What is the composition of fused zirconium corundum brick？

What is the composition of fused zirconium corundum brick？

The composition of zirconium corundum brick is in the triangle of Al2O3-Zro2, 3Al2O3-2S02. Therefore, the final crystallization of the melt should be these three phases and converge at the Y point. exist

During cooling, initially in ZrO2-Al2O3. In the binary composition system, baddeleyite (ZrO2) and corundum (Al2O3) crystals are precipitated. The residual liquid phase moves to Y along the XY line, and should precipitate out Mo

To stone (3Al2O3-2S02), to Y point mullite crystallization ends. This crystallization process is carried out in an ideal pure Al2O3, ZrO2, SO2 system. Actually due to the brick

A small amount of Na2O is introduced into the mullite, which makes the mullite crystallizing zone narrow. Therefore, fused zirconium corundum is mainly composed of corundum and baddeleyite phases, and a small amount of mullite and glass phases.

Zircon in zircon corundum brick: high melting point and good chemical stability, it is a granular mineral in AZS, which is egg-shaped to drop-shaped, often aggregated into chain-shaped, fish-bone-shaped, etc. Very little soluble in glass

The phase, under the microscope, the baddeleyite zircon on the light sheet, has the largest reflectance value, looks distinctly white, and is the brightest among all light sheet compositions. but through

On the card, the baddeleyite zircon particles are dark gray or black, and have metallic luster. In AZS, baddeleyite is the mineral with the strongest corrosion resistance to glass liquid.

Corundum in zirconium corundum bricks: higher melting point, a-A12O3 is a stable phase, in AZS it exists as a rhombohedral columnar framework, in the light sheet, it is the second reflective mineral, bright gray

The corrosion resistance of corundum to glass liquid is not as good as that of baddeleyite zircon at high temperature.

The eutectic of baddeleyite zircon and corundum: on the rhombohedral columnar corundum crystal, granular baddeleyite crystals are evenly distributed, and this structure is embedded in the corundum crystal, which is called

The symbiotic crystals of plinthite and corundum in zircon corundum bricks, referred to as eutectic, and this grid-like embedded structure is called sieve-like structure (generally eutectic occupies about 60% in AS. It can be

In order to prevent the corundum from being damaged by the glass liquid prematurely. In AZS-11, in addition to the eutectoid, droplet-shaped monoclinic zirconite also appears, in the form of a string or a dense droplet structure.

The structure is the petrographic feature of high zirconium AZ5, which is more resistant to glass liquid erosion

Glass phase in zirconium corundum bricks: also known as matrix glass, all the components that do not form with the matrix components of the melt, so all the components of the melt or mixed crystals will eventually form intercrystalline glass with silica and then melt.

In terms of the crystal phase of the bulk, the glass filled between the crystal grains is called the glass phase. This glass phase has a very low softening point, and when heated to a high temperature, a liquid phase will appear.

overflowing the table. The remaining micropores will penetrate into the glass liquid in the kiln and aggravate the erosion of brick materials, so the performance of glass relative to AZS is unfavorable.

Mullite: This crystalline phase is undesirable in AZS. As the mullite content increases, the jade and glass phases decrease. But in fact, some ASS

Products often contain less than 3% mullite: when AZS is heated to above 1300 ℃, secondary mullite will appear in the glass phase, and the increase will increase with the increase of temperature.

The reason is that the glass phase in the AZS of the dope is exuded from the center to the surface, which reduces the Na2O in the residual glass phase, which creates the conditions for the formation of mullite.