Linear Change On Reheating Of Corundum Block
Linear change on reheating means that the size of refractory products is irreversible changed when the refractory products are heated to high temperature. A positive value indicates expansion which is called expansion of linear change on reheating; negative value indicates contraction which is called contraction of linear change on reheating.
Due to corundum block is used at high temperature and maybe further sintered and phase changed which will cause the change of volume, then produce expansion or contraction of linear change on reheating. It is also an aspect to express the high temperature volume stability and an important quality index of zircon block. For instance, if the contraction of linear change on reheating of the upper blocks in a glass furnace is too big, this will cause the refractory block shedding and the roof collapsing. So linear change on reheating of corundum blockhas great significance to discriminate its high temperature volume stability which can ensure stability of furnace, reduce gap of masonry, improve the tightness and corrosion resistance, and avoid the destruction of the whole structure of glass furnace.
Factors affecting the linear change on reheating
1. Chemical mineral composition and microstructure
It will expanse when the density of the reaction product is less than the density of the reactants. Otherwise, it will shrink.
2. Sinter
Sintering is an important process in process of reheating, which is the important reason for linear change on reheating. The porosity, liquid phase, liquid phase composition and grain size of refractory can greatly affect the sintering. The more liquid phase it has, the smaller the grain size is, the more porosity is, the easier the sintering, and the bigger the linear change is.
3. Manufacturing technology
It can shorten the distance between the refractory material and the thermodynamic equilibrium state when improve the sintering temperature and prolong the holding time of the products, which will reduce the linear change on reheating
Zhengzhou Sunrise Refractory Co., Ltd can provide corundum block (one kind of glass refractory) which has passed the ISO international certified. Over 30 years producing and marketing experience, with reliable quality, competitive price and prompt delivery, Sunrise has established long-term business and cooperation relationship with many customers in different countries and regions. For any further information, Contact us, we will do our best to help you.