Skip to content
Material World
Application

Refractory lining

Materials that line furnaces, kilns and reactors — the reason it is possible to contain a process hotter than most metals survive.

Every high-temperature industrial process needs a container that survives it, and that container is almost always a ceramic or mineral lining rather than a metal shell. Steelmaking, glassmaking, cement kilns and non-ferrous smelting all run at temperatures that would soften or melt the steel structure holding them.

The demands are unusual because they compete. A lining must resist heat, resist chemical attack from molten metal or slag, survive repeated thermal cycling without spalling, and ideally insulate — and the materials best at one are frequently poor at another, so linings are built in layers with different jobs.

Uses

Blast furnace and steel ladle linings, glass tank blocks, cement kiln linings, foundry crucibles and the firebrick in domestic stoves and chimneys.

Materials divide by what they must resist. Silica and fireclay serve where conditions are moderate; alumina and magnesia where they are not; carbon and silicon carbide where thermal shock or slag attack dominates. Olivine and chromite are used as foundry sands and linings for the same reason — high melting point and low reactivity with molten metal.

Medium confidence Weak evidence

How we know: checked recently · only one source, so there is nothing to cross-check it against · stated directly by the source.

How this connects

Where a connection has been confirmed by an outside reference, that reference is named beside it.

uses

  • Olivine — mineral · foundry sand and furnace lining — high melting point, low reactivity with molten metal
  • Aluminium oxide — compound · the standard high-alumina refractory where conditions are severe
  • Technical ceramic — material · kiln furniture and furnace components
  • Silicon carbide — compound · where thermal shock resistance matters more than pure refractoriness
  • Clay — material · fireclay brick, the oldest and cheapest lining material
  • Feldspar — mineral · as the alumina source in ceramic bodies
  • Forsterite — mineral · olivine brick and foundry sand, which resist molten iron and slag
  • Beta quartz — mineral · not as a material but as a constraint: the inversion through 573 °C governs how fast refractory and ceramic ware may be fired and cooled
  • Refractory brick — material · chosen to match the slag it will meet rather than for how hot it can get
  • Zirconia — compound · as a thermal barrier sprayed a fraction of a millimetre thick on turbine blades, which is what lets the turbine run hotter than its alloy could survive

Sources

  • Material World
    Our own writing

Questions this page answers

Where it comes from, and what it becomes

Follow Refractory lining back to what it starts as, and forward into what it becomes. Each step is a documented one — a real route material takes, not a chain of inference.

Upstream — what it comes from

  • Refractory lining → uses (the standard high-alumina refractory where conditions are severe) → Aluminium oxide → is sourced from (dissolved out with hot caustic soda in the Bayer process) → Bauxite → is sourced from (the residue of prolonged tropical weathering, which strips the silica and alkalis out of an aluminosilicate rock and leaves the aluminium behind — basalt is one common parent among several) → Basalt → is sourced from (partial melting of mantle peridotite is what basalt magma is — the residue left behind stays peridotite, depleted of what went into the melt) → Peridotite → is composed of (the mineral that defines the rock and gives it its name — a peridotite is olivine-dominant by definition) → Olivine
  • Refractory lining → uses (where thermal shock resistance matters more than pure refractoriness) → Silicon carbide → is produced by (the product the process was built for, crystallised out of sand and coke at around 2,500 °C) → Acheson process → takes as input (sand and coke, heated to 2,500 °C, which is how silicon carbide has been made since 1893) → Sand → is sourced from (the ultimate source of most of it — granite weathers, the feldspar becomes clay and washes out, and the quartz survives as grains) → Granite → is composed of (by volume, alongside feldspar and lesser mica) → Quartz
  • Refractory lining → uses (kiln furniture and furnace components) → Technical ceramic → is composed of (alumina is the most-used engineering ceramic) → Aluminium oxide → is sourced from (dissolved out with hot caustic soda in the Bayer process) → Bauxite → is sourced from (the residue of prolonged tropical weathering, which strips the silica and alkalis out of an aluminosilicate rock and leaves the aluminium behind — basalt is one common parent among several) → Basalt → is composed of (an early-crystallising constituent of basaltic magma) → Olivine
  • Refractory lining → uses (chosen to match the slag it will meet rather than for how hot it can get) → Refractory brick → is composed of (calcined, as the alumina source for the high-alumina grades) → Bauxite → is sourced from (the residue of prolonged tropical weathering, which strips the silica and alkalis out of an aluminosilicate rock and leaves the aluminium behind — basalt is one common parent among several) → Basalt → is sourced from (partial melting of mantle peridotite is what basalt magma is — the residue left behind stays peridotite, depleted of what went into the melt) → Peridotite → is composed of (the mineral that defines the rock and gives it its name — a peridotite is olivine-dominant by definition) → Olivine
  • Refractory lining → uses (as a thermal barrier sprayed a fraction of a millimetre thick on turbine blades, which is what lets the turbine run hotter than its alloy could survive) → Zirconia → is produced by (from zircon sand, dissociated at high temperature and then stabilised with yttria or magnesia to stop it shattering as it cools through a phase change) → Calcination → takes as input (heated until the carbonate decomposes to lime and carbon dioxide) → Limestone → is sourced from (precipitated from it, mostly by organisms building shells and skeletons out of dissolved calcium and carbonate) → Seawater → is composed of (about 96.5 per cent by mass — seawater is 3.5 per cent dissolved solids and the rest of it is this) → Water
  • Refractory lining → uses (fireclay brick, the oldest and cheapest lining material) → Clay → is sourced from (clay is chiefly what feldspar becomes when it weathers) → Orthoclase

These are the most distinct paths back. Refractory lining can be traced through others besides.