Calcium aluminate cement (CAC), also sold as high alumina cement or aluminous cement, is the hydraulic binder of refractory castables: a ground clinker built on monocalcium aluminate (CA) that sets with water into hydrates. Those hydrates hold a castable together until a ceramic bond forms at high temperature.
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.
Named refractory grades run from about 40 % to about 81 % Al2O3, and their lime falls from 36 to 40 % CaO in an iron-rich 40 % product to about 18 % in an 80 % product. Castable dosage runs from 20 % in a conventional reference mix down to 0.5 % as a set initiator, and across that range the cement bonds monolithic refractory materials by hydration, the bond family that the overview of refractory materials places among binders and additives.
EN 14647:2005 + AC:2006 covers the 40 % family with an initial set of at least 90 minutes, while the 70 and 80 % grades are assessed under EAD 150002-00-0301. On first heat-up the bond releases free water near 100 °C (212 °F), bound water up to about 549 °C (1,020 °F), and loses its hydrates between about 800 and 1100 °C (1,472 and 2,012 °F).
The identity card below collects the fixed data of the substance.
| Attribute | Value |
|---|---|
| Name and abbreviation | Calcium aluminate cement (CAC); high alumina cement (HAC), aluminous cement |
| CAS and EC | CAS 65997-16-2; EC 266-045-5 (ECHA) |
| Main phase | Monocalcium aluminate CA (CaO·Al2O3, CaAl2O4, CAS 12042-68-1); the cement itself is polyphasic |
| Phases in named products | ISTRA 40: CA with minor C4AF, C2AS and C12A7 (Calucem data sheet, May 2024); EL-61: CA with secondary CA2 (US Electrofused Minerals data sheet) |
| Grades | About 40 to about 81 % Al2O3 across named products (Table 2) |
| Standards | EN 14647:2005 + AC:2006 (40 % family); EAD 150002-00-0301 (refractory cement, CABRC) |
| CLP | No Annex VI entry; see Table 6 for the ECHA C&L notification line |
| Main use | Hydraulic binder of castables, gunning mixes, hydraulic mortars and insulating concretes |
What Is Calcium Aluminate Cement?#
Calcium aluminate cement is a polyphasic substance registered under CAS 65997-16-2 and EC 266-045-5, and its main phase CA (CaO·Al2O3) carries its own CAS number, 12042-68-1, which never identifies the cement. The CA phase has a molar mass of 158.04 g/mol (PubChem CID 159415).
Within a castable the cement supplies the hydraulic bond, the strength that develops after mixing with water and before any firing. Other refractory additives and binders bond by gelation, by chemical reaction or by heat, so the cement is the one binder family that sets by hydration of calcium aluminates among the refractory additives and binders.
Names, Trade Names and Cement Notation#
Calcium aluminate cement goes by six common names: high alumina cement (HAC), aluminous cement, ciment fondu, Tonerdezement, calcium aluminate binder and refractory cement binder, and the EAD calls the refractory product calcium aluminate based refractory cement (CABRC). Cement notation writes C for CaO, A for Al2O3 and H for H2O, so CA2 is calcium dialuminate and CAH10 a hydrate with ten water molecules. The first commercial calcium aluminate cement, Ciment Fondu, was patented by J. Bied of Lafarge in 1908, according to a producer statement.
The trade names of four makers are listed below, in alphabetical order of maker.
- Almatis: CA-14 W, CA-14 M, CA-14 S, CA-270, CA-470 TI, CA-25 R, CA-25 M, CA-25 C
- Calucem: ISTRA 40, ISTRA 50, LUMNITE MG
- Imerys: Ciment Fondu, Secar 51, Secar 71, Secar 712, Secar 80, Secar Plenium, Secar XA, Secar XR, Secar XT
- US Electrofused Minerals: EL-61, EL-70
Calcium Aluminate Cement Grades by Alumina Content#
Refractory calcium aluminate cements are graded by Al2O3 content into 40, 70 and 80 % families, and across the named products CaO falls as Al2O3 rises. Iron oxide falls too, from double digits in the 40 % family to a few tenths of a percent in the higher grades.
