| 摘要 |
In a process for producing Portland cement, composite Portland cements and blast furnace cements by charging pulverulent limestone marl and/or a limestone/clay sand mixture and additives in countercurrent to the off-gas at the off-gas end of a rotary kiln for driving off CO2, sintering and forming a clinker material, the novelty is that an aluminium concentrate, in the form of a residue from salt slag processing, is added in the hot raw material delivery region at the off-gas end of the kiln. Preferably, the aluminium concentrate is added in amount /}5 wt.% and has the composition (by wt.) 3.2 % CaO, 11.6 % SiO2, 2.9 % Fe2O3, 67 % Al2O3, 8.8 % MgO, 0.2 % K2O, 0.5 % Na2O and 0.3 % SO3.
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