Produced by calcining industrial aluminium oxide and fine limestone under strict mineralogical control in rotary kilns into clinker, cooling then grinding in ball mill.The content of alumina is approx. 80% in CA80 Produced by calcining industrial aluminium oxide and fine limestone under strict mineralogical control in rotary kilns into clinker, cooling then grinding in ball mill.The content of alumina is approx. 80% in CA80 aluminate cement.