controlling problem is normal abrasion, concentrated impact, flow shift, loose fixings, build-up or a damaged support shell.
This inspection and relining checklist helps mining and aggregate maintenance teams document the stationary chute immediately after a crusher. It does not cover internal crusher wear parts such as jaw plates, mantles, concaves, blow bars or rotor components, and it does not replace the crusher OEM’s clearance or safety requirements.
Define the inspection boundary first
| Area | Typical responsibility | Inspection question |
|---|---|---|
| Crusher internals | OEM crushing chamber and machine wear components. | Is the item inside the crushing chamber or controlled OEM clearance? |
| Outlet throat/adaptor | Interface between crusher and fixed discharge structure. | Who owns the mating dimensions, and has the opening or flange moved? |
| Stationary discharge chute | Impact, rear, sidewall, transition and lip liner panels. | Which liner-map revision matches the installed chute? |
| Receiving equipment | Feeder, screen, conveyor loading zone or bin inlet. | Where does the chute end and the downstream wear package begin? |
Use separate part numbers and drawings for these boundaries. The related product page is Crusher Discharge Chute Liner Plates. Upstream feed protection belongs under Crusher Feed Chute Liners, while a belt head-chute application belongs under Conveyor Discharge Chute Liner Plates.
Safety and isolation before inspection
Do not enter, clean, measure or release liner fixings until the site has isolated the crusher, feeder, conveyor and every relevant source of stored energy. Control gravity, retained material, hydraulic or pneumatic energy, rotating equipment, suspended parts and the mass of any liner that can move after its last fixing is removed.
Crusher areas can also contain significant respirable dust. NIOSH identifies the crusher and associated transfer points as important dust-generation areas and describes isolation or ventilation controls for crushing facilities. See the official NIOSH crushing-facilities guidance. The operating site must determine applicable legal requirements, entry classification, PPE, ventilation, lifting and work permits.
Record evidence before cleaning
Dirty-condition photographs can reveal build-up, leakage paths, dust escape, packed fines behind a lifted edge and the actual material trajectory. Photograph the complete chute from identified access points before removing accumulated material. Add a scale or known reference, equipment tag, flow arrow and panel IDs.
Then repeat photographs after controlled cleaning so cracks, polished bands, craters, hole elongation, shell exposure and joint steps are visible. Keep dirty and clean photographs paired by the same viewpoint.
Quick wear-pattern triage table
| Observed pattern | Possible question | Evidence to collect |
|---|---|---|
| Deep local crater | Is the stream striking a small unsupported target? | Impact footprint, drop, support span and rebound marks. |
| Long polished band | Is sliding abrasion stable along the intended path? | Thickness grid along and across the band. |
| One-sided wear | Has loading, crusher condition or build-up shifted the stream? | Left/right measurements, operating changes and trajectory photos. |
| Crack with substantial thickness | Are impact, restraint, misfit or support controlling failure? | Crack origin, shell contact, gap, fixing and panel geometry. |
| Raised edge or packed fines | Is an upstream joint facing flow or a fixing loose? | Joint step, gap, overlap, fastener condition and backing. |
| Dust or spillage around one seam | Is the shell, seal or liner interface open? | Dirty photographs, enclosure pressure context and leak route. |
Zone 1: outlet throat and crusher interface
The outlet throat may have the smallest clearance and the most sensitive equipment boundary. Inspect for reduced opening, liner movement toward the stream, trapped oversize material, flange distortion, contact with an OEM-controlled surface and cracks near adaptor fixings. Compare the as-built opening with the approved drawing rather than assuming the worn sample defines the original shape.
If material is bridging, record maximum lump, moisture, crusher setting and the exact obstruction before clearing it. Do not enlarge the opening or reduce protective thickness without engineering approval.
Zone 2: first-impact surface
The first-impact zone often develops a crater, peened area, edge breakage or cracks near a support. Mark the centre and full envelope of contact; surge conditions may move the footprint beyond the normal polished area. Check whether the panel is continuously backed, spans a damaged shell or carries load through only a few fixings.
A harder or thicker replacement does not automatically correct concentrated load. The review may need to compare panel support, toughness, segmentation, impact angle and an approved impact-plate or rock-box arrangement.
Zone 3: rebound sidewalls and rear wall
Rebound wear may appear intermittent until a loading change directs more material to one side. Identify left and right panels separately. Compare upper and lower wear bands, dents, loose fixings and polished edges. One-sided wear can indicate off-centre discharge, build-up that redirects the stream or a change in upstream crusher operation.
Zone 4: sliding transition
After first impact, material may slide toward a feeder, belt or bin. Look for continuous abrasion bands, flow-facing joint steps, gouges at fastener heads and local acceleration through a taper. A smooth transition can be more important than maximum thickness if a raised upstream edge starts impact, packing or turbulence.
Use the Panel Joints, Gap, Overlap and Flow-Direction Checklist to document these interfaces.
Zone 5: lower lip and receiving-equipment interface
The lower lip can wear from convergence, carry a free edge or protrude into the receiving equipment envelope. Inspect remaining section, unsupported length, clearance, stream centring and any contact with a feeder deck, screen feed box or conveyor loading zone. A replacement must preserve the approved downstream interface.
