Mining & Wear Protection
Wear-Resistant Ceramics: The Overview
Alumina tiles and reaction-bonded SiC side by side — the two-material selection table, product forms and the honest cost arithmetic.
Read the overviewShort answer
For most mining slurry pipelines — moderate velocity, particles under about 5 mm, few impact events — alumina wear tiles (92% or 95% Al₂O₃) are the industry default and the cheapest per tonne conveyed. At high-wear points — pump internals, cyclone apexes, severe elbows, or anything running above roughly 5 m/s with coarse, sharp particles — reaction-bonded silicon carbide (RBSiC) wins on total cost because it is nearly pore-free, far harder, and has no joints or grout lines to fail.
The decision is made by six duty variables, not by hardness alone: particle size distribution, velocity, impact angle, temperature, chemistry, and how the lining is fixed. Get those right and either ceramic outlasts steel by a factor that changes the maintenance schedule, not just the budget.
Why steel loses: how slurry actually wears a pipe
Slurry wear is erosion, not friction. Particles carried in the slurry strike and slide across the pipe wall thousands of times per minute, and each contact removes a microscopic amount of metal. Three things make it brutal in mining service:
- Velocity. Erosion rate scales with roughly the square to the cube of velocity. Double the speed and the wear rate can rise four- to eight-fold — which is why the elbow downstream of a pump dies long before the straight run.
- Impact angle. Ductile steel wears fastest at shallow angles of about 20–30°, where particles plough grooves like a cutting tool. Hard ceramics are the opposite: they shrug off shallow-angle sliding but can chip under direct 90° impact. This single fact explains most ceramic lining failures — lining a rock-drop chute with brittle tiles and no impact management.
- Particle sharpness and hardness. Quartz (about 1,000–1,200 HV) and sharp fractured faces cut steel effectively; rounded river sand cuts far more slowly. The top size of the distribution matters more than the average.
Bare steel in a moderately aggressive slurry line is a consumable: 8–14 months for a concentrate or tailings duty is common, and high-wear points are replaced quarterly. The cost is not the steel — it is every shutdown, hot-work permit and crane lift that comes with it.
The two ceramics that do the work
Almost every wear lining in mining service is one of two materials. They are not competitors so much as complements.
| Property (typical) | DA-92 / DA-95 alumina tiles | DA-SC-R reaction-bonded SiC |
|---|---|---|
| Composition | 92% / 95% Al₂O₃ | SiC ≈ 85–90%, free Si 8–12% |
| Bulk density (g/cm³) | 3.5–3.7 | 3.02–3.10 |
| Hardness (HV) | ≈ 1,000–1,400 | 2,200–2,500 |
| Porosity | Dense sintered body | < 0.1% (silicon-infiltrated) |
| Flexural strength (MPa) | 200–300 | 250–350 |
| Fracture toughness (MPa·m1/2) | 3.5–4.2 | 3.8–4.5 |
| Slurry erosion resistance | Very good | Best of the affordable ceramics |
| Form factor | Tiles: square, rectangular, hexagonal | Cast segments, pipes, cones — near-net shapes |
| Relative cost per kg | Low | ≈ 2–3× alumina |
Alumina tiles are the default because they are cheap, hard and infinitely repairable. Any surface — pipe, chute, hopper, fan casing — can be lined tile by tile, and a worn patch is replaced in minutes without touching the rest of the lining. The system has two weak points, and both are worth knowing before you buy: the tiles are brittle under direct impact, and the fixing layer (adhesive or grout) is usually what fails first in hot or chemically aggressive service.
Reaction-bonded SiC is the specialist for severe points. It is made by infiltrating molten silicon into a SiC skeleton, so the finished body is fully dense — under 0.1% porosity — with no tile joints, no grout and nothing to peel. Where a tiled elbow needs disciplined workmanship to survive, an RBSiC elbow simply is the lining. It costs more per kilogram and it is cast in specific shapes, so it earns its price at the points where failure is expensive: pump wear plates, cyclone cones and apexes, burner and spray nozzles, and the elbows that eat steel quarterly.
