Preparation of light weight constructional materials from chrome containing buffing dust solid waste generated in leather industry

An alternative and environmentally benign method of disposing the buffing dust, generated from leather industry was carried out in the present investigation. The buffing dust (finished solid waste) was charred in a controlled oxygen atmosphere by coupled pyrolysis and the resultant material was gauged for the application of light weight cement blocks. The results confirmed that, at a flow rate of 1 LPM oxygen supplied for 30 min produced nanostructured fibrous carbon material which was further confirmed through SEM and EDX analyses. Iron nanoparticles were used to inhibit the conversion of trivalent chromium to hexavalent chromium in fibrous carbon before being utilized for making light weight cement block. The addition of iron nanoparticles supplements the mechanical strength by compositional bonding in cement block. The XRD results elucidate that the hexavalent chromium has reduced to trivalent chromium due to the addition of iron nanoparticles in the residue material. The as-prepared light weight cement blocks were fabricated (7 cm × 7 cm × 7 cm) for compression test, simultaneously cement block devoid of iron nanoparticles was prepared as a control. The compressive strength of the light weight cement block comprising of iron nanoparticles (20.7 kN/cm²) was found to be higher than the block without iron nanoparticles (3.82 kN/cm²).