High Alumina Refractory Mortar physic-chemical propertyindex
High alumina refractory mortar is a kind of aggregate and powder mineral material with high refractoriness and water resistance, which is made of refractory powder, low alkali cement and water, and stirred with a certain amount of dispersant and plasticizer. When slabs are built with high alumina in cement kiln linings and the insulation layer of the floor, they play the role of thermal insulation and connection, and the high alumina refractory mortar is often used as the material.
High alumina refractory mortar has excellent high temperature strength and thermal insulation performance. It has good adhesion to refractory material, long service life and aging resistance. To ensure the service life, it is necessary to pay attention to the selection and control of the physic-chemical property of the product. The selection and control of physic-chemical properties mainly includes the selection and control of the properties of the refractory powder, the fineness of the refractory powder, the physical and chemical properties of the cement, the content of mesopores, the modulus of rigidity, the content of alumina and the content of water.
I. The selection and control of the physic-chemical properties of the refractory powder
The refractory powder is a kind of raw material used to produce high alumina refractory mortar, and its properties are directly related to the properties of the mortar. The properties of the refractory powder should meet the following requirements: the basic shape of the mineral particles should be spherical, the number of coarse particles should be low, and the particle size should be better than 0.5mm. Composition of the refractory powder meets the requirement that the mass fraction of Al2O3 should be more than 90%, the mass fraction of CaO should be less than 0.5%, and the mass fraction of MgO should be less than 1%.
II. The control of the fineness of the refractory powder
The fineness of the refractory powder directly affects the hydration degree of the high alumina refractory mortar and its microstructure, and it is also the main factor affecting its workability. The fineness requirements of the refractory powder should meet the following requirements: when the particle size of the refractory powder is more than 0.5mm, its particle size should be no more than 10%, and its fineness should be no more than 32 times.
III. The selection and control of the physic-chemical properties of the cement
The physic-chemical properties of cement play an important role in the construction performance of high alumina refractory mortar. The cement used should be appropriate type of unhydrate cement, widely available and able to meet the requirements of the physico-chemical performance. The physic-chemical properties of the cement should have the following characteristics: it should have appropriate alkalinity, good granulation and better performance of compacting slurry and film.
IV. The control of mesopores content
The mesopores structure play an important role in maintain the stability of the high alumina refractory mortar. The mass fraction of the mesopores in the mortar should meet more than 10%.
V. The modulus of the rigidity and the content of water
The modulus of the rigidity and the content of water of the high alumina refractory mortar both play an important role in maintaining their strength and performance. The modulus of the rigidity of the mortar should meet the requirements of 13~15MPa, and the content of water in the mortar should not exceed 16%.
VI. The content of alumina
The mass fraction of alumina in high alumina refractory mortar should be more than 94%.
In summary, high alumina refractory mortar technology mainly controls and adjusts the physic-chemical properties of the refractory powder, the fineness value, the physic-chemical properties of cement, the content of mesopores, the modulus of the rigidity, the content of water, and the content of alumina, which can ensure the mechanical strength, compressive strength and durability of the alloy mortar.