Inspect joints, fasteners and backing together
| Component | Check | Escalation trigger |
|---|---|---|
| Panel joint | Gap, overlap, step, flow direction and packed material. | Raised upstream edge, shell exposure or progressive ingress. |
| Bolt/countersunk head | Head wear, seating, rotation, recess and removal access. | Head no longer retains the panel or cannot be removed safely. |
| Hole/slot | Elongation, fretting, cracking and edge ligament. | Movement, crack growth or inadequate remaining section. |
| Stud/weld | Visible cracking, distortion, attachment condition and access. | Unknown procedure, damaged shell or failed attachment. |
| Backing shell | Dents, corrosion, cracks, patches, gaps and local thinning. | Liner no longer has the support assumed by the drawing. |
For recurring movement, read the Chute Liner Fastener Failure Guide. Replacing a loose panel with the same hole pattern and damaged backing can reproduce the failure even when the material grade is correct.
Dust and spillage are interface evidence
NIOSH notes that feed and discharge points are primary dust-emission locations in crushing and grinding, and that chute or transfer design, enclosure and seals are important parts of dust control. See the official Crushing and Grinding guidance.
Visible dust or material on the floor can indicate worn seals, shell holes or an open interface, but a liner-material change alone may not correct pressure, ventilation or enclosure problems. Record the leak path and coordinate liner work with the site’s dust-control review.
Build a repeatable thickness map
Number every panel and establish measurement points from stable datums. Record original thickness, remaining thickness, date, instrument, surface condition and associated operating hours or tonnage. Use a grid dense enough to capture the crater or band rather than reporting only one minimum value.
Compare surveys at the same points. A simple loss-per-hour or loss-per-tonne value can support planning, but it remains historical evidence, not a permanent material constant. Changes in ore, moisture, throughput, crusher setting or trajectory can alter the rate. See the Wear Mapping and Replacement Planning Guide.
Separate thickness loss from mechanical damage
| Replacement driver | Typical evidence | Review focus |
|---|---|---|
| Predictable abrasion | Stable loss pattern over repeated surveys. | Wear allowance, grade, replacement interval and selective spares. |
| Impact cracking | Crack or broken edge while substantial thickness remains. | Toughness, support, panel size, impact and restraint. |
| Fixing failure | Loose bolts, elongated holes or fretting. | Joint design, backing, installation and movement. |
| Flow restriction | Build-up, bridging or reduced opening. | Clearance, joint steps, geometry and moisture. |
| Shell exposure | Perforation, open gap or displaced panel. | Immediate structural inspection and controlled repair scope. |
Choose replacement material and thickness from the pattern
Possible material families include NM-class rolled wear plate, high-chromium cast iron, Ni-Hard or a buyer-specified alloy. The final choice depends on abrasion, impact, support, temperature, processing and removal requirements. A nominal hardness number does not guarantee fit or service life.
Use the Chute Liner Material Grades Guide and Thickness Selection Framework. Check minimum clear opening, individual mass, fixing length and downstream clearance before increasing thickness.
Plan selective or complete relining
Selective replacement can preserve usable low-wear panels when joints, access and spares are designed for it. Complete relining may be justified when revisions are mixed, fixings are widely damaged, the shell needs coordinated repair or the shutdown cannot tolerate another near-term intervention. The liner map should show which panels can be removed independently and the safe sequence.
Inspection package before manufacturing
- general arrangement and controlled liner-map revision;
- dirty and clean photo set with viewpoints and panel IDs;
- remaining-thickness grid with hours or tonnage;
- crusher outlet and receiving-equipment interface dimensions;
- material, thickness, heat/batch and previous service life;
- joint, fixing and shell/backing condition;
- access opening, individual lifting limit and replacement sequence;
- required certificates, dimensional report, marking and packing plan.
RFQ checklist for crusher discharge chute liners
Send the complete arrangement before sending only a worn sample. Mark uncertain dimensions and identify which values are original, measured or proposed. Include maximum lump, grading, moisture, temperature, normal and peak throughput, crusher type, outlet boundary, downstream equipment and maintenance constraints.
For manufacturing acceptance, use the Pre-Shipment Chute Liner Inspection Checklist. Require part IDs that match the liner map and pack parts by shutdown sequence where needed.
Request a drawing-based review
Send the liner map, drawings, wear measurements and operating data, or email wear@ebcastings.com. EB China will review the manufacturing scope and identify missing RFQ information before quotation.
Technical review boundary
This article supports inspection documentation and relining decisions; it does not modify crusher OEM limits, calculate structural capacity or define a site work procedure. The equipment owner and qualified personnel must approve isolation, entry, lifting, shell repair, chute geometry, dust control, material, thickness and fixing. Updated by the EB China engineering-content team against the cited NIOSH sources.
Image and technical references
- NIOSH: Crushing Facilities.
- NIOSH: Crushing and Grinding.
- Doroszuk, Król and Wajs (2021), Energies 14(13), 4008 — featured-image source, Figure 15, CC BY 4.0.