In one of our previous posts on Magnesia Carbon refractory bricks (MgO-C), we have already discussed on the selection of various raw material ingredients required for the production of MgO-C refractory bricks with an emphasis to their grading etc. In this article we bring you one MgO-C (Mag Carbon) refractory brick composition and further guidance (tips) on its production along with the tested results of some of the refractory properties of the brick made from this composition.
Refractory Composition (Formulation) for MgO-C Refractory Bricks
Item No
|
Raw Materials
|
Grading (mm)
|
Quantity
|
1
|
China 97FM (Fused Magnesite)
|
2.0 - 4.0
|
18 %
|
2
|
do
|
0.6 - 2.0
|
42 %
|
3
|
do
|
0 - 0.6
|
20 %
|
4
|
China 98FM or Seawater DBM 98 HD
|
Flour (Ball Mill Fine)
|
7.5 %
|
5
|
Coarse Flaky Graphite (94% LOI)
|
– 0.10 (> 40 %)
|
12.5 %
|
6
|
Al-metal Powder
|
3 parts
| |
7
|
Si-metal Powder
|
1 part
| |
8
|
Liq. Resin (Durez-40)
|
3 parts
| |
9
|
Solid Resin (Powder)
|
0.6 parts
| |
10
|
Hexamine
|
0.25 parts
| |
11
|
MEG (Meth. ethyl glycol)
|
0.6 parts
|
Mag Carbon Refractory Bricks - Production (Tips)
=> Mixing Sequence:
(A) First co-mix item nos. 4, 5, 6 and 7 together in a Ball Mill for at least 6-8 hrs, unload and keep separate.
(B) Mix MEG with (0-0.6) DBM fraction (item 3). Then add the co-mix powder made in step (A) to it and remix.
(C) Take (2-4) & (0.6-2) DBM grading (item no 1 and 2), add hot Resin (item 8). Mix thoroughly to get perfect coating. Add mixture made in step (B) and remix the batch intensively. Now add powder Resin (item 9) then, Hexamine (item 10) and mix it finally. Keep the mixture (powder) in closed polythene bags 35-40 kg in each bag, for ageing 8-12 hrs.
=> Heat the liquid Resin to 60-65OC before mixing. Heating reduces the viscosity and thus help for better coating.
=> Don't use any mixture after it has dried up. Try to make mixture in perfectly pre-calculated quantities as reuse of such mixture (powder) even by adding more MEG is not advisable and should be avoided as far as possible.
=> While making any shaped brick by pneumatic Ramming it must be done continuously until the shape is complete.
=> Don't keep mixture (powder) uncovered.
Properties and Test Results
Magnesia Carbon Bricks - Properties
Properties
|
Results
|
MgO %
|
94 (min)
|
Fixed Carbon %
|
8 (min)
|
Green BD (gm/cc)
|
3.1 (min)
|
Coked BD (gm/cc)
|
2.95 (min)
|
AP %
(after coked after coked in reducing atmosphere at 1000OC )
|
14 (max)
|
AP % (original condition)
|
7 (max)
|
CCS (kg/cm2)
|
450 (min)
|
MOR at room temp (kg/cm2)
|
140 (min)
|
Related Articles