Page 32 - Curriculum Visions Dynamic Book

(Above and below) Ceramics will not melt. That allows them to be used when containers are needed that will withstand very high temperatures. This laboratory crucible is made of a ceramic, as is the supporting pipe-clay triangle. Steel and other metal furnaces
are also lined with heat-resistant ceramics – special refractory bricks.
Refractory materials
A ceramic is called a refractory (from the French réfractaire, meaning “unchanging”) when it is able to stand up to very high temperatures before it melts. Refractory materials are widely used to line the interiors of furnaces, kilns, and other devices that process things at high temperatures.
Materials that stand up to high temperatures are also often almost unchanging (inert), meaning that they will not react with other materials when they are hot. This is especially important in a metal or glass furnace, for example, where it is vital to keep out impurities, and where the liquids used are very corrosive.
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