Production of synthetic slag used in the production of cement clinker comprises adjusting silicate limestone and/or flotation residues containing silicon dioxide and electric furnace dust to a specified slag basicity

摘要

Production of synthetic slag having a composition corresponding to typical blast furnace slag and having a basicity CaO/SiO2 of 1-1.6 and an Al2O3 content of 5-20 wt.% comprises adjusting silicate limestone and/or flotation residues with a SiO2 content of 25-50 wt.% and electric furnace dust content of more than 35 wt.% to a slag basicity of 1-1.6. The Al2O3 content is adjusted by adding fly ash and/or bauxite. An independent claim is also included for an apparatus for producing synthetic slag comprising a rotating furnace (1) with an annular waste weir (2) directed upwards arranged on the outlet side of the furnace to limit a central and axial outlet for the liquid slag.