MIXTURE CONTAINING BIBENZIMIDAZOLES AND A METHOD OF ZINC, IRON, COPPER OR CADMIUM EXTRACTION Russian patent published in 1996 - IPC

FIELD: metal extraction. SUBSTANCE: mixture has bibenzimidazoles taken separately from -R, -COR, -CH₂COOR, -CH(COOR)₂ and -COOR or they together form the group taken from

where R represents nonobligatory substituted hydrocarbil-group; A and B taken together with two carbon atoms to which they bound form nonobligatory substituted benzene ring; and C and D taken together with two carbon atoms to which they bound form nonobligatory benzene ring. At least 50 wt.-% bibenzimidazoles in indicated composition has formula

where X and Y as indicated above; T, U, V and W can have similar or different values and represent H, R₁ and OR₁ at condition that at least one of members T, U, V and W represents R₁ or OR₁; and R₁ represents C_1-6-alkyl. Mixture is useful for zinc extraction from aqueous zinc solution in the presence of other metals. EFFECT: increased effectiveness of mixture. 16 cl, 5 tbl