Andalusite based raw materials for Refractory Castable : Properties and Application
The global refractory industry is currently facing several key challenges, some of them related to progressive evolution of the demand and others, more significant, related to the great uncertainness around the sustainability and volatility of the offer.
The following paper provides an overview of the technical, economical and sustainability impact of some of alumina and aluminosilicate minerals. The study is designed to offer keys for assessing potential interchangeability between minerals and mitigate the risk related to excessive exposition to one specific raw material.
Mineral products based on andalusite are widely used in the production of fired and unfired refractories, particularly when creep resistance and thermal shock resistance are essential to achieve the required performance.
On top of these properties, the specific behavior of andalusite allows additional advantages, such as in-situ mullitisation and subsequent volume expansion, which are particularly appreciated in the production of castable.
For these reasons, andalusite has been largely introduced in castable recipes in Europe and it is now progressively taking a leading position in the Asian market as well.
Production of andalusite castable requires a careful selection of andalusite type and grade, in order to meet the targeted refractory performance and control the castable setting parameters. Specific grades of andalusite have been developed on this purpose.
This paper provides a review of properties and performances of several andalusite grades designed for castable application and describe the main application of these types of castable in the refractory industry. Author Florian Ahouanto from former Imerys Refractory Minerals presented this study during IREFCON beginning 2018.