Monolithic refractories are unshaped refractory mixes that are cast, pumped, gunned, rammed, vibrated or troweled into place and form a jointless lining once they set or sinter; they fall into 13 classes from dense castables to taphole clay. Which class a lining takes depends on placement, bond and service, so how are they told apart?
Unshaped refractories is the standards term for the family, and the trade says "refractories and monolithics" to set them apart from bricks. Monolithics are one of three forms of refractory materials, next to shaped bricks and insulation.
ISO 1927-1:2012 designates monolithics by product type, chemical type, main raw material and classification temperature; ASTM C401-12(2022) calls a castable dense above 1.68 g/cm³ (105 lb/ft³) and sets classes from 1095 to 1760 °C (2,000 to 3,200 °F). Mixing water runs from 4 to 8 % in low-cement castables to 20 to 40 % in insulating ones (Jenkins 2011), and tear-out falls under the OSHA silica limit of 50 µg/m³ (29 CFR 1910.1053, effective 2016-06-23).
Every value names its standard and edition, the product data sheet or the dated source it comes from; see our methodology and fact-checking process.
What Are Monolithic Refractories?#
A monolithic refractory is an unshaped refractory, which ISO 836:2001 (term 136) defines as a "mixture of aggregate and bond, prepared ready for use as supplied or after adding one or more liquids, which satisfies the requirements of refractoriness". The term allows metallic, organic or inorganic fibers. ISO 1927-1:2012 excludes raw materials and binder-free crushed or granulated materials from the family.
China produced 23.01 Mt (25.4 million short tons) of refractories in 2022, of which 9.83 Mt (10.8 million short tons) were unshaped, according to a Chinese producer's website summarizing national statistics.
What Monolithic Refractories Are Made Of#
Monolithic refractories are made of refractory grains held by a fine matrix and a binder. The grains change with the class: tabular and calcined alumina, calcined bauxite, chamotte, mullite and kyanite in alumina-silica castables; silicon carbide and carbon in trough castables and taphole clay; silica, alumina-magnesia or magnesia in ramming masses; fused silica in thermal-shock dry vibratables; perlite, vermiculite and hollow-ball aggregates in insulating castables.
The binder, not the grain, separates the families: one high-alumina grain can sit in a cement-bonded castable, a phosphate-bonded plastic or a heat-set dry vibratable. Every grain in these mixes is described under refractory raw materials.
Types of Monolithic Refractories: 13 Classes and One Trade Term#
There are 13 classes of monolithic refractory in three groups, castables, rammed, gunned and vibrated mixes, and jointing, coating, shaped and taphole products, plus refractory cement, a trade term. Table 1 lists each class with its character, placement, bond, main lining zones and US standard.
| # | Class | Character | Placement | Bond | Main zones | US standard (edition) |
|---|---|---|---|---|---|---|
| 1 | refractory castables | dense, hydraulic-bond castables | cast and vibrated | calcium aluminate cement | reheating furnace doors, piers, lintels and car tops; refinery heaters and ducts | ASTM C401-12(2022) |
| 2 | low-cement, ultra-low-cement and no-cement castables | deflocculated castables at reduced or zero cement | cast, pumped, wet shotcrete | reduced CAC; hydratable alumina, colloidal silica or microsilica gel | steel ladles, blast furnace runners, cement kiln nose rings | ASTM C401-12(2022) class names |
| 3 | self-flow and pumpable refractory castables | castables that level without vibration | poured or pumped | low or ultra-low cement, or cement-free | congested anchors, thin sections | ASTM C1446-19(2025) consistency |
| 4 | insulating and lightweight castables | lightweight castables, classes N to V | cast or gunned | calcium aluminate cement | ladle back lining, reheating furnace skid posts, tin bath back lining | ASTM C401-12(2022) N to V |
| 5 | blast furnace trough and runner castables | Al2O3-SiC-C, carbon-containing | cast | low-cement CAC with SiC, carbon and antioxidants | blast furnace main trough, iron and slag runners | n/a |
| 6 | plastic refractories | moist mixes ready to install | rammed with a pneumatic rammer | clay or air bond; phosphate | power boilers, FCC cones and air rings, induction furnace spouts | ASTM C673-97(2022) |