The six variables that decide it
Two buyers with the same nominal pipe size can need opposite linings. These are the inputs that matter, in the order our engineers weigh them:
- Particle size distribution. The top size, not the average, drives impact energy. A 5 mm top size is a different lining problem from a 0.5 mm one at identical throughput.
- Velocity. Below 3–4 m/s, alumina nearly always suffices. Above 5 m/s, or at any point where the flow accelerates (pump discharges, restrictions, cyclone feeds), RBSiC enters the conversation.
- Impact events. Lumps dropped into chutes, loader bucket contact, rock re-entry at transfer points. Impact must be managed with geometry or a resilient backing before any ceramic is chosen.
- Temperature. The ceramic survives far more than the fixing system. Adhesive-bonded tile systems are generally limited to roughly 200–400 °C continuous depending on the adhesive; mechanical fixing and cast SiC extend this substantially.
- Chemistry. pH, reagents and chlorides attack the fixing layer long before they attack the ceramic. Acidic duty pushes the choice toward monolithic RBSiC.
- Maintainability. A lined system that can be repaired tile-by-tile during a planned window often beats a marginally longer-life monolithic one that needs a full shutdown to replace.
The selection in one table
This is the same table our engineers apply to a new duty — read your condition, then confirm with the numbers.
| Duty condition | First choice | Why |
|---|---|---|
| Chutes, hoppers, low-velocity sliding abrasion | DA-92 alumina tiles, adhesive or stud-fixed | Lowest cost per tonne handled; field-repairable |
| Tailings / concentrate line, 3–5 m/s, < 5 mm | Alumina-lined pipe segments (DA-92 / DA-95) | Industry default; replaceable segment by segment |
| Pump discharge, cyclone feed, severe elbows, > 5 m/s | DA-SC-R reaction-bonded SiC | No joints, best erosion resistance, monolithic |
| Cyclone underflow / apex | DA-SC-R cone or apex liner | Highest local velocity and acceleration in the circuit |
| Acidic or reagent-laden slurry (pH < 4) | DA-SC-R, with chemically compatible sealing | Grout and adhesives are the vulnerable part of tiled systems |
| Large-lump impact at transfer points | Ceramic-rubber composite or engineered backing first | Ceramics chip under direct impact; absorb the energy first |
Comparing costs without fooling yourself
The purchase order is the least informative line in a wear-lining budget. The number that decides the argument is cost per tonne conveyed, and it is easy to compute: lining cost divided by tonnes handled before replacement — plus the cost of every change-out, which on a live concentrator usually dwarfs the part price.
An illustrative comparison for a DN200 concentrate line running about 4 m/s (figures are typical of published site experience — run your own data before committing):
| Option | Relative installed cost | Typical first intervention | What the change-out costs |
|---|---|---|---|
| Bare 12 mm steel | 1× | Holed in roughly 8–14 months | Cut-out and re-weld, hot work, full standby |
| Alumina-tiled spools (DA-92) | ≈ 2–3× | First tile repairs at ~3–5 years | Tile-by-tile patch, no line removal |
| RBSiC spools at severe points | ≈ 3–5× | Inspection-driven; many run far longer | Segment swap at the worst point only |
Notice what the table does not say: that RBSiC is "better". At a quiet straight run it is expensive insurance. At the elbow that dies quarterly, it is the cheapest thing on the site. The engineering judgement is about where, and the honest suppliers are the ones who will tell you where not to spend.
How linings are fixed and renewed
- Adhesive bonding. Thin, cheap, smooth; suits sliding wear and moderate temperature. The adhesive is the thermal limit of the system.
- Stud-welded or mechanically anchored tiles. For hot surfaces, aggressive chemistry, or where tiles must be replaced in the field. Slightly thicker, more labour, far more forgiving.
