METHOD OF REWORKING USED SILVER CATALYSTS FOR OBTAINING FINE SILVER OR SOLUTIONS OF ITS COMPOUNDS SUITABLE FOR PREPARATION OF CATALYSTS (VERSIONS) Russian patent published in 2000 - IPC

FIELD: methods of reworking used silver catalysts for obtaining fine silver or solutions of its compounds suitable for preparation of catalysts. SUBSTANCE: prior to leaching, catalyst is subjected to heat treatment in oxidizing or reducing medium at temperature of 700 to 1050 C; leaching is performed with nitric acid till silver is completely dissolved; then residue of catalyst carrier is separated and admixtures is separated; silver is recovered from liquid phase by reduction or concentration of liquid phase to definite content of silver nitrate in solution; silver may be precipitated from solution in form of silver chloride in presence of surface-active substance; silver may be also precipitated from silver nitrate solution in form of silver oxalate; precipitation of silver oxalate is performed at excess of precipitant. EFFECT: enhanced efficiency of reworking of silver catalysts; increased degree of extraction of silver from used catalysts. 11 cl, 6 tbl, 21 ex