| 7 | ramming mass | dry or premixed masses sintered in place | rammed or vibrated between coil and former | boron addition (silica), in-situ spinel (neutral), sintered magnesia (basic) | coreless induction furnaces, EAF hearth, blast furnace troughs | ASTM C673-97(2022) (fireclay and high-alumina mixes) |
| 8 | gunning mixes and refractory shotcrete | sprayed mixes | dry gunned, wet shotcrete, hot gunned | CAC; phosphate or silicate for hot gunning | refinery shotcrete linings, boiler abrasion linings, EAF banks, BOF, ladles | ASTM C903-15(2020) specimens |
| 9 | dry vibratable mixes | completely dry, heat-set mixes | poured dry and vibrated | heat-set; phenolic resin in MgO tundish mixes | induction furnaces, tundish working lining | n/a |
| 10 | refractory mortar | jointing materials for brick | troweled or dipped | sodium silicate (air-setting), clay (heat-setting), phosphate, CAC | bed and head joints of brick linings | ASTM C1655-06(2022); C199-22 pier test |
| 11 | refractory coatings, washes and spray masses | thin hot-face layers | sprayed or brushed | MgO spray-mass binders; inorganic high-emissivity coatings | tundish working lining, reformer and cracker radiant walls | n/a |
| 12 | precast refractory shapes | castable shapes made off site | set with lifting gear | bond of the parent castable | burner blocks, EAF roof deltas, ladle well blocks | n/a (ISO 1927-7:2012 tests) |
| 13 | taphole clay | anhydrous Al2O3-SiC-C masses | injected by mud gun | coal tar pitch, low-BaP pitch, phenolic novolac, petroleum binder | blast furnace tapholes | n/a |
| 14 | refractory cement | all classes (trade term) | by product | CAC binder, cement-bonded castable, air-setting mortar or silicate paste | by product | n/a |
Rows 1 to 13 are product classes; row 14 is a trade term whose meaning depends on the product. Lining zones are detailed on each class page.
Read a row as a purchase decision: placement names the crew and equipment, and bond predicts how the lining gains strength and whether it needs a controlled first heat.
Castable Families: Dense, Low-Cement, Self-Flow, Insulating and Trough#
Castables form five of the 13 classes and are placed by casting, pumping or spraying a water-mixed dry blend. Dense conventional castables carry the most calcium aluminate cement; the lower cement levels are deflocculated, and self-flow grades among them level into congested anchor fields without vibration.
Insulating castables serve back linings of ladles, reheating furnace skid posts and tin baths (Zhou and Li, 2017). Trough and runner castables are the carbon-containing chemical type of ISO 1927-1:2012, whose silicon carbide and carbon resist wetting by iron and slag.
Rammed, Gunned and Vibrated Mixes: Plastics, Ramming Mass, Gunning and Dry Vibratables#
Four classes are placed by force rather than poured: plastics, ramming masses, gunning mixes and dry vibratables. Plastic refractories arrive moist, with a clay, air or phosphate bond, and are rammed in layers.
Ramming masses are dry or premixed and sinter in place in silica, neutral or basic chemistry. Gunning mixes are sprayed dry, wet or hot. Dry vibratable mixes are completely dry with a heat-set bond and need no cure or dry-out, according to Allied Mineral Products.
Mortars, Coatings, Precast Shapes and Taphole Clay#
Four classes do one job each: refractory mortar joints brick, coatings and spray masses form thin hot-face layers, precast shapes are cast and cured off site, and taphole clay seals the blast furnace taphole between casts. Mortar chemistry follows the brick it joins.
Precast shapes take the bond of their parent castable and are set with lifting gear. Refractory cement, the trade term in row 14, names a binder, a castable, a mortar or a furnace paste depending on the product.
How Are Monolithic Refractories Classified by ASTM and ISO?#
ISO 1927-1:2012 classifies monolithic refractories internationally by product type, chemical type, main raw material and classification temperature; in the US, ASTM C401 covers castables, C673 plastics and ramming mixes, and C1655 mortars. ISO 1927-1:2012 is edition 1 from ISO/TC 33, confirmed on 2023-09-04, and its European adoption EN ISO 1927-1:2012 is current.
ASTM subcommittee C08.09 on Monolithics holds the US methods, such as C860-15(2025) and C1446-19(2025). The two systems describe the same families, but their requirements are not equivalent.
