PROCEDURE FOR PROCESSING SALT SLAG (SLAKED LIME) FORMED AT ALUMINIUM PRODUCING ELECTROLYSER SHUT DOWN FOR REPAIR Russian patent published in 2011 - IPC C25C3/06 C22B7/00 C01F7/38 

FIELD: metallurgy.

SUBSTANCE: procedure consists in crushing, crumbling and flotation of salt slag. For 1-72 hours salt slag is preliminary poured over with fluoro-soda-bicarbonate water solution with concentration Na₂CO₃ 10-40 g/l, NaHCO₃ 0-10 g/l, NaF 0-5 g/l, Na₂SO₄ 10-70 g/l and temperature 50-85°C. Salt slag pouring over/conditioning with fluoro-soda-bicarbonate water solution and crushing/crumbling can be combined. Salt slag processing into fluoro-clay-earth-containing concentrate (purification from carbon) is performed by floatation method.

EFFECT: elimination of ammonia release.

2 cl, 1 dwg