A process for producing an alumina-containing flowing for the further processing on portland cement clinker in addition to alumina

摘要

Disintegrated clinker containing alumina is produced by melting at 1500 DEG C.-1680 DEG C. in air a mixture of clay or other angillaceous material, a calcium containing material consisting predominantly of calcium sulphate, or optionally a carbonaceous material, the clinker being slowly cooled and having a silcate modulus SiO2/Al2O3 + Fe2O3 selected within the range of (a) 0,61-0,83 at an (Al2O3 + Fe2O3) content of 25%-30% or (b) 0,39-0,48 at an (Al2O3 + Fe2O3) content of 30%-35% or (c) 0,31-0,35 at an (Al2O3 + Fe2O3) content of 35%-40%. A metal oxide such as Fe2O3 and/or Co2O3 is preferably added to the mixture so that the calcium sulphate decomposes at 900 DEG C.-1100 DEG C. before melting occurs. Alumina may be prepared from the clinker by extraction with sodium hydroxide.