Different iron smelting factories have different design of blast furnace iron troughs, such as iron storing trough and non storing iron trough, single iron trough and multi iron troughs. Blast furnace iron troughs can also be divided into main trough, branch channel, swing channel and slag channel. Different types of refractory materials can be used as per the types of iron troughs. Iron storing troughs in middle and large scale steel mills usually adopt Al-Si-C series castable.
Iron Trough Castable Characteristics
Blast furnace iron trough should endure iron liquid and molten slag intense scouring, high temperature iron liquid and molten slag chemical corrosion & permeation. So iron trough and slag trough castable should have enough mechanical strength and corrosion resistance. Once there is damage in the trough, it should be patched as soon as possible, which requires iron trough castable has good flowability, few water addition quantity and can be quickly dried. Besides, iron trough lining’s temperature fluctuates greatly, so iron trough castable should also has excellent thermal shock resistance.
Iron Trough Castable Physiochemical Index
Item
DCTC-1
DCTC-2
DCTC-3
DCTC-4
Material
Alumina silicon carbide carbon castable
Alumina silicon carbide carbon castable
Alumina silicon carbide carbon castable
High alumina silicon carbide castable
Application
Main trough slag line
Main trough iron line
Main trough iron line
Main trough slag line
Al2O3 %
60
83
77
56.9
SiC %
37
12
11
32
SiO2 %
2.5
2.5
/
/
C %
1~3
1~3
2
2
Bulk density g/cm3(1450℃,3h)
2.78
2.98
2.84
2.69
Compression strength Mpa(1450℃,3h)
50
50
35.8
/
Reheating linear change rate %(1450℃,2h)
-0.2~0.6
-0.2~0.6
-0.2~0.6
-0.1~0.2
Item
DCTC-5
DCTC-6
DCTC-7
DCTC-8
Material
Alumina silicon carbide carbon castable
Alumina silicon carbide carbon castable
High alumina silicon carbide castable
High alumina silicon carbide castable
Application
Main trough cover top
Main trough cover sides
Iron trough
Slag trough
Al2O3 %
65.3
67.1
49.1
60.4
SiC %
15
15
9.33
14
SiO2 %
/
/
/
/
C %
/
/
/
1~3
Bulk density g/cm3(1450℃,3h)
2.78
2.98
2.84
2.69
Compression strength Mpa(1400℃,3h)
2.52
2.56
2.38
2.68
Reheating linear change rate %(1400℃,3h)
0.22
±0.35
-0.12
±0.5
So alumina silicon carbide carbon castable is mainly used for the casting of blast furnace iron trough. Alumina silicon carbide carbon castable’s main materials are fused corundum(or sintered corundum, special grade bauxite clinker), graphite contains 90%~95% fixed carbon, silicon carbide and so on. During construction, additives should be added and fully mixed before casting. For slag trough, lower grade of alumina silicon carbide carbon castable can be used, It can not only meet production requirement but also has better economic benefits. High alumina silicon carbide castable, which has excellent abrasion resistance is the best choice for slag line.
In recent years, quick dry Al-SiC-C castable is developed for casting houses which only have one iron running trough. The development of self flow Al-Si-C castable brings lots of convenience for casting construction. The unit refractory consumption of per ton iron is significantly decreased with the improvement of castable quality.