ISO 1927-1 Product Types Next to the ASTM Classifications#
ISO 1927-1:2012 sorts unshaped products into five product types in clause 4, each placed beside its US classification in Table 2.
| ISO 1927-1:2012 product type | Families (Table 1 rows) | US classification (edition) | Note |
|---|---|---|---|
| 4.1 castables | rows 1 to 5, 12 | ASTM C401-12(2022) | same family, not equivalent requirements |
| 4.2 gunning materials | row 8 | n/a (C903-15(2020) prepares specimens) | n/a |
| 4.3 ramming materials | row 7 | ASTM C673-97(2022) (with plastics, row 6) | C673 covers fireclay and high-alumina mixes |
| 4.4 jointing materials | row 10 | ASTM C1655-06(2022) | fireclay and high-alumina mortars |
| 4.5 other monolithic products | rows 9, 11, 13 | n/a | n/a |
After the product type, the ISO designation adds one of four chemical types (alumina-silica, basic, special or carbon-containing), the main raw material and the classification temperature. The full designation scheme and the test parts of the series are set out under ISO 1927 monolithic (unshaped) refractory products.
Castable Classes in ASTM C401: Density, Cement Level and Temperature#
ASTM C401-12(2022) calls a castable dense above a dried bulk density of 1.68 g/cm³ (105 lb/ft³) and assigns regular castables to classes A to G, each holding permanent linear change within 1.5 % after 5 h.
| Class | Test temperature, °C as printed in the standard (°F) | Standard requirement, ASTM C401-12(2022) |
|---|---|---|
| A | 1095 (2,000) | PLC ≤ 1.5 % after 5 h |
| B | 1260 (2,300) | PLC ≤ 1.5 % after 5 h |
| C | 1370 (2,500) | PLC ≤ 1.5 % after 5 h |
| D | 1480 (2,700) | PLC ≤ 1.5 % after 5 h |
| E | 1595 (2,900) | PLC ≤ 1.5 % after 5 h |
| F | 1705 (3,100) | PLC ≤ 1.5 % after 5 h |
| G | 1760 (3,200) | PLC ≤ 1.5 % after 5 h |
| Note: dense | all regular classes | dried bulk density above 1.68 g/cm³ (105 lb/ft³) |
| Note: insulating | N 925 (1,700) to V 1760 (3,200) | PLC ≤ 1.5 %, maximum dried bulk density 0.88 to 1.68 g/cm³ (55 to 105 lb/ft³) |
Insulating castables follow a parallel ladder, N to V, whose density cap rises with the class temperature.
Lime content, among other measures, names the four cement levels of C401-12(2022), conventional (regular), low-cement, ultra-low-cement and no-cement, so a class name is a chemistry statement, not a cement percentage. Each class table of the standard is set out under ASTM C401 classification of castables.
Which Monolithic Suits Which Temperature, Metal and Lining Zone?#
The right monolithic is the class whose bond survives the zone's temperature, whose chemistry resists its metal and slag, and whose placement the access allows. Low-cement castables line ladles and runners, silica or neutral ramming masses line induction furnaces, taphole clay seals blast furnace tapholes, and plastics and gunning mixes line boilers and refinery equipment.
Steel sets the scale: "Around 70 % of refractories are sold to the steel industry," according to the World Refractories Association. A specification should name class, standard and placement for each zone, not a brand.
Monolithic Families by Industry and Lining Zone#
Nine lining applications take different monolithic families zone by zone, as Table 4 shows.
| Industry | Zones | Monolithic families |
|---|---|---|
| refractories for iron and steel | reheating furnace doors, piers and skids; EAF and converter maintenance | conventional castables, insulating castables, hot gunning mixes |
| steel ladle refractory lining | metal zone, bottom and impact pad; back lining | low-cement castables, insulating castables |
| tundish refractories | permanent and working lining | alumina-silica castables, MgO spray masses, MgO dry vibratables |
| blast furnace refractory lining | taphole, main trough, iron and slag runners | taphole clay, trough castables, low-cement castables |
| refractories for cement and lime kilns | kiln hood, nose ring and dams, preheater and calciner, grate cooler | low-cement castables, alkali-resistant castables and gunning mixes, steel-fiber castables |
| refinery and petrochemical refractories | heaters, ducts, FCC cones and air rings, reformer walls | castables and shotcrete under API Std 936, plastics, high-emissivity coatings |
| boiler refractory | boiler walls and abrasion zones | phosphate plastics (50 to 90 % alumina), gunning mixes |
| induction furnace lining | coreless and channel furnaces | silica, neutral and basic ramming masses, dry vibratables |
| melting and holding furnaces | aluminum contact | alumina dry vibratables, non-wetting gunning mixes |
Metal decides the ramming mass in coreless induction furnaces: silica for cast and ductile iron, neutral or basic masses for mild, manganese and stainless steel.
