Abstract

The two stage chrome tanning process has been investigated for its properties of high chrome exhaustion and the possibility of recycling the spent liquor. Chrome salts prepared by sugar and SO2 reduction have been used in the system. The investigations indicated that irrespective of the nature of tanning salt used the system provides waste minimisation and pollution reduction. Speciation studies support the earlier finding that higher oligomeric species of chromium provide greater hydrothermal stability regardless of the tanning methodology or tanning salt used.