Dry Anti-Permeation Castable Description
Dry anti-permeation castable is monolithic magnesia calcia based refractory. Dry anti-permeation magnesia calcia castable has high strength, low thermal conductivity, strong permeation resistance and so on.
In nonferrous metals industry, aluminum output is the highest. Aluminum industry annual refractory material consumption is far higher than that of all the rest nonferrous metals industy. Although the smelting temperature of aluminum is relatively low, molten slag and aluminum liquid has good flowability, strong corrosion and permeability, moreover, aluminum electrolytic bath temperature fluctuation is large, refractory material damage mechanisms mainly include: corrosion, permeation, and thermal shock.
Dry anti-permeation castable can prevent aluminum liquid and electrolyte permeation and corrosion. During high temperature aluminum smelting process, dry anti-permeation castable can react with other material and form dense enamel layer, which can prevent the further permeation of molten salts. So the service life of electrolytic bath is prolonged. Meanwhile, as electrolyte can’t permeate into insulating layer, the thermal conductivity of insulating layer will keep low, electric power consumption can be saved.
Anti-Permeation Castable Characteristics
Excellent cryolite corrosion resistance and aluminum liquid corrosion resistance, high strength, good thermal shock stability.
Anti-permeation castable can form nepheline layer at high temperature, which can prevent the permeation of Na+NaF vapor and aluminum liquid.
Low thermal conductivity, good energy saving effect.
High density, good homogeneity, high crushing strength, low open porosity.
The composition can be adjusted according to customer’s requirement.
| Item |
GFJ-1 |
GFJ-2 |
GFJ-3 |
| AI2O3+MgO % |
90 |
88 |
85 |
| Bulk density g/cm3 |
2.90 |
2.85 |
2.8 |
| Crushing strength Mpa |
110℃*24h |
30 |
30 |
25 |
| 1550℃*3h |
70 |
60 |
60 |
| Heating linear change rate % |
1550℃*3h |
-0.2~+1.0 |
-0.2~+1.0 |
-0.2~+1.0 |
|
Dry Anti-Permeation Castable Application
The purpose of using dry anti-permeation castable in aluminum electrolytic bath is to prevent electrolyte and aluminum liquid corrosion to insulating material. It can form permeation resistant layer, therefore, molten electrolyte can’t permeate into bath bottom and reacts wit refractory material inner lining, the problem of electrolytic bath damage and low service life is solved. Permeation resistant castable is convenient for construction and the work speed is quick. Anti-permeation castable is directly casted between insulating bricks and cathode carbon blocks, it is made firm by dry high frequency vibration, the thickness of anti-permeation layer is about 130mm. At electrolytic bath bottom and side wall, traditional Al2O3 refractory brick layer and alumina powder layer are gradually replaced by dry permeation resistant castable. What’s more, with the application of magnesia alumina dry anti-permeation castable, the quantity of Si and P impurity permeated into aluminum liquid is reduced ,the quality of aluminum ingots is improved.
