Treatment of sheepskin chrome shavings.: Isolation of high value protein products and reuse of chromium in the tanning process

During the last few years we have demonstrated that cattle hide chrome shavings, a waste coming from the leather industry, can be treated to isolate protein products and chrome sulfate. In Spain and in many other countries, the production of sheepskins is as important as the production of cattle hides. In this paper, the conversion of sheepskin chrome shavings to gelatin, hydrolysate and chrome sulfate is presented as are the chemical and physical properties of these products. The suitability of recovered chrome sulfate as a tanning agent was demonstrated by the tannage of pickled sheepskins, using matched sides comparisons; results are given for runs employing various properties of of recycled to commercial chromium. Chemical analyses in the wet blue stage and three different physical tests in the crust stage were performed on all the leather samples to evaluate the tannage. The results show that there were no significant differences in the leather that had been tanned with either the commercial chromium or the recycled chromium.