Choosing by Placement: Cast, Pumped, Gunned, Rammed or Vibrated#
Placement narrows the choice once chemistry is fixed: castables need forms and vibration, self-flow grades forms only, gunning mixes no forms, plastics a rammer and dry vibratables a former. Refractory installation methods are compared under refractory installation methods.
Gunning splits into three routes: dry gunning conveys the dry mix and adds water at the nozzle; wet shotcrete pumps a deflocculated low-cement or no-cement castable and flocculates it at the nozzle; hot gunning sprays magnesia or magnesia-chrome mixes with a phosphate or silicate bond onto a working lining between heats.
Binders and Additives in Monolithic Refractories#
Every monolithic class is defined by its bond: calcium aluminate cement in castables and gunning mixes, hydratable alumina or colloidal silica in no-cement castables, phosphate or clay in plastics and mortars, and pitch or resin in taphole clay. ISO 836:2001 (term 049) defines a deflocculated castable as one with a hydraulic bond, at least 2 % by weight of ultra-fine particles below 1 µm and at least one deflocculating agent.
The bond sets the water demand: in the Jenkins (2011) table, conventional castables take 8 to 12 % mixing water at 2,082 to 2,723 kg/m³ (130 to 170 lb/ft³), low-cement castables 4 to 8 % at 2,243 to 2,883 kg/m³ (140 to 180 lb/ft³), and insulating castables 20 to 40 % at 481 to 1,602 kg/m³ (30 to 100 lb/ft³). Each binder and additive group has its own page under refractory additives and binders.
Table 5 maps each bond or additive group to the families that use it.
| Group | Bond or additive | Families |
|---|---|---|
| Hydraulic | calcium aluminate cement for refractories | castables, insulating castables, gunning mixes, trough castables |
| Cement-free | hydratable alumina binder; colloidal silica binders; microsilica gel | no-cement castables |
| Chemical | phosphate binders (phosphoric acid, monoaluminum phosphate) | plastics, mortars, hot gunning |
| Chemical | sodium and potassium silicate binders | air-setting mortars, hot gunning |
| Clay | plastic clay | plastics, heat-setting mortars |
| Carbon | resin and pitch binders | taphole clay, MgO tundish dry vibratables |
| Sintered | boric acid and boron oxide sintering aids | silica ramming mass |
| Additive | dispersants and deflocculants; accelerators and retarders | castables |
| Additive | microsilica in refractory castables | low-cement castables |
| Additive | stainless steel fibers; organic fibers and drying agents | castables, gunning mixes |
| Additive | antioxidants for carbon-containing refractories (Si, B4C) | trough castables |
Hydraulic, Cement-Free and Chemical Bonds#
Hydraulic bonds come from calcium aluminate cement (CAS 65997-16-2, EC 266-045-5), whose hydrates CAH10, C2AH8, C3AH6 and AH3 give green strength. Those hydrates decompose between about 800 and 1100 °C (1,472 and 2,012 °F) before a ceramic bond forms, which leaves an intermediate strength dip (Almatis technical review of matrix aluminas).
Cement-free bonds replace the cement with hydratable alumina, colloidal silica or a microsilica gel. Chemical bonds set without hydration: phosphoric acid with monoaluminum phosphate in plastics, sodium silicate in air-setting mortars, and phosphate or silicate in hot gunning mixes.
Carbon, Heat-Set and Sintered Bonds#
Carbon bonds hold taphole clay: coal tar pitch and low-BaP pitch for injectability and hearth protection, petroleum-based binders for low toxicity and drillability, and phenolic novolac for rapid cure and tapping stability (de Oliveira, 2024). Pitch remains a current binder under the CTPHT rules below.
Heat-set bonds harden dry vibratables when the former is heated. Sintered bonds form in place: silica ramming masses sinter with boric acid or boron oxide, neutral masses form spinel in situ and basic masses sinter as magnesia.
Dispersants, Microsilica and Fibers in Monolithic Mixes#
Five additive groups adjust castables: dispersants cut water, set-control agents time the set, microsilica improves flow, steel fibers control cracks and organic fibers burn out to vent steam. Dispersants moved from polyphosphates to polyacrylates and polycarboxylates.
Microsilica is registered under REACH as "Fumes, silica" (EC 273-761-1), a different substance from colloidal and fumed silica. Stainless steel needle fibers reinforce the lining, while organic fibers leave channels for steam.
Standards and Test Methods for Monolithic Data Sheets#
Monolithic data sheets rest on two layers of standards: classifications that name the class (ASTM C401, C673, C1655 and ISO 1927-1) and test methods that produce the values.
