METHOD FOR COMPLEX PROCESSING OF IRON ORE WITH HIGH CONTENT OF MAGNESIUM COMPOUNDS Russian patent published in 2012 - IPC C22B1/00 C22B3/04 B03C1/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of hydraulic metallurgy and may find wide application in metallurgical industry. The method for complex processing of iron ore with high content of magnesium compounds consists in the fact that prior to annealing the initial ore is treated with a demagnetising acid agent. The acid agent used is an anhydrous phosphoric acid. After treatment the mixture is exposed to oxidising decarbonising annealing at the temperature of above 650°C. The produced ash is treated with 10% aqueous solution of sulphuric acid, leached with water to produce pH of 6.5-7.0 in last portions of washing water. After leaching the concentrate is separated from washing water, dried and sent for iron smelting. Washing water is treated with ammonia until complete deposition of magnesium-ammonium phosphate, which after drying is sent for making fertilisers. The remaining aqueous solution is treated with quicklime to produce calcium sulfate residue, which is then dried and sent for use as a binding material. The remaining water is returned for leaching.

EFFECT: higher content of iron in a concentrate with simultaneous controlled reduction of magnesium oxide content in it.

1 tbl