METHOD OF PROCESSING OF SERPENTINITE Russian patent published in 2007 - IPC C01F5/02 

FIELD: technology of inorganic agents; waste-free processing of magnesium-containing minerals, serpentinite in particular by acid methods.

SUBSTANCE: proposed method includes magnetic separation into magnetic and nonmagnetic parts, separation of sediment in form of silicon dioxide from pulp obtained after leaching-out. Neutralization of filtrate thus formed is carried out with alkaline reagent followed by separation of sediment of metal hydroxides. Leaching-out of initial raw material is carried out with nitric acid. Neutralization of filtrate formed after separation of sediment is carried out by aqueous solution of magnesium oxide. Filtrate formed after separation of metal hydroxides is treated by introduction of magnesium carbonate followed by separation of calcium carbonate. Magnesium nitrate remaining in filtrate is subjected to thermal hydrolysis by superheated steam at obtaining magnesium oxides, nitrogen oxides and water steam; water steam is subjected to condensation for obtaining nitric acid which is directed to the beginning of process for leaching-out the initial raw material. Metal hydroxides settled in the course of neutralization, are separated, washed and calcined at obtaining oxides of metals and are mixed with magnetic part obtained beforehand.

EFFECT: improved quality of magnesium oxide; enhanced efficiency of process.

9 cl, 2 dwg, 2 tbl, 2 ex