Refractory Clay

What is flint clay?

Flint clay is a representive of Chinese refractory clay. Normally, flint clay means CALCINED FLINT CLAY, it is calcined clay ore. Its Al2O3 content is about 44%, Fe2O3 less than 2%, with stable compound and dense structure,fracture surface likes broken shells. 

Flint clay has no fixed compound. It is like Kaolin clay (Al2O3/3SiO2=0.85), besides some free quartz, it also has very few ferro and alkalis mineral. Common color include: pure white, light gray, light tea-yellow, some are brown.

What can flint clay do?

Flint clay has refractoriness and sinterability. This compound of many aluminum silicate , main component is Al2O3 and SiO2. Oxide impurities will flux the material, lower its refractoriness. Lower the Na2O+K2O content, higher the refractoriness.  

As Al2O3/3SiO2 ratio near theoretical value(A/S= 0.85), flint clay is purer, refractoriness is higher, and its sinterablity is better .Top grade fint clay can reach 1750℃ refractoriness, water absorbtion less than 5%, bulk density bigger than 2.55g/cm3. 

Specifications

Item/Grade	YNS45	YNS44	YNS43	YNS42	YNS40
AL2O3 %	46-48	44-48	43-48	42-46	40-46
SiO2 %	49-52	50-53	50-53	50-53	50-54
Fe2O3 %   (max)	1	1.3	2	2.5	3
Ti02 %   (max)	0.8	0.9	1	1.1	1.2
K2O+Na2O %   (max)	0.3	0.4	0.4	0.5	0.5
Ca0+Mg0 %   (max)	0.5	0.5	0.5	0.6	0.7
Bulk density g/cm³(min)	2.58	2.52	2.45	2.4	2.37
Refractoriness °C(min)	1780	1760	1740	1720	1710
Impurities %  (max)	0.5	2	3	3.5	4

 

Advantages
1.Heat insulation 
2.heat preservation
3.low water absorption 
4.construction easily
5.Good work ability
6.Strong adhesive power