Magnesia chrome bricks are basic refractory product which’s main crystalline phase is periclase and magnesia chrome spinel. For magnesia chrome brick, the magnesia content range is 55%< MgO <80%, for chrome magnesia brick, magnesia content is between 25% and 55%. Magnesia chrome brick can be classified into ordinary magnesia chrome bricks, direct bonded MgO-Cr2O3 bricks, Rebonded(semi-rebonded) magnesia chrome bricks and unburned MgO-Cr2O3 bricks.
Ordinary Magnesia Chrome Bricks
Ordinary magnesia chrome bricks takes sintered magnesia sand and used refractory chrome bricks as raw material and are sintered in high temperature. Because the impurity content is relatively high in raw material, the bond of magnesia chrome bricks are silicate bonding, ordinary magnesia chrome bricks are also called silicate bonding magnesia chrome bricks.
The refractoriness of ordinary magnesia chrome bricks is over 2000℃, refractoriness under load is usually over 1550℃, has good high temperature volume stability, thermal shock resistance is better than thermal shock resistance.
Ordinary Magnesia Chrome Bricks Physiochemical Index
Item
MCr-8
MCr-12
MCr-16
MCr-20
MgO %
72
70
65
56
Cr2O3 %
10
13
17
22
Apparent Porosity %
18
18
18
19
Cold Crushing strength Mpa
55
55
50
50
Refractoriness under load(0.2Mpa) ℃
1600
1600
1600
1620
Bulk Densityg/cm3
3
3.02
3.05
3.07
Ordinary Magnesia Chrome Bricks Application
Ordinary magnesia chrome bricks have simpler production craft and lower price, are widely used in rotary cement kiln, glass kiln regenerative chamber, lime kiln, iron mixing furnace and inner lining of high temperature refractory material kilns.
Direct Bonded Magnesia Chrome Bricks
Direct bonded magnesia chrome bricks are made from chromite and magnesia sand with lower impurity and sintered at temperature above 1700℃, the main bonding form of crystalline grains is direct contacting. Comparing with ordinary magnesia chrome bricks, direct bonded magnesia chrome bricks have lower impurity ratio and higher sintering temperature.
Direct bonded magnesia chrome bricks have low impurity content and high direct bonding ratio, so slag resistance and high temperature performance are better. Excellent thermal shock resistance, under 1100℃ water cooling conditions can reach to 4~10 times.
Direct Bonded Magnesia Chrome Bricks Physiochemical Index
Item
DMCr-8
DMCr-10
DMCr-12
DMCr-16
MgO %
77
75.2
74
69
Cr2O3 %
9.1
11.5
14
18
Apparent Porosity %
18
18
18
18
Cold Crushing strength Mpa
50
55
55
55
Refractoriness under load(0.2Mpa) ℃
1700
1700
1700
1700
Bulk Densityg/cm3
3.04
3.05
3.06
3.08
Thermal expansion rate %1600℃
1.8
1.8
1.8
1.6
Direct Bonded Magnesia Chrome Bricks Application
Direct bonded magnesia chrome bricks are generally used in rotary cement kiln, steel making electric furnace lining, refinery furnace (RH upper groove and lower groove permanent lining, VOD furnace wall), nonferrous metals smelting furnace, glass kiln regenerative chambers, lime kilns, iron mixing furnace and so on.
RS Kiln Refractory Manufacturer’s main business includes: research & develop, production as well as sales of monolithic and shaped refractory bricks materials. For the ore than 10 years development, RS kiln Refractory has provided numerous refractory products and technical service for customers in Southeast Asia, Africa, Europe and North America. RS produces all kinds of refractory bricks, castable, refractory cement & concrete, ceramic fiber material, graphite electrode and so on. And have widely used in chemical industry, iron and steel, nonferrous metal smelting, electric power, machinery, and other industries.
If you are want to learn more details about the Magnesia Chrome Bricks, Please contact RS, We will give you back as soon as possible. RS is looking forward to cooperation with you.
