Magnesia Alumina Castable Descriptions
Magnesia alumina castable main materials are alumina and magnesia. Magnesia alumina castable can be divided into chemical bonded ( water glass bonded) magnesia alumina castable, hydration bonded (calcium alumina cement bonded) magnesia alumina castable and coagulation bonded (silica micro powder and magnesia fine powder bonded) magnesia alumina castable. By material quality, magnesia alumina castable can be divided into the following categories.
Ordinary Al2O3-MgO Castable
Ordinary Al2O3-MgO castable is composed of special class or first glass high alumina bauxite aggregate and fines, sintered magnesia sand powder. It’s bonders are silica micro powder and magnesia fines. Ordinary Al2O3-MgO castale has good slag corrosion resistance, high refractoriness under load and can be used for continuous casting ladles and extra furnace refinery ladle inner lining.
Ordinary High Alumina Spinel Castable
Ordinary high alumina spinel castable is composed of special class or first glass high alumina bauxite aggregate and fines, sintered spinel aggregate and fines. The binding methods of ordinary high alumina spinel castable are hydration( cement) binding and coagulation binding.
High Alumina Spinel Ladles Castable Physiochemical Index
| Item | Index |
| Al2O3 % | 72 |
| MgO % | 11 |
| SiO2 % | 9.5 |
| Bulk Density g.cm3(110℃, 24h) > | 2.9 |
| Apparent Porosity % (110℃, 24h)< | 16 |
| Compression Strength(110℃, 24h) Mpa > | 60 |
| Rupture Strength (110℃, 24h) Mpa > | 9.0 |
| Permanent linear change rate (110℃, 24h) % | 0~0.1 |
| Refractoriness under load( 0.2Mpa, 0.6%) > | 1410 |
High alumina spinel castable has little strength difference between middle temperature(1000℃) and high temperature (1550℃), which is beneficial to resist structural spalling caused by thermal stress. Its spalling resistance ability is better than ordinary alumina magnesia castable, is suitable to construct integral inner lining of middle and small size continuous casting ladles, inner linings of tundish permanent lining and electric furnace tapping spouts.
Pure Alumina Magnesia Castable
Pure alumina magnesia castable aggregate is fused white corundum, tabular corundum, or fused high alumina corundum. Powder materials are corundum fine powder and micro powder, active alumina powder, sintered magnesia sand powder, silica micro powder, and dispersant. Pure alumina magnesia castable belongs to coagulation binding castable.
Pure alumina magnesia castable is usually used in large scale ladle (≥100t) integral inner lining below slag line, the service life of pure alumina magnesia castable is more than twice of ordinary alumina magnesia castable. It can also be used to construct other high-temperature furnaces, vessels and launders inner linings.
Pure Alumina Spinel Castable
Pure alumina spinel castable adopts fused or sintered corundum, tabular corundum as aggregate, synthesized spinel, α-alumina micro powder, active alumina powder, pure calcium aluminate cement and dispersant as powder material. Pure alumina spinel contains 3%~8% of calcium aluminate cement, belongs to low cement bonded castable.
Self Flow Alumina Spinel Castable Physiochemical Index
| Item | Sintered white corundum | Fused white corundum | Fused brown corundum |
| Al2O3 % | 91~92 | 91~92 | 89~90 |
| MgO % | 6~7 | 6~7 | 6~7 |
| SiO2 % | 9.5 | ||
| Bulk Density g.cm3(110℃, 24h) > | 2.90 | 3.00 | 2.99 |
| Apparent Porosity % (110℃, 24h)< | 16.0 | 17.0 | 16.0 |
| Rupture Strength (110℃, 24h) Mpa > | 8.0 | 6.0 | 7.0 |
| linear change rate (1000℃,3h) % | -0.03 | -0.03 | -0.03 |
Pure Alumina Spinel Castable Applications
Pure alumina spinel castable has small linear change rate and good volume stability, is mainly used in large scale ladles integral inner linings, the service life can reach 200~260 times. It can also be used to make high power and ultra-high power electric furnace lid linings, steel ladles permeation bricks, argon blowing or powder spraying integral gunning machine lining, etc.
