How to make magnesia brick

 

Magnesia Brick Manufacturing Process: 

The manufacturing process of magnesia brick includes the following steps:

1. Break and smash: 

Crushing is the process of processing large pieces of material into ideal particle size materials. 

2. Ingredients (weighing): 

The raw materials are prepared in a predetermined proportion and mixed in a strong sand mixer. The order of feeding is magnesia aggregate – carbon fiber – binder – carbon raw material. 

3. Mixing: 

Mix thoroughly to get perfect coating. Add mixture made in step (B) and remix the batch intensively. Now add powder Resin (item 9), then Hexamine (item 10) and mix once again. 

4. Molding: 

Use a molding machine to make the mixture into bricks.

5. Drying:

Use a drying oven to dry the bricks for several hours.

6. Firing: 

Fire the bricks in a kiln at temperatures of 1550 to 1600 degrees Celsius. 

7.Finishing: 

The final step is to grind and polish the bricks to get the desired shape and size.

Types of magnesia brick:

Magnesia bricks can be divided into two categories: sintered magnesia bricks (also known as fired magnesia bricks) and chemically combined magnesia bricks (also known as unburned magnesia bricks). Magnesia bricks with high purity and firing temperature are called direct-bonded magnesia bricks due to the direct contact of periclase grains; Bricks made of fused magnesia as raw materials are called fused re-bonded magnesia bricks.

Uses of Magnesia Bricks:

Magnesia bricks are used in steelmaking furnaces, electric furnace bottom and wall, and high temperature tunnel kiln. Magnesia bricks are also used as heat storage room lattice bricks in glass kilns.

Magnesia brick is used for permanent layers in steel making converters, AOD furnaces, and more. Magnesia brick is also used to line steel ladles and Basic Oxygen Furnaces (BOFs). Magnesia bricks can be used in a variety of applications, depending on the type of brick being used. Common uses include furnaces, ladles, secondary refining vessels, and cement and glass making kilns.

Magnesia Brick for sale

The most important steps need to be considered to avoid or reduce the possibility of magnesia bricks hydration are:

1). Magnesia bricks must be transported in a container to protect the material against moisture.

2). Magnesia bricks should be stored inside storage rooms where it is dry, free of frost, ventilated, and with a temperature between 10°C and 30°C. Note that magnesia bricks storage underneath a tarpaulin cover outside is not sufficient.

3). Bricks may not be stored for more than four weeks prior to installation and preheating.

4). Lining should be protected against moisture during installation and preheating.

Article Source:How to make magnesia brick
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The refractories trend for EAF cover

Electric furnace cover with refractory material development trend is: brick - prefabricated block - the overall pouring. 

For alkaline fire brick cover, electric tile with magnets. In order to ensure the stability of the furnace cover structure and reduce the deformation and peeling of magnesia, the use of iron plaster or masonry insert iron. As the metal induced current (especially high power electric furnace cover), the formation of local overheating to non-magnetic steel fire brick, on the other hand pure magnesia brick linear expansion coefficient is too large, the amount of small. 

In addition, the whole pouring the cover. The use of the overall casting furnace cover to promote the life of the furnace to further improve. After the water is cooled, the electrode is also water-cooled around the electrode, and the high-alumina ultra-low cement castable containing 3% Cr2O3 is added from the material and the stainless steel fiber is added. The furnace cover is used in the case of slightly repaired 594 furnace and service life is 4 times than before.

Changxing refractory provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, magnesia carbon brick, clay refractory bricks and other refractory products.

Article Source：The refractories trend for EAF cover
Company name:Henan Xinmi Changxing Refractory Materials Co.,Ltd
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Ordinary sintering magnesia brick production process

The firing process usually includes magnesia carbon brick crushing, grinding, grading, batching, mixing, molding, drying and sintering processes.

1) refractory raw material requirements. Chemical composition of sintered magnesia: MgO>87%, CaO = 2.5%, SiO2 = 5%, the appearance of brown or dark brown, dense crystal, good sintering, bulk the density is larger than 3.2g/cm3, igloss <0.3%, in order to ensure the product has good structure, control C/S<0.5.

2) particles should be considered with the most compact principle. The current domestic production of ordinary sintering magnesia brick has various forms according to the actual situation, some using mixed ingredients, the single sieve, the critical particle size 3mm or 2mm, some with three ingredients of 3 ~ 1mm, 1 ~ 0mm, <0.088mm also according to the actual size of refractory brick type and the critical particle size can be enlarged to 6mm, while using four or five ingredients. In order to improve the thermal shock resistance of products, may be appropriate to increase the critical particle size, or by increasing the large particle size. In order to improve the product load softening temperature and sintering, can be increased when the content of fine powder particles, reduce the upper limit.

3) Ingredients. In a factory three ingredients for example: 3 ~ 1mm, 40 ~ 50%; 1 ~ 0mm, 20 ~ 25%; less than or equal to 0.088mm, 30 ~ 35%. binder commonly used sulfite liquor or brine, adding amount of 4% ~ 6%, adding the waste brick, the general should be <20%.

4) Mixed. Usually, in the wet grinding machine in the order of operations: coarse grain - size - bond - fine powder, net mixing time of >15 minutes, mud water <3%, generally do not need trapped material.

5) The magnesia material for forming poor materials, easy molding, blank containing water less, at around 2.5%, low mud plasticity, should adopt high pressure molding, control body density >2.95g/cm3.

6) Dry. Make the body moisture <1%. if not high water content in the body, can take the natural drying, generally >24 hours. If using drying, it generally takes 8 to 12 hours should not be too high, the drying temperature, inlet and outlet temperature control, so as to avoid cracking.

7) Firing. In the heating process will change as follows: out of the water, the generation of liquid phase sintering, particle migration, solid phase reaction, recrystallization, and finally sintering. Strength is increased and the density increases. The firing temperature is generally 1500 to 1600 degrees centigrade.

Article Source: Ordinary sintering magnesia brick production process
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/