Detailed Product Description
An aluminate cement wrought material based upon calcium aluminate;used to products with special requirements.
Definition
It is a non-metal inorganic construction material based on calcium aluminate(CaO-Al2O3)or calcium dialuminate(2CaO-Al2O3).It is made up by the way of having natural bauxite or industrial alumina and calcium carbonate(limestone) which are silicate cement,calcium aluminate cement has a higher refractoriness,thus it is widely used as binder of refractory castable.
Category
Calcium aluminate cement is sorted into two kinds by chemical composition:common calcium aluminate cement (Al2O3 53%~72%,CaO 21%~35%)and pure calcium aluminate cement (Al2O3 72%~82%,CaO 19%~23%).And common calcium aluminate cement is dividedinto low iron type(Fe2O3<2.0%)and high iron type(Fe2O3 37%~16%). The low iron type calcium aluminate cement which has a Al2O3 content of 53%~56% and CaO of 33%~35% is called bauxite cement;the one which has a Al2O3 content of 59%~61% and CaO of 27%~31% is called Aluminium-60 cement;the one which has a Al2O3 coment of 65%~70% and CaO of 21%~24% is called low calcium aluminate cement,another kind is fast hardening super early strength calcium alumiante cement.And pure calcium aluminate cement is divided into conventional type(Al2O3 content is 72%~78%) and super high alumina type (Al2O3 content is 78%~ 85%).
Property
Chemical composition and minerals of different calminate cement are listed in table 1.
Table 1 Chemical composition and minerals of different calcium aluminate cements
|
|
Chemical composition/%
|
||||
|
SiO2
|
Al2O3
|
CaO
|
Fe2O3
|
||
|
low iron type
calcium aluminate cement |
Bauxite cement
|
5~7
|
53~56
|
33~35
|
<2.0
|
|
Alumina-60 cement
|
4~5
|
59~61
|
27~31
|
<2.0
|
|
|
Low calcium cement
|
3~4
|
65~70
|
21~24
|
<1.5
|
|
|
High iron type
calcium aluminate cement |
Common
|
4~5
|
48~49
|
36~37
|
7~10
|
|
Super high alumina type
|
3~4
|
40~42
|
38~39
|
12~16
|
|
|
Pure calcium aluminate cement
|
Common
|
<0.1
|
76~78
|
20~23
|
<0.1
|
|
Fast hardening type
|
<0.1
|
72~76
|
23~26
|
0.1
|
|
|
Super high alumina type
|
0.1
|
79~83
|
16~18
|
<0.1
|
|
Table 2 Physical property of bauxite cement
|
Index
|
Specific surface area/m2·g-1
|
compressive strength
/Mpa |
breaking strength
/Mpa |
Setting time
/h |
|||
|
1d
|
3d
|
1d
|
3d
|
Initial setting
|
Final setting
|
||
|
425
|
>4500
|
26.0
|
42.5
|
4.0
|
4.5
|
~1
|
≤8
|
|
525
|
>5500
|
46.0
|
52.5
|
5.0
|
5.5
|
~1
|
≤8
|
|
625
|
>6500
|
56.0
|
62.5
|
6.0
|
6.5
|
0.5~1
|
≤8
|
|
725
|
>7000
|
66.0
|
72.5
|
7.0
|
7.5
|
0.5~1
|
≤8
|
Application
Calcium alumiante cement is mainly used as binder of refractory castable and gunning mix.Common calcium aluminate cement is applicable to low-grage and medium-grade refractory castable,such as fireclay castable and high alumina castable etc;Pure calcium aluminate cement is applicable to high-grade refractory castable,such as corundum castable,mullite castable,chrome containing corundum castable and spinel castable etc.The calcium aluminate cement addition quantiry of common refractory castable is 10%~20%,Low cement castable is 5%~10%,super low cement castable is less than 5%.Addictives which can improve workability may be added to castables bond by calcium aluminate cement so as tp meet the requirement of construction,such as setting accelerator,setting retarder,water reducer(dispersant),plasticizer etc.