Table 2 compares the chemistry, initial set and shelf life of named refractory grades.
| Product (maker data sheet) | Al2O3 % | CaO % | Fe2O3 % | Initial set (method) | Shelf life |
|---|---|---|---|---|---|
| ISTRA 40 (Calucem data sheet, May 2024) | 38 to 42 | 36 to 40 | 13 to 17 | 1 to 4 h (EN 14647 mortar, w/c 0.4) | about 6 months |
| Secar 71 (Imerys typical range) | 68.6 to 70.6 | 28.5 to 30.5 | n/a | n/a | n/a |
| CA-14 W (Almatis data sheet) | typ. 71 to 72 (min. 68 to 70) | typ. 27 to 28 (spec. 25 to 30) | ≤ 0.2 | 150 min (Vicat, NORTAB, typical) | 24 months |
| CA-14 M (Almatis data sheet) | typ. 71 to 72 (min. 68 to 70) | typ. 27 to 28 (spec. 25 to 30) | ≤ 0.2 | 230 min (Vicat, NORTAB, typical) | 24 months |
| CA-14 S (Almatis data sheet) | typ. 71 to 72 (min. 68 to 70) | typ. 27 to 28 (spec. 25 to 30) | ≤ 0.2 | 320 min (Vicat, NORTAB, typical) | 24 months |
| CA-270 (Almatis data sheet) | typ. 71 to 72 (min. 68 to 70) | typ. 27 to 28 (spec. 25 to 30) | ≤ 0.2 | 310 min (Vicat, NORTAB, typical) | 24 months |
| EL-61, fused in electric arc furnaces (US Electrofused Minerals data sheet) | 67.83 | 31.10 | 0.25 | 4 to 12 h (maker method) | n/a |
| Secar 80 (Imerys typical range) | 79.5 to 82.5 | 16.2 to 17.8 | n/a | n/a | n/a |
| Secar XT (Imerys typical range) | 78.5 to 81.0 | 18.5 to 20.5 | n/a | n/a | n/a |
| CA-25 R (Almatis data sheet) | typ. 81 (min. 78) | typ. 18 (17 to 19) | ≤ 0.2 | 50 min (Almatis typical) | n/a |
| CA-25 M (Almatis data sheet) | typ. 81 (min. 78) | typ. 18 (17 to 19) | ≤ 0.2 | 80 min (Almatis typical) | n/a |
| CA-25 C (Almatis data sheet) | typ. 81 (min. 78) | typ. 18 (17 to 19) | ≤ 0.2 | 100 min (Almatis typical) | n/a |
| 80 % grades: 70 % clinker plus fine alpha-alumina, see calcined and reactive aluminas | n/a | n/a | n/a | n/a | n/a |
Typical values of named products, mass %, from each maker's data sheet; not class requirements.
40 Percent Grades and the EN 14647 Window#
EN 14647:2005 + AC:2006 covers calcium aluminate cements with 35 to 58 % Al2O3 by mass, the window of the iron-rich 40 % grades. ISTRA 40 sits inside it with 38 to 42 % Al2O3 and 13 to 17 % Fe2O3, and its declared refractoriness of about 1270 °C (2,318 °F) is a typical value from the Calucem data sheet (May 2024), not a standard requirement. The 70 and 80 % grades fall outside the window, so the 40 % family is the only one of the three that a buyer can hold to a European cement standard.
70 Percent Grades: The Main Refractory Binder#
The 70 % grades are the binders named in most castable test mixes of Table 3, and they differ from the 40 % family by more alumina and almost no iron or silica. Secar 71 analyzes 68.6 to 70.6 % Al2O3 and 28.5 to 30.5 % CaO (Imerys typical range), and the Almatis CA-14 grades carry 71 to 72 % Al2O3 (typical values) with SiO2 at or below 0.3 % and Fe2O3 at or below 0.2 %. Low silica matters because lime and silica combine into low-melting glass on heating, as the binder problems section explains.
80 Percent Grades: Clinker Plus Fine Alumina#
An 80 % grade is a 70 % clinker milled with fine alpha-alumina: EAD 150002-00-0301 allows at least 70 % CAC clinker plus up to 30 % alumina-rich material (Al2O3 above 35 %) and up to 0.2 % additives. That rule explains why the three 80 % products in Table 2 carry about 10 percentage points less CaO than the 70 % products: the added alumina dilutes the clinker's lime. At the same dosage, an 80 % grade therefore puts less CaO into a castable, which matters for classes named by lime content.
