Utilization of Micro Fibrous Carbon Matrix from Tannery Solid Waste for Making Pavement Materials

Tannery buffing dust (TBD) contains high amount of potential chemicals including Cr (III) besides carcinogenic organic compounds. The Cr (III) present in TBD can be thermodynamically feasible to convert into carcinogenic Cr (VI). The obnoxious gases such as oxides of sulphur, ammonia and other volatile organic compounds are emitted from tannery buffing dust during the thermal decomposition. Pyrolysis of a chromium-tanned buffing dust under controlled O2 atmosphere has been carried out in a thermal reactor to eliminate the environmental burden of these toxic pollutants. The effect of process variables, such as temperature, pyrolysis time, and heating rate on the pyrolytic product distribution was studied. Flash pyrolysis upto 550°C and slow pyrolysis from 550 to 800°C with applying O2at the rate of 1LPM in the temperature range between 700 and 800°C were studied. The pyrolysed tannery buffing dust was characterized by XRD, SEM, FTIR, TGA and CHNS analyzer. The pyrolysed TBD was effectively solidified / stabilized using Portland cement and also bitumen mixture. Unconfined compressive strength of the blocks was in the range of 16-99KN. The leachability of the stabilization of Cr (III) in the solidified matrix was confirmed through XRD.