---

 

The international standard ISO1109-1975 stipulates that alkaline products with MgO ≥ 80% are magnesia bricks. Rongsheng provides 90, 95 and 98 grade magnesia bricks, and their corresponding minimum MgO content is 86%, 91%, and 96% respectively. According to different production processes, magnesia bricks are divided into fired magnesia bricks, unfired magnesia bricks, and recombined magnesia bricks.

 

Burnt Magnesia Bricks

 

Burned magnesia bricks, usually referred to as sintered magnesia bricks or magnesia bricks, are the most widely produced and applied alkaline bricks. China’s magnesite is of high quality and abundant reserves. Therefore, Rongsheng’s magnesia bricks are of high quality and low price. Free quote now!

 

Characteristics of Magnesia Bricks

 

• The refractoriness of Magnesia Bricks is above 2000℃, and its load softening temperature varies greatly with the melting point of the cementing phase and the amount of liquid phase produced at high temperatures. Generally, the load-softening temperature of Magnesia Bricks is between 1520~1600℃, while that of high-purity Magnesia Bricks can reach 1800℃. The load softening temperature of Magnesia Bricks is not much different from the collapse temperature.
• The linear expansion rate of magnesium bricks at 1000~1600℃ is generally 1.0%~2.0% and is approximately linear.
• Among refractory bricks products, the thermal conductivity of magnesium bricks is second only to carbon bricks, and decreases with increasing temperature.
• At 1100℃ and water cooling conditions, the thermal shock resistance of magnesium bricks is only 1~2 times.
• Magnesium bricks can resist the erosion of alkaline slags containing iron oxide and calcium oxide but are not resistant to acidic slags containing silicon oxide. Therefore, when using magnesium brick lining, it cannot be in direct contact with silica bricks and needs to be separated by neutral brick lining.
• The conductivity of magnesium bricks is very low at room temperature. But at high temperatures, such as 1500℃, the conductivity of magnesium bricks cannot be ignored. When used in the bottom of an electric furnace, especially when it is humid, attention should be paid.

The performance of magnesium bricks will vary greatly due to the different raw materials, production equipment, and process measures.

 

Physical and Chemical Indicators of Magnesia Bricks

Physical and chemical indicators of magnesia bricks produced by Rongsheng. The standard GB/T2275-2001 is adopted.

 

Physical and Chemical Indicators of Magnesia Bricks in Rongsheng
Items	MZ-97A	MZ-97B	MZ-95A	MZ-95B	MZ-93	MZ-91	MZ-89	MZ-87
MgO %, ≥	97	96.5	95	94.5	93	91	89	87
SiO2 %, ≤	1.0	2.0	2.0	2.0	3.5	–	–	–
CaO %, ≤	–	–	2.0	2.0	2.0	3.0	3.0	3.0
Apparent Porosity %, ≤	16	18	16	18	18	18	20	20
Compressive Strength at Normal Temperature MPa, ≥	60	60	60	60	60	60	50	50
0.2MPa Load Softening Start Temperature ℃, ≥	1700	1700	1650	1650	1620	1560	1550	1540
Re-burning Linear Change Rate (1650℃, 2h) %	0 ~ -0.2	0 ~ -0.2	0 ~ -0.3	0 ~ -0.3	0 ~ -0.4	0 ~ -0.4	0 ~ -0.6	–

 

The physical and chemical properties of magnesium bricks for glass kilns specified in the building materials industry standard JC/T 924-2003 are shown in the following table.

 

physical and Chemical Properties of Magnesium Bricks for Glass Kilns Specified in the Building Materials Industry in Ronsheng
Items	MZ95	MZ95	MZ97	MZ97	MZ98	MZ98
	Straight Bricks	Tubular Bricks	Straight Bricks	Tubular Bricks	Straight Bricks	Tubular Bricks
MgO %, ≥	95	95	97	97	98	98
SiO2 %, ≤	2.0	2.0	1.2	1.2	0.6	0.6
CaO %, ≤	2.0	2.0	1.5	1.5	1.0	1.0
Bulk Density g/cm3, ≥	2.95	2.92	3.0	2.98	3.05	3.02
Apparent Porosity %, ≤	17	18	16	17	16	17
Compressive Strength MPa, ≥	60	40	60	50	60	50
Load Softening Start Temperature ℃, ≥	1680	1650	1700	1670	1700	1700
Thermal Shock Resistance /times, Air Cooling, ≥	10	10	10	10	10	10

 

Uses of Magnesia Bricks

Magnesia bricks are widely used in the following applications due to their good high-temperature performance and strong resistance to metallurgical slag:

• Steelmaking furnace linings, ferroalloy furnaces, and mixed iron furnaces in the steel industry.
• Furnace linings for copper, lead, tin, and zinc smelting in nonferrous industrial furnaces
• Lime calcining kilns in the building materials industry.
• Glass industry heat storage chamber lattices and civil heat exchangers.
• High temperature calcining kilns in the refractory industry, such as high temperature vertical kilns for calcining magnesia sand and high temperature tunnel kilns for firing alkaline refractory bricks.

Rongsheng Refractory Bricks Manufacturer

 

Rongsheng Manufacturer is a powerful manufacturer of refractory bricks. Rongsheng’s basic refractory bricks, such as magnesia bricks, magnesia chrome bricks, magnesia spinel bricks, magnesia bricks for glass kilns, etc., have guaranteed product quality and are well received by customers. Rongsheng refractory bricks, factory direct sales, preferential prices, and fast delivery! Rongsheng Magnesia Bricks for Sale. Whether you need basic refractory bricks for cement kilns, glass kilns, AOD furnaces, or non-ferrous smelting, Rongsheng can provide basic refractory bricks in standard and customized sizes according to the actual needs of your project. If you have high-quality requirements for refractory brick products and need to save procurement costs, please choose Rongsheng. Contact Rongsheng for free samples, solutions, and quotations.