How Refractory Grades Are Produced#
Refractory clinker reaches the bag under two composition rules: EN 14647:2005 + AC:2006 requires at least 99.8 % CAC clinker with at most 0.2 % grinding aids, while EAD 150002-00-0301 admits alumina-rich additions. The fused grade in Table 2 is made from calcined alumina and calcium carbonate in electric arc furnaces, and Table 4 gives its fineness after grinding.
Hydration and Setting: How the Cement Bonds#
Calcium aluminate cement sets when its aluminate phases dissolve in the mixing water and precipitate as calcium aluminate hydrates and alumina hydrate, which give a castable its strength between placing and first heat-up. The hydrates are CAH10, C2AH8, C3AH6 and the alumina hydrate AH3. Which values does a buyer specify from this chemistry? Two: the initial setting time, which limits placing time, and early strength, which decides when formwork comes off.
Setting Time: Standard Minimum and Product Values#
EN 14647:2005 + AC:2006 requires an initial setting time of at least 90 minutes, and named refractory grades span from 50 minutes (Almatis CA-25 R) to 4 to 12 hours (EL-61) on their makers' methods. The minimum is a standard requirement for the 40 % family inside the EN 14647 window only, so the 70 and 80 % grades are not bound by it.
The methods behind Table 2 differ (Vicat on the NORTAB method, the EN 14647 mortar at a water to cement ratio of 0.4, in-house methods), so a value compares only with values measured the same way. Even within one maker, the four 70 % grades in Table 2 run from 150 to 320 minutes on the same Vicat method. A set outside a grade's window is adjusted with set-control additions, covered under accelerators and retarders for refractory castables.
Hydrate Phases and Green Strength#
The hydrates CAH10, C2AH8, C3AH6 and AH3 give a cement-bonded castable its green strength, and a conventional castable uses about 25 % of its added water to form them (Jenkins, conference paper, 2011). The rest is free water that leaves on drying, while the bound share leaves only when the hydrates decompose on heating.
Binder Problems: Bag Aging, Cold Curing and Lime-Silica Glass#
Three problems recur with the refractory binder: set delay from aged cement, weak low-temperature hydrates from cold curing and low-melting glass from lime plus silica. In producer trials, 6 weeks in paper bags at 20 °C (68 °F) delayed the setting exotherm of a 68 % CAC bauxite low-cement castable by more than 20 hours, against less than 8 hours with Secar XA (Imerys conference paper, 2025), and curing below 10 °C (50 °F) forms CAH10 and AHx gel that raises the risk of explosive spalling (Almatis technical paper).
Lime from the cement combines with microsilica on heating into low-melting glass, which brings more creep, lower hot strength and higher susceptibility to corrosion, as patent EP2996998B1 describes. This is why low-cement formulations cut the cement level while they keep microsilica for flow, the trade-off weighed under microsilica in refractory castables. High alumina cement concrete in buildings has its own problems, which are outside this reference.
Role and Dosage in Refractory Products#
In refractories, calcium aluminate cement is the hydraulic binder of conventional, low-cement and ultra-low-cement castables, self-flow castables, gunning mixes, hydraulic mortars and insulating concretes, at dosages from about 20 % down to 3 % or less. Table 3 gives the role and the dosage with its basis for each product class.
Table 3 compares the role and dosage of the cement across refractory product classes.
