Al2O3-SiO2 Refractory Material
Except for fireclay bricks and high alumina bricks, other aluminum silicate refractories used in rotary cement kiln should have good wear resistance, alkali corrosion resistance, thermal shock resistance, so special high alumina bricks such as phosphate bonded high alumina bricks, phosphate bonded high alumina wear resistant bricks, stripping proof high alumina brick and alkali resistant semi acidic fireclay bricks are developed.
Special High Alumina Bricks Physiochemical Indexes
| Item |
Phosphate bonded high alumina brick |
Wear resistant high alumina brick |
Stripping proof high alumina brick |
Chemical bonded high alumina brick |
| Al2O3 % |
≥75 |
≥75 |
>70 |
≥75 |
| Fe2O3 % |
≤3.0 |
≤3.0 |
≤2.0 |
/ |
| CaO % |
≤0.6 |
≤0.6 |
/ |
/ |
| Refractoriness ℃ |
>1770 |
>1770 |
>1780 |
>1770 |
| Bulk density g/cm3 |
≥2.65 |
≥2.70 |
2.50~2.60 |
≥2.60 |
| Apparent porosity |
18~20 |
17~19 |
20~25 |
18~20 |
| Crushing strength Mpa |
≥60 |
≥64 |
≥45 |
≥60 |
| Refractoriness under load beginning temperature ℃ |
≥1350 |
≥1300 |
≥1470 |
≥1450 |
| Thermal shock resistance /times (1100℃, water cooling) |
≥30 |
≥30 |
≥30 |
20 |
Alkali Corrosion Resistant Brick
In preheating kiln, decomposition kiln and shat Bohr kiln, etc, where alkali corrosion is severe, alkali corrosion resistant firebricks must be adopted. Al2O3 content in alkali proof bricks should be controlled about 30%. In large size rotary cement kiln charging zone, surface heat loss is great, so ling bricks should have excellent alkali corrosion resistance, so alkali corrosion resistant insulating bricks(usually semi silica bricks) can be adopted here.
Cement Kiln Alkali Resistant Bricks Physiochemical Indexes
| Item |
Alkali resistant bricks |
| Al2O3 % |
25~30 |
| SiO2 % |
60~70 |
| Fe2O3 % |
≤2.0 |
| Apparent porosity % |
≤25 |
| Cold crushing strength Mpa |
≥20 |
| Reheating linear change rate %(1350℃, 2h) |
-1.0~+0.1 |
| Thermal shock resistance /times (1100℃, water cooling) |
≥10 |
Cement Kiln Insulating Refractory
The functions of cement kiln insulating refractories are: reducing cylinder shell surface temperature and heat loss, avoiding overheat of rotary kiln shell, reducing rotary cement kiln lining refractory material weight, decreasing construction cost. Usually used cement kiln insulating refractories are calcium silicate board, lightweight clay bricks, lightweight mullite bricks, lightweight alumina bubble bricks and so on. Insulating layer stuffing material includes expanded perlite, expanded vermiculite, mineral cotton, aluminum silicate fiber and so on.
The Performance of Some Insulating Material
| Item |
Bulk density g/cm3 |
Max. working temperature ℃ |
Thermal conductivity W·(m·K)-1 |
| Diatomite raw material powder |
660~680 |
900 |
0.105+0.28*10-3t |
| Diatomite clinker powder |
420~700 |
900 |
0.083+0.21*10-3t |
| Diatomite brick |
500 |
900 |
0.110+0.145*10-3t |
| Diatomite brick |
600 |
900 |
0.145+0.314*10-3t |
| Diatomite brick |
700 |
900 |
0.198+0.267*10-3t |
| Foamed diatomite brick |
500 |
900 |
0.110+0.233*10-3t |
| Insulating fireclay brick |
400 |
900 |
0.081+0.221*10-3t |
| Asbestos fiber |
340 |
500 |
0.087+0.233*10-3t |
| Asbestos rope |
800 |
300 |
0.073+0.314*10-3t |
| Expanded vermiculite |
250 |
1000 |
0.072+0.256*10-3t |
| Calcium silicate |
220 |
650 |
0.062+0.11*10-3t |
| Expanded perlite sand |
/ |
900 |
2.21*10-4ρ+0.031 |
Cement Kiln Insulating Castable Physiochemical Indexes
| Item |
High strength corundum castable |
Steel fiber reinforced corundum castable |
Low cement high alumina castable |
High alumina castable |
Alkali proof castable |
| Al2O3 % |
≥93 |
≥87 |
75~78 |
≥70 |
≤40 |
| CaO % |
≤5.5 |
/ |
1.5~2.0 |
/ |
≤9 |
| SiO2 % |
≤0.5 |
≤2 |
12~15 |
/ |
≥55 |
| Bulk density g/cm3 (1100℃) |
≥2.70 |
2.80~2.88 |
≥2.70 |
2.60 |
2.0 |
| Crushing strength Mpa(1100℃) |
≥80 |
40~60 |
110 |
≥25 |
≥20 |
| Modulus of rupture Mpa(1100℃) |
≥8 |
9~12 |
15.7 |
/ |
≥2.5 |
| Linear expansion rate %(1000℃) |
0.8 |
0.72~0.77 |
/ |
0.50 |
0.40 |
| Thermal shock resistance /times (1100℃, water cooling) |
≥15 |
/ |
>15 |
/ |
/ |
New Type Dry Rotary Cement Kiln Refractory Material
Pre-heater & decomposition furnace
Working lining: alkali corrosion resistant fireclay brick, alkali corrosion proof castable, high alumina alkali proof castable.
Insulating lining: diatomite brick, calcium silicate board.
Tertiary air pipe
Working lining: high strength alkali proof brick, alkali resistance castable.
Insulating lining: diatomite brick, calcium silicate board, insulating castable.
Rotary cement kiln
Kiln end: steel fiber reinforced high alumina castable, high alumina alkali proof castable.
Decomposition zone: alkali proof insulating brick, CB20 CB30 insulating brick.
Transition zone I: anti-stripping high alumina brick, chemical bonded high alumina brick, phosphate bonded high alumina brick.
Transition zone II: Spinel brick, semi directly bonded magnesia chrome brick, ordinary magnesite chrome brick.
Sintering zone: direct bonded magnesia chromite brick.
Cooling zone: stripping proof high alumina brick, chemical bonded high alumina brick, semi directly bonded magnesite chrome brick, ordinary magnesite chromite brick.
Kiln head: steel fiber reinforced corundum castable, corundum castable, high alumina castable, steel fiber reinforced high alumina castable.
Kiln hood
Working lining: anti-stripping high alumina brick, high alumina brick, high alumina alkali proof castable.
Insulating layer: high temperature proof insulating brick, calcium silicate board, lightweight insulating castable.
Cooling machine
Working lining: spalling resistant high alumina brick, silicon carbide brick, phosphate bonded wear proof high alumina brick, base proof castable, high alumina alkali proof castable.
Insulating lining: high temperature proof insulating brick, diatomite brick, calcium silicate board, insulating castable.
