MgO 60 – 80% · Cr₂O₃ 8 – 20% · Max 1700 °C
Magnesia-Chrome (MgO-Cr₂O₃) Refractory Bricks
Supplier and exporter from Rajkot, India. The historical primary lining for cement rotary kiln burning zone, copper smelting and glass-tank regenerator service. Supplied subject to buyer's Cr (VI) compliance specification.
- MgO60 – 80%
- Cr₂O₃8 – 20%
- Bulk density≥ 3.00 g/cm³
- CCS≥ 45 MPa
- RUL T₀.₅≥ 1650 °C
- Max temp1700 °C
About this product
What magnesia-chrome refractory bricks are — and where they fit
Magnesia-chrome (MgO-Cr₂O₃) refractory bricks are basic refractories manufactured from sintered magnesia and natural chromite ore, fired to dense ceramic bodies in which magnesia-chromite spinel forms as the key bonding phase. Typical chemistry is 60 – 80% MgO and 8 – 20% Cr₂O₃, with controlled SiO₂ and Fe₂O₃. Apparent porosity is ≤ 18%, bulk density ≥ 3.00 g/cm³, CCS ≥ 45 MPa and RUL T₀.₅ ≥ 1650 °C. The brick is engineered for high-temperature basic-slag environments where pure magnesia would suffer from poor structural cohesion and dolomite would be chemically compromised.
What is a magnesia-chrome brick? A magnesia-chrome brick is the historical industry-standard cement-kiln burning-zone refractory and remains the preferred lining for copper smelting and glass-tank regenerator service. The chrome content delivers two performance benefits — it forms a stable spinel phase with magnesia that resists thermal-cycle micro-cracking, and it improves resistance to wetting by basic clinker melts. Compared to pure magnesia bricks, the magnesia-chrome formulation gives significantly better thermal-shock and clinker-coating performance.
Important environmental note: used magnesia-chrome refractory can develop hexavalent chromium (Cr VI) during service. This is a regulated occupational and environmental hazard in many jurisdictions, and most modern cement plants have migrated to chrome-free magnesia-spinel or magnesia-hercynite alternatives for burning-zone duty. Buyers should confirm the Cr (VI) handling, disposal and customs requirements that apply at their site — firebrickssource.com supplies magnesia-chrome refractory bricks subject to the buyer's specification, and shares the Cr (VI) handling note on dispatch.
firebrickssource.com supplies magnesia-chrome in 230 × 114 × 65 mm and in cement-kiln rotary shapes (ISO 60° / 90° taper, VDZ / ASTM key), glass-tank checker bricks and copper-smelter shapes on indent. The grade is exported to copper smelters, glass-works and non-ferrous plants in the Middle East, Southeast Asia and Africa. See cement & lime industry and non-ferrous industry for application context, and the basic refractories index for adjacent grades.
Technical specifications
Full property data — magnesia-chrome bricks
| Property | Value | Test method |
|---|---|---|
| MgO content | 60 – 80 % | IS 1528-7 |
| Cr₂O₃ content | 8 – 20 % | IS 1528-7 |
| SiO₂ content | ≤ 4 % | IS 1528-7 |
| Fe₂O₃ content | ≤ 12 % | IS 1528-7 |
| Apparent porosity | ≤ 18 % | IS 1528-8 / ASTM C20 |
| Bulk density | ≥ 3.00 g/cm³ | IS 1528-12 |
| Cold crushing strength (CCS) | ≥ 45 MPa | IS 1528-4 / ASTM C133 |
| Refractoriness under load (RUL T₀.₅) | ≥ 1650 °C | IS 1528-2 |
| Permanent linear change | ± 0.5 % | IS 1528-6 |
| Max service temperature | 1700 °C | — |
| Standard size | 230 × 114 × 65 mm | — |
| Custom sizes | Cement-kiln rotary shapes, glass checker, copper-smelter shapes — to drawing | — |
*Typical certified values — actual batch values issued on the per-shipment test certificate. Values aligned with IS 1528 / ASTM C-series / EN 993 test methods.
Applications
Where to use magnesia-chrome refractory bricks
- Cement rotary kiln burning zone (primary lining)
- Cement kiln transition zone (back-up)
- Copper smelting reverberatory furnace
- Copper Peirce-Smith converter linings
- Copper anode furnace linings
- Glass-tank regenerator chamber checker bricks
- Nickel and lead smelter linings
- Ferro-alloy submerged arc furnace linings
- Zinc fuming furnace linings
- High-temperature non-ferrous holding furnaces
Datasheet
Download technical datasheet
PDF with all certified properties, chrome-content variants, dimensional tolerances and Cr (VI) handling note. Use this for tender attachments and procurement files.
Download MgO-Cr datasheet (PDF)Quote request
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Application, kiln/vessel diameter, brick mix, Cr (VI) handling spec, Incoterm. Quote, datasheet and lead time come back the same business day or the next.
Frequently asked
MgO-Cr bricks — questions buyers ask
What is a magnesia-chrome (MgO-Cr₂O₃) brick?
Magnesia-chrome refractory bricks are basic refractories composed of 60 – 80% MgO and 8 – 20% Cr₂O₃, typically using chromite ore and sintered magnesia aggregate. The chrome content forms a magnesia-chromite spinel phase that gives the brick its distinctive resistance to alkaline cement-clinker slag and oxidising basic atmospheres up to 1700 °C.
Where are magnesia-chrome bricks used?
Typical applications include cement rotary kiln burning zone (the historical primary lining), copper smelting reverberatory and converter linings, glass-tank regenerator chamber checker bricks, lead and nickel non-ferrous smelters, and high-temperature ferro-alloy furnace linings.
Is there an environmental restriction on chrome refractories?
Yes — used magnesia-chrome refractory waste can develop hexavalent chromium (Cr VI) during high-temperature service, which is a regulated occupational and environmental hazard. Many cement plants have migrated to chrome-free magnesia-spinel or magnesia-hercynite alternatives. Buyers must confirm Cr (VI) handling, disposal and customs requirements before specifying — we share the specification on dispatch.
When is magnesia-chrome still the right choice?
Magnesia-chrome remains preferred for copper and nickel non-ferrous smelting, glass-tank regenerators, and certain cement burning-zone retrofits where customer specification permits. The brick continues to outperform chrome-free alternatives in highly oxidising basic-slag environments above 1500 °C.
What is the standard size of magnesia-chrome bricks?
Standard size is 230 × 114 × 65 mm. Cement-kiln rotary-shape (ISO 60° / 90° taper, VDZ / ASTM key shapes) and glass-tank checker shapes are produced on indent — provide kiln diameter and brick layout.
What is the typical MOQ and packaging?
Standard MOQ is 10 – 20 MT. Bricks are shrink-wrapped, edge-protected, on heat-treated wooden pallets. One 20-foot container typically carries 22 – 25 MT of magnesia-chrome refractory bricks.
Do you provide samples and test certificates?
Yes. Samples can be dispatched on request — normally chargeable plus courier. Every batch is tested for MgO, Cr₂O₃, Fe₂O₃, SiO₂, bulk density, porosity, CCS and RUL; a test certificate plus Cr (VI) handling note ship with each consignment.
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Primary application