ZINKENTFERNUNG AUS PHOSPHATSCHLAEMMEN

摘要

In a process for the removal of zinc from phosphating sludges at elevated temperatures and under reducing conditions and in the presence of fluxes, the phosphating sludges are mixed with fluxes, which can form slag-like iron compounds, calcium compounds and/or barium compounds with the phosphorus components of the phosphating sludges at elevated temperature, and the mixture is reacted at at least 800 DEG C. A prior agglomerisation, in particular pelleting, of the mixture is an advantage. In the formation of iron compounds, reaction temperatures of at least 900 DEG C, preferably at least 1000 DEG C, in particular at least 1100 DEG C, are particularly expedient, smelting works dusts being particularly suitable as fluxes. …In the formation of iron compounds, an Fe:P molar ratio of at least 1.0 should be established for a reaction temperature of /= 1050 DEG C and in the formation of Ca compounds and/or Ba compounds, a molar ratio of Ca:P or Ba:P greater than or equal to 1.5 should be established. The process can be particularly advantageously integrated into the milling process for the further processing of smelting works dusts.