ASTM C401-12(2022) itself calls on C133 for strength, C113 for linear change, C134 for bulk density, C862 for casting specimens and C865 for firing them. The full designation list, ASTM, ISO, EN and API, sits under refractory standards.
Classification and Quality Control Standards by Family#
Table 6 lists the classification and quality control standards that apply to each monolithic family, with US and ISO or EN editions side by side.
| Family | US (edition) | ISO / EN (edition) | Other |
|---|---|---|---|
| Castables | ASTM C401-12(2022) | ISO 1927-1:2012 / EN ISO 1927-1:2012 | API 936 refractory installation quality control: API Std 936, 5th ed. (March 2024) |
| Plastics and ramming mixes | ASTM C673-97(2022) | ISO 1927-1:2012 | n/a |
| Mortars | ASTM C1655-06(2022); C199-22 pier test; C198-09(2025) bond strength | ISO 13765-1:2004, -2:2004, -4:2004, -7:2021 | n/a |
| Gunning mixes | ASTM C903-15(2020) specimens | ISO 1927-1:2012 | n/a |
| Precast shapes | n/a | ISO 1927-7:2012 | n/a |
API Std 936, 5th edition (March 2024), governs installation quality control, inspection and testing of monolithic linings in refineries: qualification of materials, equipment and personnel, production sampling and dryout. The 4th edition (June 2014) is superseded.
Test Methods for Consistency, Specimens and Properties#
Specimen preparation drives every monolithic test result, so Table 7 pairs each ASTM method with its ISO or EN counterpart for the same purpose, never as an equivalent.
| Purpose | ASTM (edition) | ISO / EN (edition) |
|---|---|---|
| Castable consistency | C860-15(2025) ball-in-hand; C1445-13(2025) flow table; C1446-19(2025) self-flow | ISO 1927-4:2012 |
| Specimen preparation | C862-16(2020) casting; C865-22 firing; C903-15(2020) gunning; C1054-24 plastic and ramming pressing | n/a |
| Workability of plastics | C181-11(2025) | n/a |
| Linear change, plastics and ramming mixes | C179-14(2024) | ISO 13765-7:2021 (mortars) |
| Cold crushing strength | C133-24 | ISO 10059-1:2025 / EN ISO 10059-1:2025 |
| Modulus of rupture | C133-24 | ISO 5014:2025 / EN ISO 5014:2025 |
| Permanent linear change | C113-14(2025) | ISO 1927-6:2012 |
| Bulk density and porosity | C134-95(2023); C830-00(2023) | n/a |
| Abrasion | C704/C704M-15(2022)e1 | ISO 16282:2007 / EN ISO 16282:2008 |
On the European side, EN ISO 10059-1:2025 and EN ISO 5014:2025 replaced EN 993-5 and EN 993-6 for crushing strength and modulus of rupture on 2025-12-09.
Precision limits how far one data sheet value travels: the ACerS Bulletin overview of ASTM C08 (2021) prints C133 crushing strength on dense castables at ±7 % within and ±23 % between laboratories, and C1445 flow at ±25 % and ±40 %, figures printed for earlier editions. ASTM C830-00(2023) vacuum porosity is preferred for castables over boiling. What each value means is explained under properties of refractory materials.
Sourcing, Installing and Handling Monolithic Refractories#
Sourcing a monolithic starts with a specification naming class, standard and placement, continues with an installer who mixes, places and dries it to the maker's instructions, and ends with dust rules for silica, cement and pitch.
Customs treat the family as one heading: HS 3816 covers refractory cements, mortars, concretes and similar compositions in the US Harmonized Tariff Schedule (checked 2026-10-27), while shaped bricks fall under 6902.
What a Monolithic Specification and RFQ Contain#
A monolithic specification names class and standard before any property, so suppliers quote the same material. The five request fields are listed below.
- Class and standard: an ASTM C401-12(2022) class, ASTM C673-97(2022) or C1655-06(2022), an ISO 1927-1:2012 designation or a data-sheet reference.
- Chemistry target with basis, such as Al2O3 content.
- Maximum service or classification temperature and lining zone.
- Key properties with their test methods: bulk density, apparent porosity, crushing strength, hot modulus of rupture and permanent linear change.
- Quantity in metric tonnes or bags (US short ton = 907.2 kg), estimated with the refractory castable quantity calculator.
Quotes move with class and grade, raw-material origin, shape complexity, quantity, packaging, freight, trade-remedy duties, and installation and dry-out scope. The US BLS producer price index for clay refractories (WPU1352, 1982 = 100) stood at 405.818 in September 2026, a trend, not a price.
