Refractory Bricks Introduction

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Refractory Brick

Refractory bricks (also known as fire bricks) are shaped refractory materials made from refractory raw materials through batching, forming and high-temperature firing. They maintain stable physical and chemical properties at temperatures above 1580℃ and serve as the core lining material for industrial kilns and thermal equipment.

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Describe

Refractory Bricks Introduction

bricks (also known as fire bricks) are shaped refractory materials made from refractory raw materials through batching, forming and high-temperature firing. They maintain stable physical and chemical properties at temperatures above 1580℃ and serve as the core lining material for industrial kilns and thermal equipment.

I. Core Properties

Refractoriness: ≥1580℃, no softening or melting at high temperatures.
High-temperature strength: Withstands impact and pressure from furnace charge and molten slag.
Thermal shock resistance: Resists rapid heating and cooling, no cracking under drastic temperature changes.
Corrosion resistance: Resists corrosion by acidic/alkaline slags, molten metals and gases.
Volume stability: Small volume change at high temperatures, no shrinkage or expansion.

II. Main Classification (By Material)

1. Silica-alumina Series (Most Common)

Fireclay Bricks

Composition: Al₂O₃ 30%–48%, SiO₂ 45%–65%.
Features: Low cost, good thermal shock resistance, acid and alkali resistance.
Applications: Boilers, hot blast stoves, ceramic kilns, flues.

High-Alumina Bricks

Composition: Al₂O₃ ≥48%.
Features: High refractoriness (1750–1790℃), high strength.
Applications: Blast furnaces, electric furnaces, cement kilns, glass furnaces.

Silica Bricks

Composition: SiO₂ ≥93%.
Features: Strong acid resistance, stable volume at high temperatures.
Applications: Coke ovens, regenerators of glass furnaces.

2. Basic Refractory Bricks

Magnesite Bricks

Composition: MgO ≥80%.
Features: Excellent resistance to alkaline slags, high temperature resistance (2000℃+).
Applications: Converters, electric furnaces, burning zones of cement kilns.

3. Neutral/Special Refractory Bricks

Corundum Bricks

Composition: Al₂O₃ ≥90%.
Features: High temperature resistance, wear resistance, slag resistance, metal corrosion resistance.
Applications: Blast furnaces, converters, glass melting tanks, high-temperature kilns.

Carbon Bricks/Graphite Bricks

Composition: Carbon/Graphite.
Features: High temperature resistance, good thermal conductivity, thermal shock resistance, resistance to molten iron penetration.
Applications: Blast furnace hearths, aluminum reduction cells.

III. Industrial Application Fields

Iron & Steel: Blast furnaces, converters, electric furnaces, coke ovens, hot blast stoves.
Building Materials: Cement rotary kilns, glass melting furnaces, ceramic kilns.
Chemical Industry: Gas generators, cracking furnaces, incinerators.
Non-ferrous Metals: Aluminum reduction cells, copper/lead/zinc smelting furnaces.

IV. Selection Key Points

Temperature: Fireclay bricks for <1500℃; High-alumina bricks for 1500–1700℃; Corundum/magnesite bricks for >1700℃.
Corrosion: Silica bricks for acidic environments; Magnesite bricks for alkaline environments; High-alumina/corundum bricks for neutral environments.
Thermal Shock: Fireclay bricks and high-alumina bricks for large temperature fluctuations and frequent start-stop operations.

refractory brick series：

Refractory Brick sk :

Item	Clay / high aluminum base
International Code Name	SK35	SK36	SK37	SK38	SK40
Al₂O₃,%	≥48	≥55	≥65	≥75	≥80
Refractoriness℃,min	1750	1770	1790	1790	1790
Apparent Porosity,%	≤22	≤22	≤23	≤23	≤21
Bulk Density,g/cm³	2.25-2.35	2.25-2.35	2.25-2.35	2.25-2.35	2.25-2.35
Cold Crushing Strength Mpa	≥39	≥44	≥49	≥54	≥65
0.2Mpa Refractoriness Under Load T0.2 ℃,min	≥1420	≥1470	≥1500	≥1520	≥15

