SERPENTINITE PROCESSING METHOD Russian patent published in 2004 - IPC

FIELD: inorganic compounds technology and nonferrous metallurgy.

SUBSTANCE: method of processing serpentinite into magnesium and silica powder comprises leaching serpentinite with aqueous hydrochloric acid to give suspension containing dissolved magnesium chloride and undissolved silica. Suspension is separated into liquid (magnesium chloride solution) and solid (silica) phases. Magnesium chloride solution is freed of impurities by neutralization. Precipitated impurities (iron, nickel, and chromium hydroxides) are separated and remaining magnesium chloride solution is processed to produce anhydrous carnallite, which is subjected to electrolysis producing magnesium, anodic chlorine, and spent electrolyte. Carbon-containing blend prepared from silica is chlorinated with chlorine and resulting silicon tetrachloride is purified and subjected to vapor-phase hydrolysis to give silica powder and hydrogen chloride. The latter is used in preparation of anhydrous carnallite, after which is absorbed in water to give aqueous hydrochloric acid used for leaching of serpentinite.

EFFECT: achieved complete utilization of raw materials.

1 dwg