The thermal shock stability of magnesian chromic brick

The heatproof shake sex of firebrick product, show material is in bear when quick temperature changes, evaluate its to fight the main index of damaged ability. The thermal shock stability of magnesian chromic brick is better, this and its raw material composition has very big concern.
Magnesian chromic brick with magnesian (MgO) with 3 oxidation 2 chromium (Cr2O3) for bases, square magnesian stone and pointed spar give priority to the fireproof data products that wants mineral constituent.


Magnesian chromic brick comprises the chemistry of composition as a result of its, and make this kind of fireproof material fireproof degree tall, high temperature strength is great, fight basic slag aggressivity strong, thermal stability is excellent, also have certain adaptability at the same time to acid slag.
The main raw material that makes magnesian chromic brick is agglomeration magnesia and chromite. The purity of magnesia raw material wants as far as possible tall, ferrochrome mineralization learns the content of composition to ask to be: Cr2O3: 30 ～ 45% ; CaO: 1 ～ of ≤ 1.5% .
Magnesian chromic brick reachs the craft that make according to raw material recipe, phyletic and various, magnesian chromic brick has a lot of kinds, below introduce 3 kinds of magnesian chromic bricks simply:


1. Common magnesium chromic brick: By foreign matter more chromite and magnesia are made, firing temperature not 1550 ℃ control prep above;
2. Combine magnesian chromic brick directly: Use tall purity raw material, become via high temperature fire, firing temperature is in 1700 ℃ above, the high temperature such as square magnesian stone, pointed spar is united in wedlock directly between the photograph, the low frit photograph such as silicate distributings for Gu island shape, the high temperature strength that increases a brick significantly and the sex that fight broken bits;
3. Founding magnesium chromic brick: With magnesia and chromite and certain amount additive, after passing early days technology, via the pattern is being noted after electric frit, anneal, into produce and become, composition of structure of founding magnesium chromic brick is distributed even, fight fuse-element frit corrode, permeate, erode the gender is good;
Manage of common magnesium chromic brick changes target:


The former arrange that changes index figure and it according to the manage of magnesian chromic brick changes character. Magnesian content of spar of chromic needle of the magnesium in magnesian chromic brick and iron acid is much and linear expansion coefficient is small, in the meantime, the porosity of magnesian chromic brick is bigger than magnesia brick, so, the heat of magnesian chromic brick is expansile small.
Content of calcic magnesian olivine is few in magnesian chromic brick, cause surprise not easily to expand stress; In pointed spar of chromium of Yu Mei of dissolve of iron acid magnesian solid, solubility is big range of 2 deliquescent temperature is very wide also, the dissolve with iron magnesian acid is entered with separate out, the stress with unapt large generation. Accordingly, the thermal shock stability of magnesian chromic brick is better, water-cooling frequency can amount to the left and right sides 25 times.


The application of magnesian chromic brick in current industry domain direction:
1, the finery outside building open-hearth furnace roof, electric stove roof, furnace and all sorts of nonferrous metal smelting furnace.
2, the high temperature place of wall of furnace of freeboard power electric stove uses founding magnesium chromic brick, the finery outside furnace is tall the magnesian chromic brick that erodes an area to use synthetic makings to be made.
3, nonferrous metal shows fast fusion heat tall the magnesian chromic brick that erodes an area to use makings of founding magnesium chromic brick, synthesis to be made.
4, magnesian chromic brick still is used in cement rotary kiln firing the place such as the regenerator of belt and vitreous kiln.


So, we can use the thermal shock with magnesian chromic admirable brick to stabilize function, use it in industrial kiln furnace a lot of environments that suffer high temperature to erode.