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Refractoriness Under Load: >1700℃
Application: rotary kilns
1. Brief introduction of Phosphate bonded high alumina bricks
Phosphate bonded high alumina bricks are made of dense special grade or first grade high alumina bauxite clinker as the main raw material, phosphoric acid solution or aluminum phosphate solution as the binder, after semi-dry press molding, heat treatment at 400~600℃ Into chemically bonded refractory products. It is a non-burning brick. In order to avoid the large shrinkage of the product during high temperature use, it is generally necessary to introduce heat-expandable raw materials, such as kyanite, sillimanite, pyrophyllite, silica, etc., into the ingredients. Compared with ceramic-bonded fired high alumina bricks, its resistance to peeling is better, but its load softening temperature is lower, and its corrosion resistance is poor. Therefore, a small amount of fused corundum, mullite, etc. needs to be added to strengthen the matrix. . Phosphate bonded high alumina bricks are suitable for cement kilns, electric furnace tops, and ladle.
Phosphate high alumina bricks are made of high-quality high alumina bauxite as raw materials, combined with aluminum dihydrogen phosphate, and dried in a drying oven. Phosphate high alumina bricks are mainly used in dry-process cement production kilns, rotary kilns, phosphorous chemical kilns, etc. Phosphate high alumina bricks have high refractoriness, good wear resistance and high strength.
2. Characteristics of Phosphate bonded high alumina bricks:
(1) Higher strength and good wear resistance.
(2) Good chemical resistance. (Its alkali resistance is better than clay bricks and high alumina bricks)
(3) Good thermal shock resistance.
(4) The load softening temperature is higher. Therefore, it is often found in the transition zone of the rotary kiln, the kiln mouth, the kiln door cover, the lining of the cooler and other parts where the refractory bricks are easy to loosen and fall.
3.Technical requirements for phosphate combined with high alumina bricks
Phosphate-bonded high-aluminum brick is made of high-alumina bauxite clinker as aggregate and fine powder, phosphoric acid or aluminum phosphate as binder, semi-dry pressed and heat-treated from 400 ° C to 600 ° C. .
Phosphate combined with high alumina bricks can be divided into two codes according to the bonding agent:
1. Phosphate combined with high alumina brick (referred to as phosphate brick), the binder is a concentration of 42.5%~50% phosphoric acid solution. Codenamed P;
2, aluminum phosphate combined with high-aluminum wear-resistant brick (referred to as wear-resistant brick), the binder is a solution of industrial phosphoric acid, industrial aluminum hydroxide, the molar ratio is Al2O3: P2O5 = 1:3.2. Codenamed PA.
According to physical and chemical indicators, size and appearance can be divided into first-level and second-level.
Items | Ordinary phosphate bricks | phosphate bonded wear-resistant bricks | special phosphate bricks | phosphate composite bricks | |
P-75 | PA-75 | PT-1 | heavy part | lightweight part | |
Al2O3 % ≥ | 75 | 75 | 80 | 75 | 55 |
FeO2 % ≤ | 2.1 | 2.1 | 1.8 | 2 | 1.5 |
Refractoriness ℃ | 1770 | 1770 | 1790 | 1770 | - |
B.D. g/cm3 ≥ | 2.7 | 2.75 | 2.9 | 2.8 | ≤1 |
C.C.S. MPa ≥ | 70 | 75 | 80 | 75 | 5.5 |
0.2MPa R.U.L. ℃≥ | 1350 | 1300 | 1520 | 1350 | - |
Thermal shock resistance | 20 | 20 | 15 | - | - |
Application of Phosphate bonded high alumina bricks for rotary kiln
Where are the Phosphate bonded high alumina bricks for rotary kilns used in the rotary kiln?
1. Phosphate bonded high alumina bricks for rotary kilns are used in the preheating zone and decomposition zone of the rotary kiln
2. Phosphate bonded high alumina bricks for rotary kilns are used in the transition zone and firing zone of the rotary kiln
3. Phosphate bonded high alumina bricks for rotary kilns are used in the cooling zone and kiln mouth of the rotary kiln
These parts generally use high-alumina bricks with good peeling resistance.
