Leather industry discharge solid wastes to a tune of 07 kg/kg of raw material used.  The solid wastes are non tanned collagenous and tanned collagenous.  Land fill method, anaerobic digestion, thermal incineration have inherent problems to execute.  The high concentration of trivalent chromium along with organic/inorganic compounds in tanned solid waste such as buffing dust, shavings and sludge causes severe ground water contamination in the case of land co-disposal and chronic air pollution during thermal incineration.  In the present investigation, these tannery wastes were subjected to incineration at 800C in a Starved Air thermal incinerator under different flow rate of oxygen to optimise the flux of oxygen require to prevent the conversion of Cr³⁺ to Cr⁶⁺ (Combustion).  The energy audit of incineration of wastes under the external supply of oxygen was carried out under different conditions.  The calcined wastes were effectively solidified/stabilized using Portland cement and fine aggregate.  The solidified blocks were tested for unconfined compressive strenght and heavy metal leaching.  Unconfined compressive strength of the blocks was in the range of 120 180 kg/cm².  Leachability study through TCLP on solidified block was carried out to determine the degree of leachate and metals.  The percentage of metal fixation was 99.1 99.9% and dissolved organic concentration in the TCLP leachate was 55-66 mg/I.  Index terms - Chrome shaving, bottom ash, sludge, starved air incineration, solid wastem leather industry.

Key words: Anaerobic Digestion, Thermal Incineration, Calcination Unconfined Compressive Strenght, Leachability