Aluminium and iron in clinker
Aluminium and iron are two of the key components in Portland cement clinker. Varying their presence in clinker can have significant effects on the final clinker. Arthur Harrisson looks at some of the impacts of such variations.
Figure 1: light grey aluminate and white ferrite very slowly cooled.
The hexagonal blue alite crystal below centre is 30µm across
The four essential constituents of Portland cement clinker are usually listed as:
• calcium oxide (CaO or, in cement chemists’ notation, C)
• silicon dioxide, also known as silica (SiO2 or S)
• aluminium oxide, also known as alumina (Al2O3 or A)
• iron oxide (Fe2O3 or F).