- Bolt-on segmental liners. For chutes, hoppers and transfer points — no hot work, installed by site crews, swapped like brake pads.
- Ceramic-rubber composite pads. A resilient rubber layer bonded to ceramic tiles; used where impact and abrasion arrive together, such as crusher feeds and transfer chutes.
- Cast RBSiC segments. For pipes, cones and apexes; supplied to the housing dimensions and replaced individually.
Refurbishment follows the same logic. Tiled equipment is re-tiled patch by patch; RBSiC equipment is surveyed annually and the worst segments are swapped. Either way, the capital asset — the pipe, the chute, the cyclone — stays in service.
Five mistakes that shorten a lining's life
- Buying on hardness alone. A harder tile in an impact zone will crack where a slightly softer system with proper backing would have survived. Duty first, hardness second.
- Ignoring the grout. In tiled systems the lining usually fails at the joints. Tile shape, coverage and workmanship decide the life as much as the ceramic does.
- Lining without checking the bore. A DN200 line with 20 mm tiles runs at DN160 through the lining — pumps and flow rates must be re-checked against the reduced diameter.
- Copying another site. The same ore body at different velocities is a different problem. Copy the method of selection, not the neighbour's bill of materials.
- No spares strategy. The cheapest reliability on a mine site is a shelf of pre-lined elbows and a set of tiles. Decide the spares philosophy at purchase, not after the first hole.
Send us your duty data
Dolphin Advanced Ceramic supplies DA-92 / DA-95 alumina wear tiles, lined pipe segments and DA-SC-R reaction-bonded SiC components from Zibo, Shandong, with pressing, sintering, diamond grinding and assembly in-house. Send four numbers — top particle size, velocity, solids content, temperature — and we will come back with a lining recommendation, a tiling layout or a casting drawing, and a quotation within 24 hours, Monday to Saturday.
Use the RFQ form, email dolphintec@aliyun.com, or send the duty sheet directly on WhatsApp to +86 133 8643 4414. An overview of both materials lives on the wear-resistant ceramics page.
Frequently Asked Questions
Why does ceramic last so much longer than steel in a slurry line?
Steel wears by ductile cutting: sharp particles plough grooves in a surface that is soft compared with the mineral. Alumina at roughly 1,000–1,400 HV and reaction-bonded SiC at 2,200–2,500 HV are one to two orders of magnitude harder than the quartz particles doing the damage, so the particles cannot cut them — they can only micro-chip them, which takes far longer.
Which ceramic lining is best for a tailings pipeline?
For most tailings and concentrate lines — moderate velocity, particles under about 5 mm, few impact events — alumina tiles at 92% or 95% are the industry default and the cheapest per tonne conveyed. Where velocity exceeds roughly 5 m/s, particles are coarse and sharp, or the line contains high-wear points such as pump internals and elbows, reaction-bonded SiC usually wins on total cost.
Can a ceramic lining be repaired without replacing the whole pipe?
Yes, and that is one of the practical advantages of tiled systems. Worn areas are re-tiled in place, tile by tile or patch by patch, without removing the pipeline from service for more than the repair window itself. Cast reaction-bonded SiC is different: it is supplied as discrete segments, so a worn segment is replaced while its neighbours stay in service.
Does a ceramic lining change the pipe's hydraulics?
It slightly reduces the effective diameter and, once polished by the slurry, a ceramic surface is smoother than corroded steel, so friction losses usually stay acceptable. What matters is specifying the lining thickness at the design stage — a DN200 line lined with 20 mm tiles becomes DN160 through the lining — so pumps must be checked against the reduced bore, not the nominal one.
How should wear life claims from suppliers be evaluated?
Ask for the duty behind the number. A life figure without the particle size distribution, solids content, velocity and impact description is a marketing number. Reputable suppliers will state the duty their claim came from and will happily calculate cost per tonne conveyed on your data instead — which is the only comparison that survives contact with an operating mine.