The Difference between Sintered AZS Brick and Fused Recombinded AZS Brick

Sintered AZS Brick

Sintered AZS brick is a product made of zircon and alumina as main raw materials and pre-synthetic materials as aggregates. Since the billet is a barren material, only relying on increasing the forming pressure to increase the density of the refractory brick is not good. The increased number of pressings of large products can also lead to the phenomenon of spalling and uneven density. Measures such as adjusting the critical particle size composition, adding a composite binder and a small amount of Ti02, MgO sintering aid and strengthening sintering are needed to achieve the purpose of dense sintering.

3AI₂O₃+2ZrSiO4 —> 3AI₂O₃·2SiO₂+2ZrO₂

The production principle is based on the solid phase reaction between ZrSiO₄ - AI₂O₃:

3AI₂O₃+2ZrSiO₄ —> 3AI₂O₃·2SiO₂+2ZrO₂

This reaction is irreversible and is also called "in-situ reaction". Due to the large volume effect produced during the reaction sintering process, which leads to deformation and cracks of the green body, only pre-synthesized zirconium mullite aggregates can be prepared with sintered or fused corundum raw materials to produce mullite, oblique zircon and corundum. The material is superior to two-phase materials in terms of strength and thermal shock resistance. The microstructure of sintered AZS bricks is mainly characterized by fine zirconia particles uniformly distributed between the main crystalline phases of mullite and corundum.

Sintered AZS bricks should have a relatively stable and uniform phase composition, to avoid long-term non-uniform interphase reactions under the action of high-temperature glass solutions, so that they can operate stably in high-temperature glass solutions for a long time. For this reason, in the sintered AZS brick, the performance indicators and crystal phase structure of the raw materials, the proportion of ingredients and the required particle size composition of the ingredients must be strictly controlled, so that the product can achieve more satisfactory performance indicators and phase structure.

Fused and Recombined AZS Bricks

Fused and recombined AZS bricks are based on melting and casting AZS clinker, scrap or recycled residual bricks (clearly adhered glass) as raw materials, adding a small amount of kaolin or alumina as a binder. When heated to a high temperature, the fused AZS aggregate seeps out of the glass phase and the binder to form mullite, which promotes the sintering of the product. The peritectic reaction of the glass phase and the crystal phase in the fused AZS aggregate will also form mullite. At this time, mullite and Zr02 are in the form of being wrapped and wrapped, which is helpful for the sintering of fused cast AZS particles of different grain sizes. Using this "white sinterability" of fused cast AZS aggregate is the basic principle of producing recombined AZS bricks.

The main changes in the microstructure of AZS bricks after firing at high temperature are:

1. The glass phase of the coarse-grained material exudes to the surface of the particles and reacts with A1203, forming a mullite shell to close the exudation channel, so that the peritectic reaction proceeds inside the particles.
2. The glass phase of fusion cast AZS powder material reacts with active A1203, and the matrix is mulliteized. Combined with the microstructure of AZS bricks, the eutectic structure of mullite and corundum oblique zircon is densely combined.
3. The dialysis of the glass phase in the coarse particles is exhausted, leaving voids and gaps.

Combining the product with the electric fusion product, the phenomenon of glass phase exudation is greatly reduced, and the exudation temperature is increased, with good thermal shock resistance and high high-temperature mechanical properties. Especially the creep resistance and the glass erosion resistance are also good.

Anchor Bricks for Steel Rolling Heating Furnaces

Anchor bricks are divided into hanging bricks and bricks with holes. The anchor bricks are fired at high temperatures, with high strength, good erosion resistance, and high spalling resistance. It is an ordinary sintered brick. The role of anchor bricks is to anchor the refractory castables on the top of the heating furnace. The industrial furnace or flue wall is roughly composed of an inner lining layer, a heat insulation layer, and an outer wall layer. The inner lining is refractory bricks and the outer wall anchor bricks.

RS High-Quality Anchor Bricks

Anchor Bricks for Steel Rolling Heating Furnace

The alumina content of anchor bricks is more than 55%, and the alumina content of excellent anchor bricks can reach 75%. This kind of brick body has a soft load temperature of 1550°C, which is a high alumina refractory brick product. However, in general, the alumina content of 55% is more, because the 55% content of the anchor brick has better flexibility. In addition, it should be noted that anchor bricks are used to anchor refractory castables. The properties of anchor bricks should be consistent with the material of the castable, and the expansion and contraction should be consistent, so as to form a close combination with the castable and extend the life of the furnace lining.

Masonry of Anchor Bricks

The layout and masonry of anchor bricks during use should follow the following principles:

1. The arrangement of anchoring bricks should be determined according to the range and frequency of temperature changes and the size of the direct wall area. Usually, it should not be less than 6 blocks/m2.

2. The anchor bricks must be checked carefully before laying. If the anchor bricks have cracks at the anchor holes that affect the overall strength of the anchor bricks, they cannot be used and should be resolutely discarded.

3. When the masonry is close to the anchor brick position, bricks should be arranged in advance to determine the accurate position of the anchor brick. Use a wire brush to clean the welding part of the metal shell. Adopt the welding rod suitable for the welding parts, and weld the anchor pipe firmly.

4. After the anchoring brick is built, insert the anchoring hook, and fill the airstrike with refractory fiber felt, and plug it tightly. To form a certain degree of protection for the anchor.

The anchor brick includes a column composed of a hanging end and an anchor solid. Spaced partial grooves are opened on the surface of the anchor solid, and ribs are arranged along the length direction on at least one surface of the anchor solid. After the ribs are installed, due to the reinforcement and traction of the ribs, the tensile and flexural strength of the anchor solid is significantly improved, and the stress generated at the groove is blocked at the ribs and cannot be transmitted. Therefore, the anchor brick of this kind of structure is not easy to break.

RS Anchor Bricks for Sale

Rongsheng Anchor Bricks Manufacturer

Note: Many users have used hanging bricks with insufficient tensile strength, resulting in a serious imbalance of forces and a collapse of the furnace roof. Therefore, here is a reminder that you must carefully choose the anchor brick manufacturer. Rongsheng refractory material manufacturer is an experienced refractory material manufacturer and sales company. Rongsheng can provide anchoring bricks for rolling steel heating furnace, including high-aluminum anchoring bricks and hanging bricks. Get detailed product prices, product pictures, and other product introduction information of various anchor bricks. Please contact us, we will provide you with services according to your specific needs.