| Product class | Role of the cement | Dosage and basis | Page |
|---|---|---|---|
| Conventional castables | Hydraulic binder | 20 % CAC in a conventional reference concept, 84 % Al2O3, 5.0 % CaO, 10 % mixing water (Almatis technical paper, typical data); 10 to 30 % cement by weight in patent WO1996001700A1 (a formulation figure, not a class limit) | refractory castables |
| Low-cement castables | Binder at reduced level | 5 % CA-14 M in test mixes (Almatis technical paper) | low-cement, ultra-low-cement and no-cement castables |
| Ultra-low-cement castables | Binder with hydratable alumina | 3 % CA-14 M plus 1 % Alphabond 300 (Almatis technical paper); 2.5 % Secar 71 in a lab ULCC (Kalpakli, 2008) | low-cement page (row above) |
| No-cement microsilica-gel castables | Set initiator only | 0.5 % of a 70 % Al2O3 CAC (Elkem lab, Peng and Myhre) | low-cement page (row above) |
| Self-flow castables | Hydraulic binder | Secar 71 named as binder (Bezerra et al., Ceramics International 46 (2020) 3209-3217); level n/a | self-flow and pumpable refractory castables |
| Gunning mixes | Dry-gun binder | 12 % Secar XR in a bauxite gunning mix with 3 % silica fume (Imerys trial) | gunning mixes and refractory shotcrete |
| Trough repair mixes | Binder | 5 % in a BFA-SiC trough repair mix (Imerys trial) | blast furnace trough and runner castables |
| Hydraulic mortars | Hydraulic bond | Aggregate to cement 2.0 to 4.0 by volume (max. 6.0); water to cement 0.3 to 0.6 by volume (max. 1.0) (EAD 150002-00-0301 mix design) | refractory mortar |
| Insulating concretes | Binder | Aggregate to cement 3.0 to 5.5 by volume (max. 9.0) (EAD 150002-00-0301 mix design) | insulating and lightweight castables |
| All cement-bonded classes | Water demand of the cement fines | Set by the dispersant system | dispersants and deflocculants for castables |
Conventional, Low-Cement and Ultra-Low-Cement Castables#
Castable classes are named for the cement they contain: ASTM C401-12(2022) separates regular, low-, ultra-low- and no-cement castables by CaO content, and ISO 836:2001 names them as terms 086, 079, 135 and 090. The criterion is lime, not cement mass, so a cement percentage from a patent or a test mix is a formulation figure, not a class limit.
The test mixes in Table 3 trace a lime ladder: the 20 % cement of the conventional reference concept leaves 5.0 % CaO in the castable, while in a no-cement castable 0.5 % cement only starts the set of a microsilica gel. In the ultra-low-cement mix 1 % hydratable alumina shares the bond and adds hydraulic strength without lime. Each step down in cement cuts the lime available to form glass with silica and the water bound in hydrates.
Gunning Mixes, Mortars and Insulating Concretes#
Outside cast linings the cement binds dry-gunning mixes, hydraulic mortars and insulating concretes, at dosages that producer trials and EAD 150002-00-0301 state by mass or by volume. The EAD mix designs run leaner for concretes (aggregate to cement up to 9.0) than for mortars (up to 6.0). The gunning trial in Table 3 pairs 12 % cement with 3 % silica fume, the lime and silica pairing whose glass formation is described under binder problems.
Industries Where Cement-Bonded Linings Serve#
Five lining types show how the cement level follows the service, as listed below.
- Steel ladles: low-cement and ultra-low-cement castables carry a CAC bond in the steel ladle refractory lining, and Nippon Steel has developed an SrO-Al2O3 cement with a higher melting point than CAC (Matsui and Taki, Nippon Steel Technical Report No. 125, 2020).
- Aluminum furnaces: low-cement and ultra-low-cement castables carry the CAC bond in refractories for aluminium service, and chlorine fluxes degrade that bond.
- Refinery linings: conventional or low-cement castables with a hydraulic CAC bond serve as refinery and petrochemical refractories, with quality control under API Std 936, 5th ed. (March 2024).
- CFB boilers: low-cement CAC-bonded castables serve as boiler refractory at CaO 1.2 % and 1.5 %, typical values of EZ CUBED 80-15 and EZ CUBED 56SCPC, Resco data sheets.
- Cement-kiln preheaters: in refractories for cement and lime kilns, no-cement bonds resisted alkali-sulfate cycling better than CAC bonds in a Vesuvius refill test of 6 cycles at 1200 °C (2,192 °F).
Properties of the Cement and of the Bond It Forms#
The cement's own data, fineness, set and mortar strength, describe how it will place, while the strength of the bond after drying and after firing describes how a castable will behave in service. Table 4 keeps standard requirements and typical values of named products in separate columns.