Corundum refractory brick：

Corundum base
ITEM		HD-CH1	HD-CH2	HD-CH3
CHEM（%） ≥	Al₂o₃	90	-	-
	Al₂o₃	-	-	95
	Al₂O₃+Cr₂O₃	90	—	90
	Al₂O₃+Zr O₂	—	93	—
	Al₂O₃+Cr₂O₃+Zr O₂	-	95	-
BD	110℃ × 24h	3.2	3.3	3
MOR	110℃ × 24 h	10	10	10
（MPa） ≥	1500℃ × 3 h	12	12	12
CCS	110℃ × 24 h	40	40	30
（MPa） ≥	1500℃ × 3 h	100	100	80
PLC	110℃ × 24 h	±0.1	±0.1	±0.1
（%） ≤	1500℃ × 3 h	+0.3～-0.5	+0.3～-0.5	+0.3～-0.5

Mg – C brick / al – mg – c brick / mg-al brick :

item	MGO C BRICK					AL₂O₃ – MGO – C BRICK
item	MT-6A	MT-8A	MT-10A	MT-14A	MT-16A	AMC -6A	AMC -8A
MgO(%)≥	97	97	97	98	98	84	72
C(%)≥	6	8	10	14	16	6	8
AP(%)≤	4	4	4	3.5	3	10	10
BD (g/cm³)	3.1	3.05	2.9	2.85	2.8	2.9	2.85
CCS(Mpa)≥	40	40	40	35	35	40	40

MGO - AL BASE
Item	MA-80	MA-85	MA-88
MgO %	85	88	90
Al₂O₃ %	7	6.5	6.5
Bulk Density g/cm³	2.9	2.95	3
AP	4	4	4
Cold Crushing Strength Mpa	40	40	40
0.2Mpa Refractoriness Under Load °C	1610	1650	1700

Mg – chrome brick

MGO - CR
Item	MGe8	MGe12	MGe16
MgO %	72	70	65
Cr₂O₃ %	10	13	17
Fe₂O₃ %	4.8	5.5	6.5
Apparent Porosity %	18	18	18
Bulk Density g/cm³	3	3.02	3.05
Cold Crushing Strength Mpa	55	55	50
Refractoriness Under Load °C	1600	1600	1600

Item	DMGe12	DMGe16
MgO %	74	69
Cr₂O₃ %	14	18
Fe₂O₃ %	5	5.7
Apparent Porosity %	18	18
Bulk Density g/cm³	3.06	3.08
Cold Crushing Strength Mpa	55	55
Refractoriness Under Load °C	1700	1700

AL – SIC – C brick :

AL –SIC – C
Item	ASC-F1	ASC-F2	ASC-P
Al²O³，% ≥	65	60	55
SiC，% ≥	10	8	8
C，% ≥	10	12	5
Apparent porosity，% ≤	8	8	9
Bulk density，g/cm³ ≥	2.85	2.83	2.8
Compressive strength in commen temperature，Mpa ≥	50	50	45

Chrome Corundum Brick:

AL-CR-ZR BASE
Item	GG5	GG12	GG20	GG30	GG 50
Cr_²O_³ % ≥	5	12	20	30	50
ZRO2 % ≥	/	3	5	5	8
Cr₂O₃+Al₂O₃ % ≥	93	93	93	93	95
Bulk Density g/cm3 ≥	3.10	3.20	3.40	3.50	3.65
Apparent Porosity % ≤	18	18	18	18	16
Cold Crush Strength MPa ≥	100	110	120	130	135

Andalusite series:

Andalusite base
Item	A45	A60
AL₂O₃ % ≥	45	60
Fe₂O₃ % ≤	1.0	1.0
Bulk Density g/cm³ ≥	2.35	2.55
Apparent Porosity % ≤	19	18
Cold Crush Strength MPa ≥	50	80
Refractoriness Under Load (0.2MPa) ℃ ≥	1550	1600

Anti - acid brick ：

Anti - acid brick
AL₂O₃	25	20	40
MGO	/		3
SIO₂	65	75	/
BD	2.1	2.1	2.1
RUL	/	/	1350’C
REF	1650’C	1650’C	1620’C

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