$Refractory Bricks$

Zircon Brick with Good Performance and Properties

Apr 06,2017

As we all know, industrial zircon sand is grains of sand shape whose grain size is about 0.1 ~ 0.2mm, and it can’t be used to produce refractory brick directly. In order to adjust the grain’s composition of refractory bricks and reduce the sintering shrinkage, two stage production method is usually adopted which is by making zircon sand and fine powder into clumps in advance, then calcining under the decomposition temperature of zircon brick, and then crushing the mass to the appropriate size.

Sintered brick of zircon should be crushed by jaw crusher and then roll crusher. The crushed zircon sand is through iron removal by magnetic separation and then divided into particles larger than 0.5mm and less than 0.5mm. Particles less than 0.5mm can be fined to power less than 0.088mm in a vibration mill.

Due to poor sintering of zirconium quartz itself and high temperature firing will cause significant decomposition, therefore, zircon brick is usually firing in 1550 ~ 1660 C.

During the using of zircon brick, it is not easy melted by the chemical corrosion of slag duo to its high refractoriness, however, the slag can invade the internal through air hole, decompose the zircon brick, form metamorphic layer and make the brick structure collapse. In order to make the zircon brick works better, the permeability of slag must be reduced. We had adopt some measures:

1. Produce zircon brick with low porosity and permeability by adjusting the particle composition and changing the molding method.

2. Add some material into zircon brick to improve the viscidity of resultant produced by brick and slag. In the actual production, high alumina bauxite or fused alumina aluminum can be added zirconium bricks in order to improve the penetration resistance of refractory brick.

As the plasticity and sintering of zircon brick is low, clay can be added into the brick material which can make the zircon brick works better and reduce the firing temperature.

Physical & Chemical Index:

Item	Zircon- Mullite Products		Zircon bricks
Item	Index
AL2O3 % ≥	65	36-38
SiO2 % ≤	16	28-30	34
Fe2O3 % ≤	0.5	0.3	0.3
ZrO2%≥	18	26-30	64.5
Bulk Density≥ g/cm3	3.00	2.80	3.60
A.P. % ≤	18	22	20
C.C.S (Mpa) ≥	85		100
0.2mpa Refractoriness under loadT0.6 ≥ C	1650	1580	1650