Placement, Dry-Out and Contractor Work on Monolithic Linings#
Water-bearing monolithics need a controlled first heat, because castables, gunning mixes and plastics hold mixing or bound water that turns to steam. Hold temperatures, heating rates and schedules by lining type are set out under refractory dry-out and heat-up schedules.
Heat-set dry vibratables carry no mixing water, and precast shapes arrive shop-cured, dried or pre-fired, which moves drying into the factory.
In refineries, in-service inspection and assessment of linings follows API RP 982, 1st edition, released 2023-11-01, while installation testing follows API Std 936.
Crystalline Silica, Cement and Pitch Rules for Monolithic Work#
Respirable crystalline silica is the main dust hazard of alumina-silica monolithics, limited in US workplaces to 50 µg/m³ (8-h TWA) with an action level of 25 µg/m³ (29 CFR 1910.1053 and 1926.1153, effective 2016-06-23). The EU binding limit is 0.1 mg/m³, respirable fraction, under Directive (EU) 2017/2398 (transposition by 2020-01-17). Quartz (CAS 14808-60-7) carries the ECHA line "No Annex VI entry; product-specific, see supplier SDS (ECHA C&L: no majority; not classified 27.5 %, H372 25.2 %, H373 18.8 %, H350 7.7 %)", and California lists "Silica, crystalline (airborne particles of respirable size)" under Prop 65 for cancer since 1988-10-01; for cristobalite, see the supplier SDS.
Calcium aluminate cement carries "No Annex VI entry; no hazard statement in a majority of ECHA C&L notifications (H315, H318 42.5 % each; H319 38.3 %); classification is product-specific, see the product SDS" (ECHA C&L, read 2026-10-22). Separately, the text of REACH Annex XVII entry 47, as amended by Regulation (EC) No 552/2009, limits soluble Cr(VI) in cement and cement-containing mixtures, when hydrated, to 2 mg/kg (0.0002 %) of the total dry weight of the cement; whether a given product falls under the entry is not assessed here.
Coal tar pitch, high temperature (CTPHT, CAS 65996-93-2, EC 266-028-2) carries "Harmonised CLP Annex VI: H340, H350, H360FD" (index 648-055-00-5) and sits in REACH Annex XIV as entry 41 (Commission Regulation (EU) 2017/999, sunset date 2020-10-04). Boric acid carries "Harmonised CLP Annex VI: H360FD" (index 005-007-00-2, Repr. 1B, Note 11, ATP 20, in application since 2025-02-01) and has been a Candidate List substance since 2010-06-18. Phenolic binders release phenol and formaldehyde on curing. The two safety pages are listed below.
- crystalline silica and cristobalite in refractories: phases and limits.
- coal tar pitch in carbon-bonded refractories: pitch, PAH and resin fumes.
How Do Monolithics Fit Next to Bricks and Insulation?#
Monolithics compete with shaped bricks for the working lining and sit in front of insulation: a monolithic gives a jointless lining in any shape, a brick arrives with its bond formed, and insulation keeps heat in behind both. The trade-offs between a cast and a laid working lining are weighed under castable vs refractory brick.
Refractory masonry is brick laid in refractory mortar, the one monolithic class that serves shaped products. The two sibling hubs are listed below.
- refractory bricks: 15 shaped classes.
- refractory insulation: fiber, insulating firebrick and microporous backup.
What Are Refractory Repair Materials?#
Refractory repair materials are monolithics: gunning mixes, plastics, patching mortars, ramming mixes and coatings that restore a worn or damaged lining without a full reline.
Hot gunning repairs EAF banks, BOF linings and ladles between heats. Cold patching, anchor replacement and refinery repair assessment are covered under refractory repair and maintenance.
Do All Monolithic Refractories Need a Dry-Out?#
No: dry vibratables set by heat and carry no mixing water, and precast shapes arrive cured, dried or fired, while castables, gunning mixes and plastics hold water and need a controlled first heat.
What Does Refractory Mix Mean?#
Refractory mix is a buyer's word for any bagged monolithic, from a dense castable to a mortar or ramming mass, rather than a class name. Class, standard and placement from Table 1 turn it into a quotable request.
The closest trade term, refractory cement, has four senses: the calcium aluminate cement binder, a cement-bonded castable, an air-setting mortar and a sodium-silicate furnace cement paste. Each sense is explained under what the term refractory cement covers.