Real gold refractory: the purchase of spinel refractory brick, not just look at the MgO content! These physical and chemical indicators are more.

Procurement of magnesium and aluminum, Magnesia-ferrite spinel brick : MgO content

is not the only criterion. Many cement plants are accustomed to taking MgO (magnesium oxide) content as the only criterion to judge the quality of products when purchasing. However, under the complex working conditions of the firing zone and transition zone of the cement rotary kiln, only pursuing high MgO will easily lead to problems such as kiln skin hanging, thermal shock spalling, high temperature creep and brick falling in advance, which will greatly shorten the actual service life of the refractory .

MgO is only that matrix of the brick, The use effect is determined by a plurality of key physical and chemical indexes:

Core

magnesia-alumina spinel resistant to liquid phase erosion of clinker : attention should be paid to the amount of spinel formed, Instead of simply looking at the AlO content
of magnesia-magnesia spinel: relying on a reasonable ratio of iron-magnesia spinel to achieve a good effect of hanging the kiln coating; If the content of iron is too high, the high temperature performance

will be weakened. If the spinel phase is not developed enough, even if the MgO index is higher, the liquid phase penetration and exfoliation will still occur. 2.

high temperature refractoriness unde load and high temperature creep-core index

of that fired zone: the fire zone is at 1350-1480 deg C for a long time, It is suggested that the load softening temperature of mechanical extrusion
should be ≥ 1600
℃. If the creep is not qualified, the brick body will arch and the extrusion cracking

will occur. When purchasing magnesia-iron spinel bricks, do not only pay attention to the advantages of hanging kiln skin, but also check the index.

3. Thermal shock stability-The key point

of transition zone selection is that the repeated shedding of kiln skin in transition zone, frequent
alternation of cold and heat, and insufficient thermal shock performance will lead to network cracks and lamellar spalling . Directly shorten the service cycle

4. Apparent porosity-need to maintain a reasonable range

of pores too high: vulnerable to alkali steam, Excessive densification due to liquid phase erosion
of clinker: it will reduce the thermal shock resistance.

5. Impurities

shall be strictly controlled , such as CaO, SiO SiO, If the impurities such as BO exceed the standard
, low melting point phase will be generated. Damage to high temperature performance

of brick body 6. FeO content (for magnesia-hercynite brick) is not the

higher the better, which needs to be selected

comprehensively according to

raw material conditions and kiln operation rate

All can be viewed after purchase