Table 4 compares standard requirements with typical values of named products.
| Property | Standard requirement (EN 14647:2005 + AC:2006 or EAD 150002-00-0301) | Typical value (product, basis) | Page |
|---|---|---|---|
| Compressive strength at 6 h | ≥ 18 MPa (2,611 psi), EN 14647 | > 30 MPa (4,351 psi), ISTRA 40 (Calucem data sheet, May 2024) | cold crushing strength |
| Compressive strength at 24 h | ≥ 40 MPa (5,802 psi), EN 14647 | > 50 MPa (7,252 psi), ISTRA 40; 35 to 52 MPa (5,076 to 7,542 psi) cured 24 h, CA-14 and CA-270 (Almatis data sheet) | see row above |
| Cold crushing strength after drying at 105 °C (221 °F) | n/a | 55 to 74 MPa (7,977 to 10,733 psi), CA-14 and CA-270 (Almatis data sheet) | see row above |
| Cold crushing strength after firing at 1000 °C (1,832 °F) | n/a | 25 to 44 MPa (3,626 to 6,382 psi), CA-14 and CA-270 (Almatis data sheet) | see row above |
| Initial setting time | ≥ 90 min, EN 14647 | see Table 2 | n/a |
| Fineness | n/a | Blaine 3,100 to 3,700 cm²/g, 90 µm residue < 5 %, ISTRA 40; Blaine 4,441 cm²/g, 44 µm residue 0.26 %, EL-61; D50 6 to 13 µm, CA-14 and CA-270 | n/a |
| Bulk density | n/a | about 1.15 g/cm³ (72 lb/ft³), specific gravity 3.2 to 3.3, ISTRA 40 | n/a |
| Refractoriness | Tested to EN 993-12:1997 and reported, EAD 150002-00-0301 | about 1270 °C (2,318 °F), ISTRA 40; 1460 °C (2,660 °F), EL-61 (US Electrofused Minerals data sheet) | refractoriness and pyrometric cone equivalent |
| Chemical limits | Cl ≤ 0.10 %; Na2O + 0.658 K2O ≤ 0.4 %; SO3 ≤ 0.5 %; S2- ≤ 0.10 %, EN 14647 | see Table 2 | n/a |
The 40 % product clears the EN 14647 strength minimums by 12 MPa (1,740 psi) at 6 hours and by more than 10 MPa (1,450 psi) at 24 hours, the comparison a buyer of a 40 % cement makes. Declared refractoriness rises from about 1270 °C (2,318 °F) for the iron-rich 40 % product to 1460 °C (2,660 °F) for the fused 70 % product, whose Fe2O3 is 0.25 % against 13 to 17 %. EAD 150002-00-0301 sets no refractoriness limit; it requires testing to EN 993-12:1997 and reporting, so declared values compare only when both come from that method.
What Happens to the Cement Bond on First Heat-Up#
On first heat-up the cement bond gives up its water in steps: free water near 100 °C (212 °F), then bound water from the hydrates at about 227, 277 and 549 °C (440, 530 and 1,020 °F), according to HWI guidance. Each step turns water into steam inside a dense, low-permeability matrix, and steam that cannot escape fast enough spalls a wet cement-bonded lining. The aggregate carries no hydrate water, so the cement level sets how much steam a lining must release.
The hydrates are lost between about 800 and 1100 °C (1,472 and 2,012 °F) before ceramic bonding sets in, an intermediate strength dip that shows in the CA-14 and CA-270 drop from 55 to 74 MPa after drying to 25 to 44 MPa after firing at 1000 °C (1,832 °F) (Almatis technical paper and data sheet). Holds and heating rates by castable class belong to refractory dry-out and heat-up schedules.
A higher cement content carries more combined water into the heat-up. Cold-cured castables also carry CAH10 from curing below 10 °C (50 °F), so the curing temperature record matters before the first burner is lit.
Standards for Calcium Aluminate Cement#
Calcium aluminate cement is specified in Europe by EN 14647:2005 + AC:2006 for the 40 % family, while the 70 and 80 % refractory grades fall outside its window and are assessed under EAD 150002-00-0301. EN 14647 sets compressive strength of at least 18 MPa (2,611 psi) at 6 hours and 40 MPa (5,802 psi) at 24 hours on its mortar method, plus limits on chloride, alkalis, sulfate and sulfide; its corrigendum took effect on 2006-11-29, and CEN/TC 51 held no revision project on 2026-10-27.
