METHOD OF COMPLEX TREATMENT OF SERPENTINITE Russian patent published in 2009 - IPC C01F5/30 C25C3/04 C01G49/00 C01G53/09 

FIELD: chemistry; metallurgy.

SUBSTANCE: present invention pertains to metallurgy and chemistry of inorganic substances. According to the invention serpentinite is leached with hydrochloric acid. The suspension is filtered, obtaining magnesium chlorate solution and silicon dioxide. Impurities are removed from the magnesium chlorate solution through neutralisation, obtaining a nickel-iron concentrate. Carnallite is produced from the purified magnesium chlorate solution and spent electrolyte. The carnallite is dehydrated and subjected to electrolysis, obtaining magnesium, chlorine and spent electrolyte. The nickel-iron concentrate is leached by 10-15% hydrochloric acid at temperature 80°C and pH 3-5. The suspension is filtered, obtaining an iron-containing residue and a solution, containing nickel chloride. Nickel compounds are extracted from the solution containing nickel chloride by treatment with a solution of sodium hydroxide at pH=8.0-8.5. The residue is washed in water soluble salts-chlorides, dried and calcinated, obtaining a nickel concentrate.

EFFECT: increased concentration of nickel oxide in the nickel concentrate.

2 cl, 1 tbl, 1 ex