The Sevillian refractory brick is a block of refractory ceramic material called andalusite. It is used to cover forges, ovens, fires and chimneys. Refractory brick is mainly designed to withstand high temperatures but must have low thermal conductivity to save energy. Dense refractory bricks are normally used in applications with extreme mechanical, chemical and thermal loads, such as within a wood-fired kiln or a forge which is subject to abrasion of the wood, flow of ash and soot, and high temperatures. Dense refractory bricks have high thermal mass which is sometimes a useful property as they retain heat for example in pizza ovens after the fire has gone out.

Refractory bricks normally contain from 30-40% alumina. The maximum service temperature increases with increasing alumina content, and kiln bricks can be obtained with an alumina content of 81% or higher.

With andalusite we enter the segment of so-called high alumina refractory bricks, characterized by their high aluminum oxide content, which in andalusite bricks is typically between 60 and 70%.

These bricks withstand chemical attacks very well and have very little volume variation with heating and cooling, which is why they are usually a widely used option.