In the United States, ASTM C401-12(2022) classifies the castables the cement binds by CaO content, not the cement itself, and ISO 836:2001 supplies the matching terms. With no ASTM specification for the cement as a material, a US buyer specifies the cement by data sheet and the castable by its class, as set out under ASTM C401 classification of castables.
Table 5 compares the standards that apply to the cement and to the castables it binds.
| Scope | Standard (edition) | What it sets | Status |
|---|---|---|---|
| CAC with 35 to 58 % Al2O3 | EN 14647:2005 + AC:2006 (corrigendum effective 2006-11-29) | Composition, compressive strength, initial set, chemical limits, conformity | Current; no revision project in CEN/TC 51 (2026-10-27) |
| Refractory CAC (CABRC) | EAD 150002-00-0301 (July 2015, OJEU 2017) | Clinker ≥ 70 %, alumina-rich material ≤ 30 %, additives ≤ 0.2 %; refractoriness reported; class A1; Cr(VI) per entry 47 | Current EAD |
| Refractoriness test | EN 993-12:1997 | PCE method named by the EAD | Current |
| Castable classes by CaO | ASTM C401-12(2022); ISO 836:2001 terms 086, 079, 135, 090 | Class names for the castables the cement binds | Active; ISO 836 confirmed 2022-06-24 |
| Refinery linings | API Std 936, 5th ed. (March 2024) | Quality control of monolithic linings | Current |
No ASTM specification for the cement itself is listed; ASTM classifies the castables.
Regulation and Safety#
Calcium aluminate cement has no harmonised CLP classification, and no hazard statement reaches a majority of ECHA C&L notifications, so the product SDS decides its labelling. It is REACH registered as "Cement, alumina, chemicals" (EC 266-045-5, ECHA CHEM, read 2026-11-02) and is alkaline when wet, so skin and eye protection follow the product SDS. Table 6 prints the classification line verbatim.
Separately, REACH Annex XVII entry 47 (Regulation (EC) No 552/2009 text, EUR-Lex consolidated version of 2025-06-23) bars cement and cement-containing mixtures that contain, when hydrated, more than 2 mg/kg (0.0002 %) soluble chromium VI of the total dry weight of the cement, requires packing-date marking where reducing agents are used and exempts controlled closed and totally automated processes; whether a given product falls under the entry is not assessed here. EAD 150002-00-0301 requires calcium aluminate based refractory cement to meet entry 47, with monthly control only where a reducing agent is added.
Table 6 compares the classification and regulatory texts that apply to the cement.
| Topic | Rule or classification | Instrument and date |
|---|---|---|
| CLP classification | "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" | CLP Regulation (EC) No 1272/2008 Annex VI and ECHA C&L notifications, read 2026-10-22 |
| REACH registration | Registered, EC 266-045-5 | ECHA CHEM, read 2026-11-02 |
| Soluble Cr(VI) in cement | Entry text: max. 2 mg/kg (0.0002 %) of the dry cement weight when hydrated; packing-date marking where reducing agents are used | REACH Annex XVII entry 47 (Regulation (EC) No 552/2009 text), EUR-Lex consolidated version of 2025-06-23 |
| Refractory cement (CABRC) | Cr(VI) control to entry 47; reaction to fire class A1 without testing | EAD 150002-00-0301 (OJEU 2017); Decision 96/603/EC |
| Handling | Alkaline when wet; skin and eye protection per the product SDS | Product SDS |
| Hazards across refractory products | See refractory health and safety | n/a |
Buying Calcium Aluminate Cement: Grades, Shelf Life and Makers#
Calcium aluminate cement is bought by grade and data sheet, and four makers publish the refractory grades named here: Almatis, Calucem, Imerys and US Electrofused Minerals. The six points a buyer states are listed below.
- State the Al2O3 grade (40, 70 or 80 %) or the named product and accepted equivalents.
