The roasting of aluminum hydroxide is the last procedure of alumina production. Its main purposes are drying adhered water and crystallization water in aluminum hydroxide and transforming some γ-alumina into α-alumina. Most alumina manufacturer in China have totally or partly adopted fluidized roasting equipments. Fluidized roasting equipments are classified into fluidized flash roasting furnace, circulating fluidized roasting furnace and suspension roasting furnace. Refractories for these 3 types of roasting furnaces are not the same, but large quantity of unshaped refractory( plastic refractory and refractory castable) are used, more specifically, 50%~70% of refractory consumption is unshaped refractory.
Alumina gas suspension roasting furnace is the specialized equipment for aluminum hydroxide roasting. The craft and automation level are both very high, roasting process takes place at high temperature furnace body ( 1200℃) and high speed atmosphere. The processed alumina has high rigidity, good flowability, meanwhile, there are strict quality standard on alumina products, any mixing of impurity can directly affect the product performance. So the refractory materials used in alumina gas suspension roasting furnace should have the following characteristics: high refractoriness, good abrasion resistance, high strength, good thermal stability, good integrity, good tightness.
Alumina Gas Suspension Roasting Furnace Refractory
Item
SLH-1
SLH-2
SLH-3
SLH-4
Al2O3 % ≥
45
65
65
45
Refractoriness ℃
1710
1770
1730
1690
Working temperature ℃
1100
1300
1300
1100
Suggested quantity t/m3
2.50
2.60
3.30
3.25
Bulk density g/cm3
1200℃,3h
/
2.30
2.30
/
Linear change rate %
1200℃,3h
/
±0.3
±0.3
/
Cold crushing strength Mpa
1200℃,3h
/
90
60
/
Modulus of rupture Mpa
1200℃,3h
/
14
8
/
Characteristics
Good volume stability, high low & middle temperature strength, scouring resistance, abrasion resistance, thermal shock resistance
Strong adhesion ability, good volume stability, thermal shock resistance, scouring resistance, high low & middle temp. strength
Applications
The casting of low & middle temperature lining
The casting of high temperature lining
The gunning and coating of high temperature lining and low workability parts
The gunning and coating of low &middle temperature lining and low workability parts