- State the initial set window with its method, since Table 2 values compare only within one method.
- Ask for the date of manufacture on every bag, because aged cement in paper bags delays the set by hours.
- State the accepted shelf life against the data sheet (about 6 to 24 months in Table 2).
- Ask for the SDS and the REACH registration status.
- State packaging and quantity in tonnes, from paper bags to big bags.
Origin is a further quote factor: Secar 71 is produced in France, the UK, the USA, China and, since 2023, India (Imerys conference paper, 2025). Buying routes through makers and distributors are listed under refractory manufacturers and suppliers.
Price: Quote Factors Instead of a List Price#
Calcium aluminate cement is priced per quote, and six factors set the price: grade, origin, quantity, packaging, freight and payment terms. Table 8 compares each factor with what a buyer states in a request.
| Price factor | What the buyer states |
|---|---|
| Grade | Al2O3 class, named product or accepted equivalent |
| Origin | Production country |
| Quantity | Tonnes, annual or spot |
| Packaging | Bag size or big bag; date-of-manufacture limit |
| Freight | Delivery country and Incoterms |
| Payment terms | Terms the buyer accepts |
Industrial calcium aluminate cement is priced per quote.
Calcium Aluminate Cement Compared With Other Refractory Binders#
Calcium aluminate cement competes with cement-free binders that avoid lime in the matrix: hydratable alumina, colloidal silica, phosphate binders and microsilica gel. In one trial reported by Imerys (conference paper, 2025), a no-cement castable reached about 50 % higher hot modulus of rupture at 1450 °C (2,642 °F) than an ultra-low-cement one, through in-situ mullite.
The term refractory cement has more than one sense: in the binder sense it means calcium aluminate cement binding castable aggregate, while bags sold under that name can hold a castable or an air-setting mortar, as the page on refractory cement explains. Calcium aluminate cement in building products and as a cement additive is a separate topic and is not covered here.
Table 7 compares calcium aluminate cement with the alternative refractory binders.
| Binder | Bond type | Key difference from CAC (value and basis) | Page |
|---|---|---|---|
| Hydratable alumina | Hydraulic, boehmite gel and bayerite | No lime; more hygroscopic than CAC; shelf life 6 months unopened (Alcoa 1996), 12 months with new packaging (Almatis) | hydratable alumina |
| Colloidal silica | Sol-gel | 10 wt % sol (40 % solids) replaces 10 % CAC plus 8 % water; gelled by 0.01 to 0.1 wt % fine MgO; permeability up to two orders of magnitude above a CAC castable after 120 to 350 °C (248 to 662 °F) (lab, Salomao et al. 2025) | colloidal silica binders |
| Phosphate binders | Chemical, heat-set | Phosphoric acid or monoaluminum phosphate instead of a hydraulic set | phosphate binders |
| No-cement castable vs ultra-low-cement castable | In-situ mullite | About 50 % higher HMOR at 1450 °C (2,642 °F) (Imerys trial) | low-cement, ultra-low-cement and no-cement castables |
| Refractory cement, mortar and castable | Term comparison | Refractory cement in the binder sense is CAC; products sold under the name can be castables or mortars | refractory mortar vs refractory cement vs castable |
Calcium Aluminate Cement vs Portland Cement#
Calcium aluminate cement differs from Portland cement in its reactive phases and identity: CAC sets through calcium aluminates, and Portland cement is a separate substance, CAS 65997-15-1 and EC 266-043-4. Their notified hazards differ too: for Portland cement the ECHA C&L line, read 2026-10-22, is "No Annex VI entry; ECHA C&L notified classification: H315, H317, H318, H335", a majority set that includes skin sensitization, while no statement reaches a majority for calcium aluminate cement (Table 6). Because EN 14647:2005 + AC:2006 requires the cement to be almost pure CAC clinker, a calcium aluminate cement is not a Portland blend.
What Is the Main Purpose of Alumina in Cement?#
In a refractory cement, more alumina means less lime: Almatis CA-25 (typical value 81 % Al2O3) carries about 18 % CaO against 27 to 28 % for CA-14, and less lime leaves less low-melting phase in the castable matrix. The declared refractoriness in Table 4 also rises with the alumina content of the named products.